Final Prospectus Supplement

The notes will mature on January 15, 2023. Interest will accrue on the notes from July 2, 2012, and the first interest payment date will be January 15, 2013. We intend to use the net proceeds from this offering to fund our exploration, development and acquisition program and for general corporate purposes.

We may redeem some or all of the notes at any time on or after July 15, 2017 at the redemption prices set forth in this prospectus supplement. We may also redeem up to 35% of the aggregate principal amount of the notes prior to July 15, 2015 at the redemption price set forth herein with cash proceeds we receive from certain equity offerings. In addition, we may redeem the notes, in whole or in part, at any time before July 15, 2017 at a redemption price plus an applicable make-whole premium set forth in this prospectus supplement. If we undergo a change of control on or prior to July 15, 2013, we may redeem all, but not less than all, of the notes at a redemption price equal to 110% of the principal amount of the notes redeemed plus accrued and unpaid interest. We must offer to purchase the notes if we experience specific kinds of changes of control or sell assets under certain circumstances.

The notes will be our senior unsecured obligations and will rank senior in right of payment to any of our future indebtedness that is expressly subordinated to the notes. The notes will rank equally in right of payment with all our existing and future senior indebtedness, including our revolving credit facility and our outstanding series of senior notes, and will rank effectively junior in right of payment to all of our secured indebtedness (to the extent of the value of the collateral securing such indebtedness), including borrowings we guarantee under our revolving credit facility which are secured by substantially all of our consolidated assets. In addition, the notes will rank structurally junior in right of payment to any of the indebtedness and liabilities of any of our subsidiaries that do not guarantee the notes.

The notes initially will be guaranteed on a senior basis by all our existing material subsidiaries and certain future material restricted subsidiaries. The guarantees will be senior unsecured obligations of the guarantors and will rank senior in right of payment to any of their future indebtedness that is expressly subordinated to the guarantees. The guarantees will rank equally in right of payment with all existing and future senior indebtedness of the guarantors, including our borrowings and guarantees under our revolving credit facility and their guarantees of our outstanding series of senior notes, and will rank effectively junior in right of payment to all of the guarantors’ secured indebtedness (to the extent of the value of the collateral securing such indebtedness), including the guarantors’ borrowings and guarantees under our revolving credit facility.

Investing in the notes involves risk. See “Risk factors” beginning on page S-16 of this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The notes will not be listed on a securities exchange. Currently, there is no public market for the notes.

We expect that delivery of the notes will be made on or about July 2, 2012 in book-entry form through The Depository Trust Company for the account of its participants, including Clearstream Banking société anonyme and Euroclear Bank S.A./N.V.

This document is in two parts. The first part is the prospectus supplement and the documents incorporated by reference herein, which describes the specific terms of this offering of the notes. The second part is the accompanying prospectus, which gives more general information, some of which may not apply to the notes or this offering. If the information relating to the offering varies between the prospectus supplement and the accompanying prospectus, you should rely on the information in this prospectus supplement.

You should rely only on the information contained in or incorporated by reference into this prospectus supplement, the accompanying prospectus and any related free writing prospectus. We have not, and the underwriters have not, authorized any dealer, salesman or other person to provide you with additional or different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus supplement and the accompanying prospectus are not an offer to sell or the solicitation of an offer to buy any securities other than the securities to which they relate and are not an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make an offer or solicitation in that jurisdiction. You should not assume that the information contained in this prospectus supplement is accurate as of any date other than the date on the front cover of this prospectus supplement, or that the information contained in any document incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus supplement or any sale of a security.

Unless otherwise indicated or the context otherwise requires, all references in this prospectus supplement to “we,” “us,” “our,” “Oasis Petroleum” and the “company” refer to Oasis Petroleum LLC and its subsidiaries before the completion of our corporate reorganization in connection with our initial public offering in June 2010 and Oasis Petroleum Inc. and its subsidiaries as of the completion of our corporate reorganization and thereafter, the term “Oasis” refers to Oasis Petroleum Inc., and the term “Subsidiary Guarantor” refers to a guarantor of the notes.

We file annual, quarterly and current reports and other information with the Securities and Exchange Commission (the “SEC”) (File No. 001-34776) pursuant to the Securities Exchange Act of 1934 (the “Exchange Act”). You may read and copy any documents that are filed at the SEC’s public reference room at 100 F Street, N.E., Washington, D.C. 20549. You may also obtain copies of these documents at prescribed rates from the public reference section of the SEC at its Washington address. Please call the SEC at 1-800-SEC-0330 for further information.

Our filings are also available to the public through the SEC’s website at http://www.sec.gov.

The SEC allows us to “incorporate by reference” information that we file with them, which means that we can disclose important information to you by referring you to documents previously filed with the SEC. The information incorporated by reference is an important part of this prospectus supplement, and the information that we later file with the SEC will automatically update and supersede this information. The following documents we filed with the SEC pursuant to the Exchange Act are incorporated herein by reference:

These reports contain important information about us, our financial condition and our results of operations.

All future documents filed pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act (excluding any information furnished pursuant to Item 2.02 or Item 7.01 on any Current Report on Form 8-K) before the termination of the offering of securities under this prospectus supplement shall be deemed to be incorporated in this prospectus supplement by reference and to be a part hereof from the date of filing of such documents. Any statement contained herein, or in a document incorporated or deemed to be incorporated by reference herein, shall be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained herein or in any subsequently filed document that also is or is deemed to be incorporated by reference herein, modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

You may request a copy of these filings at no cost by writing or telephoning us at the following address and telephone number:

We also maintain a website at http://www.oasispetroleum.com. However, the information on our website is not part of this prospectus supplement or the accompanying prospectus.

Various statements contained in or incorporated by reference into this prospectus supplement that express a belief, expectation, or intention, or that are not statements of historical fact, are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 (the “Securities Act”) and Section 21E of the Exchange Act. These forward-looking statements include statements, projections and estimates concerning our operations, performance, business strategy, oil and natural gas reserves, drilling program, capital expenditures, liquidity and capital resources, the timing and success of specific projects, outcomes and effects of litigation, claims and disputes, derivative activities and potential financing. Forward-looking statements are generally accompanied by words such as “estimate,” “project,” “predict,” “believe,” “expect,” “anticipate,” “potential,” “could,” “may,” “foresee,” “plan,” “goal” or other words that convey the uncertainty of future events or outcomes. Forward-looking statements are not guarantees of performance. We have based these forward-looking statements on our current expectations and assumptions about future events. These statements are based on certain assumptions and analyses made by us in light of our experience and our perception of historical trends, current conditions and expected future developments as well as other factors we believe are appropriate under the circumstances. Actual results may differ materially from those implied or expressed by the forward-looking statements. These forward-looking statements speak only as of the date of this prospectus supplement, or if earlier, as of the date they were made. We disclaim any obligation to update or revise these statements unless required by securities law, and we caution you not to rely on them unduly. While our management considers these expectations and assumptions to be reasonable, they are inherently subject to significant business, economic, competitive, regulatory and other risks, contingencies and uncertainties relating to, among other matters, the risks discussed in “Risk Factors,” in our Annual Report on Form 10-K for the year ended December 31, 2011, our Quarterly Report on Form 10-Q for the quarter ended March 31, 2012 and our subsequent SEC filings, as well as those factors summarized below:

Reserve engineering is a process of estimating underground accumulations of oil and natural gas that cannot be measured in an exact way. The accuracy of any reserve estimate depends on the quality of available data, the interpretation of such data and price and cost assumptions made by our reserve engineers. In addition, the results of drilling, testing and production activities may justify revisions of estimates that were made previously. If significant, such revisions would change the schedule of any further production and development drilling. Accordingly, reserve estimates may differ from the quantities of oil and natural gas that are ultimately recovered.

Summary

This summary provides a brief overview of information contained elsewhere in this prospectus supplement, the accompanying prospectus and the documents we incorporate by reference. Because it is abbreviated, this summary does not contain all of the information that you should consider before investing in the notes. You should read carefully the entire prospectus supplement, the accompanying prospectus and the documents incorporated by reference before making an investment decision, including the information presented under the headings “Risk factors,” and “Cautionary statement regarding forward-looking statements” beginning on pages S-16 and S-iv, respectively, of this prospectus supplement. We have provided definitions for certain oil and natural gas terms used in this prospectus supplement in the “Glossary of oil and natural gas terms” beginning on page A-1 of this prospectus supplement.

In this prospectus supplement, unless otherwise indicated or the context otherwise requires, the terms “we,” “us,” “our,” “Oasis Petroleum” and the “company” refer to Oasis Petroleum LLC and its subsidiaries before the completion of our corporate reorganization in connection with our initial public offering in June 2010 (“IPO”) and Oasis Petroleum Inc. and its subsidiaries as of the completion of our corporate reorganization and thereafter, the term “Oasis” refers to Oasis Petroleum Inc., and the term “Subsidiary Guarantor” refers to a guarantor of the notes.

Overview

We are an independent exploration and production company focused on the acquisition and development of unconventional oil and natural gas resources in the Montana and North Dakota regions of the Williston Basin. As of December 31, 2011, we have accumulated 307,430 net leasehold acres in the Williston Basin. We are currently exploiting significant resource potential from the Bakken and Three Forks formations, which are present across a substantial portion of our acreage. We believe the location, size and concentration of our acreage in our primary project areas create an opportunity for us to achieve cost, recovery and production efficiencies through the large-scale development of our project inventory. Our management team has a proven track record in identifying, acquiring and executing large, repeatable development drilling programs, which we refer to as “resource conversion” opportunities, and has substantial Williston Basin experience. During the three months ended March 31, 2012, we completed and placed on production 26 gross operated wells in the Williston Basin and achieved 100% success in the finding of hydrocarbons (all of which are economic based on current prices as of March 31, 2012) through the application of the latest drilling and completion techniques. We have built our Williston Basin leasehold acreage position primarily through acquisitions in our three primary project areas: West Williston, East Nesson and Sanish. DeGolyer and MacNaughton, our independent reserve engineers, estimated our net proved reserves to be 78.7 MMBoe as of December 31, 2011, 46% of which were classified as proved developed and 88% of which were

comprised of oil. The following table presents summary data for each of our primary project areas as of December 31, 2011, unless otherwise indicated:


			Estimated net proved reserves as of December 31, 2011				Average net daily production(1)
	Net Acreage		MMBoe		% Developed		(Boe/d)

West Williston		201,265		51.6		46%		12,131
East Nesson		97,756		21.1		35%		3,541
Sanish		8,409		6.0		75%		1,961

Total		307,430		78.7		46%		17,633

(1)

Represents average net daily production for the three months ended March 31, 2012.

Currently, our total 2012 capital expenditure budget is $884 million, which includes $846 million for exploration and production (“E&P”) capital expenditures and $38 million for non-E&P capital expenditures. Our 2012 capital expenditure budget primarily consists of:

•

$758 million of development capital for operated and non-operated wells (including expected savings from services provided by Oasis Well Services LLC, or OWS);

•

$57 million for constructing infrastructure to support production in our core project areas, primarily related to salt water disposal systems that will lower lease operating expenses;

•

$25 million for maintaining and expanding our leasehold position;

•

$6 million for micro-seismic work, purchasing seismic data and other test work;

•

$15 million for OWS, including $12 million for equipment budgeted and ordered in 2011 that arrived in the first quarter of 2012; and

•

$23 million for other non-E&P capital expenditures, including items such as district tools, administrative capital and capitalized interest.

While we currently have budgeted $884 million for these purposes, the ultimate amount of capital we will expend may fluctuate materially based on market conditions and the success of our drilling results as the year progresses. The amount, timing and allocation of capital expenditures is largely discretionary and within our control. If oil and natural gas prices decline or costs increase significantly, we could defer a significant portion of our budgeted capital expenditures until later periods to prioritize capital projects that we believe have the highest expected returns and potential to generate near-term cash flows. We routinely monitor and adjust our capital expenditures in response to changes in prices, availability of financing, drilling and acquisition costs, industry conditions, the timing of regulatory approvals, the availability of rigs, success or lack of success in drilling activities, contractual obligations, internally generated cash flows and other factors both within and outside our control.

Our business strategy

Our goal is to enhance value by investing capital to build reserves, production and cash flows at attractive rates of return through the following strategies:

•

Develop our Williston Basin leasehold position. We intend to continue to drill and develop our acreage position to maximize the value of our resource potential. During 2011, we completed and brought on production 63 gross (49.2 net) operated Bakken and Three Forks wells in the Williston Basin. As of March 31, 2012, we had 26 gross (20.6 net) operated wells awaiting completion and 7 gross (5.0 net) operated wells in the process of being drilled in the Bakken and Three Forks formations. We have the ability to increase or decrease the number of wells drilled during 2012 based on market conditions and program results.

•

Focus on operational and cost efficiencies. Our management team is focused on continuous improvement of our operations and has significant experience in successfully converting early-stage resource conversion opportunities into cost-efficient development projects. We believe the magnitude and concentration of our acreage within our project areas provide us with the opportunity to capture economies of scale, including the ability to drill multiple wells from a single drilling pad, utilizing centralized production and oil, gas and water fluid handling facilities and reducing the time and cost of rig mobilization.

•

Adopt and employ leading drilling and completion techniques. Our management team is focused on enhancing our drilling and completion techniques to maximize overall well economics. We believe these techniques have significantly evolved over the last several years, resulting in increased initial production rates and recoverable hydrocarbons per well through the implementation of techniques such as drilling longer laterals and more tightly spacing fracturing stimulation stages. We continuously evaluate our internal drilling and completion results and monitor the results of other operators to improve our operating practices. This continued evolution may enhance our initial production rates, ultimate recovery factors and rate of return on invested capital.

•

Pursue strategic acquisitions with significant resource potential. As opportunities arise, we intend to identify and acquire additional acreage and producing assets in the Williston Basin to supplement our existing operations. Going forward, we may selectively target additional basins that would allow us to employ our resource conversion strategy on large undeveloped acreage positions similar to what we have accumulated in the Williston Basin.

•

Maintain financial flexibility and conservative financial position. We are committed to maintaining a conservative financial strategy by managing our liquidity position and leverage levels. As of June 25, 2012, we had no outstanding borrowings under our revolving credit facility and no outstanding letters of credit issued under our revolving credit facility. As of June 25, 2012, after giving effect to this offering, we would have had $1.2 billion of liquidity available, including $679.2 million in cash and short-term investments and $500 million available under our revolving credit facility, subject to periodic borrowing base redeterminations. This liquidity position, along with internally generated cash flows, will provide additional financial flexibility as we continue to develop our acreage position in the Williston Basin. We now have access to the public equity and debt markets, and we intend to maintain a conservative, balanced capital structure by prudently raising proceeds from future offerings as additional capital needs arise.

Our competitive strengths

We have a number of competitive strengths that we believe will help us to successfully execute our business strategies:

•

Substantial leasehold position in one of North America’s leading unconventional oil-resource plays. As of December 31, 2011, our 307,430 net leasehold acres in the Williston Basin was highly prospective in the Bakken formation and 88% of our 78.7 MMBoe net proved reserves in this area were comprised of oil. We believe our acreage is one of the larger concentrated leasehold positions that is prospective in the Bakken formation, and much of our acreage is in areas of significant drilling activity by other exploration and production companies. While our current drilling plans primarily target the Bakken formation, we are also actively drilling and evaluating what we believe to be significant prospectivity in the Three Forks formation that underlies a large portion of our acreage. We expect that the scale and concentration of our acreage will enable us to improve our drilling and completion costs and operational efficiency as we begin infill drilling during 2012 and move to full development mode in 2013.

•

Large, multi-year project inventory. We believe we have a large inventory of potential drilling locations that we have not yet drilled, a majority of which is operated by us.

•

Management team with proven operating and acquisition skills. Our senior management team has extensive expertise in the oil and gas industry. Our senior technical team has an average of more than 25 years of industry experience, including experience in multiple North American resource plays as well as experience in international basins. We believe our management and technical team is one of our principal competitive strengths relative to our industry peers due to our team’s proven track record in identification, acquisition and execution of resource conversion opportunities. In addition, our technical team possesses substantial expertise in horizontal drilling techniques and managing and acquiring large development programs and also has prior experience in the Williston Basin.

•

Incentivized management team. As of March 31, 2012, our executive officers owned approximately 6% of our common stock. We believe our executive officers’ ownership interest in us provides them with significant incentives to grow the value of our business for the benefit of all stakeholders.

•

Operating control over the majority of our portfolio. In order to maintain better control over our asset portfolio, we have established a leasehold position comprised primarily of properties that we expect to operate. We expect to operate approximately 57% of our gross drilling locations, or 90% of our net drilling locations. As of December 31, 2011, over 90% of our total proved reserves were attributable to properties that we expect to operate. Approximately 95% of our estimated 2012 drilling and completion capital expenditure budget is related to operated wells, which we anticipate will result in an increase in 2012 of the percentage of our proved reserves attributable to properties we expect to operate. As of December 31, 2011, our average working interest in our operated and non-operated identified drilling locations was 69% and 10%, respectively. Controlling operations will allow us to dictate the pace of development as well as the costs, type and timing of exploration and development activities. We believe that maintaining operational control over the majority of our acreage will allow us to better pursue our strategies of enhancing returns through operational and cost efficiencies

and maximizing hydrocarbon recovery through continuous improvement of drilling and completion techniques. We are also better able to control infrastructure investment to reduce operating costs and increase gas production and oil price realizations.

Recent developments

Amendment to revolving credit facility and redetermination of borrowing base. On April 3, 2012, we entered into an amendment to our amended and restated revolving credit facility. In connection with this amendment, the semi-annual redetermination of our borrowing base was completed, which resulted in our borrowing base increasing from $350 million to $500 million. The next scheduled redetermination of our borrowing base is October 1, 2012. On June 25, 2012, our lenders waived the mandatory reduction of our borrowing base that otherwise would have occurred as a result of the issuance of the notes offered hereby. For more information regarding our revolving credit facility, see “Description of other indebtedness.”

Marketing and transportation

The Williston Basin crude oil transportation and refining infrastructure has grown substantially in recent years, largely in response to drilling activity in the Bakken formation. According to a presentation from the North Dakota Pipeline Authority dated January 24, 2012, there were approximately 415,000 barrels per day of crude oil pipeline transportation capacity in the Williston Basin as of December 31, 2011. In addition, approximately 300,000 barrels per day of specifically dedicated railcar transportation capacity has been placed into service as of December 31, 2011. Based on publicly announced expansion projects, pipeline transportation and refining capacity for Williston Basin oil production could increase by approximately 222,000 barrels per day by the end of 2013. As of December 31, 2011, we sold a substantial majority of our oil production directly at the wellhead and were not responsible for its transportation. However, the price we receive at the wellhead is impacted by transportation and refining infrastructure constraints. For a discussion of the potential risks to our business that could result from transportation and refining infrastructure constraints in the Williston Basin, please see “Risk factors—Risks related to the oil and natural gas industry and our business—Insufficient transportation or refining capacity in the Williston Basin could cause significant fluctuations in our realized oil and natural gas prices.”

Corporate information

Our principal executive offices are located at 1001 Fannin Street, Suite 1500, Houston, Texas 77002, and our telephone number at that address is (281) 404-9500. Our website is located at http://www.oasispetroleum.com. Information contained on our website (other than the documents listed under “Where you can find more information”) or any other website is not incorporated by reference herein and does not constitute a part of this prospectus supplement and the accompanying prospectus.

The offering

The following summary contains basic information about the notes and is not complete. For a more complete understanding of the notes, please refer to the section entitled “Description of notes” in this prospectus supplement and “Description of Debt Securities” in the accompanying base prospectus. For purposes of this section of the summary and the description of the notes included in this prospectus supplement, references to “we,” “our,” “us,” “the Company,” or “Oasis” refer only to Oasis Petroleum Inc. and do not include its subsidiaries.

Issuer

Oasis Petroleum Inc.

Notes offered

$400,000,000 aggregate principal amount of 6.875% senior notes due 2023.

Maturity

January 15, 2023.

Interest payment dates

January 15 and July 15 of each year, beginning on January 15, 2013. Interest will accrue from July 2, 2012.

Guarantees

The notes will be jointly and severally guaranteed on a senior unsecured basis by all our existing material subsidiaries and certain future subsidiaries. See “Description of notes—Covenants—Subsidiary guarantees.”

Ranking

The notes will be our general senior unsecured obligations and will:

•

rank senior in right of payment to any future subordinated indebtedness of Oasis;

•

rank pari passu in right of payment with any existing and future senior indebtedness of Oasis;

•

rank effectively junior in right of payment to Oasis’ existing and future secured indebtedness, including indebtedness under our revolving credit facility, to the extent of the value of the assets of Oasis constituting collateral securing such indebtedness; and

•

rank structurally junior in right of payment to any indebtedness or liabilities of any of our subsidiaries that do not guarantee the notes.

As of March 31, 2012, on an as adjusted basis after giving effect to the sale of the notes, the application of the net proceeds therefrom as described under “Use of proceeds” in this prospectus supplement, Oasis would have had no indebtedness outstanding, other than the notes offered hereby and its $800 million of outstanding senior unsecured notes, and Oasis would have had $350 million of secured borrowing capacity available under its revolving credit facility. As of March 31, 2012, the non-guarantor subsidiaries of Oasis had no material assets and no indebtedness outstanding.

The guarantees will be the guarantors’ general senior unsecured obligations and will:

•

rank senior in right of payment to any future subordinated indebtedness of such Subsidiary Guarantor;

•

rank pari passu in right of payment with any existing and future senior indebtedness of such Subsidiary Guarantor, including its guarantee of Oasis’ outstanding senior unsecured notes; and

•

rank effectively junior in right of payment to all existing and future secured indebtedness of such Subsidiary Guarantor (including any indebtedness under our revolving credit facility), to the extent of the value of the assets of such Subsidiary Guarantor constituting collateral securing such indebtedness.

As of March 31, 2012, on an as adjusted basis and after giving effect to the sale of the notes and the application of the net proceeds therefrom as described under “Use of proceeds” in this prospectus supplement, our material subsidiaries (all of which will initially guarantee the notes) collectively had no consolidated indebtedness, except for their guarantees of the notes offered hereby and Oasis’ outstanding senior unsecured notes.

Use of proceeds

We intend to use the net proceeds from this offering to fund our exploration, development and acquisition program and for general corporate purposes. Please see “Use of proceeds.”

Optional redemption

We will have the option to redeem the notes, in whole or in part, at any time on or after July 15, 2017, in each case at the redemption prices described in this prospectus supplement under the heading “Description of notes—Optional redemption,” together with any accrued and unpaid interest to the date of such redemption.

At any time prior to July 15, 2017, we may redeem the notes, in whole or in part, at a redemption price plus an applicable “make-whole” premium described in this prospectus supplement under “Description of notes—Optional redemption,” together with any accrued and unpaid interest to the date of such redemption.

In addition, prior to July 15, 2015, we may, from time to time, redeem up to 35% of the aggregate principal amount of the notes with the net cash proceeds of certain equity offerings at a redemption price equal to 106.875% of the principal amount of the notes, plus any accrued and unpaid interest to the date of redemption.

If certain transactions that would constitute a change of control occur on or prior to July 15, 2013, we may redeem all, but not less than all, of the notes at a redemption price equal to 110% of the principal amount of the notes redeemed plus any accrued and unpaid interest to the date of such redemption.

Change of control; asset sales

Upon the occurrence of a change of control (as defined in the indenture for the notes), holders of the notes will have the right to require us to repurchase all or a portion of the notes at a price equal to 101% of the aggregate principal amount of the notes repurchased, together with any accrued and unpaid interest to the date of purchase. In connection with certain asset sales, we will be required to use the net cash proceeds of the asset sale to make an offer to purchase the notes at 100% of the principal amount, together with any accrued and unpaid interest to the date of purchase.

Certain covenants

We will issue the notes under an indenture with U.S. Bank National Association, as trustee. The indenture will, among other things, limit our and our restricted subsidiaries’ ability to:

•

make investments;

•

incur additional indebtedness or issue preferred stock;

•

create liens;

•

sell assets;

•

enter into agreements that restrict dividends or other payments by restricted subsidiaries;

•

consolidate, merge or transfer all or substantially all of the assets of our company;

•

engage in transactions with our affiliates;

•

pay dividends or make other distributions on capital stock or prepay subordinated indebtedness; and

•

create unrestricted subsidiaries.

These covenants are subject to important exceptions and qualifications, which are described in this prospectus supplement under “Description of notes—Covenants.” However, most of the covenants will terminate if both Standard & Poor’s Ratings Services and Moody’s Investors Service, Inc. assign the notes an investment grade rating and no default exists with respect to the notes.

Additional notes

We may from time to time create and issue additional notes having the same terms as the notes being issued in this offering, so that such additional notes shall be consolidated and form a single series with the notes offered hereby.

No prior market

The notes will be new securities for which there is no market. Although the underwriters have informed us that they intend to make a market in the notes, they are not obligated to do so and may discontinue market making at any time without notice. Accordingly, a liquid market for the notes may not develop or be maintained.

Summary historical consolidated financial data

You should read the following summary financial data in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in each of our Annual Report on Form 10-K for the year ended December 31, 2011 and our Quarterly Report on Form 10-Q for the period ended March 31, 2012 incorporated by reference into this prospectus supplement. We believe that the assumptions underlying the preparation of our historical consolidated financial statements are reasonable. The financial information included in this prospectus supplement may not be indicative of our future results of operations, financial position and cash flows.

Set forth below is our summary historical consolidated financial data for the years ended December 31, 2009, 2010 and 2011 and balance sheet data at December 31, 2009, 2010 and 2011, all of which have been derived from our audited consolidated financial statements incorporated by reference in this prospectus supplement. Our historical financial data below for the three months ended March 31, 2011 and 2012 and as of March 31, 2012 are derived from our unaudited condensed consolidated financial statements and the notes thereto included in our Quarterly Report on Form 10-Q for the period ended March 31, 2012 and incorporated by reference in this prospectus supplement and, in our opinion, have been prepared on a basis consistent with the audited consolidated financial statements and the notes thereto and include all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of this information.


	Year ended December 31,									Three months ended March 31,
(Dollars in thousands)	2009(1)			2010			2011			2011			2012


Statement of operations data:
Revenues:
Oil and gas revenues	$	37,755		$	128,927		$	330,422		$	58,744		$	137,906
Well services revenues		—			—			—			—			660

Total revenues		37,755			128,927			330,422			58,744			138,566


Expenses:
Lease operating expenses(2)		8,473			14,118			32,707			5,630			9,816
Wells services operating expenses		—			—			—			—			477
Marketing, transportation and gathering expenses		218			464			1,365			312			2,569
Production taxes		3,810			13,768			33,865			6,083			13,266
Depreciation, depletion and amortization		16,670			37,832			74,981			13,812			38,886
Exploration expenses		1,019			297			1,685			32			2,835
Rig termination(3)		3,000			—			—			—			—
Impairment of oil and gas properties		6,233			11,967			3,610			1,381			368
(Gain) loss on sale of properties		(1,455	)		—			207			—			—
Stock-based compensation expenses(4)		—			8,743			—			—			—
General and administrative expenses		9,342			19,745			29,435			5,950			12,199

Total expenses		47,310			106,934			177,855			33,200			80,416

Operating income (loss)		(9,555	)		21,993			152,567			25,544			58,150

Other income (expense):
Net (loss) gain on derivative instruments		(4,747	)		(7,653	)		1,595			(31,666	)		(18,586	)
Interest expense		(912	)		(1,357	)		(29,618	)		(5,198	)		(13,899	)
Other income (expense)		5			284			1,635			312			598

Total other income (expense)		(5,654	)		(8,726	)		(26,388	)		(36,552	)		(31,887	)

Income (loss) before income taxes		(15,209	)		13,267			126,179			(11,008	)		26,263
Income tax (expense) benefit(5)		—			(42,962	)		(46,789	)		4,161			(9,822	)

Net income (loss)	$	(15,209	)	$	(29,695	)	$	79,390		$	(6,847	)	$	16,441

(1)

Our statement of operations data for the year ended December 31, 2009 does not include the effects of the acquisition of interests in certain oil and gas properties from Kerogen Resources, Inc. and Fidelity Exploration and Production Company for the full twelve months of 2009. We acquired such interests on June 15, 2009 and September 30, 2009, respectively. See Note 6 to our audited consolidated financial statements incorporated by reference into this prospectus supplement.

(2)

For the years ended December 31, 2009, 2010 and 2011 and for the three months ended March 31, 2011, lease operating expenses excludes marketing, transportation and gathering expenses to conform such amounts to current year classifications.

(3)

During the first quarter of 2009, we paid $3.0 million in rig termination expenses in connection with the early termination of two drilling rig contracts entered into in 2008.

(4)

In March 2010, we recorded a $5.2 million stock-based compensation charge associated with Oasis Petroleum Management LLC (“OPM”) granting 1.0 million Class C common unit interests (“C Units”) to certain of our employees. During the fourth quarter of 2010, we recorded an additional $3.5 million in stock-based compensation expense primarily associated with OPM granting discretionary shares of our common stock to certain of our employees who were not C Unit holders and certain contractors. See Note 10 to our audited consolidated financial statements incorporated by reference into this prospectus supplement.

(5)

Prior to our corporate reorganization, we were a limited liability company not subject to entity-level income tax. Accordingly, no provision for federal or state corporate income taxes was recorded for the year ended December 31, 2009, as the taxable income was allocated directly to our equity holders. In connection with the closing of our IPO, we merged into a corporation and became subject to federal and state entity-level taxation. See Note 11 to our audited consolidated financial statements incorporated by reference into this prospectus supplement.


	As of December 31,						As of March 31,
(Dollars in thousands)	2009		2010		2011		2012


Balance sheet data:
Cash and cash equivalents	$	40,562	$	143,520	$	470,872	$	287,298
Net property, plant and equipment		181,573		483,683		1,079,955		1,339,012
Total assets		239,553		691,852		1,727,382		1,813,410
Long-term debt		35,000		—		800,000		800,000
Total members’/stockholders’ equity		171,850		551,794		634,238		651,089


	Year ended December 31,									Three months ended March 31,
(Dollars in thousands, except ratios)	2009			2010			2011			2011			2012


Other financial data:
Net cash provided by operating activities	$	6,148		$	49,612		$	176,024		$	22,845		$	62,765
Net cash used in investing activities		(80,756	)		(309,535	)		(629,390	)		(200,789	)		(245,133	)
Net cash provided by (used in) financing activities		113,600			362,881			780,718			389,414			(1,206	)
Adjusted EBITDA(1)		16,668			82,223			234,500			41,096			101,137
Ratio of earnings to fixed charges(2)(3)		—			9.72			4.74			—			2.72

(1)

Adjusted EBITDA is a non-GAAP financial measure. For a definition of Adjusted EBITDA and a reconciliation of Adjusted EBITDA to our net income (loss) and net cash provided by operating activities, see “—Non-GAAP financial measure” below.

(2)

The ratio of earnings to fixed charges is calculated as earnings divided by fixed charges. Earnings consist of pre-tax income from continuing operations before fixed charges. Fixed charges consist of interest expensed and capitalized, amortized capitalized expenses related to indebtedness and an estimate of interest within rental expense.

(3)

Due to our net pre-tax loss for the year ended December 31, 2009 and the three month period ended March 31, 2011, the ratio of earnings to fixed charges was less than 1:1. The Company would have needed additional earnings of $15.2 million and $11.0 million for the year ended December 31, 2009 and the three month period ended March 31, 2011, respectively, to achieve a coverage of 1:1.

Non-GAAP financial measure

Adjusted EBITDA is a supplemental non-GAAP financial measure that is used by management and external users of our consolidated financial statements, such as industry analysts, investors, lenders and rating agencies.

We define Adjusted EBITDA as earnings before interest expense, income taxes, depreciation, depletion, amortization, exploration expenses and other similar non-cash charges. Adjusted EBITDA is not a measure of net income or cash flows as determined by United States generally accepted accounting principles, or GAAP.

Management believes Adjusted EBITDA is useful because it allows us to more effectively evaluate our operating performance and compare the results of our operations from period to period without regard to our financing methods or capital structure. We exclude the items listed above from net income in arriving at Adjusted EBITDA because these amounts can vary substantially from company to company within our industry depending upon accounting methods and book values of assets, capital structures and the method by which the assets were acquired. Adjusted EBITDA should not be considered as an alternative to, or more meaningful than, net income or cash flows from operating activities as determined in accordance with GAAP or as an indicator of our operating performance or liquidity. Certain items excluded from Adjusted EBITDA are significant components in understanding and assessing a company’s financial performance, such as a company’s cost of capital and tax structure, as well as the historic costs of depreciable assets, none of which are components of Adjusted EBITDA. Our computations of Adjusted EBITDA may not be comparable to other similarly titled measures of other companies. We believe that Adjusted EBITDA is a widely followed measure of operating performance and may also be used by investors to measure our ability to meet debt service requirements.

The following tables present a reconciliation of the non-GAAP financial measure of Adjusted EBITDA to the GAAP financial measures of net income (loss) and net cash provided by operating activities, respectively.


	Year ended December 31,									Three months ended March 31,
(Dollars in thousands)	2009			2010			2011			2011			2012


Adjusted EBITDA reconciliation to net income (loss):
Net income (loss)	$	(15,209	)	$	(29,695	)	$	79,390		$	(6,847	)	$	16,441
Change in unrealized (gain) loss on derivative instruments		7,043			7,533			(5,436	)		31,154			17,295
Interest expense		912			1,357			29,618			5,198			13,899
Depreciation, depletion and amortization		16,670			37,832			74,981			13,812			38,886
Impairment of oil and gas properties		6,233			11,967			3,610			1,381			368
Exploration expenses		1,019			297			1,685			32			2,835
Loss on sale of properties		—			—			207			—			—
Stock-based compensation expenses		—			9,970			3,656			527			1,591
Income tax expense (benefit)		—			42,962			46,789			(4,161	)		9,822

Adjusted EBITDA	$	16,668		$	82,223		$	234,500		$	41,096		$	101,137


	Year ended December 31,									Three months ended March 31,
(Dollars in thousands)	2009			2010			2011			2011			2012


Adjusted EBITDA reconciliation to net cash provided by operating activities:
Net cash provided by operating activities	$	6,148		$	49,612		$	176,024		$	22,845		$	62,765
Realized gain (loss) on derivative instruments		2,296			(120	)		(3,841	)		(512	)		(1,291	)
Interest expense		912			1,357			29,618			5,198			13,899
Exploration expenses		1,019			297			1,685			32			2,835
Gain on sale of properties		1,455			—			—			—			—
Debt discount amortization and other		(95	)		(470	)		(1,561	)		(256	)		(648	)
Changes in working capital		4,933			31,547			32,575			13,789			23,577

Adjusted EBITDA	$	16,668		$	82,223		$	234,500		$	41,096		$	101,137

Summary historical operating and reserve data

The following table presents summary data with respect to our estimated net proved oil and natural gas reserves as of the dates indicated. For additional information regarding our reserves, as well as the impact of the SEC’s rules governing the presentation of reserve information, see the section entitled “Business” in our Annual Report on Form 10-K for the year ended December 31, 2011. The reserve estimates presented in the table below are based on reports prepared by DeGolyer and MacNaughton, our independent reserve engineers, and were prepared consistent with the SEC’s rules regarding oil and natural gas reserve reporting that are currently in effect.


	At December 31,
	2009		2010		2011


Reserve data(1):
Estimated proved reserves:
Oil (MMBbls)		12.4		36.6		69.1
Natural gas (Bcf)		5.3		19.4		57.9
Total estimated proved reserves (MMBoe)		13.3		39.8		78.7
Percent oil		93%		92%		88%
Estimated proved developed reserves (MMBoe)		5.6		17.0		35.8
Percent proved developed		42%		43%		46%
Estimated proved undeveloped reserves (MMBoe)		7.7		22.8		42.9
PV-10 (in millions)(2)	$	133.5	$	697.8	$	1,903.7
Standardized Measure (in millions)(3)	$	133.5	$	485.7	$	1,319.5

(1)

Our estimated proved reserves and related future net revenues, PV-10 and Standardized Measure were determined using index prices for oil and natural gas, without giving effect to derivative transactions, and were held constant throughout the life of the properties. The unweighted arithmetic average first-day-of-the-month prices for the prior 12 months were $61.04/Bbl for oil and $3.87/MMBtu for natural gas, $79.40/Bbl for oil and $4.38/MMBtu for natural gas, and $96.23/Bbl for oil and $4.12/MMBtu for natural gas for the years ended December 31, 2009, 2010 and 2011, respectively. These prices were adjusted by lease for quality, transportation fees, geographical differentials, marketing bonuses or deductions and other factors affecting the price received at the wellhead.

(2)

PV-10 is a non-GAAP financial measure and generally differs from Standardized Measure, the most directly comparable GAAP financial measure, because it does not include the effects of income taxes on discounted future net cash flows. However, our PV-10 and our Standardized Measure are equivalent at December 31, 2009 because as of December 31, 2009, we were a limited liability company not subject to entity level taxation. Accordingly, no provision for federal or state corporate income taxes was provided prior to our IPO and corporate reorganization because taxable income passed through to our equity holders. In connection with the closing of our IPO, we merged into a corporation and became subject to federal and state entity-level taxation. See Note 11 to our audited consolidated financial statements incorporated by reference into this prospectus supplement. As of December 31, 2010 and 2011, the effect of income tax on our discounted future net cash flows was $212.1 million and $584.2 million, resulting in a Standardized Measure of $485.7 million and $1,319.5 million, respectively. Neither PV-10 nor Standardized Measure represents an estimate of the fair market value of our oil and natural gas properties. The oil and gas industry uses PV-10 as a measure to compare the relative size and value of proved reserves held by companies without regard to the specific tax characteristics of such entities.

(3)

Standardized Measure represents the present value of estimated future net cash flows from proved oil and natural gas reserves, less estimated future development, production, plugging and abandonment costs and income tax expenses (if applicable), discounted at 10% per annum to reflect timing of future cash flows.

The following table sets forth summary data with respect to our production results, average sales prices and production costs on a historical basis for the periods presented:


	Year ended December 31,						Three months ended March 31,
	2009(1)		2010		2011		2011		2012


Operating data:
Net production volumes:
Oil (MBbls)		658		1,792		3,732		694		1,474
Natural gas (MMcf)		326		651		1,092		202		785
Oil equivalents (MBoe)		712		1,900		3,914		728		1,605
Average daily production (Boe/d)		1,950		5,206		10,724		8,090		17,633

Average sales prices:
Oil, without realized derivatives (per Bbl)(2)	$	55.32	$	69.60	$	86.18	$	82.33	$	88.10
Oil, with realized derivatives (per Bbl)(2)(3)		58.82		69.53		85.15		81.59		87.23
Natural gas (per Mcf)(4)		4.24		6.52		8.02		7.78		8.32

Costs and expenses (per Boe):
Lease operating expenses(5)	$	11.90	$	7.43	$	8.36	$	7.73	$	6.12
Marketing, transportation and gathering expenses		0.31		0.24		0.34		0.43		1.60
Production taxes		5.35		7.25		8.65		8.35		8.27
Depreciation, depletion and amortization		23.42		19.91		19.16		18.97		24.23
General and administrative expenses		13.12		10.39		7.52		8.17		7.60
Stock-based compensation expenses(6)		—		4.60		—		—		—

(1)

Our operating data for the year ended December 31, 2009 does not include the effects of the acquisition of interests in certain oil and gas properties from Kerogen Resources, Inc. and Fidelity Exploration and Production Company for the full twelve months of 2009. We acquired such interests on June 15, 2009 and September 30, 2009, respectively. See Note 6 to our audited consolidated financial statements incorporated by reference into this prospectus supplement.

(2)

For the three months ended March 31, 2012, average sales prices for oil are calculated using total oil revenues, excluding bulk purchase sales of $1.5 million, divided by oil production. We had no bulk purchase sales included in oil revenues for the years ended December 31, 2009, 2010 and 2011 and for the three month period ended March 31, 2011.

(3)

Realized prices include realized gains or losses on cash settlements for our commodity derivatives, which do not qualify for and were not designated as hedging instruments for accounting purposes.

(4)

Natural gas prices include the value for natural gas and natural gas liquids.

(5)

(6)

In March 2010, we recorded a $5.2 million stock-based compensation charge associated with OPM granting 1.0 million C Units to certain of our employees. During the fourth quarter of 2010, we recorded an additional $3.5 million in stock-based compensation expense primarily associated with OPM granting discretionary shares of our common stock to certain of our employees who were not C Unit holders and certain contractors. See Note 10 to our audited consolidated financial statements incorporated by reference into this prospectus supplement.

An investment in the notes involves risks. In addition to the risks described below, you should also carefully read all of the other information included in this prospectus supplement, the accompanying prospectus and the documents we have incorporated by reference into this prospectus supplement in evaluating an investment in the notes. If any of the described risks actually were to occur, our business, financial condition, results of operations or growth prospects could be affected materially and adversely. In that case, our ability to fulfill our obligations under the notes could be materially affected, and you could lose all or part of your investment.

The risks described below are not the only ones that we face. Additional risks not presently known to us or that we currently deem immaterial individually or in the aggregate may also impair our business operations.

This prospectus supplement, the accompanying prospectus and the documents we have incorporated by reference into this prospectus supplement also contain forward-looking statements that involve risks and uncertainties, some of which are described in the documents incorporated by reference into this prospectus supplement. Our actual results could differ materially from those anticipated in these forward-looking statements as a result of various factors, including the risks and uncertainties faced by us described below or incorporated by reference into this prospectus supplement.

We may not be able to generate enough cash flow to meet our debt obligations.

We expect our earnings and cash flow to vary significantly from year to year due to the nature of our industry. As a result, the amount of debt that we can manage in some periods may not be appropriate for us in other periods. Additionally, our future cash flow may be insufficient to meet our debt obligations and other commitments, including our obligations under the notes. Any insufficiency could negatively impact our business. A range of economic, competitive, business and industry factors will affect our future financial performance, and, as a result, our ability to generate cash flow from operations and to pay our debt, including our obligations under the notes. Many of these factors, such as oil and natural gas prices, economic and financial conditions in our industry and the global economy and initiatives of our competitors, are beyond our control. If we do not generate enough cash flow from operations to satisfy our debt obligations, we may have to undertake alternative financing plans, such as:

If for any reason we are unable to meet our debt service and repayment obligations, we would be in default under the terms of the agreements governing our debt, which would allow our creditors at that time to declare all outstanding indebtedness to be due and payable, which would in turn trigger cross-acceleration or cross-default rights between the relevant agreements. In addition, our lenders could compel us to apply all of our available cash to repay our borrowings or they could prevent us from making payments on the notes. If amounts

outstanding under our revolving credit facility, our $800 million of outstanding senior unsecured notes or the notes offered hereby were to be accelerated, we cannot be certain that our assets would be sufficient to repay in full the money owed to the lenders or to our other debt holders, including you as a noteholder.

We may be able to incur substantially more debt. This could exacerbate the risks associated with our indebtedness.

We and our subsidiaries may be able to incur substantial additional indebtedness in the future, including under our revolving credit facility. Our $1 billion revolving credit facility currently has a borrowing base of $500 million for secured borrowings, subject to periodic borrowing base redeterminations. As of March 31, 2012, we had no outstanding indebtedness under our revolving credit facility, which had $350 million of secured borrowing capacity available, and no outstanding letters of credit issued under our revolving credit facility. Please see “Description of other indebtedness.” Any borrowings under the revolving credit facility will be secured, and as a result, effectively senior to the notes and the guarantees of the notes by the guarantors, to the extent of the value of the collateral securing that indebtedness. In addition, the holders of any future debt we may incur that ranks equally with the notes will be entitled to share ratably with the holders of the notes in any proceeds distributed in connection with any insolvency, liquidation, reorganization, dissolution or other winding-up of us. This may have the effect of reducing the amount of proceeds paid to you. If new debt is added to our current debt levels, the related risks that we and our subsidiaries now face could intensify.

Payment of principal and interest on the notes will be effectively subordinated to our senior secured debt to the extent of the value of the assets securing that debt and structurally subordinated to the liabilities of any of our subsidiaries that do not guarantee the notes.

The notes are not secured. Therefore, the notes will be effectively subordinated to claims of our secured creditors, and the subsidiary guarantees will be effectively subordinated to the claims of the secured creditors of our subsidiary guarantors. As of March 31, 2012, we and our subsidiary guarantors had no outstanding indebtedness under our revolving credit facility and no outstanding issued letters of credit under our revolving credit facility. Holders of our secured obligations, including obligations under the credit agreement that governs our revolving credit facility, will have claims that are prior to claims of the holders of the notes with respect to the assets securing those obligations. On April 3, 2012, we entered into an amendment to our revolving credit facility, in order to, among other things, increase our borrowing base from $350 million to $500 million of secured borrowings. On June 25, 2012, our lenders waived the mandatory reduction of our borrowing base that otherwise would have occurred as a result of the issuance of the notes offered hereby. For more information on our revolving credit facility, please read “Description of other indebtedness.” In the event of a liquidation, dissolution, reorganization, bankruptcy or any similar proceeding, our assets and those of our subsidiaries will be available to pay obligations on the notes and the guarantees only after holders of our senior secured debt have been paid the value of the assets securing such debt. Although all of our material subsidiaries will initially guarantee the notes, in the future, under certain circumstances, the guarantees are subject to release and we may have subsidiaries that are not guarantors. In that case, the notes would be structurally subordinated to the claims of all creditors, including trade creditors and tort claimants, of our subsidiaries that are not guarantors. In the event of the liquidation, dissolution, reorganization, bankruptcy or similar proceeding of the business of a subsidiary that is not a guarantor, creditors of that subsidiary would generally

have the right to be paid in full before any distribution is made to us or the holders of the notes. Accordingly, there may not be sufficient funds remaining to pay amounts due on all or any of the notes.

Our revolving credit facility and the indentures governing our outstanding senior unsecured notes all contain, and the indenture governing the notes offered hereby will contain, operating and financial restrictions that may restrict our business and financing activities.

Our revolving credit facility and the indentures governing our outstanding senior unsecured notes all contain, the indenture governing the notes offered hereby will contain, and any future indebtedness we incur may contain, a number of restrictive covenants that will impose significant operating and financial restrictions on us, including restrictions on our ability to, among other things:

As a result of these covenants, we will be limited in the manner in which we conduct our business, and we may be unable to engage in favorable business activities or finance future operations or capital needs.

Our ability to comply with some of the covenants and restrictions contained in our revolving credit facility and the indentures governing our outstanding senior unsecured notes may be affected by events beyond our control. If market or other economic conditions deteriorate, our ability to comply with these covenants may be impaired. A failure to comply with the covenants, ratios or tests in our revolving credit facility, the indentures governing our outstanding senior unsecured notes or any future indebtedness could result in an event of default under our revolving credit facility, the indentures governing our outstanding senior unsecured notes or our future indebtedness, which, if not cured or waived, could have a material adverse effect on our business, financial condition and results of operations. If an event of default under our revolving credit facility occurs and remains uncured, the lenders thereunder:

A payment default or an acceleration under our revolving credit facility could result in an event of default and an acceleration under the indentures for our outstanding senior unsecured notes.

If the indebtedness under the notes were to be accelerated, there can be no assurance that we would have, or be able to obtain, sufficient funds to repay such indebtedness in full. In addition, our obligations under our revolving credit facility are collateralized by perfected first priority liens and security interests on substantially all of our assets, including mortgage liens on oil and natural gas properties having at least 80% of the reserve value as determined by reserve reports, and if we are unable to repay our indebtedness under the revolving credit facility, the lenders could seek to foreclose on our assets. Please see “Description of notes” and “Description of other indebtedness.”

Because all of our operations are conducted through our subsidiaries, our ability to service our debt is largely dependent on our receipt of distributions or other payments from our subsidiaries.

We are a holding company, and all of our operations are conducted through our subsidiaries. As a result, our ability to service our debt is largely dependent on the earnings of our subsidiaries and the payment of those earnings to us in the form of dividends, loans or advances and through repayment of loans or advances from us. Our subsidiaries are legally distinct from us and, except for our subsidiaries that have guaranteed our debt, have no obligation to pay amounts due on our debt or to make funds available to us for such payment. The ability of our subsidiaries to pay dividends, repay intercompany notes or make other advances to us is subject to restrictions imposed by applicable laws, tax considerations and the agreements governing our subsidiaries. In addition, such payment may be restricted by claims against our subsidiaries by their creditors, including suppliers, vendors, lessors and employees.

In the event of a change of control (as defined in the indenture for the notes), we will be required, subject to certain conditions, to offer to purchase all outstanding notes at a price equal to 101% of the principal amount thereof, plus accrued and unpaid interest thereon to the date of purchase. The holders of our outstanding senior unsecured notes have substantially the same put rights upon a change of control, which would increase the amount of indebtedness that we would be required to offer to repurchase. If a change of control were to occur today, we would not have sufficient funds available to purchase all of the outstanding notes were they to be tendered in response to an offer made as a result of a change of control. We cannot assure you that we will have sufficient funds available or that we will be permitted by our other debt instruments to fulfill these obligations upon a change of control in the future. Furthermore, certain change of control events would constitute an event of default under our credit agreement. Please see “Description of notes—Repurchase at the option of holders—Change of control.”

In a published decision, the Chancery Court of Delaware has raised the possibility that a change of control put right occurring as a result of a failure to have “continuing directors” comprising a majority of a board of directors may be unenforceable on public policy grounds. Therefore, you may not be entitled to receive this protection under the indenture.

The term “change of control” is limited to certain specified transactions and may not include other events that might adversely affect our financial condition. Our obligation to repurchase the notes upon a change of control would not necessarily afford holders of the notes protection in the event of a highly leveraged transaction, reorganization, merger or similar transaction involving us.

Many of the covenants contained in the indenture will terminate if the notes are rated investment grade by both Standard & Poor’s and Moody’s and no default has occurred and is continuing.

Many of the covenants in the indenture governing the notes will terminate if the notes are rated investment grade by both Standard & Poor’s and Moody’s, provided at such time no default with respect to the notes has occurred and is continuing. These covenants will restrict, among other things, our ability to pay dividends, incur debt and to enter into certain other transactions. There can be no assurance that the notes will ever be rated investment grade, or that if they are rated investment grade, that the notes will maintain such ratings. However, termination of these covenants would allow us to engage in certain transactions that would not be permitted while these covenants were in force. Please see “Description of notes—Covenant termination.”

The guarantees by certain of our subsidiaries of the notes could be deemed fraudulent conveyances under certain circumstances, and a court may try to subordinate or void these subsidiary guarantees.

Under U.S. bankruptcy law and comparable provisions of state fraudulent transfer laws, a guarantee can be voided, or claims under a guarantee may be subordinated to all other debts of that guarantor if, among other things, the guarantor, at the time it incurred the indebtedness evidenced by its guarantee:

In addition, any payment by that guarantor under a guarantee could be voided and required to be returned to the guarantor or to a fund for the benefit of the creditors of the guarantor. The measures of insolvency for purposes of these fraudulent transfer laws will vary depending upon the law applied in any proceeding to determine whether a fraudulent transfer has occurred. Generally, however, a subsidiary guarantor would be considered insolvent if:

Your ability to transfer the notes may be limited by the absence of a trading market.

The notes will be new securities for which currently there is no trading market. Although the underwriters have informed us that they currently intend to make a market in the notes, they are not obligated to do so. In addition, they may discontinue any such market making at any time without notice. The liquidity of any market for the notes will depend on the number of holders of the notes, the interest of securities dealers in making a market in the notes and other factors. Accordingly, we cannot assure you as to the development or liquidity of any market for the notes. Historically, the market for noninvestment grade debt has been subject to disruptions that have caused substantial volatility in the prices of securities similar to the notes. We cannot assure you that the market, if any, for the notes will be free from similar disruptions. Any such disruption may adversely affect the noteholders’ ability to transfer the notes.

A substantial or extended decline in oil and, to a lesser extent, natural gas prices may adversely affect our business, financial condition or results of operations and our ability to meet our capital expenditure obligations and financial commitments, including our ability to make payments on the notes and our other debt obligations.

The price we receive for our oil and, to a lesser extent, natural gas, heavily influences our revenue, profitability, access to capital and future rate of growth. Oil and natural gas are commodities and, therefore, their prices are subject to wide fluctuations in response to relatively minor changes in supply and demand. Historically, the markets for oil and natural gas have been volatile. These markets will likely continue to be volatile in the future. The prices we receive for our production, and the levels of our production, depend on numerous factors beyond our control. These factors include the following:

Substantially all of our production is sold to purchasers under short-term (less than 12-month) contracts at market-based prices. Lower oil and natural gas prices will reduce our cash flows, borrowing ability and the present value of our reserves. See “—Our exploration, development and exploitation projects require substantial capital expenditures. We may be unable to obtain needed capital or financing on satisfactory terms, which could lead to expiration of our leases or a decline in our oil and natural gas reserves.” Lower oil and natural gas prices may also reduce the amount of oil and natural gas that we can produce economically and may affect our proved reserves. See also “—The present value of future net revenues from our proved reserves will not necessarily be the same as the current market value of our estimated oil and natural gas reserves” below.

Drilling for and producing oil and natural gas are high-risk activities with many uncertainties that could adversely affect our business, financial condition or results of operations.

Our future financial condition and results of operations will depend on the success of our exploitation, exploration, development and production activities. Our oil and natural gas exploration and production activities are subject to numerous risks beyond our control, including the risk that drilling will not result in commercially viable oil or natural gas production. Our decisions to purchase, explore, develop or otherwise exploit drilling locations or properties will depend in part on the evaluation of data obtained through geophysical and geological analyses, production data and engineering studies, the results of which are often inconclusive or subject to varying interpretations. For a discussion of the uncertainty involved in these processes, see “—Our estimated proved reserves are based on many assumptions that may turn out to be inaccurate. Any significant inaccuracies in these reserve estimates or underlying assumptions will materially affect the quantities and present value of our reserves” below. Our cost of drilling, completing and operating wells is often uncertain before drilling commences. Overruns in budgeted expenditures are common risks that can make a particular project uneconomical. Further, many factors may curtail, delay or cancel our scheduled drilling projects, including the following:

Our estimated proved reserves are based on many assumptions that may turn out to be inaccurate. Any significant inaccuracies in these reserve estimates or underlying assumptions will materially affect the quantities and present value of our reserves.

The process of estimating oil and natural gas reserves is complex. It requires interpretations of available technical data and many assumptions, including assumptions relating to current and future economic conditions and commodity prices. Any significant inaccuracies in these interpretations or assumptions could materially affect the estimated quantities and present value of reserves shown in this prospectus supplement. See “Business—Our operations” in our Annual Report on Form 10-K for the year ended December 31, 2011 for information about our estimated oil and natural gas reserves and the PV-10 and Standardized Measure of discounted future net revenues as of December 31, 2011, 2010 and 2009.

In order to prepare our estimates, we must project production rates and the timing of development expenditures. We must also analyze available geological, geophysical, production and engineering data. The extent, quality and reliability of this data can vary. The process also requires economic assumptions about matters such as oil and natural gas prices, drilling and operating expenses, capital expenditures, taxes and availability of funds. Although the reserve information contained herein is reviewed by our independent reserve engineers, estimates of oil and natural gas reserves are inherently imprecise.

Actual future production, oil and natural gas prices, revenues, taxes, development expenditures, operating expenses and quantities of recoverable oil and natural gas reserves will vary from our estimates. Any significant variance could materially affect the estimated quantities and present value of reserves shown in this prospectus supplement. In addition, we may adjust estimates of proved reserves to reflect production history, results of exploration and development, prevailing oil and natural gas prices and other factors, many of which are beyond our control. Due to the limited production history of our undeveloped acreage, the estimates of future production associated with such properties may be subject to greater variance to actual production than would be the case with properties having a longer production history.

The present value of future net revenues from our proved reserves will not necessarily be the same as the current market value of our estimated oil and natural gas reserves.

You should not assume that the present value of future net revenues from our proved reserves is the current market value of our estimated oil and natural gas reserves. In accordance with SEC requirements for the years ended December 31, 2011, 2010 and 2009, we based the estimated discounted future net revenues from our proved reserves on the 12-month unweighted arithmetic average of the first-day-of-the-month price for the preceding twelve months without giving effect to derivative transactions. Actual future net revenues from our oil and natural gas properties will be affected by factors such as:

The timing of both our production and our incurrence of expenses in connection with the development and production of oil and natural gas properties will affect the timing and amount

of actual future net revenues from proved reserves, and thus their actual present value. In addition, the 10% discount factor we use when calculating discounted future net revenues may not be the most appropriate discount factor based on interest rates in effect from time to time and risks associated with us or the oil and natural gas industry in general.

Actual future prices and costs may differ materially from those used in the present value estimates included in this prospectus supplement. Any significant future price changes will have a material effect on the quantity and present value of our proved reserves.

The unavailability or high cost of additional drilling rigs, equipment, supplies, personnel and oilfield services could adversely affect our ability to execute our exploration and development plans within our budget and on a timely basis.

Shortages or the high cost of drilling rigs, equipment, supplies, personnel or oilfield services could delay or adversely affect our development and exploration operations or cause us to incur significant expenditures that are not provided for in our capital budget, which could have a material adverse effect on our business, financial condition or results of operations.

Part of our strategy involves drilling in existing or emerging shale plays using some of the latest available horizontal drilling and completion techniques. The results of our planned exploratory drilling in these plays are subject to drilling and completion technique risks and drilling results may not meet our expectations for reserves or production. As a result, we may incur material write-downs and the value of our undeveloped acreage could decline if drilling results are unsuccessful.

Operations in the Bakken and the Three Forks formations involve utilizing the latest drilling and completion techniques as developed by us and our service providers in order to maximize cumulative recoveries and therefore generate the highest possible returns. Risks that we face while drilling include, but are not limited to, landing our well bore in the desired drilling zone, staying in the desired drilling zone while drilling horizontally through the formation, running our casing the entire length of the well bore and being able to run tools and other equipment consistently through the horizontal well bore. Risks that we face while completing our wells include, but are not limited to, being able to fracture stimulate the planned number of stages, being able to run tools the entire length of the well bore during completion operations and successfully cleaning out the well bore after completion of the final fracture stimulation stage.

Our experience with horizontal drilling utilizing the latest drilling and completion techniques specifically in the Bakken and Three Forks formations is limited. Ultimately, the success of these drilling and completion techniques can only be evaluated over time as more wells are drilled and production profiles are established over a sufficiently long time period. If our drilling results are less than anticipated or we are unable to execute our drilling program because of capital constraints, lease expirations, access to gathering systems and limited takeaway capacity or otherwise, and/or natural gas and oil prices decline, the return on our investment in these areas may not be as attractive as we anticipate. We could incur material write-downs of unevaluated properties, and the value of our undeveloped acreage could decline in the future.

Our exploration, development and exploitation projects require substantial capital expenditures. We may be unable to obtain needed capital or financing on satisfactory terms, which could lead to expiration of our leases or a decline in our oil and natural gas reserves.

Our exploration and development activities are capital intensive. We make and expect to continue to make substantial capital expenditures in our business for the development, exploitation, production and acquisition of oil and natural gas reserves. Our cash flows used in

investing activities were $613.2 million and $312.9 million (including $86.4 million for the acquisition of oil and gas properties in 2010) related to capital and exploration expenditures for the years ended December 31, 2011 and 2010, respectively. Currently, our capital expenditure budget for 2012 is approximately $884 million, with approximately $758 million allocated for drilling and completion operations. Since our IPO, our capital expenditures have been financed with proceeds from our IPO, net cash provided by operating activities and proceeds from our $800 million of senior unsecured notes. DeGolyer and MacNaughton projects that we will incur capital costs (including abandonment obligations) in excess of $760 million over the next four years to develop the proved undeveloped reserves in the Williston Basin covered by its December 31, 2011 reserve report. Because these costs cover less than 10% of our total drilling locations, we will be required to generate or raise multiples of this amount of capital to develop all of our potential drilling locations should we elect to do so. The actual amount and timing of our future capital expenditures may differ materially from our estimates as a result of, among other things, commodity prices, actual drilling results, the availability of drilling rigs and other services and equipment, and regulatory, technological and competitive developments.

A significant improvement in product prices could result in an increase in our capital expenditures. We intend to finance our future capital expenditures primarily through cash flows provided by operating activities, borrowings under our revolving credit facility, net proceeds from our $800 million of senior unsecured notes and net proceeds from this offering; however, our financing needs may require us to alter or increase our capitalization substantially through the issuance of additional debt or equity securities or the sale of non-strategic assets. The issuance of additional debt or equity may require that a portion of our cash flows provided by operating activities be used for the payment of principal and interest on our debt, thereby reducing our ability to use cash flows to fund working capital, capital expenditures and acquisitions. The issuance of additional equity securities could have a dilutive effect on the value of our common stock. In addition, upon the issuance of certain debt securities (other than on a borrowing base redetermination date), our borrowing base under our revolving credit facility will be automatically reduced by an amount equal to 25% of the aggregate principal amount of such debt securities.

Our cash flows provided by operating activities and access to capital are subject to a number of variables, including:

If the borrowing base under our revolving credit facility or our revenues decrease as a result of lower oil or natural gas prices, operating difficulties, declines in reserves or for any other reason, we may have limited ability to obtain the capital necessary to sustain our operations at current

levels. If additional capital is needed, we may not be able to obtain debt or equity financing on terms favorable to us, or at all. If cash generated by operations or cash available under our revolving credit facility is not sufficient to meet our capital requirements, the failure to obtain additional financing could result in a curtailment of our operations relating to development of our drilling locations, which in turn could lead to a possible expiration of our leases and a decline in our oil and natural gas reserves, and could adversely affect our business, financial condition and results of operations.

If oil and natural gas prices decrease, we may be required to take write-downs of the carrying values of our oil and natural gas properties.

We review our proved oil and natural gas properties for impairment whenever events and circumstances indicate that a decline in the recoverability of their carrying value may have occurred. Based on specific market factors and circumstances at the time of prospective impairment reviews, and the continuing evaluation of development plans, production data, economics and other factors, we may be required to write down the carrying value of our oil and natural gas properties, which may result in a decrease in the amount available under our revolving credit facility. A write-down constitutes a non-cash charge to earnings. We may incur impairment charges in the future, which could have a material adverse effect on our ability to borrow under our revolving credit facility and our results of operations for the periods in which such charges are taken.

We will not be the operator on all of our drilling locations, and, therefore, we will not be able to control the timing of exploration or development efforts, associated costs, or the rate of production of any non-operated assets.

We expect that we will not be the operator on approximately 40% of our identified gross drilling locations (approximately 10% of our identified net drilling locations). As we carry out our exploration and development programs, we may enter into arrangements with respect to existing or future drilling locations that result in a greater proportion of our locations being operated by others. As a result, we may have limited ability to exercise influence over the operations of the drilling locations operated by our partners. Dependence on the operator could prevent us from realizing our target returns for those locations. The success and timing of exploration and development activities operated by our partners will depend on a number of factors that will be largely outside of our control, including:

This limited ability to exercise control over the operations of some of our drilling locations may cause a material adverse effect on our results of operations and financial condition.

Substantially all of our producing properties and operations are located in the Williston Basin region, making us vulnerable to risks associated with operating in one major geographic area.

As of December 31, 2011, 100% of our proved reserves and as of March 31, 2012, 100% of our production were located in the Williston Basin in northeastern Montana and northwestern North

Dakota. As a result, we may be disproportionately exposed to the impact of delays or interruptions of production from these wells caused by transportation capacity constraints, curtailment of production, availability of equipment, facilities, personnel or services, significant governmental regulation, natural disasters, adverse weather conditions, plant closures for scheduled maintenance or interruption of transportation of oil or natural gas produced from the wells in this area. In addition, the effect of fluctuations on supply and demand may become more pronounced within specific geographic oil and natural gas producing areas such as the Williston Basin, which may cause these conditions to occur with greater frequency or magnify the effect of these conditions. Due to the concentrated nature of our portfolio of properties, a number of our properties could experience any of the same conditions at the same time, resulting in a relatively greater impact on our results of operations than they might have on other companies that have a more diversified portfolio of properties. Such delays or interruptions could have a material adverse effect on our financial condition and results of operations.

Our business depends on oil and natural gas gathering and transportation facilities, most of which are owned by third parties.

The marketability of our oil and natural gas production depends in part on the availability, proximity and capacity of gathering and pipeline systems owned by third parties. The unavailability of, or lack of, available capacity on these systems and facilities could result in the shut-in of producing wells or the delay, or discontinuance of, development plans for properties. See also “—Market conditions or operational impediments may hinder our access to oil and natural gas markets or delay our production” and “—Insufficient transportation or refining capacity in the Williston Basin could cause significant fluctuations in our realized oil and natural gas prices.” We generally do not purchase firm transportation on third party pipeline facilities, and therefore, the transportation of our production can be interrupted by other customers that have firm arrangements.

The disruption of third-party facilities due to maintenance, weather or other interruptions of service could also negatively impact our ability to market and deliver our products. We have no control over when or if such facilities are restored. A total shut-in of our production could materially affect us due to a resulting lack of cash flow, and if a substantial portion of the production is hedged at lower than market prices, those financial hedges would have to be paid from borrowings absent sufficient cash flow.

Insufficient transportation or refining capacity in the Williston Basin could cause significant fluctuations in our realized oil and natural gas prices.

The Williston Basin crude oil business environment has historically been characterized by periods when oil production has surpassed local transportation and refining capacity, resulting in substantial discounts in the price received for crude oil versus prices quoted for West Texas Intermediate (“WTI”) crude oil. For example, the difference between the WTI crude oil price and quoted prices for Bakken Crude Oil on December 31, 2010 and 2011 was approximately negative $4.00 per barrel and negative $3.00 per barrel, respectively. Although additional Williston Basin transportation takeaway capacity was added in 2010 and 2011, production also increased due to the elevated drilling activity in these years. The increased production coupled with the planned turnaround at the Tesoro Corporation Mandan refinery and outages and disruptions on Enbridge’s 6A and 6B lines caused price differentials at times to be at the high-end of the historical average range of approximately 10% to 15% of the WTI crude oil index price in 2010 and the first quarter of 2011. During the second and third quarters of 2011, the difference

between WTI and ICE Brent crude oil (“Brent”) increased substantially, reaching its widest month in September 2011 when WTI traded at an average discount to Brent of $24.00 per barrel. During that same time, quoted prices for Bakken Crude Oil were at a premium to WTI, averaging approximately $5.00 per barrel above WTI. On barrels that are transported over pipelines to either Clearbrook or Guernsey, our realized price for crude oil is generally the quoted price for Bakken Crude Oil less transportation costs from the point where the crude oil is sold. During the fourth quarter of 2011, the difference between WTI and Brent decreased, and the quoted price for Bakken Crude Oil fell below WTI. Furthermore, in February 2012, the quoted prices for Bakken Crude Oil were substantially less than prices quoted for WTI due to refinery and transportation constraints. Such fluctuations and discounts could have a material adverse effect on our financial condition and results of operations.

The development of our proved undeveloped reserves in the Williston Basin and other areas of operation may take longer and may require higher levels of capital expenditures than we currently anticipate. Therefore, our undeveloped reserves may not be ultimately developed or produced.

Approximately 54% of our total proved reserves were classified as proved undeveloped as of December 31, 2011. Development of these reserves may take longer and require higher levels of capital expenditures than we currently anticipate. Delays in the development of our reserves or increases in costs to drill and develop such reserves will reduce the PV-10 value of our estimated proved undeveloped reserves and future net revenues estimated for such reserves and may result in some projects becoming uneconomic. In addition, delays in the development of reserves could cause us to have to reclassify our proved reserves as unproved reserves.

Unless we replace our oil and natural gas reserves, our reserves and production will decline, which would adversely affect our business, financial condition and results of operations.

Unless we conduct successful development, exploitation and exploration activities or acquire properties containing proved reserves, our proved reserves will decline as those reserves are produced. Producing oil and natural gas reservoirs generally are characterized by declining production rates that vary depending upon reservoir characteristics and other factors. Our future oil and natural gas reserves and production, and therefore our cash flows and income, are highly dependent on our success in efficiently developing and exploiting our current reserves and economically finding or acquiring additional recoverable reserves. We may not be able to develop, exploit, find or acquire additional reserves to replace our current and future production at acceptable costs. If we are unable to replace our current and future production, the value of our reserves will decrease, and our business, financial condition and results of operations would be adversely affected.

Market conditions or operational impediments may hinder our access to oil and natural gas markets or delay our production.

Market conditions or the unavailability of satisfactory oil and natural gas transportation arrangements may hinder our access to oil and natural gas markets or delay our production. The availability of a ready market for our oil and natural gas production depends on a number of factors, including the demand for and supply of oil and natural gas and the proximity of reserves to pipelines and terminal facilities. Our ability to market our production depends, in substantial part, on the availability and capacity of gathering systems, pipelines and processing facilities owned and operated by third-parties. Our failure to obtain such services on acceptable terms could materially harm our business. We may be required to shut in wells due to lack of a market or inadequacy or

unavailability of crude oil or natural gas pipelines or gathering system capacity. If our production becomes shut-in for any of these or other reasons, we would be unable to realize revenue from those wells until other arrangements were made to deliver the products to market.

We may incur substantial losses and be subject to substantial liability claims as a result of our oil and natural gas operations. Additionally, we may not be insured for, or our insurance may be inadequate to protect us against, these risks.

We are not insured against all risks. Losses and liabilities arising from uninsured and underinsured events could materially and adversely affect our business, financial condition or results of operations. Our oil and natural gas exploration and production activities are subject to all of the operating risks associated with drilling for and producing oil and natural gas, including the possibility of:

Any of these risks could adversely affect our ability to conduct operations or result in substantial losses to us as a result of:

We may elect not to obtain insurance if we believe that the cost of available insurance is excessive relative to the risks presented. In addition, pollution and environmental risks generally are not fully insurable. The occurrence of an event that is not fully covered by insurance could have a material adverse effect on our business, financial condition and results of operations.

For the year ended December 31, 2011, we had net income of $79.4 million. However, for the years ended December 31, 2010 and 2009, we incurred net losses of $29.7 million and $15.2 million, respectively. Our development of and participation in an increasingly larger number of drilling locations has required and will continue to require substantial capital expenditures, including currently planned capital expenditures for 2012 of approximately $884 million.

The uncertainty and risks described in this prospectus supplement may impede our ability to economically find, develop, exploit and acquire oil and natural gas reserves. As a result, we may not be able to achieve or sustain profitability or positive cash flows provided by operating activities in the future.

Drilling locations that we decide to drill may not yield oil or natural gas in commercially viable quantities.

We describe some of our drilling locations and our plans to explore those drilling locations in this prospectus supplement. Our drilling locations are in various stages of evaluation, ranging from a location which is ready to drill to a location that will require substantial additional interpretation. There is no way to predict in advance of drilling and testing whether any particular location will yield oil or natural gas in sufficient quantities to recover drilling or completion costs or to be economically viable. The use of technologies and the study of producing fields in the same area will not enable us to know conclusively prior to drilling whether oil or natural gas will be present or, if present, whether oil or natural gas will be present in sufficient quantities to be economically viable. Even if sufficient amounts of oil or natural gas exist, we may damage the potentially productive hydrocarbon bearing formation or experience mechanical difficulties while drilling or completing the well, resulting in a reduction in production from the well or abandonment of the well. If we drill additional wells that we identify as dry holes in our current and future drilling locations, our drilling success rate may decline and materially harm our business. We cannot assure you that the analogies we draw from available data from other wells, more fully explored locations or producing fields will be applicable to our drilling locations. Further, initial production rates reported by us or other operators in the Williston Basin may not be indicative of future or long-term production rates. In sum, the cost of drilling, completing and operating any well is often uncertain, and new wells may not be productive.

Our potential drilling location inventories are scheduled to be drilled over several years, making them susceptible to uncertainties that could materially alter the occurrence or timing of their drilling. In addition, we may not be able to raise the substantial amount of capital that would be necessary to drill a substantial portion of our potential drilling locations.

Our management has identified and scheduled drilling locations as an estimation of our future multi-year drilling activities on our existing acreage. These potential drilling locations, including those without proved undeveloped reserves, represent a significant part of our growth strategy. Our ability to drill and develop these locations is subject to a number of uncertainties, including the availability of capital, seasonal conditions, regulatory approvals, oil and natural gas prices, costs and drilling results. Because of these uncertainties, we do not know if the numerous potential drilling locations we have identified will ever be drilled or if we will be able to produce oil or natural gas from these or any other potential drilling locations. Pursuant to existing SEC rules and guidance, subject to limited exceptions, proved undeveloped reserves may only be booked if they relate to wells scheduled to be drilled within five years of the date of booking. These rules and guidance may limit our potential to book additional proved undeveloped reserves as we pursue our drilling program.

Our acreage must be drilled before lease expiration, generally within three to five years, in order to hold the acreage by production. In the highly competitive market for acreage, failure to drill sufficient wells in order to hold acreage will result in a substantial lease renewal cost, or if renewal is not feasible, loss of our lease and prospective drilling opportunities.

Unless production is established within the spacing units covering the undeveloped acres on which some of the locations are identified, the leases for such acreage will expire. As of December 31, 2011, we had leases representing 31,905 net acres expiring in 2012, 35,055 net acres expiring in 2013 and 18,192 net acres expiring in 2014. The cost to renew such leases may increase significantly, and we may not be able to renew such leases on commercially reasonable terms or at all. In addition, on certain portions of our acreage, third-party leases become immediately effective if our leases expire. As such, our actual drilling activities may materially differ from our current expectations, which could adversely affect our business. During the years ended December 31, 2011, 2010 and 2009, we recorded non-cash impairment charges of $3.6 million, $12.0 million and $5.4 million, respectively, for unproved property leases that expired during the period.

Our operations are subject to environmental and occupational health and safety laws and regulations that may expose us to significant costs and liabilities.

Our oil and natural gas exploration and production operations are subject to stringent federal, regional, state and local laws and regulations governing occupational health and safety aspects of our operations, the discharge of materials into the environment or otherwise relating to environmental protection. These laws and regulations may impose numerous obligations that are applicable to our operations including the acquisition of a permit before conducting drilling or underground injection activities; the restriction of types, quantities and concentration of materials that can be released into the environment; the limitation or prohibition of drilling activities on certain lands lying within wilderness, wetlands and other protected areas; the application of specific health and safety criteria addressing worker protection; and the imposition of substantial liabilities for pollution resulting from operations. Numerous governmental authorities, such as the U.S. Environmental Protection Agency (the “EPA”), and analogous state agencies have the power to enforce compliance with these laws and regulations and the permits issued under them, oftentimes requiring difficult and costly actions. Failure to comply with these laws and regulations may result in the assessment of administrative, civil or criminal penalties; the imposition of investigatory or remedial obligations; and the issuance of injunctions limiting or preventing some or all of our operations.

There is inherent risk of incurring significant environmental costs and liabilities in the performance of our operations as a result of our handling of petroleum hydrocarbons and wastes, because of air emissions and waste water discharges related to our operations and due to historical industry operations and waste disposal practices. Under certain environmental laws and regulations, we could be subject to joint and several, strict liability for the removal or remediation of previously released materials or property contamination regardless of whether we were responsible for the release or contamination or if the operations were in compliance with all applicable laws at the time those actions were taken. Private parties, including the owners of properties upon which our wells are drilled and facilities where our petroleum hydrocarbons or wastes are taken for reclamation or disposal, may also have the right to pursue legal actions to enforce compliance as well as to seek damages for non-compliance with environmental laws and regulations or for personal injury or property damage. In addition, the risk of accidental spills or releases could expose us to significant liabilities that could have a material adverse effect on our financial condition or results of well drilling, construction,

completion on water management activities or operations. Changes in environmental laws and regulations occur frequently, and any changes that result in more stringent or costly waste handling, storage, transport, disposal or cleanup requirements could require us to make significant expenditures to attain and maintain compliance and may otherwise have a material adverse effect on our own results of operations, competitive position or financial condition. We may not be able to recover some or any of these costs from insurance.

Failure to comply with federal, state and local laws could adversely affect our ability to produce, gather and transport our oil and natural gas and may result in substantial penalties.

Our operations are substantially affected by federal, state and local laws and regulations, particularly as they relate to the regulation of oil and natural gas production and transportation. These laws and regulations include regulation of oil and natural gas exploration and production and related operations, including a variety of activities related to the drilling of wells, the interstate transportation of oil and natural gas by federal agencies such as the FERC, as well as state agencies. In addition, federal laws prohibit market manipulation in connection with the purchase or sale of oil and/or natural gas. Failure to comply with federal, state and local laws could adversely affect our ability to produce, gather and transport our oil and natural gas and may result in substantial penalties.

Climate change laws and regulations restricting emissions of “greenhouse gases” could result in increased operating costs and reduced demand for the oil and natural gas that we produce while the physical effects of climate change could disrupt our production and cause us to incur significant costs in preparing for or responding to those effects.

Based on findings by the EPA in December 2009 that emissions of carbon dioxide, methane and other greenhouse gases (“GHGs”) present an endangerment to public health and the environment because emissions of such gases are contributing to warming of the Earth’s atmosphere and other climatic changes, the EPA adopted regulations under existing provisions of the federal Clean Air Act that restrict emissions of GHGs, including one that requires a reduction in emissions of GHGs from motor vehicles and another one that requires certain construction and operating permit reviews for GHG emissions from certain large stationary sources. These EPA rules could adversely affect our operations and restrict or delay our ability to obtain air permits for new or modified facilities. The EPA has also adopted rules requiring the monitoring and reporting of GHG emissions from specified sources in the United States, including, among others, certain onshore oil and natural gas production facilities, which may include certain of our operations. In addition, Congress has from time to time considered legislation to reduce emissions of GHGs, and almost one-half of the states have already taken legal measures to reduce emissions of GHGs, primarily through the planned development of GHG emission inventories and/or regional GHG cap and trade programs. The adoption and implementation of any legislation or regulations imposing reporting obligations on, or limiting emissions of GHGs from, our equipment and operations could require us to incur costs to reduce emissions of GHGs associated with our operations or could adversely affect demand for the oil and natural gas we produce. Finally, it should be noted that some scientists have concluded that increasing concentrations of GHGs in the Earth’s atmosphere may produce climate changes that have significant physical effects, such as increased frequency and severity of storms, floods and other climatic events; if any such effects were to occur, they could have an adverse effect on our exploration and production operations.

Recently approved final rules regulating air emissions from natural gas production operations could cause us to incur increased capital expenditures and operating costs, which may be significant.

On April 17, 2012, the EPA approved final regulations under the Clean Air Act that, among other things, require additional emissions controls for natural gas and natural gas liquids production, including New Source Performance Standards to address emissions of sulfur dioxide and volatile organic compounds (“VOC”) and a separate set of emission standards to address hazardous air pollutants frequently associated with such production activities. The final regulations require the reduction of VOC emissions from natural gas wells through the use of reduced emission completions or “green completions” on all hydraulically fractured wells constructed or refractured after January 1, 2015. For well completion operations occurring at such well sites before January 1, 2015, the final regulations allow operators to capture and direct flowback emissions to completion combustion devices, such as flares, in lieu of performing green completions. These regulations also establish specific new requirements regarding emissions from dehydrators, storage tanks and other production equipment. We are currently reviewing this new rule and assessing its potential impacts. Compliance with these requirements could increase our costs of development and production, though we do not expect these requirements to be any more burdensome to us than to other similarly situated companies involved in oil and natural gas exploration and production activities.

Federal and state legislative and regulatory initiatives relating to hydraulic fracturing could result in increased costs and additional operating restrictions or delays in the completion of oil and natural gas wells.

Hydraulic fracturing is an important and common practice that is used to stimulate production of natural gas and/or oil from dense subsurface rock formations. The process involves the injection of water, sand and chemicals under pressure into the formation to fracture the surrounding rock and stimulate production. We routinely use hydraulic fracturing techniques in many of our drilling and completion programs. The process is typically regulated by state oil and natural gas commissions, but the EPA has asserted federal regulatory authority over certain hydraulic fracturing activities involving diesel under the federal Safe Drinking Water Act and, on May 4, 2012, the EPA issued draft permitting guidance for hydraulic fracturing activities using diesel. In addition, legislation has been introduced before Congress to provide for federal regulation of hydraulic fracturing under the Safe Drinking Water Act and to require disclosure of the chemicals used in the hydraulic fracturing process. At the state level, some states have adopted, and other states are considering adopting legal requirements that could impose more stringent permitting, public disclosure or well construction requirements on hydraulic fracturing activities. If new or more stringent federal, state, or local legal restrictions relating to the hydraulic fracturing process are adopted in areas where we operate, we could incur potentially significant added costs to comply with such requirements, experience delays or curtailment in the pursuit of exploration, development, or production activities, and perhaps even be precluded from drilling wells.

In addition, certain governmental reviews are either underway or being proposed that focus on environmental aspects of hydraulic fracturing practices. The White House Council on Environmental Quality is coordinating an administration-wide review of hydraulic fracturing practices, and a committee of the United States House of Representatives has conducted an investigation of hydraulic fracturing practices. The EPA has commenced a study of the potential environmental effects of hydraulic fracturing on drinking water and groundwater, with initial

results expected to be available by late 2012 and final results by 2014. Moreover, the EPA has announced that it will develop effluent limitations for the treatment and discharge of wastewater resulting from hydraulic fracturing activities by 2014. Other governmental agencies, including the U.S. Department of Energy and the U.S. Department of the Interior, are evaluating various other aspects of hydraulic fracturing, with the U.S. Department of the Interior announcing on May 4, 2012 proposed rules that, if adopted, would require disclosure of chemicals used in hydraulic fracturing activities upon federal and Indian lands and also would strengthen standards for well-bore integrity and the management of fluids that return to the surface during and after fracturing operations on federal and Indian lands. These ongoing or proposed studies, depending on their degree of pursuit and any meaningful results obtained, could spur initiatives to further regulate hydraulic fracturing under the federal Safe Drinking Water Act or other regulatory mechanisms.

Competition in the oil and natural gas industry is intense, making it more difficult for us to acquire properties, market oil and natural gas and secure trained personnel.

Our ability to acquire additional drilling locations and to find and develop reserves in the future will depend on our ability to evaluate and select suitable properties and to consummate transactions in a highly competitive environment for acquiring properties, marketing oil and natural gas and securing equipment and trained personnel. Also, there is substantial competition for capital available for investment in the oil and natural gas industry. Many of our competitors possess and employ financial, technical and personnel resources substantially greater than ours. Those companies may be able to pay more for productive oil and natural gas properties and exploratory drilling locations or to identify, evaluate, bid for and purchase a greater number of properties and locations than our financial or personnel resources permit. Furthermore, these companies may also be better able to withstand the financial pressures of unsuccessful drilling attempts, sustained periods of volatility in financial markets and generally adverse global and industry-wide economic conditions, and may be better able to absorb the burdens resulting from changes in relevant laws and regulations, which would adversely affect our competitive position. In addition, companies may be able to offer better compensation packages to attract and retain qualified personnel than we are able to offer. The cost to attract and retain qualified personnel has increased over the past few years due to competition and may increase substantially in the future. We may not be able to compete successfully in the future in acquiring prospective reserves, developing reserves, marketing hydrocarbons, attracting and retaining quality personnel and raising additional capital, which could have a material adverse effect on our business.

The loss of senior management or technical personnel could adversely affect our operations.

To a large extent, we depend on the services of our senior management and technical personnel. The loss of the services of our senior management or technical personnel, including Thomas B. Nusz, our Chairman, President and Chief Executive Officer, and Taylor L. Reid, our Executive Vice President and Chief Operating Officer, could have a material adverse effect on our operations. We do not maintain, nor do we plan to obtain, any insurance against the loss of any of these individuals.

Seasonal weather conditions adversely affect our ability to conduct drilling activities in some of the areas where we operate.

Oil and natural gas operations in the Williston Basin are adversely affected by seasonal weather conditions. In the Williston Basin, drilling and other oil and natural gas activities cannot be

conducted as effectively during the winter months. Severe winter weather conditions limit and may temporarily halt our ability to operate during such conditions. These constraints and the resulting shortages or high costs could delay or temporarily halt our operations and materially increase our operating and capital costs.

Our derivative activities could result in financial losses or could reduce our income.

To achieve more predictable cash flows and to reduce our exposure to adverse fluctuations in the prices of oil and natural gas, we currently, and may in the future, enter into derivative arrangements for a portion of our oil and natural gas production, including collars and fixed-price swaps. We have not designated any of our derivative instruments as hedges for accounting purposes and record all derivative instruments on our balance sheet at fair value. Changes in the fair value of our derivative instruments are recognized in earnings. Accordingly, our earnings may fluctuate significantly as a result of changes in the fair value of our derivative instruments.

Derivative arrangements also expose us to the risk of financial loss in some circumstances, including when:

In addition, some of these types of derivative arrangements limit the benefit we would receive from increases in the prices for oil and natural gas and may expose us to cash margin requirements.

The recent adoption of derivatives legislation by the United States Congress could have an adverse effect on our ability to use derivative instruments to reduce the effect of commodity price, interest rate and other risks associated with our business.

The United States Congress recently adopted comprehensive financial reform legislation that establishes federal oversight and regulation of the over-the-counter derivatives market and entities, such as us, that participate in that market. The new legislation was signed into law by the President on July 21, 2010 and requires the Commodities Futures Trading Commission (the “CFTC”) and the SEC to promulgate rules and regulations implementing the new legislation within 360 days from the date of enactment. The CFTC has also proposed regulations to set position limits for certain futures and option contracts in the major energy markets, although it is not possible at this time to predict whether or when the CFTC will adopt those rules or include comparable provisions in its rulemaking under the new legislation. The financial reform legislation may also require us to comply with margin requirements and with certain clearing and trade-execution requirements in connection with its derivative activities, although the application of those provisions to us is uncertain at this time. The financial reform legislation may also require the counterparties to our derivative instruments to spin off some of their derivative activities to a separate entity, which may not be as creditworthy as the current counterparty. The new legislation and any new regulations could significantly increase the cost of derivative contracts (including through requirements to post collateral which could adversely affect our available liquidity), materially alter the terms of derivative contracts, reduce the availability of derivatives to protect against risks we encounter, reduce our ability to monetize or restructure existing derivative contracts, and increase our exposure to less creditworthy counterparties. If we

reduce our use of derivatives as a result of the legislation and regulations, our results of operations may become more volatile and our cash flows may be less predictable, which could adversely affect our ability to plan for and fund capital expenditures. Finally, the legislation was intended, in part, to reduce the volatility of oil and natural gas prices, which some legislators attributed to speculative trading in derivatives and commodity instruments related to oil and natural gas. Our revenues could therefore be adversely affected if commodity prices decline as a consequence of the legislation and regulations. Any of these consequences could have a material adverse effect on us, our financial condition and our results of operations.

Our business and operating results can be harmed by factors such as the availability, terms and cost of capital, increases in interest rates or a reduction in credit rating. Changes in any one or more of these factors could cause our cost of doing business to increase, limit our access to capital, limit our ability to pursue acquisition opportunities, reduce our cash flows available for drilling and place us at a competitive disadvantage. Recent and continuing disruptions and volatility in the global financial markets may lead to an increase in interest rates or a contraction in credit availability impacting our ability to finance our operations. We require continued access to capital. A significant reduction in the availability of credit could materially and adversely affect our ability to achieve our planned growth and operating results.

Our level of indebtedness may increase and reduce our financial flexibility.

As of June 25, 2012, we had no indebtedness outstanding under our revolving credit facility, $500 million available for future secured borrowings under our revolving credit facility and $800 million outstanding in senior unsecured notes. Please see “Description of other indebtedness.” In addition, this is an offering by us for $400 million aggregate principal amount of senior unsecured notes. In the future, we may incur significant additional indebtedness in order to make future acquisitions or to develop our properties.

Our level of indebtedness could affect our operations in several ways, including the following:

A high level of indebtedness increases the risk that we may default on our debt obligations. Our ability to meet our debt obligations and to reduce our level of indebtedness depends on our future performance. General economic conditions, oil and natural gas prices and financial, business and other factors affect our operations and our future performance. Many of these factors are beyond our control. We may not be able to generate sufficient cash flows to pay the interest on our debt and future working capital, and borrowings or equity financing may not be available to pay or refinance such debt. Factors that will affect our ability to raise cash through an offering of our capital stock or a refinancing of our debt include financial market conditions, the value of our assets and our performance at the time we need capital.

In addition, our bank borrowing base is subject to periodic redeterminations. We could be forced to repay a portion of our bank borrowings due to redeterminations of our borrowing base. If we are forced to do so, we may not have sufficient funds to make such repayments. If we do not have sufficient funds and are otherwise unable to negotiate renewals of our borrowings or arrange new financing, we may have to sell significant assets. Any such sale could have a material adverse effect on our business and financial results.

The inability of one or more of our customers to meet their obligations to us may adversely affect our financial results.

Our principal exposures to credit risk are through receivables resulting from the sale of our oil and natural gas production ($78.5 million in receivables at March 31, 2012), which we market to energy marketing companies, refineries and affiliates, advances to joint interest parties ($3.3 million at March 31, 2012) and joint interest receivables ($67.0 million at March 31, 2012).

We are subject to credit risk due to the concentration of our oil and natural gas receivables with several significant customers. This concentration of customers may impact our overall credit risk since these entities may be similarly affected by changes in economic and other conditions. For the three months ended March 31, 2012, sales to Enserco Energy Inc. and Plains All American Pipeline, L.P. accounted for approximately 15% and 12%, respectively, of our total sales. For the year ended December 31, 2011, sales to Texon L.P., Plains All American Pipeline, L.P. and Enserco Energy Inc. accounted for approximately 18%, 16% and 15%, respectively, of our total sales. For the year ended December 31, 2010, sales to Plains All American Pipeline, L.P., Texon L.P. and Whiting Petroleum Corporation accounted for approximately 28%, 19% and 11%, respectively, of our total sales. For the year ended December 31, 2009, sales to Tesoro Refining and Marketing Company and Texon L.P. accounted for approximately 32% and 30%, respectively, of our total sales. No other purchasers accounted for more than 10% of our total oil and natural gas sales for the years ended December 31, 2011, 2010 and 2009. We do not require our customers to post collateral. The inability or failure of our significant customers to meet their obligations to us or their insolvency or liquidation may adversely affect our financial results.

Joint interest receivables arise from billing entities who own a partial interest in the wells we operate. These entities participate in our wells primarily based on their ownership in leases on which we wish to drill. We have limited ability to control participation in our wells. In addition, our oil and natural gas derivative arrangements expose us to credit risk in the event of nonperformance by counterparties.

We may be subject to risks in connection with acquisitions and the integration of significant acquisitions may be difficult.

We periodically evaluate acquisitions of reserves, properties, prospects and leaseholds and other strategic transactions that appear to fit within our overall business strategy. The successful acquisition of producing properties requires an assessment of several factors, including:

The accuracy of these assessments is inherently uncertain. In connection with these assessments, we perform a review of the subject properties that we believe to be generally consistent with industry practices. Our review will not reveal all existing or potential problems nor will it permit us to become sufficiently familiar with the properties to fully assess their deficiencies and potential recoverable reserves. Inspections may not always be performed on every well, and environmental problems are not necessarily observable even when an inspection is undertaken. Even when problems are identified, the seller may be unwilling or unable to provide effective contractual protection against all or part of the problems. We often are not entitled to contractual indemnification for environmental liabilities and acquire properties on an “as is” basis.

Significant acquisitions and other strategic transactions may involve other risks, including:

The process of integrating operations could cause an interruption of, or loss of momentum in, the activities of our business. Members of our senior management may be required to devote considerable amounts of time to this integration process, which will decrease the time they will have to manage our business. If our senior management is not able to effectively manage the integration process, or if any significant business activities are interrupted as a result of the integration process, our business could suffer.

If we fail to realize the anticipated benefits of a significant acquisition, our results of operations may be lower than we expect.

The success of a significant acquisition will depend, in part, on our ability to realize anticipated growth opportunities from combining the acquired assets or operations with those of ours. Even if a combination is successful, it may not be possible to realize the full benefits we may expect in estimated proved reserves, production volume, cost savings from operating synergies or other

benefits anticipated from an acquisition or realize these benefits within the expected time frame. Anticipated benefits of an acquisition may be offset by operating losses relating to changes in commodity prices, or in oil and natural gas industry conditions, or by risks and uncertainties relating to the exploratory prospects of the combined assets or operations, or an increase in operating or other costs or other difficulties. If we fail to realize the benefits we anticipate from an acquisition, our results of operations may be adversely affected.

We may incur losses as a result of title defects in the properties in which we invest.

It is our practice in acquiring oil and gas leases or interests not to incur the expense of retaining lawyers to examine the title to the mineral interest. Rather, we rely upon the judgment of oil and gas lease brokers or landmen who perform the fieldwork in examining records in the appropriate governmental office before attempting to acquire a lease in a specific mineral interest.

Prior to the drilling of an oil or gas well, however, it is the normal practice in our industry for the person or company acting as the operator of the well to obtain a preliminary title review to ensure there are no obvious defects in the title to the well. Frequently, as a result of such examinations, certain curative work must be done to correct defects in the marketability of the title, and such curative work entails expense. Our failure to cure any title defects may adversely impact our ability in the future to increase production and reserves. There is no assurance that we will not suffer a monetary loss from title defects or title failure. Additionally, undeveloped acreage has greater risk of title defects than developed acreage. If there are any title defects or defects in assignment of leasehold rights in properties in which we hold an interest, we will suffer a financial loss.

Certain U.S. federal income tax deductions currently available with respect to oil and gas exploration and development may be eliminated as a result of proposed legislation.

The Budget for Fiscal Year 2013 sent to Congress by President Obama on February 13, 2012, contains recommendations that, if enacted into law, would eliminate certain key U.S. federal income tax incentives currently available to oil and natural gas exploration and production companies. These changes include, (i) the repeal of the percentage depletion allowance for oil and natural gas properties, (ii) the elimination of current deductions for intangible drilling and development costs, (iii) the elimination of the deduction for certain domestic production activities, and (iv) an extension of the amortization period for certain geological and geophysical expenditures. Several bills have been introduced in Congress that would implement these proposals. It is unclear whether these or similar changes will be enacted and, if enacted, how soon any such changes could become effective. The passage of this legislation or any similar changes in U.S. federal income tax laws could eliminate or postpone certain tax deductions that are currently available with respect to oil and natural gas exploration and development, and any such changes could have an adverse effect on our financial position, results of operations and cash flows.

The following table sets forth our ratios of consolidated earnings to fixed charges for the periods presented:

For purposes of computing the ratio of earnings to fixed charges, “earnings” consists of pre-tax income from continuing operations before fixed charges. “Fixed charges” consists of interest expensed and capitalized, amortized capital expenses related to indebtedness and an estimate of interest within rental expense.

We estimate that the net proceeds from this offering will be approximately $392.4 million after deducting the underwriters’ discount and our estimated offering expenses. We intend to use all of the net proceeds from this offering to fund our exploration, development and acquisition program and for general corporate purposes.

The following table sets forth our consolidated cash and cash equivalents and our consolidated capitalization as of March 31, 2012 on:

This table should be read in conjunction with “Use of proceeds” and “Description of other indebtedness,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report on Form 10-K for the year ended December 31, 2011, our Quarterly Report on Form 10-Q for the quarter ended March 31, 2012 and our consolidated financial statements, including the accompanying notes, incorporated by reference in this prospectus supplement.

Our credit agreement with Wells Fargo Bank, National Association, as administrative agent, provides for a senior secured revolving credit facility, which we refer to as our revolving credit facility. Oasis Petroleum North America LLC, our wholly owned subsidiary, is the borrower under the revolving credit facility, and we and certain of our other subsidiaries are guarantors under the revolving credit facility. Borrowings under the revolving credit facility are collateralized by perfected first priority liens and security interests on substantially all of our assets, including mortgage liens on oil and natural gas properties having at least 80% of the reserve value as determined by reserve reports.

The revolving credit facility provides for semi-annual redeterminations on April 1 and October 1 of each year. On April 3, 2012, in connection with the amendment to our revolving credit facility described below, a redetermination of our borrowing base was completed, which resulted in our borrowing base increasing from $350 million to $500 million. On June 25, 2012, our lenders waived the mandatory reduction of our borrowing base that otherwise would have occurred as a result of the issuance of the notes offered hereby. The next scheduled redetermination of our borrowing base is October 1, 2012.

Contemporaneously with our borrowing base redetermination, we entered into a sixth amendment to our revolving credit facility in order to add two lenders to the bank group.

As of June 25, 2012, we had no borrowings outstanding under the revolving credit facility and no outstanding letters of credit issued under the revolving credit facility.

Borrowings under the revolving credit facility are subject to varying rates of interest based on (1) the total outstanding borrowings (including the value of all outstanding letters of credit) in relation to the borrowing base and (2) whether the loan is a London Interbank Offered Rate (“LIBOR”) loan or a bank prime interest rate loan (defined in the revolving credit facility as an Alternate Based Rate, or “ABR” loan). The LIBOR and ABR loans bear their respective interest rates plus the applicable margin indicated in the following table:

An ABR loan does not have a set maturity date and may be repaid at any time upon us providing advance notification to the lenders. Interest is paid quarterly on ABR loans based on the number of days an ABR loan is outstanding as of the last business day in March, June, September and December. We have the option to convert an ABR loan to a LIBOR-based loan upon providing

advance notification to the lenders. The minimum available loan term is one month and the maximum loan term is six months for LIBOR-based loans. Interest for LIBOR loans is paid upon maturity of the loan term. Interim interest is paid every three months for LIBOR loans that have loan terms that are greater than three months in duration. At the end of a LIBOR loan term, our revolving credit facility allows us to elect to continue a LIBOR loan with the same or a differing loan term or convert the borrowing to an ABR loan.

On a quarterly basis, we also pay a commitment fee ranging from 0.375% to 0.500% on the daily amount of borrowing base capacity not utilized during the quarter and fees calculated on the daily amount of letter of credit balances outstanding during the quarter.

Our revolving credit facility contains various covenants that include, among others:

Our revolving credit facility also contains covenants that, among other things, require us to maintain specified ratios or conditions as follows:

We are currently in compliance with the terms of our revolving credit facility. If an event of default exists under the credit agreement, the lenders will be able to accelerate the maturity of the credit agreement and exercise other rights and remedies. Each of the following will be an event of default:

On February 2, 2011, we issued $400 million of 7.25% senior unsecured notes (the “2019 Notes”) due February 1, 2019. Interest is payable on the 2019 Notes semi-annually in arrears on each February 1 and August 1, commencing August 1, 2011. The 2019 Notes are guaranteed on a senior unsecured basis by our material subsidiaries. The issuance of these 2019 Notes resulted in net proceeds to us of approximately $390 million, which we will use to fund our exploration, development and acquisition program and for general corporate purposes.

At any time prior to February 1, 2014, we may redeem up to 35% of the 2019 Notes at a redemption price of 107.25% of the principal amount, plus accrued and unpaid interest to the redemption date, with the proceeds of certain equity offerings so long as the redemption occurs within 180 days of completing such equity offering and at least 65% of the aggregate principal amount of the 2019 Notes remains outstanding after such redemption. Prior to February 1, 2015, we may redeem some or all of the 2019 Notes for cash at a redemption price equal to 100% of their principal amount plus an applicable make-whole premium and accrued and unpaid interest to the redemption date. On and after February 1, 2015, we may redeem some or all of the 2019 Notes at redemption prices (expressed as percentages of the principal amount) equal to 103.625% for the twelve-month period beginning on February 1, 2015, 101.813% for the twelve-month period beginning February 1, 2016 and 100.00% beginning on February 1, 2017, plus accrued and unpaid interest to the redemption date.

The indenture governing the 2019 Notes restricts our ability and the ability of certain of our subsidiaries to: (i) incur additional debt or enter into sale and leaseback transactions; (ii) pay distributions on, redeem or repurchase equity interests; (iii) make certain investments; (iv) incur liens; (v) enter into transactions with affiliates; (vi) merge or consolidate with another company; and (vii) transfer and sell assets. These covenants are subject to a number of important exceptions and qualifications. If at any time when the 2019 Notes are rated investment grade by both Moody’s Investors Service, Inc. and Standard & Poor’s Ratings Services and no default (as defined in the indenture) has occurred and is continuing, many of such covenants will terminate and we will cease to be subject to such covenants.

At March 31, 2012, we were in compliance with our covenants in the indenture governing the 2019 Notes.

On November 10, 2011, we issued $400 million of 6.5% senior unsecured notes (the “2021 Notes”) due November 1, 2021. Interest is payable on the 2021 Notes semi-annually in arrears on each May 1 and November 1, commencing May 1, 2012. The 2021 Notes are guaranteed on a senior unsecured basis by our material subsidiaries. The issuance of these 2021 Notes resulted in net proceeds to us of approximately $393 million, which we will use to fund our exploration, development and acquisition program and for general corporate purposes.

At any time prior to November 1, 2014, we may redeem up to 35% of the 2021 Notes at a redemption price of 106.5% of the principal amount, plus accrued and unpaid interest to the redemption date, with the proceeds of certain equity offerings so long as the redemption occurs within 180 days of completing such equity offering and at least 65% of the aggregate principal amount of the 2021 Notes remains outstanding after such redemption. Prior to November 1, 2016, we may redeem some or all of the 2021 Notes for cash at a redemption price equal to 100% of their principal amount plus an applicable make-whole premium and accrued and unpaid interest to the redemption date. On and after November 1, 2016, we may redeem some or all of the 2021 Notes at redemption prices (expressed as percentages of principal amount) equal to 103.25% for the twelve-month period beginning on November 1, 2016, 102.167% for the twelve-month period beginning November 1, 2017, 101.083% for the twelve-month period beginning on November 1, 2018 and 100.00% beginning on November 1, 2019, plus accrued and unpaid interest to the redemption date. If a change in control occurs at any time on or prior to January 1, 2013, we may redeem all, but not less than all, of the 2021 Notes, at a redemption price equal to 110% of the principal amount plus accrued and unpaid interest to the redemption date.

The indenture governing the 2021 Notes restricts our ability and the ability of certain of our subsidiaries to: (i) incur additional debt or enter into sale and leaseback transactions; (ii) pay distributions on, redeem or repurchase equity interests; (iii) make certain investments; (iv) incur liens; (v) enter into transactions with affiliates; (vi) merge or consolidate with another company; and (vii) transfer and sell assets. These covenants are subject to a number of important exceptions and qualifications. If at any time when the 2021 Notes are rated investment grade by both Moody’s Investors Service, Inc. and Standard & Poor’s Ratings Services and no default (as defined in the indenture) has occurred and is continuing, many of such covenants will terminate and we will cease to be subject to such covenants.

At March 31, 2012, we were in compliance with our covenants in the indenture governing the 2021 Notes.

We will issue the notes under a base indenture, dated as of November 10, 2011, among us, the Subsidiary Guarantors party thereto and U.S. Bank National Association, as trustee, as amended and supplemented by a supplemental indenture, to be dated as of the Issue Date, among us, the initial Subsidiary Guarantors and United States Bank National Association, as trustee. In this description of notes, when we refer to the indenture, we mean such base indenture as supplemented by such supplemental indenture. The terms of the notes include those stated in the indenture and those made part of the indenture by reference to the Trust Indenture Act of 1939, as amended. The indenture permits us to issue senior debt securities in different series from time to time in an unlimited aggregate principal amount, although the issuance of notes in this offering will be limited to $400 million.

This description of notes, together with the “Description of Debt Securities” included in the accompanying base prospectus, is intended to be a useful overview of the material provisions of the notes and the indenture. Since this description of notes and such “Description of Debt Securities” are only summaries, you should refer to the indenture for a complete description of our obligations and your rights. This description of notes supersedes the “Description of Debt Securities” in the accompanying base prospectus to the extent it is inconsistent with such “Description of Debt Securities.”

You can find the definitions of terms used in this description of notes below under the caption “—Definitions.” Capitalized terms used in this description but not defined below under the caption “—Definitions” have the meanings assigned to them in the indenture. In this description, the words “Oasis,” “we,” “us,” and “our” refer only to Oasis Petroleum Inc., and not to any of its Subsidiaries or Affiliates.

The registered holder of a note will be treated as the owner of it for all purposes. Only registered holders will have rights under the indenture.

As of March 31, 2012, on a pro forma basis after giving effect to the sale of the notes, the application of the net proceeds therefrom as described under “Use of proceeds” in this

prospectus supplement, Oasis would have had no indebtedness outstanding, other than the notes offered hereby and its outstanding 2019 Notes and 2021 Notes, and Oasis would have had $350 million of secured borrowing capacity available under the revolving credit facility.

The notes will be guaranteed on a senior unsecured basis by all our existing material Subsidiaries on the Issue Date; however, in the future, we will not be required to cause any Subsidiary to guarantee the notes, except in the circumstances described below under “—Covenants—Subsidiary guarantees.”

As of March 31, 2012, on a pro forma basis and after giving effect to the sale of the notes and the application of the net proceeds therefrom as described under “Use of proceeds” in this prospectus supplement, our Subsidiaries collectively had no consolidated Indebtedness, other than their Guarantees of the Notes offered hereby and Oasis’ outstanding $400 million of 2019 Notes and $400 million of 2021 Notes.

As of the Issue Date, all of our material Subsidiaries will be “Restricted Subsidiaries.” However, under the circumstances described below under the caption “—Covenants—Designation of restricted and unrestricted subsidiaries,” we will be permitted to designate Subsidiaries as “Unrestricted Subsidiaries.” Our Unrestricted Subsidiaries will not be subject to many of the restrictive covenants in the indenture, and will not guarantee the notes.

On the Issue Date, we will issue $400 million in aggregate principal amount of notes in this offering. We may issue additional notes (“Additional Notes”) under the indenture from time to time after this offering. Any issuance of Additional Notes is subject to all of the covenants in the indenture, including the covenant described below under the caption “—Covenants—Incurrence of indebtedness and issuance of preferred stock.” The notes, together with any Additional Notes subsequently issued under the indenture, will be treated as a single class for all purposes under the indenture, including, without limitation, waivers, amendments, redemptions and offers to purchase. We may also issue other debt securities under the indenture. If issued, such other debt securities will not vote together with the notes offered in this offering on any matter. The notes will mature on January 15, 2023, and will be issued in denominations of $2,000 and integral multiples of $1,000 in excess of $2,000.

Interest on the notes will accrue at the rate of 6.875% per annum and will be payable semi-annually in arrears on January 15 and July 15, beginning on January 15, 2013. Interest on overdue principal, premium, if any, and interest will accrue at the applicable interest rate on the notes. Oasis will make each interest payment to the holders of record of the notes on the immediately preceding January 1 and July 1. Interest on the notes will accrue from the date of original issuance or, if interest has already been paid, from the date it was most recently paid. Interest will be computed on the basis of a 360-day year comprised of twelve 30-day months. If a payment date is a Legal Holiday at a place of payment, payment may be made at that place on the next succeeding day that is not a Legal Holiday, and no interest shall accrue on such payment for the intervening period.

If a holder of notes has given wire transfer instructions to Oasis, Oasis will pay all principal, interest and premium, if any, on that holder’s notes in accordance with those instructions. All other payments on the notes will be made at the office or agency of the paying agent and registrar in New York, New York, unless we elect to make interest payments by check mailed to the noteholders at their address set forth in the register of holders.

The trustee will initially act as paying agent and registrar for the notes. Oasis may change the paying agent or registrar without prior notice to the holders of the notes, and Oasis or any of the Restricted Subsidiaries may act as paying agent or registrar.

A holder may transfer or exchange notes in accordance with the indenture. The registrar and the trustee may require a holder, among other things, to furnish appropriate endorsements and transfer documents in connection with a transfer of the notes, and Oasis may require a holder to pay any taxes and fees required by law or permitted by the indenture. Oasis will not be required to transfer or exchange any note (or portion of a note) selected for redemption. Also, Oasis will not be required to transfer or exchange any note for a period of 15 days before a selection of notes to be redeemed.

Our payment obligations with respect to the notes will be jointly and severally guaranteed on a senior, unsecured basis by the Subsidiary Guarantors. Initially, all of our material Subsidiaries will be Subsidiary Guarantors. Additional Subsidiaries will be required to become Subsidiary Guarantors under the circumstances described under “—Covenants—Subsidiary guarantees.” The Subsidiary Guarantees will be joint and several obligations of the Subsidiary Guarantors and limited to the maximum amount the Guarantors are permitted to guarantee under applicable law without creating a fraudulent conveyance. See “Risk factors—Risks related to the notes—The guarantees by certain of our subsidiaries of the notes could be deemed fraudulent conveyances under certain circumstances, and a court may try to subordinate or void these subsidiary guarantees.”

A Subsidiary Guarantor may not sell or otherwise dispose of all or substantially all of its properties or assets to, or consolidate with or merge with or into (regardless of whether such Subsidiary Guarantor is the surviving Person), another Person, other than Oasis or another Subsidiary Guarantor, unless:

(1) immediately after giving effect to that transaction, no Default or Event of Default exists; and

(a) (i) such Subsidiary Guarantor is the surviving Person or (ii) the Person acquiring the properties or assets in any such sale or other disposition or the Person formed by or surviving any such consolidation or merger (if other than such Subsidiary Guarantor) assumes all the obligations of such Subsidiary Guarantor under the indenture (including its Subsidiary Guarantee) pursuant to a supplemental indenture satisfactory to the trustee; or

(b) such transaction does not violate the provisions of the indenture described under the caption “—Repurchase at the option of holders—Asset sales.”

The Subsidiary Guarantee of a Subsidiary Guarantor will be released as set forth under the caption “—Covenants—Subsidiary guarantees,” and will also be released immediately:

(1) upon any sale or other disposition of all or substantially all of the properties or assets of such Subsidiary Guarantor (including by way of merger or consolidation) to a Person that is not (either before or after giving effect to such transaction) Oasis or a Restricted Subsidiary, if the sale or other disposition does not violate the provisions of the indenture described below under the caption “—Repurchase at the option of holders—Asset sales;”

(2) upon any sale or other disposition of the Capital Stock of such Subsidiary Guarantor to a Person that is not (either before or after giving effect to such transaction) Oasis or a Restricted Subsidiary, if the sale or other disposition does not violate the provisions of the indenture described under “—Repurchase at the option of holders—Asset sales” and such Subsidiary Guarantor no longer qualifies as a Subsidiary of Oasis as a result of such disposition;

(3) upon designation of such Subsidiary Guarantor as an Unrestricted Subsidiary, in accordance with the provisions of the indenture described below under the caption “—Covenants—Designation of restricted and unrestricted subsidiaries;”

(4) upon legal defeasance, covenant defeasance or satisfaction and discharge of the indenture as provided pursuant to the defeasance or satisfaction and discharge provisions of the indenture as described below under the captions “—Legal defeasance and covenant defeasance” and “—Satisfaction and discharge;” or

(5) upon the liquidation or dissolution of such Subsidiary Guarantor, provided no Default or Event of Default occurs as a result thereof or has occurred or is continuing.

Except as described below in this section or in the next-to-last paragraph of “—Repurchase at the option of holders—Change of control,” the notes are not redeemable until July 15, 2017. On

and after July 15, 2017, Oasis may redeem all or a part of the notes, from time to time, at the following redemption prices (expressed as a percentage of principal amount) plus accrued and unpaid interest, if any, on the notes redeemed to the applicable redemption date (subject to the rights of holders of notes on the relevant record date to receive interest due on the relevant interest payment date), if redeemed during the twelve-month period beginning on July 15 of the years indicated below:

At any time or from time to time prior to July 15, 2017, Oasis may also redeem all or a part of the notes, at a redemption price equal to the Make-Whole Price, subject to the rights of holders of notes on the relevant record date to receive interest due on the relevant interest payment date.

“Make-Whole Price” with respect to any notes to be redeemed, means an amount equal to the greater of:

(2) the sum of the present values of (a) the redemption price of such notes at July 15, 2017 (as set forth above) and (b) the remaining scheduled payments of interest from the redemption date to July 15, 2017 (not including any portion of such payments of interest accrued as of the redemption date) discounted back to the redemption date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate (as defined below) plus 50 basis points;

plus, in the case of both (1) and (2), accrued and unpaid interest on such notes, if any, to the redemption date.

“Comparable Treasury Issue” means, with respect to notes to be redeemed, the U.S. Treasury security selected by an Independent Investment Banker as having a maturity most nearly equal to the period from the redemption date to July 15, 2017, that would be utilized at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of a comparable maturity; provided that if such period is less than one year, then the U.S. Treasury security having a maturity of one year shall be used.

“Comparable Treasury Price” means, with respect to any redemption date, (1) the average of the Reference Treasury Dealer Quotations for such redemption date, after excluding the highest and lowest of such Reference Treasury Dealer Quotations, or (2) if the trustee obtains fewer than five such Reference Treasury Dealer Quotations, the average of all such Reference Treasury Dealer Quotations.

“Independent Investment Banker” means J.P. Morgan Securities LLC, Citigroup Global Markets Inc., or one of their respective successors, or, if such firms or their respective successors, if any, as the case may be, are unwilling or unable to select the Comparable Treasury Issue, an independent investment banking institution of national standing appointed by Oasis.

“Reference Treasury Dealer” means each of J.P. Morgan Securities LLC, Citigroup Global Markets Inc., a primary Government Securities dealer in New York City (each a “Primary Treasury Dealer”) designated by Wells Fargo Securities, LLC and two additional Primary Treasury Dealers selected by Oasis, and their respective successors; provided, however, that if any such firm or any such successor, as the case may be, shall cease to be a Primary Treasury Dealer, Oasis shall substitute therefor another Primary Treasury Dealer.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any redemption date, the average, as determined by the trustee, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the trustee by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third Business Day preceding such redemption date.

“Treasury Rate” means, with respect to any redemption date, (1) the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently published statistical release designated “H.15(159)” or any successor publication that is published weekly by the Board of Governors of the Federal Reserve System and that establishes yields on actively traded U.S. Treasury securities adjusted to constant maturity under the caption “Treasury Constant Maturities,” for the maturity corresponding to the Comparable Treasury Issue (if no maturity is within three months before or after the stated maturity, yields for the two published maturities most closely corresponding to the Comparable Treasury Issue shall be determined, and the Treasury Rate shall be interpolated or extrapolated from such yields on a straight-line basis, rounding to the nearest month) or (2) if such release (or any successor release) is not published during the week preceding the calculation date or does not contain such yields, the rate per annum equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such redemption date. The Treasury Rate shall be calculated on the third Business Day preceding the redemption date.

The notice of redemption with respect to the foregoing redemption need not set forth the Make-Whole Price but only the manner of calculation thereof. Oasis will notify the trustee of the Make-Whole Price with respect to any redemption promptly after the calculation, and the trustee shall not be responsible for such calculation.

Prior to July 15, 2015, Oasis may on any one or more occasions redeem up to 35% of the principal amount of the notes with all or a portion of the net cash proceeds of one or more Equity Offerings at a redemption price equal to 106.875% of the principal amount thereof, plus accrued and unpaid interest, if any, on the notes redeemed to the redemption date (subject to the right of holders of record on the relevant record date to receive interest due on the relevant interest payment date); provided that

(1) at least 65% of the aggregate principal amount of the notes issued on the Issue Date (excluding notes held by Oasis and its Subsidiaries) remains outstanding after each such redemption; and

(2) the redemption occurs within 180 days after the closing of such Equity Offering.

Notice of any redemption upon an Equity Offering may be given prior to the completion of the related Equity Offering, and any such redemption or notice may at Oasis’ discretion, be subject to one or more conditions precedent, including, but not limited to completion of the related Equity Offering.

Unless Oasis defaults in the payment of the redemption price, interest, if any, will cease to accrue on the notes or portions thereof called for redemption on the applicable redemption date.

If a Change of Control occurs at any time on or prior to July 15, 2013, Oasis may, at its option, redeem all, but not less than all, of the notes, at a redemption price equal to 110.0% of the principal amount of the notes redeemed, plus accrued and unpaid interest, if any, to the redemption date (subject to the rights of holders of notes on the relevant record date to receive interest due on the relevant interest payment date). If Oasis elects to exercise this redemption right, it must do so by mailing a redemption notice to each holder with a copy to the trustee within 60 days following the Change of Control (or, at Oasis’s option, prior to such Change of Control but after the transaction giving rise to such Change of Control is publicly announced). Any such redemption may be conditioned upon the Change of Control occurring if the notice is mailed prior to the Change of Control. If Oasis exercises the Change of Control redemption right, it may elect not to make the Change of Control Offer described below under “—Repurchase at the option of holders—Change of control” unless it defaults in payments due upon redemption.

If less than all of the notes are to be redeemed at any time, the trustee will select notes for redemption on a pro rata basis (or, in the case of notes in global form, the trustee will select notes for redemption based on DTC’s method that most nearly approximates a pro rata selection), unless otherwise required by law or applicable stock exchange requirements.

No notes of $2,000 or less can be redeemed in part. Notices of redemption will be mailed by first class mail at least 30 but not more than 60 days before the redemption date to each holder of notes to be redeemed at its registered address, except that redemption notices may be mailed more than 60 days prior to a redemption date if the notice is issued in connection with a defeasance of the notes or a satisfaction and discharge of the indenture.

If any note is to be redeemed in part only, the notice of redemption that relates to such note shall state the portion of the principal amount thereof to be redeemed. A new note in principal amount equal to the unredeemed portion thereof will be issued in the name of the holder thereof upon cancellation of the original note. Notes called for redemption become due on the date fixed for redemption, unless the redemption is subject to a condition precedent that is not satisfied or waived. On and after the redemption date, interest ceases to accrue on notes or portions of notes called for redemption, unless Oasis defaults in making the redemption payment. Any redemption or notice of redemption may, at our discretion, be subject to one or more conditions precedent and, in the case of a redemption with the net cash proceeds of an Equity Offering, be given prior to the completion of the related Equity Offering.

We may at any time and from time to time purchase notes in the open market or otherwise. We are not required to make mandatory redemption or sinking fund payments with respect to the notes. However, under certain circumstances, we may be required to offer to purchase notes pursuant to the covenants described under the caption “—Repurchase at the option of holders.”

If a Change of Control occurs, each holder of notes will have the right to require Oasis to repurchase all or any part (equal to $2,000 or an integral multiple of $1,000 in excess of $2,000) of that holder’s notes pursuant to an offer (a “Change of Control Offer”) on the terms set forth in the indenture. In the Change of Control Offer, Oasis will offer a payment in cash (the “Change of Control Payment”) equal to not less than 101% of the aggregate principal amount of notes repurchased plus accrued and unpaid interest, if any, on the notes repurchased to the date of purchase (the “Change of Control Payment Date”), subject to the rights of holders of notes on the relevant record date to receive interest due on the relevant interest payment date. Within 30 days following any Change of Control, Oasis will mail a notice to each holder describing the transaction or transactions that constitute the Change of Control and offering to repurchase notes on the Change of Control Payment Date specified in the notice, which date will be no earlier than 30 days and no later than 60 days from the date such notice is mailed, pursuant to the procedures required by the indenture and described in such notice. Oasis will comply with the requirements of Rule 14e-1 under the Exchange Act and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the notes as a result of a Change of Control. To the extent that the provisions of any securities laws or regulations conflict with the Change of Control provisions of the indenture, Oasis will comply with the applicable securities laws and regulations and will not be deemed to have breached its obligations under the Change of Control provisions of the indenture by virtue of such compliance.

(1) accept for payment all notes or portions of notes properly tendered pursuant to the Change of Control Offer;

(2) deposit with the paying agent an amount equal to the Change of Control Payment in respect of all notes or portions of notes properly tendered; and

(3) deliver or cause to be delivered to the trustee the notes properly accepted together with an Officers’ Certificate stating the aggregate principal amount of notes or portions of notes being purchased by Oasis.

The paying agent will promptly mail or wire transfer to each holder of notes properly tendered the Change of Control Payment for such notes (or, if all the notes are then in global form, make such payment through the facilities of DTC), and the trustee will promptly authenticate and mail (or cause to be transferred by book entry) to each holder a new note equal in principal amount to any unpurchased portion of the notes surrendered, if any; provided that each such new note will be in a principal amount of $2,000 or an integral multiple of $1,000 in excess of $2,000. Any note so accepted for payment will cease to accrue interest on and after the Change of Control Payment Date unless Oasis defaults in making the Change of Control Payment. Oasis will publicly announce the results of the Change of Control Offer on or as soon as practicable after the Change of Control Payment Date.

The provisions described herein that require Oasis to make a Change of Control Offer following a Change of Control will be applicable regardless of whether any other provisions of the indenture are applicable. Except as described above with respect to a Change of Control, the indenture will

not contain provisions that permit the holders of the notes to require that Oasis repurchase or redeem the notes in the event of a takeover, recapitalization or similar transaction.

Oasis will not be required to make a Change of Control Offer upon a Change of Control if a third party makes the Change of Control Offer in the manner, at the price, at the times and otherwise in compliance with the requirements set forth in the indenture applicable to a Change of Control Offer made by Oasis and purchases all notes properly tendered and not withdrawn under the Change of Control Offer.

A Change of Control Offer may be made in advance of a Change of Control, and conditioned upon the occurrence of such Change of Control, if a definitive agreement is in place for the Change of Control at the time of making the Change of Control Offer. Notes repurchased by Oasis pursuant to a Change of Control Offer will have the status of notes issued but not outstanding or will be retired and cancelled, at Oasis’ option. Notes purchased by a third party pursuant to the preceding paragraph will have the status of notes issued and outstanding.

The definition of Change of Control includes a phrase relating to the direct or indirect sale, lease, transfer, conveyance or other disposition of “all or substantially all” of the properties or assets of Oasis and its Restricted Subsidiaries taken as a whole. Although there is a limited body of case law interpreting the phrase “substantially all,” there is no precise established definition of the phrase under applicable law. Accordingly, the ability of a holder of notes to require Oasis to repurchase its notes as a result of a sale, lease, transfer, conveyance or other disposition of less than all of the properties or assets of Oasis and its Restricted Subsidiaries taken as a whole to another Person or group may be uncertain.

In the event that holders of at least 90% of the aggregate principal amount of the outstanding notes accept a Change of Control Offer and Oasis (or any third party making such Change of Control Offer, in lieu of Oasis, as described above) purchases all of the notes held by such holders, Oasis will have the right, upon not less than 30 nor more than 60 days’ prior notice, given not more than 30 days following a Change of Control Payment Date, to redeem all, but not less than all, of the notes that remain outstanding at a redemption price equal to the Change of Control Payment plus, to the extent not included in the Change of Control Payment, accrued and unpaid interest, if any, on the notes that remain outstanding, to the date of redemption (subject to the right of holders on the relevant record date to receive interest due on the relevant interest payment date).

The indentures governing the 2019 Notes and 2021 Notes, respectively, provide that upon the occurrence of certain change-of-control events, each holder of 2019 Notes or 2021 Notes, as the case may be, will have the right to require Oasis to purchase all or any part of such holder’s senior notes. In such event, Oasis may not have available funds sufficient to pay the aggregate purchase price of such senior notes tendered by such holders exercising such right. The failure of Oasis to purchase the 2019 Notes or 2021 Notes as required pursuant to the change of control covenant in the indenture governing such series of notes would result in the occurrence of an event of default under such indenture, which would entitle the applicable indenture trustee or the holders of 25% in aggregate principal amount of such series of notes to accelerate all notes of such series. Such an acceleration would result in an event of default under the indenture governing the notes offered hereby, which similarly could result in an acceleration of all our payment obligations in respect thereof. In such event, we might not be able to satisfy such obligations. See “Risk factors—Risks related to the notes—We may not be able to fund a change of control offer.”

Oasis will not, and will not permit any of its Restricted Subsidiaries to, consummate an Asset Sale unless:

(1) Oasis (or the Restricted Subsidiary, as the case may be) receives consideration at the time of such Asset Sale at least equal to the Fair Market Value of the assets or Equity Interests issued or sold or otherwise disposed of; and

(2) at least 75% of the aggregate consideration received in respect of such Asset Sale by Oasis or such Restricted Subsidiary (considered together on a cumulative basis, with all consideration received by Oasis or any of its Restricted Subsidiaries in respect of other Asset Sales consummated since the Issue Date), is in the form of cash or Cash Equivalents. For purposes of this provision, each of the following will be deemed to be cash:

(a) any liabilities, as shown on Oasis’ most recent consolidated balance sheet, of Oasis or any Restricted Subsidiary (other than contingent liabilities, Subordinated Debt and any obligations in respect of preferred stock) that are assumed by the transferee of any such assets or Equity Interests pursuant to a customary novation agreement (or other legal documentation with the same effect) that includes a full release of Oasis or such Restricted Subsidiary from any and all liability therefor;

(b) any securities, notes or other obligations received by Oasis or any such Restricted Subsidiary from such transferee that are converted by Oasis or such Restricted Subsidiary into cash within 90 days after the date of the Asset Sale, to the extent of the cash received in that conversion; and

Notwithstanding the foregoing, the 75% limitation referred to above shall be deemed satisfied with respect to any Asset Sale in which the cash or Cash Equivalents portion of the consideration received therefrom, determined in accordance with the foregoing provision on an after-tax basis, is equal to or greater than what the after-tax proceeds would have been had such Asset Sale complied with the aforementioned 75% limitation.

Within 365 days after the receipt of any Net Proceeds from an Asset Sale or, if Oasis has entered into a binding commitment or commitments with respect to any of the actions described in clauses (2) or (3) below, within the later of (x) 365 days after the receipt of any Net Proceeds from an Asset Sale or (y) 120 days after the entering into of such commitment or commitments, Oasis (or the applicable Restricted Subsidiary, as the case may be) may apply such Net Proceeds:

(3) to make capital expenditures in respect of a Related Business of Oasis or any of its Restricted Subsidiaries.

However, pending application or investment of such Net Proceeds as provided in clauses (1) through (3), such Net Proceeds may be applied to temporarily reduce revolving credit Indebtedness. An amount equal to any Net Proceeds from Asset Sales that are not applied or invested as provided in clauses (1) through (3) above will constitute “Excess Proceeds.”

Within ten Business Days after the aggregate amount of Excess Proceeds exceeds $20.0 million, Oasis will make an offer (an “Asset Sale Offer”) to all holders of notes and all holders of other Indebtedness that is pari passu with the notes containing provisions similar to those set forth in the indenture with respect to offers to purchase or redeem with the proceeds of sales of assets, to purchase the maximum principal amount of notes and such other pari passu Indebtedness that may be purchased out of the Excess Proceeds. The offer price in any Asset Sale Offer will be equal to 100% of the principal amount plus accrued and unpaid interest, if any, to the date of purchase, and will be payable in cash. If any Excess Proceeds remain after consummation of an Asset Sale Offer, Oasis or any Restricted Subsidiary may use those Excess Proceeds for any purpose not otherwise prohibited by the indenture. If the aggregate principal amount of notes and other pari passu Indebtedness tendered into such Asset Sale Offer exceeds the amount of Excess Proceeds, Oasis will use the Excess Proceeds to purchase the notes and such other pari passu Indebtedness on a pro rata basis. Upon completion of each Asset Sale Offer, the amount of Excess Proceeds will be reset at zero.

Notwithstanding the foregoing, the sale, conveyance or other disposition of all or substantially all of the properties or assets of Oasis and its Restricted Subsidiaries, taken as a whole, will be governed by the provisions of the indenture described under the caption “—Repurchase at the option of holders—Change of control” and/or the provisions described under the caption “—Covenants—Merger, consolidation or sale of substantially all assets” and not by the provisions of the Asset Sales covenant.

Oasis will comply with the requirements of Rule 14e-1 under the Exchange Act and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable in connection with each repurchase of notes pursuant to an Asset Sale Offer. To the extent that the provisions of any securities laws or regulations conflict with the Asset Sales provisions of the indenture, or compliance with the Asset Sales provisions of the indenture would constitute a violation of any such laws or regulations, Oasis will comply with the applicable securities laws and regulations and will not be deemed to have breached its obligations under the Asset Sales provisions of the indenture by virtue of such compliance.

The Senior Credit Agreement contains, and future agreements may contain, prohibitions of certain events, including events that would constitute a Change of Control or an Asset Sale and including repurchases of or other prepayments in respect of the notes. The exercise by the holders of notes of their right to require Oasis to repurchase the notes upon a Change of Control or an Asset Sale could cause a default under these other agreements, even if the Change of Control or Asset Sale itself does not, due to the financial effect of such repurchases on Oasis or otherwise. In the event a Change of Control or Asset Sale occurs at a time when Oasis is prohibited from purchasing notes, Oasis could seek the consent of the applicable lenders to the purchase of notes or could attempt to refinance the Indebtedness that contain such prohibitions. If Oasis does not obtain a consent or repay that Indebtedness, Oasis will remain prohibited from purchasing notes. In that case, Oasis’ failure to purchase tendered notes would constitute an Event of Default under the indenture which could, in turn, constitute a default under other Indebtedness. Finally, Oasis’ ability to pay cash to the holders of notes upon a repurchase may be limited by Oasis’ then-existing financial resources. See “Risk factors—Risks related to the notes—We may not be able to fund a change of control offer.”

Oasis will not, and will not permit any of its Restricted Subsidiaries to, directly or indirectly:

(1) declare or pay any dividend or make any other payment or distribution on account of Oasis’ or any of its Restricted Subsidiaries’ Equity Interests (including, without limitation, any payment in connection with any merger or consolidation involving Oasis or any of its Restricted Subsidiaries) or to the direct or indirect holders of Oasis’ or any of its Restricted Subsidiaries’ Equity Interests in their capacity as such (other than dividends or distributions payable in Equity Interests (other than Disqualified Stock) of Oasis and other than dividends or distributions payable to Oasis or any Restricted Subsidiary);

(2) purchase, redeem or otherwise acquire or retire for value (including, without limitation, any such purchase, redemption, acquisition or retirement made in connection with any merger or consolidation involving Oasis) any Equity Interests of Oasis or any direct or indirect parent company of Oasis;

(3) make any payment on or with respect to, or purchase, redeem, defease or otherwise acquire or retire for value any Subordinated Debt, except a payment of interest or principal at the Stated Maturity thereof (excluding (a) any intercompany Indebtedness between or among Oasis and any of its Restricted Subsidiaries or (b) the purchase or other acquisition of Subordinated Debt acquired in anticipation of satisfying a sinking fund obligation, principal installment or final maturity, in each case due within one year of the date of such purchase or other acquisition); or

(all such payments and other actions set forth in clauses (1) through (4) above being collectively referred to as “Restricted Payments”), unless, at the time of and after giving effect to such Restricted Payment:

(1) no Default or Event of Default has occurred and is continuing or would occur as a consequence of such Restricted Payment;

(2) Oasis would, at the time of such Restricted Payment and after giving pro forma effect thereto as if such Restricted Payment had been made at the beginning of the applicable four-quarter period, have been permitted to incur at least $1.00 of additional Indebtedness pursuant to the Fixed Charge Coverage Ratio test set forth in the first paragraph of the covenant described below under the caption “—Incurrence of indebtedness and issuance of preferred stock;” and

(3) such Restricted Payment, together with the aggregate amount of all other Restricted Payments made by Oasis and its Restricted Subsidiaries since the Prior Issue Date (excluding Restricted Payments permitted by clauses (2), (3), (4), (5), (6), (7), (8), (9) and (12) of the next succeeding paragraph), is equal to or less than the sum, without duplication, of:

(a) 50% of the Consolidated Net Income of Oasis for the period (taken as one accounting period) from the beginning of the most recent fiscal quarter commencing before the Prior Issue Date to the end of Oasis’ most recently ended fiscal quarter for which internal financial statements are available at the time of such Restricted Payment (or, if such Consolidated Net Income for such period is a deficit, less 100% of such deficit); plus

(b) 100% of (A) (i) the aggregate net cash proceeds and (ii) the Fair Market Value of (x) marketable securities (other than marketable securities of Oasis or an Affiliate of Oasis), (y) Capital Stock of a Person (other than Oasis or an Affiliate of Oasis) engaged primarily in any Related Business and (z) other assets used or useful in any Related Business, in each case received by Oasis since the Prior Issue Date as a contribution to its common equity capital or from the issue or sale of Equity Interests of Oasis (other than Disqualified Stock) or from the issue or sale of convertible or exchangeable Disqualified Stock or convertible or exchangeable debt securities of Oasis that have been converted into or exchanged for such Equity Interests (other than Equity Interests (or Disqualified Stock or debt securities) sold to a Subsidiary of Oasis), (B) with respect to Indebtedness that is incurred on or after the Prior Issue Date, the amount by which such Indebtedness of Oasis or any of its Restricted Subsidiaries is reduced on Oasis’ consolidated balance sheet upon the conversion or exchange after the Prior Issue Date of any such Indebtedness into or for Equity Interests of Oasis (other than Disqualified Stock), and (C) the aggregate net cash proceeds, if any, received by Oasis or any of its Restricted Subsidiaries upon any conversion or exchange described in clause (A) or (B) above; plus

(c) with respect to Restricted Investments made by Oasis and its Restricted Subsidiaries after the Prior Issue Date, an amount equal to the sum, without duplication, of (A) the net reduction in such Restricted Investments in any Person resulting from (i) repayments of loans or advances, or other transfers of assets, in each case to Oasis or any Restricted Subsidiary, (ii) other repurchases, repayments or redemptions of such Restricted Investments, (iii) the sale of any such Restricted Investment to a purchaser other than Oasis or a Subsidiary of Oasis or (iv) the release of any Guarantee (except to the extent any amounts are paid under such Guarantee) that constituted a Restricted Investment plus (B) with respect to any Unrestricted Subsidiary designated as such after the Prior Issue Date that is redesignated as a Restricted Subsidiary after the Prior Issue Date, the lesser of (i) the Fair Market Value of Oasis’ Investment in such Subsidiary held by Oasis or any of its Restricted Subsidiaries at the time of such redesignation and (ii) the aggregate amount of Investments made by Oasis or any of its Restricted Subsidiaries in such Subsidiary upon or after designation of such Subsidiary as an Unrestricted Subsidiary and prior to the redesignation of such Subsidiary as a Restricted Subsidiary; plus

(d) 100% of any dividends received by Oasis or a Restricted Subsidiary after the Prior Issue Date from an Unrestricted Subsidiary, to the extent such dividends were not otherwise included in the Consolidated Net Income of Oasis for such period.

(1) the payment of any dividend or the consummation of any irrevocable redemption within 60 days after the date of declaration of the dividend or giving of the redemption notice, as the case may be, if at the date of declaration or notice, the dividend or redemption payment would have complied with the provisions of the indenture;

(2) the making of any Restricted Payment in exchange for, or out of the net cash proceeds from the substantially concurrent sale (other than to a Subsidiary of Oasis) of, Equity Interests of Oasis (other than Disqualified Stock and other than Equity Interests issued or sold to an employee stock ownership plan, option plan or similar trust to the extent such sale to an employee stock ownership plan, option plan or similar trust is financed by loans from or Guaranteed by Oasis or any of its Restricted Subsidiaries unless such loans have been repaid

with cash on or prior to the date of determination) or from the substantially concurrent contribution of common equity capital to Oasis; provided that the amount of any such net cash proceeds that are utilized for any such Restricted Payment will be excluded from clause (3)(b) of the preceding paragraph and clause (7) of this paragraph;

(3) the purchase, redemption, defeasance or other acquisition or retirement for value of Subordinated Debt (including the payment of any required premium and any fees and expenses incurred in connection with such purchase, redemption, defeasance or other acquisition or retirement) with the net cash proceeds from a substantially concurrent incurrence of Permitted Refinancing Indebtedness;

(4) the purchase, redemption or other acquisition or retirement for value of any Equity Interests of Oasis or any Restricted Subsidiary held by any of Oasis’ or any of its Restricted Subsidiaries’ current or former directors or employees in connection with the exercise or vesting of any equity compensation (including, without limitation, stock options, restricted stock and phantom stock) in order to satisfy Oasis’ or such Restricted Subsidiary’s tax withholding obligation with respect to such exercise or vesting;

(5) purchases of Capital Stock deemed to occur upon the exercise of stock options if such Capital Stock represents a portion of the exercise price thereof;

(6) payments to fund the purchase, redemption or other acquisition or retirement for value by Oasis of fractional Equity Interests arising out of stock dividends, splits or combinations, business combinations or other transactions permitted by the indenture;

(7) as long as no Default has occurred and is continuing or would be caused thereby, the purchase, redemption or other acquisition or retirement for value of any Equity Interests of Oasis or any Restricted Subsidiary held by any of Oasis’ (or any of its Restricted Subsidiaries’) current or former directors or employees; provided that the aggregate price paid for all such purchased, redeemed, acquired or retired Equity Interests may not exceed the sum of (a) $20.0 million plus (b) the aggregate amount of cash proceeds received by Oasis from the sale of Oasis’ Equity Interests (other than Disqualified Stock) to any such directors or employees that occurs after the Prior Issue Date; provided that the amount of such cash proceeds utilized for any such purchase, redemption or other acquisition or retirement will be excluded from clause (3)(b) of the immediately preceding paragraph and clause (2) of this paragraph plus (c) the cash proceeds of key man life insurance policies received by Oasis and its Restricted Subsidiaries after the Prior Issue Date;

(8) as long as no Default has occurred and is continuing or would be caused thereby, the declaration and payment of regularly scheduled or accrued dividends to holders of any class or series of Disqualified Stock of Oasis or any class or series of preferred stock of any Restricted Subsidiary issued on or after the Prior Issue Date in accordance with the Fixed Charge Coverage Ratio test described below under the caption “—Incurrence of indebtedness and issuance of preferred stock;”

(9) the payment of any dividend (or, in the case of any partnership or limited liability company, any similar distribution) by a Restricted Subsidiary to the holders of Equity Interests (other than Disqualified Stock) of such Restricted Subsidiary; provided that such dividend or similar distribution is paid to all holders of such Equity Interests on a pro rata basis based on their respective holdings of such Equity Interests;

(10) purchases of Subordinated Debt at a purchase price not greater than (a) 101% of the principal amount of such Subordinated Debt and accrued and unpaid interest thereon in the event of a Change of Control or (b) 100% of the principal amount of such Subordinated Debt and accrued and unpaid interest thereon in the event of an Asset Sale in connection with any change of control offer or asset sale offer required by the terms of such Subordinated Debt, but only if:

(i) in the case of a Change of Control, Oasis has first complied with and fully satisfied its obligations under the covenant described under “—Repurchase at the option of holders—Change of control;” or

(ii) in the case of an Asset Sale, Oasis has complied with and fully satisfied its obligations under the covenant described under “—Repurchase at the option of holders—Asset sales;”

(11) payments or distributions to dissenting stockholders pursuant to applicable law in connection with a merger, consolidation or transfer of all or substantially all of the assets of Oasis that complies with the provisions described under the caption “—Merger, consolidation or sale of substantially all assets;” and

(12) other Restricted Payments since the Prior Issue Date in an aggregate amount at any time outstanding not to exceed $25.0 million.

The amount of all Restricted Payments (other than cash) shall be the Fair Market Value, on the date of such Restricted Payment, of the Restricted Investment proposed to be made or the asset(s) or securities proposed to be paid, transferred or issued by Oasis or such Restricted Subsidiary, as the case may be, pursuant to such Restricted Payment, except that the Fair Market Value of any non-cash dividend made within 60 days after the date of declaration shall be determined as of such date. The Fair Market Value of any cash Restricted Payment shall be its face amount, and the Fair Market Value of any non-cash Restricted Payment shall be determined in accordance with the definition of that term. For purposes of determining compliance with this covenant, in the event that a Restricted Payment meets the criteria of more than one of the exceptions described in (1) through (12) above or is entitled to be made pursuant to the first paragraph of this covenant, Oasis shall, in its sole discretion, classify such Restricted Payment, or later classify, reclassify or re-divide all or a portion of such Restricted Payment, in any manner that complies with this covenant.

Oasis will not, and will not permit any of its Restricted Subsidiaries to directly or indirectly create, incur, issue, assume, Guarantee or otherwise become directly or indirectly liable, contingently or otherwise, with respect to (collectively, “incur;” with “incurrence” having a correlative meaning) any Indebtedness (including Acquired Debt), and Oasis will not issue any Disqualified Stock and will not permit any of its Restricted Subsidiaries to issue any preferred stock; provided, however, that Oasis may incur Indebtedness (including Acquired Debt) and issue Disqualified Stock, and Subsidiary Guarantors may incur Indebtedness (including Acquired Debt) and issue preferred stock, if (a) the Fixed Charge Coverage Ratio for Oasis’ most recently ended four full fiscal quarters for which internal financial statements are available immediately preceding the date on which such additional Indebtedness is incurred or such Disqualified Stock or preferred stock is issued, as the case may be, would have been at least 2.25 to 1.0, determined on a pro forma basis

(including a pro forma application of the net proceeds therefrom), as if the additional Indebtedness had been incurred or the Disqualified Stock or preferred stock had been issued, as the case may be, at the beginning of such four-quarter period and (b) no Default would occur as a consequence of, and no Event of Default would be continuing following, the incurrence of the Indebtedness or the transactions relating to such incurrence, including any related application of the proceeds thereof.

Notwithstanding the foregoing, the first paragraph of this covenant will not prohibit the incurrence of any of the following items of Indebtedness or the issuance of any Disqualified Stock or preferred stock described in clauses (5) and (7) below (collectively, “Permitted Debt”):

(1) the incurrence by Oasis and any Subsidiary Guarantor of Indebtedness under Credit Facilities in an aggregate principal amount at any one time outstanding under this clause (1) (with letters of credit being deemed to have a principal amount equal to the maximum potential liability of Oasis and its Restricted Subsidiaries thereunder) not to exceed the greater of (i) $200.0 million and (ii) the sum of $100.0 million plus an amount equal to 25.0% of Adjusted Consolidated Net Tangible Assets of Oasis, determined as of the date of the incurrence of such Indebtedness after giving pro forma effect to such incurrence and the application of the proceeds therefrom;

(2) the incurrence by Oasis and its Restricted Subsidiaries of Existing Indebtedness;

(3) the incurrence by Oasis of Indebtedness represented by the notes to be issued on the Issue Date;

(4) the incurrence by Oasis or any of its Restricted Subsidiaries of Indebtedness represented by Capital Lease Obligations, mortgage financings or purchase money obligations, in each case, incurred for the purpose of financing all or any part of the purchase price or cost of design, construction, installation, improvement, deployment, refurbishment or modification of property, plant or equipment or furniture, fixtures and equipment, in each case, used in the business of Oasis or any of its Restricted Subsidiaries, in an aggregate principal amount at any time outstanding, including all Permitted Refinancing Indebtedness incurred to extend, renew, refund, refinance, replace, defease, discharge or otherwise retire for value any Indebtedness incurred pursuant to this clause (4), not to exceed the greater of (a) $15.0 million and (b) 2.0% of Adjusted Consolidated Net Tangible Assets of Oasis, determined as of the date of the incurrence of such Indebtedness;

(5) the incurrence or issuance by Oasis or any of its Restricted Subsidiaries of Permitted Refinancing Indebtedness in exchange for, or the net proceeds of which are used to extend, renew, refund, refinance, replace, defease, discharge or otherwise retire for value any Indebtedness (other than intercompany Indebtedness) or Disqualified Stock of Oasis, or Indebtedness (other than intercompany Indebtedness) or preferred stock of any Restricted Subsidiary, in each case that was permitted by the indenture to be incurred or issued under the first paragraph of this covenant or clause (2), (3), (4), (10), (14) or (15) of this paragraph or this clause (5);

(6) the incurrence by Oasis or any of its Restricted Subsidiaries of intercompany Indebtedness between or among Oasis and any of its Restricted Subsidiaries; provided, however, that (a) if Oasis or any Subsidiary Guarantor is the obligor on such Indebtedness and the payee is not Oasis or a Subsidiary Guarantor, such Indebtedness must be expressly subordinated to the prior payment in full in cash of all obligations then due with respect to the notes, in the case

of Oasis, or the Subsidiary Guarantee, in the case of a Subsidiary Guarantor; and (b) (i) any subsequent issuance or transfer of Equity Interests that results in any such Indebtedness being held by a Person other than Oasis or a Restricted Subsidiary and (ii) any sale or other transfer of any such Indebtedness to a Person that is not either Oasis or a Restricted Subsidiary will be deemed, in each case, to constitute an incurrence of such Indebtedness by Oasis or such Restricted Subsidiary, as the case may be, that was not permitted by this clause (6);

(7) the issuance by any of Oasis’ Restricted Subsidiaries to Oasis or to any of its Restricted Subsidiaries of any preferred stock; provided, however, that:

(a) any subsequent issuance or transfer of Equity Interests that results in any such preferred stock being held by a Person other than Oasis or a Restricted Subsidiary; and

(b) any sale or other transfer of any such preferred stock to a Person that is not either Oasis or a Restricted Subsidiary, will be deemed, in each case, to constitute an issuance of such preferred stock by such Restricted Subsidiary that was not permitted by this clause (7);

(8) the incurrence of obligations of Oasis or a Restricted Subsidiary pursuant to Interest Rate and Currency Hedges, in each case entered into in the ordinary course of business for the non-speculative purpose of limiting risks that arise in the ordinary course of business of Oasis and its Restricted Subsidiaries;

(9) the Guarantee by Oasis or any of the Subsidiary Guarantors of Indebtedness of Oasis or a Restricted Subsidiary that was permitted to be incurred by another provision of this covenant; provided that if the Indebtedness being Guaranteed is subordinated to or pari passu with the notes, then the Guarantee shall be subordinated or pari passu, as applicable, to the same extent as the Indebtedness Guaranteed;

(10) the incurrence by Oasis or any Restricted Subsidiary of Permitted Acquisition Indebtedness;

(11) the incurrence by Oasis or any Restricted Subsidiary of Indebtedness arising from the honoring by a bank or other financial institution of a check, draft or similar instrument inadvertently drawn against insufficient funds, so long as such Indebtedness is covered within five Business Days;

(12) the incurrence by Oasis or any Restricted Subsidiary of Indebtedness consisting of the financing of insurance premiums in customary amounts consistent with the operations and business of Oasis and its Restricted Subsidiaries;

(13) the incurrence by Oasis or any Restricted Subsidiary of Indebtedness constituting reimbursement obligations with respect to letters of credit; provided that, upon the drawing of such letters of credit, such obligations are reimbursed within 30 days following such drawing;

(14) the incurrence by any Foreign Subsidiary of Indebtedness that, in the aggregate together with all other Indebtedness of all Foreign Subsidiaries, (including all Permitted Refinancing Indebtedness incurred to extend, renew, refund, refinance, replace, defease, discharge or otherwise retire for value any Indebtedness incurred pursuant to this clause (14)) does not exceed the greater of (a) 20.0% of the Adjusted Consolidated Net Tangible

Assets of all Foreign Subsidiaries, considered as a consolidated enterprise, determined as of the date of the incurrence of such Indebtedness after giving pro forma effect to such incurrence and the application of the proceeds therefrom and (b) $25.0 million; and

(15) the incurrence by Oasis or any of the Subsidiary Guarantors of Indebtedness in an aggregate principal amount that, when taken together with all other Indebtedness of Oasis and its Restricted Subsidiaries outstanding on the date of such incurrence (other than Indebtedness permitted by clauses (1) through (14) above or the first paragraph of this covenant) and any Permitted Refinancing Indebtedness incurred to extend, renew, refund, refinance, replace, defease, discharge or otherwise retire for value any Indebtedness incurred pursuant to this clause (15) does not exceed the greater of (a) 5.0% of Adjusted Consolidated Net Tangible Assets of Oasis, determined as of the date of the incurrence of such Indebtedness after giving pro forma effect to such incurrence and the application of the proceeds therefrom and (b) $35.0 million.

Oasis will not incur, and will not permit any Subsidiary Guarantor to incur, any Indebtedness (including Permitted Debt) that is contractually subordinated in right of payment to any other Indebtedness of Oasis or such Subsidiary Guarantor unless such Indebtedness is also contractually subordinated in right of payment to the notes and the applicable Subsidiary Guarantee, on substantially identical terms; provided, however, that no Indebtedness will be deemed to be contractually subordinated in right of payment to any other Indebtedness of Oasis solely by virtue of being unsecured or by virtue of being secured on a first or junior Lien basis.

For purposes of determining compliance with this “—Incurrence of indebtedness and issuance of preferred stock” covenant, (a) in the event that an item of proposed Indebtedness, Disqualified Stock or preferred stock meets the criteria of more than one of the categories of Permitted Debt described in clauses (1) through (15) of the second paragraph of this covenant, or is entitled to be incurred or issued pursuant to the first paragraph of this covenant, Oasis will be permitted to divide and classify such item on the date of its incurrence or issuance, or later divide and reclassify all or a portion of such item, in any manner that complies with this covenant and (b) all Indebtedness outstanding on the Issue Date under the Senior Credit Agreement shall be deemed incurred on the Issue Date under clause (1) of the second paragraph of this covenant. The accrual of interest, the accretion or amortization of original issue discount, the payment of interest on any Indebtedness in the form of additional Indebtedness with the same terms, the reclassification of preferred stock as Indebtedness due to a change in accounting principles, and the payment of dividends on Disqualified Stock or preferred stock in the form of additional Disqualified Stock or preferred stock of the same class will be deemed not to be an incurrence of Indebtedness or an issuance of Disqualified Stock or preferred stock for purposes of this covenant; provided, in each such case, that the amount of any such accrual, accretion or payment is included in Fixed Charges of Oasis as accrued.

For purposes of determining compliance with any U.S. dollar-denominated restriction on the incurrence of Indebtedness, the U.S. dollar-equivalent principal amount of Indebtedness denominated in a foreign currency shall be calculated based on the relevant currency exchange rate in effect on the date such Indebtedness was incurred, in the case of term Indebtedness, or first committed, in the case of revolving credit Indebtedness; provided that if such Indebtedness is incurred to refinance other Indebtedness denominated in a foreign currency, and such refinancing would cause the applicable U.S. dollar-denominated restriction to be exceeded if calculated at the relevant currency exchange rate in effect on the date of such refinancing, such U.S. dollar-denominated restriction shall be deemed not to have been exceeded so long as the

principal amount of such refinancing Indebtedness does not exceed the principal amount of such Indebtedness being refinanced. Notwithstanding any other provision of this covenant, the maximum amount of Indebtedness that Oasis or any Restricted Subsidiary may incur pursuant to this covenant shall not be deemed to be exceeded solely as a result of fluctuations in the exchange rate of currencies. The principal amount of any Permitted Refinancing Indebtedness incurred to refinance other Indebtedness, if incurred in a different currency from the Indebtedness being refinanced, shall be calculated based on the currency exchange rate applicable to the currencies in which such Permitted Refinancing Indebtedness is denominated that is in effect on the date of such refinancing.

Oasis will not, and will not permit any of its Restricted Subsidiaries to, directly or indirectly, create, incur or permit to exist any Lien (the “Initial Lien”), other than Permitted Liens, upon any of its property or assets (including Capital Stock and Indebtedness of any Subsidiaries of Oasis and including any income or profits from such property or assets), whether owned on the Issue Date or thereafter acquired, which Lien secures any Subordinated Debt or other Indebtedness, unless:

(1) in the case of Liens securing Subordinated Debt of Oasis or a Subsidiary Guarantor, the notes or Subsidiary Guarantee, as applicable, are secured by a Lien on such property or assets on a senior basis to the Subordinated Debt so secured with the same priority as the notes or such Subsidiary Guarantee, as applicable, has to such Subordinated Debt until such time as such Subordinated Debt is no longer so secured by a Lien; and

(2) in the case of Liens securing other Indebtedness of Oasis or a Subsidiary Guarantor, the notes or Subsidiary Guarantees, as applicable, are secured by a Lien on such property or assets on an equal and ratable basis with the other Indebtedness so secured until such time as such other Indebtedness is no longer so secured by a Lien.

Any Lien securing the notes or Subsidiary Guarantees created pursuant to the preceding paragraph shall provide by its terms that such Lien shall be automatically and unconditionally released and discharged upon the unconditional release and discharge of the Initial Lien.

Oasis will not, and will not permit any of its Restricted Subsidiaries to, directly or indirectly, create or permit to exist or become effective any consensual encumbrance or restriction on the ability of any Restricted Subsidiary to:

(a) pay dividends or make any other distributions on its Capital Stock to Oasis or any of its Restricted Subsidiaries, or pay any Indebtedness owed to Oasis or any of its Restricted Subsidiaries;

However, the preceding restrictions will not apply to encumbrances or restrictions existing under, by reason of or with respect to:

(1) the Senior Credit Agreement, any Existing Indebtedness, Capital Stock or any other agreements or instruments, in each case in effect on the Issue Date and any amendments,

restatements, modifications, renewals, extensions, supplements, increases, refundings, replacements or refinancings thereof; provided that the encumbrances and restrictions in any such amendments, restatements, modifications, renewals, extensions, supplements, increases, refundings, replacements or refinancings are, in the reasonable good faith judgment of the Chief Executive Officer and the Chief Financial Officer of Oasis, no more restrictive, taken as a whole, than those contained in the applicable agreements or instruments as in effect on the Issue Date;

(3) applicable law, rule, regulation, order, approval, permit or similar restriction;

(4) any instrument governing Indebtedness or Capital Stock of a Person acquired by Oasis or any of its Restricted Subsidiaries as in effect at the time of such acquisition (except to the extent such Indebtedness or Capital Stock was incurred in connection with or in contemplation of such acquisition), which encumbrance or restriction is not applicable to any Person, or the properties or assets of any Person, other than the Person, or the property or assets of the Person, so acquired and any amendments, restatements, modifications, renewals, extensions, supplements, increases, refundings, replacements or refinancings thereof; provided, that the encumbrances and restrictions in any such amendments, restatements, modifications, renewals, extensions, supplements, increases, refundings, replacements or refinancings are, in the reasonable good faith judgment of the Chief Executive Officer and Chief Financial Officer of Oasis, no more restrictive, taken as a whole, than those in effect on the date of the acquisition; provided, further, that, in the case of Indebtedness, such Indebtedness was permitted by the terms of the indenture to be incurred;

(5) customary non-assignment provisions in contracts, leases and licenses (including, without limitation, licenses of intellectual property) entered into in the ordinary course of business;

(6) any agreement for the sale or other disposition of the Equity Interests in, or all or substantially all of the properties or assets of, a Restricted Subsidiary, that restricts distributions by the applicable Restricted Subsidiary pending the sale or other disposition;

(7) Permitted Refinancing Indebtedness; provided that the restrictions contained in the agreements governing such Permitted Refinancing Indebtedness are not materially more restrictive, taken as a whole, than those contained in the agreements governing the Indebtedness being refinanced;

(8) Liens permitted to be incurred under the provisions of the covenant described above under the caption “—Limitation on liens” that limit the right of the debtor to dispose of the assets subject to such Liens;

(9) the issuance of preferred stock by a Restricted Subsidiary or the payment of dividends thereon in accordance with the terms thereof; provided that issuance of such preferred stock is permitted pursuant to the covenant described under the caption “—Incurrence of indebtedness and issuance of preferred stock” and the terms of such preferred stock do not expressly restrict the ability of a Restricted Subsidiary to pay dividends or make any other distributions on its Capital Stock (other than requirements to pay dividends or liquidation preferences on such preferred stock prior to paying any dividends or making any other distributions on such other Capital Stock);

(10) other Indebtedness of Oasis or any of its Restricted Subsidiaries permitted to be incurred pursuant to an agreement entered into subsequent to the Issue Date in accordance with the

covenant described under the caption “—Incurrence of indebtedness and issuance of preferred stock;” provided that the provisions relating to such encumbrance or restriction contained in such Indebtedness are not materially less favorable to Oasis and its Restricted Subsidiaries, taken as a whole, in the reasonable good faith judgment of the Chief Executive Officer and Chief Financial Officer of Oasis, than the provisions contained in the Senior Credit Agreement as in effect on the Issue Date;

(11) Indebtedness incurred or Capital Stock issued by any Restricted Subsidiary, provided that the restrictions contained in the agreements or instruments governing such Indebtedness or Capital Stock (a) apply only in the event of a payment default or a default with respect to a financial covenant in such agreement or instrument or (b) will not materially affect Oasis’ ability to pay all principal, interest and premium, if any, on the notes, in the reasonable good faith judgment of the Chief Executive Officer and Chief Financial Officer of Oasis;

(12) customary provisions restricting subletting or assignment of any lease governing a leasehold interest;

(14) restrictions on cash or other deposits or net worth imposed by customers under contracts entered into in the ordinary course of business; and

(15) with respect only to encumbrances or restrictions of the type referred to in clause (c) of the immediately preceding paragraph:

(a) customary nonassignment provisions (including provisions forbidding subletting) in leases governing leasehold interests or Farm-In Agreements or Farm-Out Agreements relating to leasehold interests in oil and gas properties to the extent such provisions restrict the transfer of the lease, the property leased thereunder or the other interests therein;

(b) provisions limiting the disposition or distribution of assets or property in, or transfer of Capital Stock of, joint venture agreements, asset sale agreements, sale-leaseback agreements, stock sale agreements and other similar agreements entered into (i) in the ordinary course of business, or (ii) with the approval of Oasis’ Board of Directors, which limitations are applicable only to the assets, property or Capital Stock that are the subject of such agreements; and

(c) Capital Lease Obligations, security agreements, mortgages, purchase money agreements or similar instruments to the extent such encumbrance or restriction restricts the transfer of the property (including Capital Stock) subject to such Capital Lease Obligations, security agreements, mortgages, purchase money agreements or similar instruments.

Oasis will not, and will not permit any of its Restricted Subsidiaries to, make any payment to, or sell, lease, transfer or otherwise dispose of any of its properties or assets to, or purchase any property or assets from, or enter into or make or amend any transaction, contract, agreement, understanding, loan, advance or Guarantee with, or for the benefit of, any Affiliate of Oasis (each, an “Affiliate Transaction”), unless:

(1) the Affiliate Transaction is on terms that are no less favorable to Oasis or the relevant Restricted Subsidiary than those that would have been obtained in a comparable transaction by Oasis or such Restricted Subsidiary with a Person that is not an Affiliate of Oasis; and

(a) with respect to any Affiliate Transaction or series of related Affiliate Transactions involving aggregate consideration in excess of $15.0 million, a resolution of the Board of Directors of Oasis set forth in an Officers’ Certificate certifying that such Affiliate Transaction or series of related Affiliate Transactions complies with this covenant and that such Affiliate Transaction or series of related Affiliate Transactions has been approved by a majority of the disinterested members of the Board of Directors of Oasis; and

(b) with respect to any Affiliate Transaction or series of related Affiliate Transactions involving aggregate consideration in excess of $30.0 million, an opinion as to the fairness to Oasis or such Restricted Subsidiary of such Affiliate Transaction or series of related Affiliate Transactions from a financial point of view issued by an accounting, appraisal or investment banking firm of national standing.

The following items will not be deemed to be Affiliate Transactions and, therefore, will not be subject to the provisions of the prior paragraph:

(1) any employment, consulting or similar agreement or arrangement, stock option or stock ownership plan, employee benefit plan, officer or director indemnification agreement, restricted stock agreement, severance agreement or other compensation plan or arrangement entered into by Oasis or any of its Restricted Subsidiaries in the ordinary course of business and payments, awards, grants or issuances of securities pursuant thereto;

(3) transactions with a Person (other than an Unrestricted Subsidiary) that is an Affiliate of Oasis solely because Oasis owns, directly or through a Subsidiary, an Equity Interest in, or controls, such Person;

(4) reasonable fees and expenses and compensation paid to, and indemnity or insurance provided on behalf of, officers, directors or employees of Oasis or any of its Restricted Subsidiaries;

(5) any issuance of Equity Interests (other than Disqualified Stock) of Oasis to, or receipt of a capital contribution from, Affiliates of Oasis;

(6) Restricted Payments that do not violate the provisions of the indenture described above under the caption “—Restricted payments” or any Permitted Investments;

(7) loans or advances to employees in the ordinary course of business or consistent with past practice;

(8) advances to or reimbursements of employees for moving, entertainment and travel expenses, drawing accounts and similar expenditures in the ordinary course of business;

(9) the performance of obligations of Oasis or any of its Restricted Subsidiaries under the terms of any written agreement to which Oasis or any of its Restricted Subsidiaries was a party on the Issue Date, as these agreements may be amended, modified or supplemented from time to time; provided, however, that any future amendment, modification or supplement entered into after the Issue Date will be permitted to the extent that its terms

do not materially and adversely affect the rights of any holders of the notes (as determined in good faith by the Board of Directors of Oasis) as compared to the terms of the agreements in effect on the Issue Date;

(10) (a) guarantees of performance by Oasis and its Restricted Subsidiaries of Unrestricted Subsidiaries in the ordinary course of business, except for Guarantees of Indebtedness in respect of borrowed money, and (b) pledges of Equity Interests of Unrestricted Subsidiaries for the benefit of lenders of Unrestricted Subsidiaries;

(11) transactions between Oasis or any Restricted Subsidiary and any Person, a director of which is also a director of Oasis or any direct or indirect parent company of Oasis and such director is the sole cause for such Person to be deemed an Affiliate of Oasis or any Restricted Subsidiary; provided, however, that such director abstains from voting as director of Oasis or such direct or indirect parent company of Oasis, as the case may be, on any matter involving such other Person; and

(12) transactions with customers, clients, suppliers, or purchasers or sellers of goods or services, in each case in the ordinary course of business and otherwise in compliance with the terms of the indenture, provided that in the reasonable determination of the Board of Directors of Oasis or the senior management of Oasis, such transactions are on terms not materially less favorable to Oasis or the relevant Restricted Subsidiary than those that could reasonably be expected to be obtained in a comparable transaction at such time on an arm’s-length basis from a Person that is not an Affiliate of Oasis.

The Board of Directors of Oasis may designate any Restricted Subsidiary to be an Unrestricted Subsidiary if that designation would not cause a Default. If a Restricted Subsidiary is designated as an Unrestricted Subsidiary, the aggregate Fair Market Value of all outstanding Investments owned by Oasis and its Restricted Subsidiaries in the Subsidiary designated as an Unrestricted Subsidiary will be deemed to be an Investment made as of the time of the designation. That designation will only be permitted if the applicable Restricted Subsidiary meets the definition of an Unrestricted Subsidiary and if such Investment would be permitted at that time, either pursuant to (a) the covenant described above under the caption “—Restricted payments” or (b) the definition of Permitted Investment.

Any designation of a Subsidiary of Oasis as an Unrestricted Subsidiary will be evidenced to the trustee by filing with the trustee a certified copy of a resolution of the Board of Directors of Oasis giving effect to such designation and an Officers’ Certificate certifying that such designation complied with the preceding conditions and was permitted by the covenant described above under the caption “—Restricted payments.” If, at any time, any Unrestricted Subsidiary would fail to meet the requirements of the definition of “Unrestricted Subsidiary” set forth below under “—Definitions,” it will thereafter cease to be an Unrestricted Subsidiary for purposes of the indenture and any Indebtedness of such Subsidiary will be deemed to be incurred by a Restricted Subsidiary as of such date and, if such Indebtedness is not permitted to be incurred as of such date under the covenant described under the caption “—Incurrence of indebtedness and issuance of preferred stock,” Oasis will be in Default of such covenant.

The Board of Directors of Oasis may at any time designate any Unrestricted Subsidiary to be a Restricted Subsidiary; provided that such designation will be deemed to be an incurrence of Indebtedness by a Restricted Subsidiary of any outstanding Indebtedness of such Unrestricted

Subsidiary, and such designation will only be permitted if (1) such Indebtedness is permitted under the covenant described under the caption “—Incurrence of indebtedness and issuance of preferred stock,” calculated on a pro forma basis as if such designation had occurred at the beginning of the four-quarter reference period; and (2) no Default or Event of Default would be in existence following such designation.

Regardless of whether required by the rules and regulations of the SEC, so long as any notes are outstanding, Oasis will file with the SEC for public availability, within the time periods specified in the SEC’s rules and regulations (unless the SEC will not accept such a filing, in which case Oasis will comply with the requirements described in the second succeeding paragraph):

(1) all quarterly and annual reports that would be required to be filed with the SEC on Forms 10-Q and 10-K if Oasis were required to file such reports; and

(2) all current reports that would be required to be filed with the SEC on Form 8-K if Oasis were required to file such reports.

All such reports will be prepared in all material respects in accordance with all of the rules and regulations applicable to such reports. Each annual report on Form 10-K will include a report on Oasis’ consolidated financial statements by Oasis’ certified independent accountants.

If, at any time, Oasis is no longer subject to the periodic reporting requirements of the Exchange Act for any reason, Oasis will nevertheless continue filing the reports specified in the preceding paragraphs of this covenant with the SEC within the time periods specified above unless the SEC will not accept such a filing. Oasis will not take any action for the purpose of causing the SEC not to accept any such filings. If, notwithstanding the foregoing, the SEC will not accept Oasis’ filings for any reason, Oasis will post the reports referred to in the preceding paragraphs on its website within the time periods that would apply if Oasis were required to file those reports with the SEC.

If Oasis has designated any of its Subsidiaries as Unrestricted Subsidiaries, then the quarterly and annual financial information required by the preceding paragraphs will include a reasonably detailed presentation, either on the face of the financial statements or in the footnotes thereto, and in Management’s Discussion and Analysis of Financial Condition and Results of Operations, of the financial condition and results of operations of Oasis and its Restricted Subsidiaries separate from the financial condition and results of operations of the Unrestricted Subsidiaries.

If, after the Issue Date, (a) any Material Domestic Subsidiary that is not already a Subsidiary Guarantor incurs any Indebtedness in excess of a De Minimis Amount, or issues any preferred stock or (b) any Domestic Restricted Subsidiary incurs any Indebtedness whatsoever in respect of obligations under the Senior Credit Agreement, then such Subsidiary (referred to in clause (a) or (b) of this sentence) will become a Subsidiary Guarantor by executing and delivering a supplemental indenture, in the form provided for in the indenture, to the trustee within 30 days of the date on which it incurred such Indebtedness or issued such preferred stock (in each case, referred to in clause (a) or (b) of this sentence). The Subsidiary Guarantee of a Subsidiary Guarantor will be released upon request of the Subsidiary Guarantor at such time as such Subsidiary Guarantor is not liable for any Indebtedness and has no preferred stock outstanding,

as long as at the time of such release, (i) no Default or Event of Default has occurred and is continuing, (ii) the Subsidiary Guarantor is not an obligor party to any undrawn Credit Facility or any Credit Facility under which letters of credit are outstanding or any instrument governing the terms of undrawn Indebtedness or any Guarantee thereof and (iii) the Subsidiary Guarantor has not been liable under any Indebtedness whatsoever during the immediately preceding 181 consecutive days.

Oasis will not (1) consolidate or merge with or into another Person (regardless of whether Oasis is the surviving corporation), convert into another form of entity or continue in another jurisdiction; or (2), directly or indirectly, sell, assign, transfer, lease, convey or otherwise dispose of all or substantially all of its properties or assets, in one or more related transactions, to another Person, unless:

(1) either: (a) Oasis is the surviving corporation; or (b) the Person formed by or surviving any such consolidation or merger or resulting from such conversion (if other than Oasis) or to which such sale, assignment, transfer, lease, conveyance or other disposition has been made is a corporation, limited liability company or limited partnership organized or existing under the laws of the United States, any state of the United States or the District of Columbia;

(2) the Person formed by or surviving any such conversion, consolidation or merger (if other than Oasis) or the Person to which such sale, assignment, transfer, lease, conveyance or other disposition has been made assumes all the obligations of Oasis under the notes and the indenture pursuant to a supplemental indenture reasonably satisfactory to the trustee;

provided that, unless such Person is a corporation, a corporate co-issuer of the notes will be added to the indenture by a supplement reasonably satisfactory to the trustee;

(3) immediately after such transaction or transactions, no Default or Event of Default exists; and

(4) Oasis or the Person formed by or surviving any such consolidation or merger (if other than Oasis), or to which such sale, assignment, transfer, lease, conveyance or other disposition has been made, would (on the date of such transaction after giving pro forma effect thereto and to any related financing transactions as if the same had occurred at the beginning of the applicable four-quarter period) either (a) be permitted to incur at least $1.00 of additional Indebtedness pursuant to the Fixed Charge Coverage Ratio test set forth in the first paragraph of the covenant described above under the caption “—Incurrence of indebtedness and issuance of preferred stock;” or (b) have a Fixed Charge Coverage Ratio that is not less than the Fixed Charge Coverage Ratio of Oasis and its Restricted Subsidiaries immediately before such transaction.

For purposes of this covenant, the sale, assignment, transfer, lease, conveyance or other disposition of all or substantially all of the properties or assets of one or more Subsidiaries of Oasis, which properties or assets, if held by Oasis instead of such Subsidiaries, would constitute all or substantially all of the properties or assets of Oasis on a consolidated basis, shall be deemed to be the transfer of all or substantially all of the properties or assets of Oasis.

The surviving entity will succeed to, and be substituted for, and may exercise every right and power of, Oasis under the indenture; provided, however, that Oasis will not be released from the

obligation to pay the principal of, premium, if any, and interest on the notes in the case of a lease of all or substantially all of Oasis’ properties or assets in a transaction that is subject to, and that complies with the provisions of, this covenant.

Notwithstanding the restrictions described in the foregoing clause (4), any Restricted Subsidiary may consolidate with, merge into or dispose of all or part of its properties or assets to Oasis, Oasis may merge into a Restricted Subsidiary for the purpose of reincorporating Oasis in another jurisdiction, and any Restricted Subsidiary may consolidate with, merge into or dispose of all or part of its properties or assets to another Restricted Subsidiary.

Although there is a limited body of case law interpreting the phrase “substantially all,” there is no precise established definition of the phrase under applicable law. Accordingly, in certain circumstances there may be a degree of uncertainty as to whether a particular transaction would involve “all or substantially all” of the properties or assets of a Person.

From and after the occurrence of an Investment Grade Rating Event, we and our Restricted Subsidiaries will no longer be subject to the following provisions of the indenture (collectively, the “Terminated Covenants”):

(a) clause (4) of the covenant described under “Covenants—Merger, consolidation or sale of substantially all assets” and

(b) the provisions of the indenture described above under the following headings:

Furthermore, after an Investment Grade Rating Event, Oasis may not designate any of its Subsidiaries as Unrestricted Subsidiaries.

Consequently, after the date on which we and our Restricted Subsidiaries are no longer subject to the Terminated Covenants, the notes will be entitled to substantially reduced covenant protection. However, we and our Restricted Subsidiaries will remain subject to all other covenants in the indenture, including those described above under “—Repurchase at the option of holders—Change of control” and “—Covenants—Subsidiary guarantees.”

Under the indenture, each of the following will constitute an “Event of Default” with respect to the notes:

(2) default in the payment when due of the principal of, or premium, if any, on the notes;

(3) failure by Oasis to comply with its obligations under “—Covenants—Merger, consolidation or sale of substantially all assets” or to consummate a purchase of notes when required pursuant to the covenants described under the caption “—Repurchase at the option of holders;”

(4) failure by Oasis or any of its Restricted Subsidiaries for 30 days after written notice from the trustee or the holders of at least 25% in aggregate principal amount of the then outstanding notes to comply with the provisions described under the captions “—Covenants—Restricted payments” or “—Covenants—Incurrence of indebtedness and issuance of preferred stock” or to comply with the provisions described under the captions “—Repurchase at the option of holders” to the extent not described in clause (3) above;

(5) failure by Oasis or any of its Restricted Subsidiaries for 60 days (or 180 days in the case of a Reporting Failure) after written notice from the trustee or the holders of at least 25% in aggregate principal amount of the then outstanding notes to comply with any of the other agreements in the indenture or the notes;

(6) default under any mortgage, indenture or instrument under which there may be issued or by which there may be secured or evidenced any Indebtedness for money borrowed by Oasis or any of its Restricted Subsidiaries (or the payment of which is Guaranteed by Oasis or any of its Restricted Subsidiaries), other than Indebtedness owed to Oasis or any of its Restricted Subsidiaries, whether such Indebtedness or Guarantee now exists, or is created after the Issue Date, which default:

(a) is caused by a failure to pay principal of, or interest or premium, if any, on such Indebtedness prior to the expiration of the grace period provided in such Indebtedness (“Payment Default”); or

and, in each case, the principal amount of any such Indebtedness, together with the principal amount of any other such Indebtedness under which there has been a Payment Default or the maturity of which has been so accelerated, aggregates $10.0 million or more;

(7) failure by Oasis or any Significant Subsidiary or group of Oasis’ Restricted Subsidiaries that, taken together (as of the latest audited consolidated financial statements for Oasis and its Restricted Subsidiaries), would constitute a Significant Subsidiary to pay final judgments aggregating in excess of $10.0 million (net of any amounts that a reputable and creditworthy insurance company has acknowledged liability for in writing), which judgments are not paid, discharged or stayed for a period of 60 days;

(8) except as permitted by the indenture, any Subsidiary Guarantee is held in a judicial proceeding to be unenforceable or invalid or ceases for any reason to be in full force and effect, or any Subsidiary Guarantor, or any Person acting on behalf of any Subsidiary Guarantor, denies or disaffirms its obligations under its Subsidiary Guarantee; or

(9) certain events of bankruptcy, insolvency or reorganization with respect to Oasis or a Significant Subsidiary or group of Restricted Subsidiaries that, taken together (as of the latest audited consolidated financial statements for Oasis and its Restricted Subsidiaries), would constitute a Significant Subsidiary.

The indenture will provide that in the case of an Event of Default arising from certain events of bankruptcy or insolvency with respect to Oasis, any Restricted Subsidiary that is a Significant Subsidiary or any group of Restricted Subsidiaries that, taken together, would constitute a Significant Subsidiary, all then outstanding notes will become due and payable immediately without further action or notice. However, the effect of such provision may be limited by applicable law. If any other Event of Default occurs and is continuing, the trustee or the holders

of at least 25% in aggregate principal amount of the then outstanding notes may declare all of the notes to be due and payable immediately by notice in writing to Oasis and, in case of a notice by holders, also to the trustee specifying the respective Event of Default and that it is a notice of acceleration.

Subject to certain limitations, holders of a majority in aggregate principal amount of the then outstanding notes may direct the trustee in its exercise of any trust or power with respect to the notes. The trustee may withhold from holders of the notes notice of any continuing Default or Event of Default if it determines that withholding notice is in their interest, except a Default or Event of Default relating to the payment of principal, interest or premium, if any.

Subject to the provisions of the indenture relating to the duties of the trustee in case an Event of Default occurs and is continuing, the trustee will be under no obligation to exercise any of the rights or powers under the indenture at the request or direction of any holders of notes unless such holders have offered to the trustee reasonable indemnity or security against any loss, liability or expense. Except to enforce the right to receive payment of principal, premium, if any, or interest, when due, no holder of a note may pursue any remedy with respect to the indenture or the notes unless:

(a) such holder has previously given the trustee notice of a continuing Event of Default;

(b) holders of at least 25% in aggregate principal amount of the then outstanding notes have made a written request to the trustee to pursue the remedy;

(d) the trustee has not complied with such request within 60 days after the receipt of the request and the offer of security or indemnity; and

(e) holders of a majority in aggregate principal amount of the then outstanding notes have not given the trustee a direction that is inconsistent with such request within such 60-day period.

The holders of a majority in aggregate principal amount of the then outstanding notes by notice to the trustee may, on behalf of the holders of all of the notes, rescind an acceleration or waive any existing Default or Event of Default and its consequences under the indenture except a continuing Default or Event of Default in the payment of interest or premium, if any, on, or the principal of, the notes.

Notwithstanding the foregoing, if an Event of Default specified in clause (6) above shall have occurred and be continuing, such Event of Default and any consequential acceleration (to the extent not in violation of any applicable law or in conflict with any judgment or decree of a court of competent jurisdiction) shall be automatically rescinded if (a) (i) the Indebtedness that is the subject of such Event of Default has been repaid or (ii) if the default relating to such Indebtedness is waived by the holders of such Indebtedness or cured and if such Indebtedness has been accelerated, then the holders thereof have rescinded their declaration of acceleration in respect of such Indebtedness, in each case within 20 days after the declaration of acceleration with respect thereto, and (b) any other existing Events of Default, except nonpayment of principal, premium, if any, or interest on the Notes that became due solely because of the acceleration of the Notes, have been cured or waived.

Oasis is required to deliver to the trustee annually an Officers’ Certificate regarding compliance with the indenture. Upon becoming aware of any Default or Event of Default, Oasis is required within five Business Days to deliver to the trustee a statement specifying such Default or Event of Default.

No director, officer, employee, incorporator, stockholder, member, manager or partner of Oasis or any Subsidiary Guarantor, as such, will have any liability for any obligations of Oasis or the Subsidiary Guarantors under the notes, the indenture, the Subsidiary Guarantees or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each holder of notes by accepting a note waives and releases all such liability. The waiver and release are part of the consideration for issuance of the notes. The waiver may not be effective to waive liabilities under the federal securities laws.

Oasis may, at any time, at the option of its Board of Directors evidenced by a resolution set forth in an Officers’ Certificate, elect to have all of its obligations discharged with respect to the outstanding notes and all obligations of the Subsidiary Guarantors discharged with respect to their Subsidiary Guarantees (“Legal Defeasance”) except for:

(1) the rights of holders of outstanding notes to receive payments in respect of the principal of, or interest or premium, if any, on such notes when such payments are due from the trust referred to below;

(2) Oasis’ obligations with respect to the notes concerning issuing temporary notes, registration of notes, mutilated, destroyed, lost or stolen notes and the maintenance of an office or agency for payment and money for security payments held in trust;

(3) the rights, powers, trusts, duties and immunities of the trustee, and Oasis’ and the Subsidiary Guarantors’ obligations in connection therewith; and

In addition, Oasis may, at its option and at any time, elect to have the obligations of Oasis and the Subsidiary Guarantors released with respect to the provisions of the indenture described above under “—Repurchase at the option of holders” and under “—Covenants” (other than the covenant described under “—Covenants—Merger, consolidation or sale of substantially all assets,” except to the extent described below) and the limitation imposed by clause (4) under “—Covenants—Merger, consolidation or sale of substantially all assets” (such release and termination being referred to as “Covenant Defeasance”), and thereafter any omission to comply with such obligations or provisions will not constitute a Default or Event of Default with respect to the notes. In the event Covenant Defeasance occurs in accordance with the indenture, the Events of Default described under clauses (3) through (7) under the caption “—Events of default” and the Event of Default described under clause (9) under the caption “—Events of default” (but only with respect to Subsidiaries of Oasis), in each case, will no longer constitute an Event of Default with respect to the notes. In addition, upon the occurrence of Covenant Defeasance all obligations of the Subsidiary Guarantors with respect to their Subsidiary Guarantees will be discharged.

(1) Oasis must irrevocably deposit with the trustee, in trust, for the benefit of the holders of the notes, cash in U.S. dollars, non-callable Government Securities, or a combination of cash in U.S. dollars and non-callable Government Securities, in amounts as will be sufficient, in the opinion of a nationally recognized investment bank, appraisal firm or firm of independent public accountants to pay the principal of, or interest and premium, if any, on the outstanding notes on the stated date for payment thereof or on the applicable redemption date, as the case may be, and Oasis must specify whether the notes are being defeased to such stated date for payment or to a particular redemption date;

(2) in the case of Legal Defeasance, Oasis must deliver to the trustee an opinion of counsel reasonably acceptable to the trustee confirming that (a) Oasis has received from, or there has been published by, the Internal Revenue Service a ruling or (b) since the Issue Date, there has been a change in the applicable U.S. federal income tax law, in either case to the effect that, and based thereon such opinion of counsel will confirm that, the holders of the outstanding notes will not recognize income, gain or loss for U.S. federal income tax purposes as a result of such Legal Defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner and at the same times as would have been the case if such Legal Defeasance had not occurred;

(3) in the case of Covenant Defeasance, Oasis has delivered to the trustee an opinion of counsel reasonably acceptable to the trustee confirming that the holders of the outstanding notes will not recognize income, gain or loss for U.S. federal income tax purposes as a result of such Covenant Defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner and at the same times as would have been the case if such Covenant Defeasance had not occurred;

(4) no Default or Event of Default has occurred and is continuing on the date of such deposit (other than a Default or Event of Default resulting from the borrowing of funds to be applied to such deposit or the grant of Liens securing such borrowing);

(5) such Legal Defeasance or Covenant Defeasance and the related deposit will not result in a breach or violation of, or constitute a default under, any material agreement or instrument (other than the indenture) to which Oasis or any of its Subsidiaries is a party or by which Oasis or any of its Subsidiaries is bound;

(6) Oasis must deliver to the trustee an Officers’ Certificate stating that the deposit was not made by Oasis with the intent of preferring the holders of notes over the other creditors of Oasis with the intent of defeating, hindering, delaying or defrauding any creditors of Oasis or others;

(7) Oasis must deliver to the trustee an Officers’ Certificate, stating that all conditions precedent set forth in clauses (1) through (6) of this paragraph have been complied with; and

(8) Oasis must deliver to the trustee an opinion of counsel, stating that all conditions precedent set forth in clauses (2), (3) and (5) of this paragraph have been complied with.

Except as provided in the next two succeeding paragraphs, the indenture, the debt securities issued thereunder (including the notes) or any Guarantee thereof may be amended or supplemented with the consent of the holders of a majority in aggregate principal amount of the

then-outstanding debt securities of each series affected by such amendment or supplemental indenture, with each such series voting as a separate class (including, without limitation, consents obtained in connection with a purchase of, or tender offer or exchange offer for, debt securities) and, subject to certain exceptions relating to waivers of past Defaults and rights of holders of notes to receive payment, any existing Default or Event of Default or compliance with any provision of the indenture or the debt securities issued thereunder (including the notes) or any Guarantee thereof may be waived with respect to each series of debt securities with the consent of the holders of a majority in aggregate principal amount of the then- outstanding debt securities of such series voting as a separate class (including, without limitation, consents obtained in connection with a purchase of, or tender offer or exchange offer for, debt securities).

Without the consent of each holder of the outstanding debt securities affected, an amendment, supplement or waiver may not (with respect to any notes held by a non-consenting holder):

(1) change the Stated Maturity of the principal of, or any installment of principal of or interest on, any debt security, or reduce the principal amount thereof or the rate of interest thereon or any premium payable upon the redemption thereof, or reduce the amount of the principal of an original issue discount security that would be due and payable upon a declaration of acceleration of the maturity thereof pursuant to the indenture, or change any place of payment where, or the coin or currency in which, any debt security or any premium or the interest thereon is payable, or impair the right to institute suit for the enforcement of any such payment on or after the Stated Maturity thereof (or, in the case of redemption, on or after the redemption date therefor);

(2) reduce the percentage in principal amount of the then-outstanding debt securities of any series, the consent of whose holders is required for any such amendment, supplement or waiver;

(3) modify any of the provisions set forth in (i) the provisions of the indenture related to the holder’s unconditional right to receive principal, premium, if any, and interest on the debt securities or (ii) the provisions of the indenture related to the waiver of past Defaults under such indenture except to increase any such percentage or to provide that certain other provisions of such indenture cannot be modified or waived without the consent of the holder of each then-outstanding debt security affected thereby;

(4) waive a redemption payment with respect to any debt security; provided, however, that any purchase or repurchase of debt securities shall not be deemed a redemption of the debt securities;

(5) release any Subsidiary Guarantor from any of its obligations under its Subsidiary Guarantee or the indenture, except in accordance with the terms of such indenture (as supplemented by any supplemental indenture); or

(6) make any change in the foregoing amendment and waiver provisions of the indenture.

Notwithstanding the foregoing, without the consent of any holder of debt securities, Oasis, the Subsidiary Guarantors (if any) and the trustee may amend or supplement the indenture or the debt securities or the Guarantees thereof issued thereunder to:

(1) cure any ambiguity or defect or to correct or supplement any provision therein that may be inconsistent with any other provision therein;

(2) evidence the succession of another Person to Oasis and the assumption by any such successor of the covenants of Oasis therein and, to the extent applicable, to the debt securities;

(3) provide for uncertificated notes in addition to or in place of certificated notes;

(4) add a Subsidiary Guarantee and cause any Person to become a Subsidiary Guarantor, and/or to evidence the succession of another Person to a Subsidiary Guarantor and the assumption by any such successor of the Subsidiary Guarantee of such Subsidiary Guarantor therein;

(6) add to the covenants of Oasis such further covenants, restrictions, conditions or provisions as Oasis shall consider to be appropriate for the benefit of the holders of all or any series of debt securities (and if such covenants, restrictions, conditions or provisions are to be for the benefit of less than all series of debt securities, stating that such covenants are expressly being included solely for the benefit of such series) or to surrender any right or power therein conferred upon Oasis and to make the occurrence, or the occurrence and continuance, of a Default in any such additional covenants, restrictions, conditions or provisions an Event of Default permitting the enforcement of all or any of the several remedies provided in the indenture as set forth therein; provided, that in respect of any such additional covenant, restriction, condition or provision, such supplemental indenture may provide for a particular period of grace after Default (which period may be shorter or longer than that allowed in the case of other Defaults) or may provide for an immediate enforcement upon such an Event of Default or may limit the remedies available to the trustee upon such an Event of Default or may limit the right of the holders of a majority in aggregate principal amount of the debt securities of such series to waive such an Event of Default;

(7) make any change to any provision of the indenture that would provide any additional rights or benefits to the holders of the debt securities issued thereunder or that does not adversely affect the rights or interests of any such holder;

(8) provide for the issuance of additional debt securities in accordance with the provisions set forth in the indenture on the date of such indenture;

(9) add any additional Defaults or Events of Default in respect of all or any series of debt securities;

(10) change or eliminate any of the provisions of the indenture; provided that any such change or elimination shall become effective only when there is no debt security outstanding of any series created prior to the execution of such supplemental indenture that is entitled to the benefit of such provision;

(11) establish the form or terms of debt securities of any series as permitted thereunder, including to reopen any series of any debt securities as permitted thereunder;

(12) evidence and provide for the acceptance of appointment thereunder by a successor trustee with respect to the debt securities of one or more series and to add to or change any of the provisions of the indenture as shall be necessary to provide for or facilitate the administration of the trusts thereunder by more than one trustee, pursuant to the requirements of such indenture;

(13) conform the text of the indenture (and/or any supplemental indenture) or any debt securities issued thereunder to any provision of a description of such debt securities appearing in a prospectus or prospectus supplement or an offering memorandum or offering circular pursuant to which such debt securities were offered to the extent that such provision was intended to be a verbatim recitation of a provision of such indenture (and/or any supplemental indenture) or any debt securities or Guarantees issued thereunder;

(14) add a corporate co-issuer in accordance with the covenant set forth under the caption “—Covenants—Merger, consolidation or sale of substantially all assets;” or

(15) modify, eliminate or add to the provisions of the indenture to such extent as shall be necessary to effect the qualification of such indenture under the Trust Indenture Act, or under any similar federal statute subsequently enacted, and to add to such indenture such other provisions as may be expressly required under the Trust Indenture Act.

The consent of the holders is not necessary under the indenture to approve the particular form of any proposed amendment, supplement or waiver, but it is sufficient if such consent approves the substance thereof. After an amendment, supplement or waiver under the indenture requiring approval of the holders becomes effective, Oasis shall mail to the holders of debt securities affected thereby a notice briefly describing such amendment, supplement or waiver. However, the failure to give such notice to all such holders, or any defect therein, will not impair or affect the validity of the applicable amendment, supplement or waiver.

The indenture will be discharged and will cease to be of further effect as to all notes issued thereunder (except as to surviving rights of registration of transfer or exchange of the notes and as otherwise specified in the indenture), when:

(a) all notes that have been authenticated, except lost, stolen or destroyed notes that have been replaced or paid and notes for whose payment money has been deposited in trust and thereafter repaid to Oasis, have been delivered to the trustee for cancellation; or

(b) all notes that have not been delivered to the trustee for cancellation have become due and payable by reason of the mailing of a notice of redemption or otherwise or will become due and payable within one year and Oasis or any Subsidiary Guarantor has irrevocably deposited or caused to be deposited with the trustee as trust funds in trust solely for the benefit of the holders, cash in U.S. dollars, non-callable Government Securities, or a combination of cash in U.S. dollars and non-callable Government Securities, in amounts as will be sufficient, without consideration of any reinvestment of interest, to pay and discharge the entire Indebtedness on the notes not delivered to the trustee for cancellation for principal, premium, if any, and accrued interest to the date of maturity or redemption;

(2) no Default or Event of Default has occurred and is continuing on the date of the deposit (other than a Default or Event of Default resulting from the borrowing of funds to be applied to such deposit or the grant of Liens securing such borrowing);

(3) such deposit will not result in a breach or violation of, or constitute a default under, any material agreement or instrument (other than the indenture) to which Oasis or any Subsidiary Guarantor is a party or by which Oasis or any Subsidiary Guarantor is bound;

(4) Oasis or any Subsidiary Guarantor has paid or caused to be paid all sums payable by it under the indenture; and

(5) Oasis has delivered irrevocable instructions to the trustee to apply the deposited money toward the payment of the notes at maturity or on the redemption date, as the case may be.

In addition, Oasis must deliver to the trustee (a) an Officers’ Certificate, stating that all conditions precedent set forth in clauses (1) through (5) above have been satisfied and (b) an opinion of counsel, stating that all conditions precedent set forth in clauses (3) and (5) above have been satisfied.

If the trustee becomes a creditor of Oasis or any Subsidiary Guarantor, the indenture will limit the right of the trustee to obtain payment of claims in certain cases, or to realize on certain property received in respect of any such claim as security or otherwise. The trustee will be permitted to engage in other transactions; however, if it acquires any conflicting interest (as defined in the Trust Indenture Act) after a Default has occurred and is continuing, it must eliminate such conflict within 90 days, apply to the SEC for permission to continue as trustee (if the indenture has been qualified under the Trust Indenture Act) or resign.

The holders of a majority in aggregate principal amount of the then outstanding notes will have the right to direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee, subject to certain exceptions. If an Event of Default occurs and is continuing, the trustee will be required, in the exercise of its powers, to use the degree of care of a prudent man in the conduct of his own affairs. Subject to such provisions, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any holder of notes, unless such holder has offered to the trustee reasonable security or indemnity against any loss, liability or expense.

The indenture, the notes and the Subsidiary Guarantees will be governed by the laws of the State of New York.

Notes will be issued either in registered, global form or in registered, certificated form in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof. Notes will be issued at the closing of this offering only against payment in immediately available funds.

Initially, all Notes will be represented by one or more notes in registered, global form without interest coupons (collectively, the “Global Notes”). The Global Notes will be deposited upon issuance with the trustee as custodian for The Depository Trust Company (“DTC”), and registered in the name of DTC or its nominee, in each case for credit to an account of a direct or indirect participant in DTC as described below. Beneficial interests in the Global Notes may be held through Euroclear Bank S.A./N.V. as the operator of the Euroclear System (“Euroclear”), and Clearstream Banking société anonyme (“Clearstream”) (as indirect participants in DTC).

Except as set forth below, the Global Notes may be transferred, in whole and not in part, only to another nominee of DTC or to a successor of DTC or its nominee. Beneficial interests in the Global Notes may not be exchanged for definitive notes in registered certificated form (“Certificated Notes”) except in the limited circumstances described below. See “—Exchange of global notes for certificated notes.” Except in the limited circumstances described below, owners of beneficial interests in the Global Notes will not be entitled to receive physical delivery of notes in certificated form.

Transfers of beneficial interests in the Global Notes will be subject to the applicable rules and procedures of DTC and its direct or indirect participants (including, if applicable, those of Euroclear and Clearstream), which may change from time to time.

The following description of the operations and procedures of DTC, Euroclear and Clearstream are provided solely as a matter of convenience. These operations and procedures are solely within the control of the respective settlement systems and are subject to changes by them. Oasis takes no responsibility for these operations and procedures and urges investors to contact the system or their participants directly to discuss these matters.

DTC has advised Oasis that DTC is a limited-purpose trust company created to hold securities for its participating organizations (collectively, the “Participants”) and to facilitate the clearance and settlement of transactions in those securities between the Participants through electronic book-entry changes in accounts of its Participants. The Participants include securities brokers and dealers (including the underwriters), banks, trust companies, clearing corporations and certain other organizations. Access to DTC’s system is also available to other entities such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a Participant, either directly or indirectly (collectively, the “Indirect Participants”). Persons who are not Participants may beneficially own securities held by or on behalf of DTC only through the Participants or the Indirect Participants. The ownership interests in, and transfers of ownership interests in, each security held by or on behalf of DTC are recorded on the records of the Participants and Indirect Participants.

(1) upon deposit of the Global Notes, DTC will credit the accounts of the Participants designated by the underwriters with portions of the principal amount of the Global Notes; and

(2) ownership of these interests in the Global Notes will be shown on, and the transfer of ownership of these interests will be effected only through, records maintained by DTC (with respect to the Participants) or by the Participants and the Indirect Participants (with respect to other owners of beneficial interests in the Global Notes).

Investors in the Global Notes who are Participants may hold their interests therein directly through DTC. Investors in the Global Notes who are not Participants may hold their interests therein indirectly through organizations (including Euroclear and Clearstream) which are Participants. Euroclear and Clearstream may hold interests in the Global Notes on behalf of their participants through customers’ securities accounts in their respective names on the books of their respective depositories, which are Euroclear Bank S.A./N.V., as operator of Euroclear, and Citibank, N.A., as operator of Clearstream. All interests in a Global Note, including those held

through Euroclear or Clearstream, may be subject to the procedures and requirements of DTC. Those interests held through Euroclear or Clearstream may also be subject to the procedures and requirements of such systems. The laws of some states require that certain Persons take physical delivery in definitive form of securities that they own. Consequently, the ability to transfer beneficial interests in a Global Note to such Persons will be limited to that extent. Because DTC can act only on behalf of the Participants, which in turn act on behalf of the Indirect Participants, the ability of a Person having beneficial interests in a Global Note to pledge such interests to Persons that do not participate in the DTC system, or otherwise take actions in respect of such interests, may be affected by the lack of a physical certificate evidencing such interests.

Except as described below, beneficial owners of interests in the Global Notes will not have notes registered in their names, will not receive physical delivery of Certificated Notes and will not be considered the registered owners or “holders” thereof under the indenture for any purpose.

Payments in respect of the principal of, and interest and premium, if any, on a Global Note registered in the name of DTC or its nominee will be payable to DTC in its capacity as the registered holder under the indenture. Under the terms of the indenture, Oasis, the Subsidiary Guarantors and the trustee will treat the Persons in whose names the notes, including the Global Notes, are registered as the owners thereof for the purpose of receiving payments and for all other purposes. Consequently, neither Oasis, the Subsidiary Guarantors, the trustee nor any agent of any of them has or will have any responsibility or liability for:

(1) any aspect of DTC’s records or any Participant’s or Indirect Participant’s records relating to or payments made on account of beneficial ownership interest in the Global Notes or for maintaining, supervising or reviewing any of DTC’s records or any Participant’s or Indirect Participant’s records relating to the beneficial ownership interests in the Global Notes; or

(2) any other matter relating to the actions and practices of DTC or any of its Participants or Indirect Participants.

DTC has advised Oasis that its current practice, at the due date of any payment in respect of securities such as the notes (including principal and interest), is to credit the accounts of the relevant Participants with the payment on the payment date unless DTC has reason to believe that it will not receive payment on such payment date. Each relevant Participant is credited with an amount proportionate to its beneficial ownership of an interest in the principal amount of the relevant security as shown on the records of DTC. Payments by the Participants and the Indirect Participants to the beneficial owners of notes will be governed by standing instructions and customary practices and will be the responsibility of the Participants or the Indirect Participants and will not be the responsibility of DTC, the trustee or Oasis. Neither Oasis nor the trustee will be liable for any delay by DTC or any of its Participants in identifying the beneficial owners of the notes, and Oasis and the trustee may conclusively rely on and will be protected in relying on instructions from DTC or its nominee for all purposes.

Transfers between Participants in DTC will be effected in accordance with DTC’s procedures, and will be settled in same-day funds, and transfers between participants in Euroclear and Clearstream will be effected in accordance with their respective rules and operating procedures.

Cross-market transfers between the Participants in DTC, on the one hand, and Euroclear or Clearstream participants, on the other hand, will be effected through DTC in accordance with DTC’s rules on behalf of Euroclear or Clearstream, as the case may be, by its depository; however, such cross-market transactions will require delivery of instructions to Euroclear or Clearstream, as

the case may be, by the counterparty in such system in accordance with the rules and procedures and within the established deadlines (Brussels time) of such system. Euroclear or Clearstream, as the case may be, will, if the transaction meets its settlement requirements, deliver instructions to its depository to take action to effect final settlement on its behalf by delivering or receiving interests in the relevant Global Note in DTC, and making or receiving payment in accordance with normal procedures for same-day funds settlement applicable to DTC. Euroclear participants and Clearstream participants may not deliver instructions directly to the depositories for Euroclear or Clearstream.

DTC has advised Oasis that it will take any action permitted to be taken by a holder of notes only at the direction of one or more Participants to whose account DTC has credited the interests in the Global Notes and only in respect of such portion of the aggregate principal amount of the notes as to which such Participant or Participants has or have given such direction. However, if there is an Event of Default under the notes, DTC reserves the right to exchange the Global Notes for legended notes in certificated form, and to distribute such notes to its Participants.

Although DTC, Euroclear and Clearstream have agreed to the foregoing procedures to facilitate transfers of interests in the Global Notes among participants in DTC, Euroclear and Clearstream, they are under no obligation to perform or to continue to perform such procedures, and may discontinue such procedures at any time. Neither Oasis nor the trustee nor any of their respective agents will have any responsibility for the performance by DTC, Euroclear or Clearstream or their respective participants or indirect participants of their respective obligations under the rules and procedures governing their operations.

(1) DTC (a) notifies Oasis that it is unwilling or unable to continue as depositary for the Global Note or (b) has ceased to be a clearing agency registered under the Exchange Act, and in each case Oasis fails to appoint a successor depositary within 90 days;

(2) Oasis, at its option, notifies the trustee in writing that it elects to cause the issuance of Certificated Notes (DTC has advised Oasis that, in such event, under its current practices, DTC would notify its Participants of Oasis’ request, but will only withdraw beneficial interests from a Global Note at the request of each Participant); or

(3) a Default or Event of Default has occurred and is continuing and DTC notifies the trustee of its decision to exchange the Global Note for Certificated Notes.

In addition, beneficial interests in a Global Note may be exchanged for Certificated Notes upon prior written notice given to the trustee by or on behalf of DTC in accordance with the indenture. In all cases, Certificated Notes delivered in exchange for any Global Note or beneficial interests in Global Notes will be registered in the names, and issued in any approved denominations, requested by or on behalf of the depositary (in accordance with its customary procedures).

Certificated Notes may not be exchanged for beneficial interests in any Global Note.

Oasis will make payments in respect of the notes represented by the Global Notes (including principal, premium, if any, and interest) by wire transfer of immediately available funds to the accounts specified by DTC or its nominee. Oasis will make all payments of principal, interest and premium, if any, with respect to Certificated Notes by wire transfer of immediately available funds to the accounts specified by the holders thereof or, if no such account is specified, by mailing a check to each such holder’s registered address. The notes represented by the Global Notes are expected to trade in DTC’s Same-Day Funds Settlement System, and any permitted secondary market trading activity in such notes will, therefore, be required by DTC to be settled in immediately available funds. Oasis expects that secondary trading in any Certificated Notes will also be settled in immediately available funds.

Because of time zone differences, the securities account of a Euroclear or Clearstream participant purchasing an interest in a Global Note from a Participant in DTC will be credited, and any such crediting will be reported to the relevant Euroclear or Clearstream participant, during the securities settlement processing day (which must be a business day for Euroclear and Clearstream) immediately following the settlement date of DTC. DTC has advised Oasis that cash received in Euroclear or Clearstream as a result of sales of interests in a Global Note by or through a Euroclear or Clearstream participant to a Participant in DTC will be received with value on the settlement date of DTC but will be available in the relevant Euroclear or Clearstream cash account only as of the business day for Euroclear or Clearstream following DTC’s settlement date.

(1) Indebtedness of any other Person existing at the time such other Person is merged with or into or became a Subsidiary of such specified Person, regardless of whether such Indebtedness is incurred in connection with, or in contemplation of, such other Person merging with or into, or becoming a Restricted Subsidiary of, such specified Person, but excluding Indebtedness which is extinguished, retired or repaid in connection with such Person merging with or becoming a Subsidiary of such specified Person; and

(2) Indebtedness secured by a Lien encumbering any asset acquired by such specified Person.

(1) any property or assets (other than Indebtedness and Capital Stock) to be used by Oasis or a Restricted Subsidiary in a Related Business;

(2) the Capital Stock of a Person that becomes a Restricted Subsidiary as a result of the acquisition of such Capital Stock by Oasis or another Restricted Subsidiary;

(3) Capital Stock constituting a minority interest in any Person that at such time is a Restricted Subsidiary; or

(4) Capital Stock of any Restricted Subsidiary; provided that all the Capital Stock of such Subsidiary held by Oasis or any of its Restricted Subsidiaries shall entitle Oasis or such Restricted Subsidiary to not less than a pro rata portion of all dividends or other distributions made by such Subsidiary upon any of such Capital Stock;

provided, however, that, in the case of clauses (2), (3) and (4), such Subsidiary is primarily engaged in a Related Business.

“Adjusted Consolidated Net Tangible Assets” means, with respect to any specified Person or Persons (all of such specified Persons, whether one or more, being referred to in this definition as the “Referent Person”), as of the date of determination (without duplication), the remainder of:

(i) discounted future net revenues from proved oil and gas reserves of such Person and its Restricted Subsidiaries calculated in accordance with SEC guidelines before any provincial, territorial, state, federal or foreign income taxes, as estimated by Oasis in a reserve report prepared as of the end of Oasis’ most recently completed fiscal year for which audited financial statements are available and giving effect to applicable Oil and Natural Gas Hedging Contracts, (A) as increased by, as of the date of determination, the estimated discounted future net revenues from (1) estimated proved oil and gas reserves acquired since such year end, which reserves were not reflected in such year end reserve report, and (2) estimated oil and gas reserves attributable to upward revisions of estimates of proved oil and gas reserves (including previously estimated development costs incurred during the period and the accretion of discount since the prior period end) since such year end due to exploration, development, exploitation or other activities, and (B) as decreased by, as of the date of determination, the estimated discounted future net revenues from (1) estimated proved oil and gas reserves reflected in such reserve report produced or disposed of since such year end, and (2) estimated oil and gas reserves attributable to downward revisions of estimates of proved oil and gas reserves reflected in such reserve report since such year end due to changes in geological conditions or other factors that would, in accordance with standard industry practice, cause such revisions, in each case described in this clause (i) calculated in accordance with SEC guidelines and estimated by Oasis’ petroleum engineers or any independent petroleum engineers engaged by Oasis for that purpose;

(ii) the capitalized costs that are attributable to oil and gas properties of the Referent Person and its Restricted Subsidiaries to which no proved oil and gas reserves are attributable, based on Oasis’ books and records as of a date no earlier than the date of Oasis’ latest available annual or quarterly financial statements;

(iii) the Net Working Capital of the Referent Person on a date no earlier than the date of Oasis’ latest annual or quarterly financial statements; and

(iv) the greater of (A) the net book value of other tangible assets of the Referent Person and its Restricted Subsidiaries, as of a date no earlier than the date of Oasis’ latest annual or quarterly financial statements, and (B) the appraised value, as estimated by independent appraisers, of other tangible assets of the Referent Person and its Restricted Subsidiaries, as of a date no earlier than the date of Oasis’ latest audited financial statements (provided that Oasis shall not be required to obtain such appraisal solely for the purpose of determining this value); minus

(i) the net book value of any Capital Stock of a Restricted Subsidiary of the Referent Person that is not owned by the Referent Person or another Restricted Subsidiary of the Referent Person;

(ii) to the extent not otherwise taken into account in determining Adjusted Consolidated Net Tangible Assets of the Referent Person, any net gas-balancing liabilities of the Referent Person and its Restricted Subsidiaries reflected in Oasis’ latest audited financial statements;

(iii) to the extent included in (a)(i) above, the discounted future net revenues, calculated in accordance with SEC guidelines (utilizing the prices utilized in Oasis’ year-end reserve report), attributable to reserves that are required to be delivered by the Referent Person to third parties to fully satisfy the obligations of the Referent Person and its Restricted Subsidiaries with respect to Volumetric Production Payments (determined, if applicable, using the schedules specified with respect thereto); and

(iv) the discounted future net revenues, calculated in accordance with SEC guidelines, attributable to reserves subject to Dollar-Denominated Production Payments that, based on the estimates of production and price assumptions included in determining the discounted future net revenues specified in (a)(i) above, would be necessary to fully satisfy the payment obligations of the Referent Person and its Subsidiaries with respect to Dollar-Denominated Production Payments (determined, if applicable, using the schedules specified with respect thereto).

If Oasis changes its method of accounting from the successful efforts or a similar method to the full cost method of accounting, “Adjusted Consolidated Net Tangible Assets” of the Referent Person will continue to be calculated as if Oasis were still using the successful efforts or a similar method of accounting.

“Affiliate” of any specified Person means any other Person directly or indirectly controlling or controlled by or under direct or indirect common control with such specified Person. For purposes of this definition, “control,” as used with respect to any Person, means the possession, directly or indirectly, of the power to direct or cause the direction of the management or policies of such Person, whether through the ownership of voting securities, by agreement or otherwise. For purposes of this definition, the terms “controlling,” “controlled by” and “under common control with” have correlative meanings.

(1) the sale, lease, conveyance or other disposition of any assets or rights (including by way of a Production Payment or a sale and leaseback transaction); provided that the sale, lease, conveyance or other disposition of all or substantially all of the assets of Oasis and its Restricted Subsidiaries taken as a whole will be governed by the provisions of the indenture described above under the caption “—Repurchase at the option of holders—Change of control” and/or the provisions described above under the caption “—Covenants—Merger, consolidation or sale of substantially all assets” and not by the provisions of the Asset Sales covenant; and

(2) the issuance of Equity Interests in any of Oasis’ Restricted Subsidiaries (other than directors’ qualifying shares) or the sale of Equity Interests held by Oasis or its Subsidiaries in any of its Subsidiaries.

Notwithstanding the preceding, none of the following items will be deemed to be an Asset Sale:

(1) any single transaction or series of related transactions that involves assets having a Fair Market Value of less than $10.0 million;

(2) a transfer of assets between or among Oasis and its Restricted Subsidiaries;

(3) an issuance of Equity Interests by a Restricted Subsidiary to Oasis or to a Restricted Subsidiary;

(4) the sale, lease or other disposition of equipment, inventory, products, services, accounts receivable or other assets in the ordinary course of business, including in connection with any compromise, settlement or collection of accounts receivable, and any sale or other disposition of damaged, worn-out or obsolete assets or assets that are no longer useful in the conduct of the business of Oasis and its Restricted Subsidiaries;

(6) a Restricted Payment that does not violate the covenant described above under the caption “—Covenants—Restricted payments,” including the issuance or sale of Equity Interests or the sale, lease or other disposition of products, services, equipment, inventory, accounts receivable or other assets pursuant to any such Restricted Payment;

(7) the consummation of a Permitted Investment, including, without limitation, unwinding any Hedging Obligations, and including the issuance or sale of Equity Interests or the sale, lease or other disposition of products, services, equipment, inventory, accounts receivable or other assets pursuant to any such Permitted Investment;

(8) a disposition of Hydrocarbons or mineral products inventory in the ordinary course of business;

(9) the farm-out, lease or sublease of developed or undeveloped crude oil or natural gas properties owned or held by Oasis or any Restricted Subsidiary in exchange for crude oil and natural gas properties owned or held by another Person;

(10) the creation or perfection of a Lien (but not, except as contemplated in clause (11) below, the sale or other disposition of the properties or assets subject to such Lien);

(11) the creation or perfection of a Permitted Lien and the exercise by any Person in whose favor a Permitted Lien is granted of any of its rights in respect of that Permitted Lien;

(12) the licensing or sublicensing of intellectual property, including, without limitation, licenses for seismic data, in the ordinary course of business and which do not materially interfere with the business of Oasis and its Restricted Subsidiaries;

(13) surrender or waiver of contract rights or the settlement, release or surrender of contract, tort or other claims of any kind;

(14) any Production Payments and Reserve Sales; provided that all such Production Payments and Reserve Sales (other than incentive compensation programs on terms that are reasonably customary in the oil and gas business for geologists, geophysicists and other providers of technical services to Oasis or a Restricted Subsidiary) shall have been created, incurred, issued, assumed or Guaranteed in connection with the financing of, and within 60 days after the acquisition of, the oil and gas properties that are subject thereto;

(15) the sale or other disposition (regardless of whether in the ordinary course of business) of oil and gas properties; provided that, at the time of such sale or other disposition, such properties do not have attributed to them any proved reserves; and

(16) any trade or exchange by Oasis or any Restricted Subsidiary of properties or assets used or useful in a Related Business for other properties or assets used or useful in a Related Business owned or held by another Person (including Capital Stock of a Person engaged in a Related Business that is or becomes a Restricted Subsidiary), including any cash or Cash Equivalents necessary in order to achieve and exchange of equivalent value, provided that the Fair Market Value of the properties or assets traded or exchanged by Oasis or such Restricted Subsidiary (including any cash or Cash Equivalents to be delivered by Oasis or such Restricted Subsidiary) is reasonably equivalent to the Fair Market Value of the properties or assets (together with any cash or Cash Equivalents) to be received by Oasis or such Restricted Subsidiary, and provided, further, that any cash received in the transaction must be applied in accordance with the covenant described above under “—Repurchase at the option of holders—Asset Sales” as if such transaction were an Asset Sale.

“Beneficial Owner” has the meaning assigned to such term in Rule 13d-3 and Rule 13d-5 under the Exchange Act, except that in calculating the beneficial ownership of any particular “person” (as that term is used in Section 13(d)(3) of the Exchange Act), such “person” will be deemed to have beneficial ownership of all securities that such “person” has the right to acquire by conversion or exercise of other securities, whether such right is currently exercisable or is exercisable only after the passage of time or upon the occurrence of a subsequent condition. The terms “Beneficially Owns,” “Beneficially Owned” and “Beneficially Owning” will have a corresponding meaning.

(1) with respect to a corporation, the board of directors of the corporation or any committee thereof duly authorized to act on behalf of such board;

(2) with respect to a partnership, the board of directors of the general partner of the partnership;

(3) with respect to a limited liability company, the managers or managing member or members of such limited liability company (as applicable) or any duly authorized committee of managers or managing members (as applicable) thereof; and

(4) with respect to any other Person, the board of directors or duly authorized committee of such Person serving a similar function.

“Capital Lease Obligation” means, at the time any determination is to be made, the amount of the liability in respect of a capital lease that would at that time be required to be capitalized on a balance sheet in accordance with GAAP, and the Stated Maturity thereof shall be the date of the last payment of rent or any other amount due under such lease prior to the first date upon which such lease may be prepaid by the lessee without payment of a penalty.

(2) in the case of an association or business entity, any and all shares, interests, participations, rights or other equivalents (however designated) of corporate stock;

(3) in the case of a partnership or limited liability company, partnership interests (whether general or limited) or membership interests; and

(4) any other interest or participation that confers on a Person the right to receive a share of the profits and losses of, or distributions of assets of, the issuing Person, but excluding from all of the foregoing any debt securities convertible into Capital Stock, regardless of whether such debt securities include any right of participation with Capital Stock.

(2) Government Securities having maturities of not more than one year from the date of acquisition;

(3) marketable general obligations issued by any state of the United States of America or any political subdivision of any such state or any public instrumentality thereof maturing within one year from the date of acquisition thereof and, at the time of acquisition thereof, having a credit rating of “A” or better from either S&P or Moody’s;

(4) certificates of deposit, demand deposit accounts and eurodollar time deposits with maturities of one year or less from the date of acquisition, bankers’ acceptances with maturities not exceeding one year and overnight bank deposits, in each case, with any domestic commercial bank having capital and surplus in excess of $500.0 million and a Thomson Bank Watch Rating of “B” or better;

(5) repurchase obligations with a term of not more than seven days for underlying securities of the types described in clauses (2), (3) and (4) above entered into with any financial institution meeting the qualifications specified in clause (4) above;

(6) commercial paper having one of the two highest ratings obtainable from Moody’s or S&P and, in each case, maturing within one year after the date of acquisition;

(7) money market funds at least 95% of the assets of which constitute Cash Equivalents of the kinds described in clauses (1) through (6) of this definition; and

(8) deposits in any currency available for withdrawal on demand with any commercial bank that is organized under the laws of any country in which Oasis or any Restricted Subsidiary maintains its chief executive office or is engaged in the Related Business; provided that all such deposits are made in such accounts in the ordinary course of business.

(1) any “person” or “group” of related persons (as such terms are used in Section 13(d) of the Exchange Act) is or becomes a Beneficial Owner, directly or indirectly, of more than 50% of the total voting power of the Voting Stock of Oasis (or its successor by merger, consolidation or purchase of all or substantially all of its properties or assets) (for the purposes of this clause, such person or group shall be deemed to Beneficially Own any Voting Stock of Oasis held by an entity, if such person or group Beneficially Owns, directly or indirectly, more than 50% of the voting power of the Voting Stock of such entity);

(2) the first day on which a majority of the members of the Board of Directors of Oasis are not Continuing Directors;

(3) the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets of Oasis and its Restricted Subsidiaries taken as a whole to any “person” (as such term is used in Section 13(d) of the Exchange Act); or

(4) the adoption or approval by the stockholders of Oasis of a plan for the liquidation or dissolution of Oasis.

“Consolidated Cash Flow” means, with respect to any specified Person for any period, the Consolidated Net Income of such Person for such period plus, without duplication:

(1) provision for taxes based on income or profits of such Person and its Restricted Subsidiaries for such period, to the extent that such provision for taxes was deducted in computing such Consolidated Net Income; plus

(2) the Fixed Charges of such Person and its Restricted Subsidiaries for such period, to the extent that such Fixed Charges were deducted in computing such Consolidated Net Income; plus

(3) exploration and abandonment expense (if applicable) to the extent deducted in calculating Consolidated Net Income; plus

(4) depreciation, depletion, amortization (including amortization of intangibles but excluding amortization of prepaid cash expenses that were paid in a prior period), impairment, other non-cash expenses and other non-cash items (excluding any such non-cash expense to the extent that it represents an accrual of or reserve for cash expenses in any future period or amortization of a prepaid cash expense that was paid in a prior period) of such Person and its Restricted Subsidiaries for such period to the extent that such depreciation, depletion, amortization, impairment and other non-cash expenses were deducted in computing such Consolidated Net Income; plus

(5) any interest expense attributable to any Oil and Natural Gas Hedging Contract, to the extent that such interest expense was deducted in computing such Consolidated Net Income; minus

(6) non-cash items increasing such Consolidated Net Income for such period, other than items that were accrued in the ordinary course of business, and minus

(7) the sum of (a) the amount of deferred revenues that are amortized during such period and are attributable to reserves that are subject to Volumetric Production Payments and (b) amounts recorded in accordance with GAAP as repayments of principal and interest pursuant to Dollar-Denominated Production Payments;

in each case, on a consolidated basis and determined in accordance with GAAP. Notwithstanding the preceding sentence, clauses (1) through (5) relating to amounts of a Restricted Subsidiary of the referent Person will be added to Consolidated Net Income to compute Consolidated Cash Flow of such Person only to the extent (and in the same proportion) that the Net Income of such Restricted Subsidiary was included in calculating the Consolidated Net Income of such Person and, to the extent the amounts set forth in clauses (1) through (5) are in excess of those necessary to offset a net loss of such Restricted Subsidiary or if such Restricted Subsidiary has net income for such period included in Consolidated Net Income, only if a corresponding amount would be permitted at the date of determination to be dividended to the referent Person by such Restricted Subsidiary without prior governmental approval (that has not been obtained), pursuant to the terms of its charter and all agreements, instruments, judgments, decrees, orders, statutes, rules and governmental regulations applicable to that Restricted Subsidiary or the holders of its Capital Stock.

“Consolidated Net Income” means, with respect to any specified Person for any period, the aggregate of the Net Income of such Person and its Restricted Subsidiaries for such period, on a consolidated basis, determined in accordance with GAAP; provided that:

(1) the Net Income (but not loss) of any Person that is not a Restricted Subsidiary or that is accounted for by the equity method of accounting will be included only to the extent of the amount of dividends or similar distributions paid in cash to the specified Person or a Restricted Subsidiary of the Person;

(2) the Net Income of any Restricted Subsidiary will be excluded to the extent that the declaration or payment of dividends or similar distributions by that Restricted Subsidiary of that Net Income is not at the date of determination permitted without any prior governmental approval (that has not been obtained) or, directly or indirectly, by operation of the terms of its charter or any agreement, instrument, judgment, decree, order, statute, rule or governmental regulation applicable to that Restricted Subsidiary or its stockholders, members or partners;

(3) the cumulative effect of a change in accounting principles will be excluded;

(4) any gain (loss) realized upon the sale or other disposition of any property, plant or equipment of such Person or its consolidated Restricted Subsidiaries (including pursuant to any sale or leaseback transaction) that is not sold or otherwise disposed of in the ordinary course of business and any gain (loss) realized upon the sale or other disposition of any Capital Stock of any Person will be excluded;

(5) any asset impairment writedowns on oil and gas properties under GAAP or SEC guidelines will be excluded;

(6) any non-cash mark-to-market adjustments to assets or liabilities resulting in unrealized gains or losses in respect of Hedging Obligations (including those resulting from the application of SFAS 133) shall be excluded; and

(7) to the extent deducted in the calculation of Net Income, any non-cash or other charges associated with any premium or penalty paid, write-off of deferred financing costs or other financial recapitalization charges in connection with redeeming or retiring any Indebtedness will be excluded.

“Consolidated Tangible Assets” means, with respect to any Person as of any date, the amount which, in accordance with GAAP, would be set forth under the caption “Total Assets” (or any like caption) on a consolidated balance sheet of such Person and its Restricted Subsidiaries, less all goodwill, patents, tradenames, trademarks, copyrights, franchises, experimental expenses, organization expenses and any other amounts classified as intangible assets in accordance with GAAP.

“Continuing Directors” means, as of any date of determination, any member of the Board of Directors of Oasis who:

(2) was nominated for election or elected to such Board of Directors with the approval of a majority of the Continuing Directors who were members of such Board of Directors at the time of such nomination or election.

“Credit Facilities” means, with respect to Oasis or any of its Restricted Subsidiaries, one or more debt facilities (including, without limitation, the Senior Credit Agreement), commercial paper facilities or Debt Issuances providing for revolving credit loans, term loans, receivables financing (including through the sale of receivables to any lenders, other financiers or to special purpose entities formed to borrow from (or sell such receivables to) any lenders or other financiers against such receivables), letters of credit, bankers’ acceptances, other borrowings or Debt Issuances, in each case, as amended, restated, modified, renewed, extended, refunded, replaced or refinanced (in each case, without limitation as to amount), in whole or in part, from time to time (including through one or more Debt Issuances).

“Currency Agreement” means in respect of a Person any foreign exchange contract, currency swap agreement or other similar agreement as to which such Person is a party or a beneficiary.

“Debt Issuances” means, with respect to Oasis or any Restricted Subsidiary, one or more issuances after the Issue Date of Indebtedness evidenced by notes, debentures, bonds or other similar securities or instruments.

“Default” means any event which is, or after notice or passage of time or both would be, an Event of Default.

“De Minimis Amount” means a principal amount of Indebtedness that does not exceed $1.0 million.

“Disqualified Stock” means any Capital Stock that, by its terms (or by the terms of any security into which it is convertible, or for which it is exchangeable, in each case at the option of the holder of the Capital Stock), or upon the happening of any event, matures or is mandatorily redeemable, pursuant to a sinking fund obligation or otherwise, or redeemable at the option of the holder of the Capital Stock, in whole or in part, on or prior to the date that is 91 days after the date on which the notes mature. Notwithstanding the preceding sentence, any Capital Stock that would constitute Disqualified Stock solely because the holders of the Capital Stock have the right to require Oasis to repurchase or redeem such Capital Stock upon the occurrence of a Change of Control or an Asset Sale will not constitute Disqualified Stock if the terms of such Capital Stock provide that Oasis may not repurchase or redeem any such Capital Stock pursuant to such provisions unless such repurchase or redemption complies with the covenant described above under the caption “—Covenants—Restricted payments.” The amount of Disqualified Stock deemed to be outstanding at any time for purposes of the indenture will be the maximum amount that Oasis and its Restricted Subsidiaries may become obligated to pay upon the maturity of, or pursuant to any mandatory redemption provisions of, such Disqualified Stock, exclusive of accrued dividends.

“Dollar-Denominated Production Payments” means production payment obligations recorded as liabilities in accordance with GAAP, together with all undertakings and obligations in connection therewith.

“Domestic Restricted Subsidiary” means any Restricted Subsidiary that was formed under the laws of the United States or any state of the United States or the District of Columbia or that Guarantees or otherwise provides direct credit support for any Indebtedness of Oasis or any Restricted Subsidiary (other than a Foreign Subsidiary).

“Equity Interests” means Capital Stock and all warrants, options or other rights to acquire Capital Stock (but excluding any debt security that is convertible into, or exchangeable for, Capital Stock).

“Equity Offering” means (1) an offering for cash by Oasis of its Capital Stock (other than Disqualified Stock), or options, warrants or rights with respect to its Capital Stock or (2) a cash contribution to Oasis’ common equity capital from any Person.

“Existing Indebtedness” means Indebtedness of Oasis and its Subsidiaries (other than Indebtedness under the Senior Credit Agreement, the notes and the Subsidiary Guarantees) in existence on the Issue Date, until such amounts are repaid.

“Fair Market Value” means the value that would be paid by a willing buyer to an unaffiliated willing seller in a transaction not involving distress or necessity of either party. Fair Market Value of an asset or property in excess of $10.0 million shall be determined by the Board of Directors of Oasis acting in good faith, whose determination shall be conclusive and evidenced by a resolution of such Board of Directors, and any lesser Fair Market Value may be determined by an officer of Oasis acting in good faith.

“Farm-In Agreement” means an agreement whereby a Person agrees to pay all or a share of the drilling, completion or other expenses of an exploratory or development well (which agreement may be subject to a maximum payment obligation, after which expenses are shared in accordance with the working or participation interests therein or in accordance with the agreement of the parties) or perform the drilling, completion or other operation on such well in exchange for an ownership interest in an oil or gas property.

“Farm-Out Agreement” means a Farm-In Agreement, viewed from the standpoint of the party that transfers an ownership interest to another.

“Fixed Charge Coverage Ratio” means with respect to any specified Person for any four-quarter reference period, the ratio of the Consolidated Cash Flow of such Person for such period to the Fixed Charges of such Person for such period. In the event that the specified Person or any of its Restricted Subsidiaries incurs, assumes, Guarantees, repays, repurchases, redeems, defeases or otherwise discharges any Indebtedness (other than ordinary working capital borrowings) or issues, repurchases or redeems preferred stock subsequent to the commencement of the period for which the Fixed Charge Coverage Ratio is being calculated and on or prior to the date on which the event for which the calculation of the Fixed Charge Coverage Ratio is made (the “Calculation Date”), then the Fixed Charge Coverage Ratio will be calculated giving pro forma effect to such incurrence, assumption, Guarantee, repayment, repurchase, redemption, defeasance or other discharge of Indebtedness, or such issuance, repurchase or redemption of preferred stock, and the use of the proceeds therefrom, as if the same had occurred at the beginning of the applicable four-quarter reference period.

(1) acquisitions that have been made by the specified Person or any of its Restricted Subsidiaries, including through mergers, consolidations or otherwise (including acquisitions of assets used or useful in a Related Business), or any Person or any of its Restricted Subsidiaries acquired by the specified Person or any of its Restricted Subsidiaries, and including in each case any related financing transactions and increases in ownership of Restricted Subsidiaries, during the four-quarter reference period or subsequent to such reference period and on or prior to the Calculation Date will be given pro forma effect as if they had occurred on the first day of the four-quarter reference period, and any Consolidated Cash Flow for such period will be calculated giving pro forma effect to any

operating improvements or cost savings that have occurred or are reasonably expected to occur in the reasonable judgment of the principal accounting officer or Chief Financial Officer of Oasis (regardless of whether those operating improvements or cost savings could then be reflected in pro forma financial statements prepared in accordance with Regulation S-X under the Securities Act or any other regulation or policy of the SEC related thereto);

(2) the Consolidated Cash Flow attributable to discontinued operations, as determined in accordance with GAAP, and operations or businesses (and ownership interests therein) disposed of prior to the Calculation Date, will be excluded;

(3) the Fixed Charges attributable to discontinued operations, as determined in accordance with GAAP, and operations or businesses (and ownership interests therein) disposed of prior to the Calculation Date, will be excluded, but only to the extent that the obligations giving rise to such Fixed Charges will not be obligations of the specified Person or any of its Restricted Subsidiaries following the Calculation Date;

(4) any Person that is a Restricted Subsidiary on the Calculation Date will be deemed to have been a Restricted Subsidiary at all times during such four-quarter period;

(5) any Person that is not a Restricted Subsidiary on the Calculation Date will be deemed not to have been a Restricted Subsidiary at any time during such four-quarter period; and

(6) if any Indebtedness bears a floating rate of interest, the interest expense on such Indebtedness will be calculated as if the rate in effect on the Calculation Date had been the applicable rate for the entire period (taking into account any Hedging Obligation applicable to such Indebtedness, but if the remaining term of such Hedging Obligation is less than 12 months, then such Hedging Obligation shall only be taken into account for that portion of the period equal to the remaining term thereof).

“Fixed Charges” means, with respect to any specified Person for any period, the sum, without duplication, of:

(1) the consolidated interest expense of such Person and its Restricted Subsidiaries for such period, whether paid or accrued (excluding (i) any interest attributable to Production Payments and Reserve Sales, (ii) write-off of deferred financing costs and (iii) accretion of interest charges on future plugging and abandonment obligations, future retirement benefits and other obligations that do not constitute Indebtedness, but including, without limitation, amortization of debt issuance costs and original issue discount, noncash interest payments, the interest component of any deferred payment obligations other than that attributable to any Oil and Natural Gas Hedging Contract, the interest component of all payments associated with Capital Lease Obligations, commissions, discounts and other fees and charges incurred in respect of letter of credit or bankers’ acceptance financings), and net of the effect of all payments made or received pursuant to Interest Rate Agreements; plus

(2) the consolidated interest expense of such Person and its Restricted Subsidiaries that was capitalized during such period; plus

(3) any interest on Indebtedness of another Person that is Guaranteed by the specified Person or one or more of its Restricted Subsidiaries or secured by a Lien on assets of such specified Person or one or more of its Restricted Subsidiaries, regardless of whether such Guarantee or Lien is called upon; plus

(4) all dividends, whether paid or accrued and regardless of whether in cash, on any series of preferred stock of such Person or any of its Restricted Subsidiaries, other than dividends on Equity Interests payable solely in Equity Interests of Oasis (other than Disqualified Stock) or to Oasis or a Restricted Subsidiary,

“Foreign Subsidiary” means any Restricted Subsidiary other than a Domestic Restricted Subsidiary.

“GAAP” means generally accepted accounting principles in the United States, which are in effect from time to time. All ratios and computations based on GAAP contained in the indenture will be computed in conformity with GAAP. At any time after the Issue Date, Oasis may elect to apply International Financial Reporting Standards, or IFRS, accounting principles in lieu of GAAP and, upon any such election, references herein to GAAP shall thereafter be construed to mean IFRS (except as otherwise provided in the indenture); provided that any such election, once made, shall be irrevocable; provided, further, that any calculation or determination in the indenture that requires the application of GAAP for periods that include fiscal quarters ended prior to Oasis’ election to apply IFRS shall remain as previously calculated or determined in accordance with GAAP. Oasis shall give notice of any such election made in accordance with this definition to the trustee and the holders of notes.

“Government Securities” means direct obligations of, or obligations Guaranteed by, the United States of America, and the payment for which the United States pledges its full faith and credit.

“Guarantee” means a guarantee other than by endorsement of negotiable instruments for collection in the ordinary course of business, direct or indirect, in any manner including, without limitation, by way of a pledge of assets or through letters of credit or reimbursement agreements in respect thereof, of all or any part of any Indebtedness (whether arising by virtue of partnership arrangements, or by agreements to keep-well, to purchase assets, goods, securities or services or to take or pay or to maintain financial statement conditions or otherwise), or entered into for purposes of assuring in any other manner the obligee of such Indebtedness of the payment thereof or to protect such obligee against loss in respect thereof (in whole or in part). “Guarantee” used as a verb has a correlative meaning.

“Hedging Obligations” of any Person means the obligations of such Person pursuant to any Interest Rate and Currency Hedges and any Oil and Natural Gas Hedging Contracts.

“Hydrocarbons” means oil, gas, casinghead gas, drip gasoline, natural gasoline, condensate, distillate, liquid hydrocarbons, gaseous hydrocarbons and all constituents, elements or compounds thereof and products refined or processed therefrom.

“Indebtedness” means, with respect to any specified Person, without duplication, any indebtedness of such Person, regardless of whether contingent:

(2) evidenced by bonds, notes, credit agreements, debentures or similar instruments or letters of credit (or reimbursement agreements in respect thereof);

(5) in respect of any Guarantee by such Person of production or payment with respect to a Production Payment (but not any other contractual obligation in respect of such Production Payment);

(6) representing the balance deferred and unpaid of the purchase price of any property or services due more than six months after such property is acquired or such services are completed, except any such balance that constitutes an accrued expense or a trade payable; or

if and to the extent any of the preceding items (other than letters of credit and Interest Rate and Currency Hedges) would appear as a liability upon a balance sheet of the specified Person prepared in accordance with GAAP. In addition, the term “Indebtedness” includes (a) all Indebtedness of any other Person, of the types described above in clauses (1) through (7), secured by a Lien on any asset of the specified Person (regardless of whether such Indebtedness is assumed by the specified Person); provided that the amount of such Indebtedness will be the lesser of (i) the Fair Market Value of such asset at such date of determination and (ii) the amount of such Indebtedness of such other Person, and (b) to the extent not otherwise included, the Guarantee by the specified Person of any Indebtedness of any other Person, of the types described above in clauses (1) through (7) above. Furthermore, the amount of any Indebtedness outstanding as of any date will be the accreted value thereof, in the case of any Indebtedness issued with original issue discount; and the principal amount thereof, together with any interest thereon that is more than 30 days past due, in the case of any other Indebtedness.

Notwithstanding the foregoing, the following shall not constitute “Indebtedness:”

(i) accrued expenses and trade accounts payable arising in the ordinary course of business;

(ii) except as provided in clause (5) of the first paragraph of this definition, any obligation in respect of any Production Payment and Reserve Sales;

(iv) any indebtedness which has been defeased in accordance with GAAP or defeased pursuant to the deposit of cash or Government Securities (in an amount sufficient to satisfy all such indebtedness obligations at maturity or redemption, as applicable, and all payments of interest and premium, if any) in a trust or account created or pledged for the sole benefit of the holders of such indebtedness, and subject to no other Liens, and the other applicable terms of the instrument governing such indebtedness;

(v) oil or natural gas balancing liabilities incurred in the ordinary course of business and consistent with past practice;

(vii) any unrealized losses or charges in respect of Hedging Obligations (including those resulting from the application of the Financial Standards Accounting Board’s Accounting Standards Codification (ASC) 815);

(viii) any obligations in respect of (a) bid, performance, completion, surety, appeal and similar bonds, (b) obligations in respect of bankers’ acceptances, (c) insurance obligations or bonds and other similar bonds and obligations and (d) any Guarantees or letters of credit

functioning as or supporting any of the foregoing bonds or obligations; provided, however, that such bonds or obligations mentioned in subclause (a), (b), (c) or (d) of this clause (viii), are incurred in the ordinary course of the business of Oasis and its Restricted Subsidiaries and do not relate to obligations for borrowed money;

(ix) any Disqualified Stock of Oasis or preferred stock of a Restricted Subsidiary;

(x) any obligation arising from any agreement providing for indemnities, guarantees, purchase price adjustments, holdbacks, contingency payment obligations based on the performance of the acquired or disposed assets or similar obligations (other than Guarantees of Indebtedness) incurred by any Person in connection with the acquisition or disposition of assets; and

(xi) all contracts and other obligations, agreements instruments or arrangements described in clauses (20), (21), (22) and (23) of the definition of “Permitted Liens.”

“Interest Rate Agreement” means with respect to any Person any interest rate protection agreement, interest rate future agreement, interest rate option agreement, interest rate swap agreement, interest rate cap agreement, interest rate collar agreement, interest rate hedge agreement or other similar agreement or arrangement as to which such Person is party or a beneficiary.

“Interest Rate and Currency Hedges” of any Person means the obligations of such Person pursuant to any Interest Rate Agreement or Currency Agreement.

or, if either such entity ceases to rate the notes for reasons outside of the control of Oasis, the equivalent investment grade credit rating from any other Rating Agency.

“Investment Grade Rating Event” means the first day on which (a) the notes have an Investment Grade Rating from at least two Rating Agencies, (b) no Default with respect to the notes has occurred and is then continuing under the indenture and (c) Oasis has delivered to the trustee an Officers’ Certificate certifying as to the satisfaction of the conditions set forth in clauses (a) and (b) of this definition.

“Investments” means, with respect to any Person, all direct or indirect investments by such Person in other Persons (including Affiliates) in the forms of loans (including Guarantees or other obligations, advances or capital contributions (excluding endorsements of negotiable instruments and documents in the ordinary course of business, and commission, travel and similar advances to officers, employees and consultants made in the ordinary course of business), purchases or other acquisitions for consideration of Indebtedness, Equity Interests or other securities, together with all items that are or would be classified as investments on a balance sheet of such Person prepared in accordance with GAAP. If Oasis or any Restricted Subsidiary sells or otherwise disposes of any Equity Interests of any direct or indirect Restricted Subsidiary such that, after giving effect to any such sale or disposition, such Person is no longer a Restricted Subsidiary, Oasis will be deemed to have made an Investment on the date of any such sale or disposition equal to the Fair Market Value of Oasis’ Investments in such Restricted Subsidiary that were not

sold or disposed of in an amount determined as provided in the final paragraph of the covenant described above under the caption “—Covenants—Restricted payments.” The acquisition by Oasis or any Subsidiary of Oasis of a Person that holds an Investment in a third Person will be deemed to be an Investment by Oasis or such Subsidiary in such third Person in an amount equal to the Fair Market Value of the Investments held by the acquired Person in such third Person in an amount determined as provided in the final paragraph of the covenant described above under the caption “—Covenants—Restricted payments.” Except as otherwise provided in the indenture, the amount of an Investment will be determined at the time the Investment is made and without giving effect to subsequent changes in value.

“Issue Date” means the first date on which notes are issued under the indenture.

“Legal Holiday” means a Saturday, a Sunday or a day on which banking institutions in the City of New York or at a place of payment are authorized by law, regulation or executive order to remain closed.

“Lien” means, with respect to any asset, any mortgage, lien, pledge, charge, security interest or encumbrance of any kind in respect of such asset, regardless of whether filed, recorded or otherwise perfected under applicable law, including any conditional sale or other title retention agreement, any lease in the nature thereof, any option or other agreement to sell or give a security interest in and any filing of or agreement to give any financing statement under the Uniform Commercial Code (or equivalent statutes) of any jurisdiction other than a precautionary financing statement respecting a lease not intended as a security agreement.

“Material Domestic Subsidiary” means any Domestic Restricted Subsidiary having Consolidated Tangible Assets that constitute more than 0.5% of Oasis’ Consolidated Tangible Assets.

“Moody’s” means Moody’s Investors Service, Inc. or any successor to the rating agency business thereof.

“Net Income” means, with respect to any specified Person, the net income (loss) of such Person, determined in accordance with GAAP and before any reduction in respect of non-cash preferred stock dividends, excluding, however:

(1) any gain or loss, together with any related provision for taxes on such gain or loss, realized in connection with: (a) any Asset Sale (including, without limitation, any cash received pursuant to any sale and leaseback transaction) or (b) the disposition of any securities by such Person or the extinguishment of any Indebtedness of such Person; and

(2) any extraordinary gain or loss, together with any related provision for taxes on such extraordinary gain or loss.

“Net Proceeds” means the aggregate cash proceeds received by Oasis or any of its Restricted Subsidiaries in respect of any Asset Sale (including, without limitation, any cash received upon the sale or other disposition of any non-cash consideration received in any Asset Sale), net of:

(1) all legal, accounting, investment banking, title and recording tax expenses, commissions and other fees and expense incurred, and all federal, state, provincial, foreign and local taxes required to be paid or accrued as a liability under GAAP (after taking into account any available tax credits or deductions and any tax sharing agreements), as a consequence of such Asset Sale;

(2) all payments made on any Indebtedness which is secured by any assets subject to such Asset Sale, in accordance with the terms of such Indebtedness, or which must by its terms, or in order to obtain a necessary consent to such Asset Sale, or by applicable law be repaid out of the proceeds from such Asset Sale;

(3) all distributions and other payments required to be made to holders of minority interests in Subsidiaries or joint ventures as a result of such Asset Sale; and

(4) the deduction of appropriate amounts to be provided by the seller as a reserve, in accordance with GAAP, or held in escrow, in either case for adjustment in respect of the sale price or for any liabilities associated with the assets disposed of in such Asset Sale and retained by Oasis or any Restricted Subsidiary after such Asset Sale.

“Net Working Capital” means (a) all current assets of Oasis and its Restricted Subsidiaries except current assets from Oil and Natural Gas Hedging Contracts, less (b) all current liabilities of Oasis and its Restricted Subsidiaries, except (i) current liabilities included in Indebtedness, (ii) current liabilities associated with asset retirement obligations relating to oil and gas properties and (iii) any current liabilities from Oil and Natural Gas Hedging Contracts, in each case as set forth in the consolidated financial statements of Oasis prepared in accordance with GAAP (excluding any adjustments made pursuant to the Financial Standards Accounting Board’s Accounting Standards Codification (ASC) 815).

(1) as to which neither Oasis nor any Restricted Subsidiary (a) provides any Guarantee or credit support of any kind (including any undertaking, Guarantee, indemnity, agreement or instrument that would constitute Indebtedness) or (b) is directly or indirectly liable (as a guarantor or otherwise), in each case other than Liens on and pledges of the Equity Interests of any Unrestricted Subsidiary or any joint venture owned by Oasis or any Restricted Subsidiary to the extent securing otherwise Non-Recourse Debt of such Unrestricted Subsidiary or joint venture;

(2) no default with respect to which (including any rights that the holders thereof may have to take enforcement action against an Unrestricted Subsidiary) would permit (upon notice, lapse of time or both) any holder of any other Indebtedness of Oasis or any Restricted Subsidiary to declare a default under such other Indebtedness or cause the payment thereof to be accelerated or payable prior to its Stated Maturity; and

(3) the explicit terms of which provide there is no recourse against any of the assets of Oasis or its Restricted Subsidiaries, except for any Equity Interests referred to in clause (1) of this definition.

“Obligations” means any principal, interest, penalties, fees, indemnifications, reimbursements, damages and other liabilities payable under the documentation governing any Indebtedness.

“Officer” means, in the case of Oasis, the Chairman of the Board, the Chief Executive Officer, the President, the Chief Financial Officer, any Vice President, the Treasurer or the Secretary of Oasis and, in the case of any Subsidiary Guarantor, the Chairman of the Board, the Chief Executive Officer, the President, the Chief Financial Officer, any Vice President, the Treasurer or the Secretary of such Subsidiary Guarantor.

“Officers’ Certificate” means, in the case of Oasis, a certificate signed by two Officers or by an Officer and either an Assistant Treasurer or an Assistant Secretary of Oasis and, in the case of any

Subsidiary Guarantor, a certificate signed by two Officers or by an Officer and either an Assistant Treasurer or an Assistant Secretary of such Subsidiary Guarantor.

“Oil and Natural Gas Hedging Contract” means any Hydrocarbon hedging agreements and other agreements or arrangements entered into in the ordinary course of business in the oil and gas industry for the purpose of protecting against fluctuations in Hydrocarbon prices.

“OPNA” means Oasis Petroleum North America LLC, a Delaware limited liability company and a Subsidiary of Oasis.

“Permitted Acquisition Indebtedness” means Indebtedness or Disqualified Stock of Oasis or any of Oasis’ Restricted Subsidiaries to the extent such Indebtedness or Disqualified Stock was Indebtedness or Disqualified Stock of:

(1) a Subsidiary prior to the date on which such Subsidiary became a Restricted Subsidiary; or

(2) a Person that was merged or consolidated into Oasis or a Restricted Subsidiary;

provided that on the date such Subsidiary became a Restricted Subsidiary or the date such Person was merged or consolidated into Oasis or a Restricted Subsidiary, as applicable, after giving pro forma effect thereto,

(a) the Restricted Subsidiary or Oasis, as applicable, would be permitted to incur at least $1.00 of additional Indebtedness pursuant to the Fixed Charge Coverage Ratio test described under “—Covenants—Incurrence of indebtedness and issuance of preferred stock,” or

(b) the Fixed Charge Coverage Ratio for Oasis would be greater than the Fixed Charge Coverage Ratio for Oasis immediately prior to such transaction.

“Permitted Business Investments” means Investments and expenditures made in the ordinary course of, and of a nature that is or shall have become customary in, a Related Business as means of actively exploiting, exploring for, acquiring, developing, processing, gathering, marketing or transporting oil, natural gas, other Hydrocarbons and minerals (including with respect to plugging and abandonment) through agreements, transactions, interests or arrangements that permit one to share risks or costs of such activities or comply with regulatory requirements regarding local ownership, including without limitation, (a) ownership interests in oil, natural gas, other Hydrocarbons and minerals properties, liquefied natural gas facilities, processing facilities, gathering systems, pipelines, storage facilities or related systems or ancillary real property interests; (b) Investments in the form of or pursuant to operating agreements, working interests, royalty interests, mineral leases, processing agreements, Farm-In Agreements, Farm-Out Agreements, contracts for the sale, transportation or exchange of oil, natural gas, other Hydrocarbons and minerals, production sharing agreements, participation agreements, development agreements, area of mutual interest agreements, unitization agreements, pooling agreements, joint bidding agreements, service contracts, joint venture agreements, partnership agreements (whether general or limited), subscription agreements, stock purchase agreements, stockholder agreements and other similar agreements (including for limited liability companies) with third parties; and (c) direct or indirect ownership interests in drilling rigs and related equipment, including, without limitation, transportation equipment.

(3) any Investment by Oasis or any Restricted Subsidiary in a Person, if as a result of such Investment:

(b) such Person is merged or consolidated with or into, or transfers or conveys substantially all of its properties or assets to, or is liquidated into, Oasis or a Restricted Subsidiary;

(4) any Investment made as a result of the receipt of non-cash consideration from an Asset Sale that was made pursuant to and in compliance with the covenant described above under the caption “—Repurchase at the option of holders—Asset sales;”

(5) any Investments received in compromise or resolution of (a) obligations of trade creditors or customers that were incurred in the ordinary course of business of Oasis or any of its Restricted Subsidiaries, including pursuant to any plan of reorganization or similar arrangement upon the bankruptcy or insolvency of any trade creditor or customer; or (b) litigation, arbitration or other disputes with Persons who are not Affiliates;

(7) advances to or reimbursements of employees for moving, entertainment and travel expenses, drawing accounts and similar expenditures in the ordinary course of business, in each case to the extent they constitute Investments;

(8) loans or advances to employees in the ordinary course of business or consistent with past practice, in each case to the extent they constitute Investments;

(9) advances and prepayments for asset purchases in the ordinary course of business in a Related Business of Oasis or any of its Restricted Subsidiaries;

(10) receivables owing to Oasis or any Restricted Subsidiary created or acquired in the ordinary course of business and payable or dischargeable in accordance with customary trade terms; provided, however, that such trade terms may include such concessionary trade terms as Oasis or any such Restricted Subsidiary deems reasonable under the circumstances;

(11) surety and performance bonds and workers’ compensation, utility, lease, tax, performance and similar deposits and prepaid expenses in the ordinary course of business;

(12) guarantees by Oasis or any of its Restricted Subsidiaries of operating leases (other than Capital Lease Obligations) or of other obligations that do not constitute Indebtedness, in each case entered into by Oasis or any such Restricted Subsidiary in the ordinary course of business;

(13) Investments of a Restricted Subsidiary acquired after the Issue Date or of any entity merged into Oasis or merged into or consolidated with a Restricted Subsidiary in accordance with the covenant described under “—Covenants—Merger, consolidation or sale of substantially all assets” or the covenant described in the third paragraph under “—Subsidiary guarantees of the notes” (as applicable) to the extent that such Investments were not made in contemplation of or in connection with such acquisition, merger or consolidation and were in existence on the date of such acquisition, merger or consolidation;

(15) Investments received as a result of a foreclosure by Oasis or any of its Restricted Subsidiaries with respect to any secured Investment in default;

(17) Investments existing on the Issue Date, and any extension, modification or renewal of any such Investments existing on the Issue Date, but only to the extent not involving additional advances, contributions or other Investments of cash or other assets or other increases of such Investments (other than as a result of the accrual or accretion of interest or original issue discount or the issuance of pay-in-kind securities, in each case, pursuant to the terms of such Investments as in effect on the Issue Date);

(19) other Investments in any Person having an aggregate Fair Market Value (measured on the date each such Investment was made and without giving effect to subsequent changes in value), when taken together with all other Investments made pursuant to this clause (19) that are at the time outstanding not to exceed the greater of (a) 3.0% of Adjusted Consolidated Net Tangible Assets of Oasis and (b) $20.0 million.

(1) Liens securing Indebtedness incurred under Credit Facilities pursuant to subparagraph (1) of the second paragraph of the covenant described under the caption “—Covenants—Incurrence of indebtedness and issuance of preferred stock;” provided that the aggregate amount of such indebtedness does not exceed the aggregate amount that would be allowed under such subparagraph (1);

(2) Liens to secure Indebtedness (including Capital Lease Obligations) permitted by clause (4) of the second paragraph of the covenant entitled “—Covenants—Incurrence of indebtedness and issuance of preferred stock” covering only the assets acquired with or financed by such Indebtedness;

(3) pledges or deposits by such Person under workers’ compensation laws, unemployment insurance laws or similar legislation, or good faith deposits in connection with bids, tenders, contracts (other than for the payment of Indebtedness) or leases to which such Person is a party, or deposits to secure public or statutory obligations of such Person or deposits or cash or United States government bonds to secure surety or appeal bonds to which such Person is a party, or deposits as security for contested taxes or import or customs duties or for the payment of rent, in each case incurred in the ordinary course of business;

(4) landlords’, carriers’, warehousemen’s, mechanics’, materialmen’s, repairmen’s or similar Liens arising by contract or statute in the ordinary course of business and with respect to amounts which are not yet delinquent or are being contested in good faith by appropriate proceedings;

(5) Liens for taxes, assessments or other governmental charges or which are being contested in good faith by appropriate proceedings provided appropriate reserves required pursuant to GAAP have been made in respect thereof;

(6) Liens in favor of the issuers of surety or performance bonds or bankers’ acceptances issued pursuant to the request of and for the account of such Person in the ordinary course of its business;

(7) encumbrances, easements or reservations of, or rights of others for, licenses, rights of way, sewers, electric lines, telegraph and telephone lines and other similar purposes, or zoning or other restrictions as to the use of real properties or Liens incidental to the conduct of the business of such Person or to the ownership of its properties which do not in the aggregate materially adversely affect the value of said properties or materially impair their use in the operation of the business of such Person;

(8) leases and subleases of real property which do not materially interfere with the ordinary conduct of the business of Oasis and its Restricted Subsidiaries, taken as a whole;

(10) Liens for the purpose of securing the payment of all or a part of the purchase price of, or Capital Lease Obligations with respect to, or the repair, improvement or construction cost of, assets or property acquired or repaired, improved or constructed in the ordinary course of business; provided that:

(a) the aggregate principal amount of Indebtedness secured by such Liens is otherwise permitted to be incurred under the indenture and does not exceed the cost of the assets or property so acquired or repaired, improved or constructed plus fees and expenses in connection therewith; and

(b) such Liens are created within 180 days of repair, improvement or construction or acquisition of such assets or property and do not encumber any other assets or property of Oasis or any Restricted Subsidiary other than such assets or property and assets affixed or appurtenant thereto (including improvements);

(11) Liens arising solely by virtue of any statutory or common law provisions relating to banker’s Liens, rights of set-off or similar rights and remedies as to deposit accounts or other funds maintained or deposited with a depositary institution; provided that:

(a) such deposit account is not a dedicated cash collateral account and is not subject to restrictions against access by Oasis in excess of those set forth by regulations promulgated by the Federal Reserve Board; and

(b) such deposit account is not intended by Oasis or any Restricted Subsidiary to provide collateral to the depository institution;

(12) Liens arising from Uniform Commercial Code financing statement filings regarding operating leases entered into by Oasis and its Restricted Subsidiaries in the ordinary course of business;

(14) Liens on property at the time Oasis or a Restricted Subsidiary acquired the property, including any acquisition by means of a merger or consolidation with or into Oasis or a Restricted Subsidiary; provided, however, that such Liens are not created, incurred or assumed in connection with, or in contemplation of, such acquisition; provided further, however, that such Liens may not extend to any other property owned by Oasis or any Restricted Subsidiary other than those of the Person merged or consolidated with Oasis or such Restricted Subsidiary;

(15) Liens on property or Capital Stock of a Person at the time such Person becomes a Restricted Subsidiary; provided, however, that such Liens are not created, incurred or assumed in connection with, or in contemplation of, such other Person becoming a Restricted Subsidiary; provided further, however, that such Liens may not extend to any other property owned by Oasis or any Restricted Subsidiary;

(16) Liens securing Indebtedness or other obligations of a Restricted Subsidiary owing to Oasis or a Subsidiary Guarantor;

(17) Liens securing the notes, the Subsidiary Guarantees and other obligations arising under the indenture;

(18) Liens securing Permitted Refinancing Indebtedness of Oasis or a Restricted Subsidiary incurred to refinance Indebtedness of Oasis or a Restricted Subsidiary that was previously so secured; provided that any such Lien is limited to all or part of the same property or assets (plus improvements, accessions, proceeds or dividends or distributions in respect thereof) that secured (or, under the written arrangements under which the original Lien arose, could secure) the Indebtedness being refinanced or is in respect of property or assets that is the security for a Permitted Lien hereunder;

(21) Liens arising under joint venture agreements, partnership agreements, oil and gas leases or subleases, assignments, purchase and sale agreements, division orders, contracts for the sale, purchasing, processing, transportation or exchange of oil or natural gas, unitization and pooling declarations and agreements, development agreements, area of mutual interest agreements, licenses, sublicenses, net profits interests, participation agreements, Farm-Out Agreements, Farm-In Agreements, carried working interest, joint operating, unitization, royalty, sales and similar agreements relating to the exploration or development of, or production from, oil and gas properties entered into in the ordinary course of business in a Related Business;

(22) Liens reserved in oil and gas mineral leases for bonus, royalty or rental payments and for compliance with the terms of such leases;

(23) Liens on, or related to, properties or assets to secure all or part of the costs incurred in the ordinary course of a Related Business for exploration, drilling, development, production, processing, transportation, marketing, storage, abandonment or operation;

(24) Liens arising under the indenture in favor of the trustee for its own benefit and similar Liens in favor of other trustees, agents and representatives arising under instruments governing Indebtedness permitted to be incurred under the indenture; provided that such Liens are solely for the benefit of the trustees, agents or representatives in their capacities as such and not for the benefit of the holders of the Indebtedness;

(25) Liens securing obligations of Oasis and its Restricted Subsidiaries under non-speculative Hedging Obligations;

(26) Liens on and pledges of the Equity Interests of any Unrestricted Subsidiary or any joint venture owned by Oasis or any Restricted Subsidiary to the extent securing Non-Recourse Debt of such Unrestricted Subsidiary or joint venture;

(27) Liens securing Indebtedness of any Foreign Subsidiary which Indebtedness is permitted by the indenture; and

(28) Liens incurred in the ordinary course of business of Oasis or any Restricted Subsidiary with respect to obligations that, at any one time outstanding, do not exceed the greater of (a) $10.0 million and (b) 1.0% of Adjusted Consolidated Net Tangible Assets of Oasis.

“Permitted Refinancing Indebtedness” means any Indebtedness of Oasis or any of its Restricted Subsidiaries, any Disqualified Stock of Oasis or any preferred stock of any Restricted Subsidiary (a) issued in exchange for, or the net proceeds of which are used to extend, renew, refund, refinance, replace, defease, discharge or otherwise retire for value, in whole or in part, or (b) constituting an amendment, modification or supplement to or a deferral or renewal of ((a) and (b) above, collectively, a “Refinancing”), any other Indebtedness of Oasis or any of its Restricted Subsidiaries (other than intercompany Indebtedness), any Disqualified Stock of Oasis or any preferred stock of a Restricted Subsidiary in a principal amount or, in the case of Disqualified Stock of Oasis or preferred stock of a Restricted Subsidiary, liquidation preference, not to exceed (after deduction of reasonable and customary fees and expenses incurred in connection with the Refinancing) the lesser of:

(1) the principal amount or, in the case of Disqualified Stock or preferred stock, liquidation preference, of the Indebtedness, Disqualified Stock or preferred stock so Refinanced (plus, in the case of Indebtedness, the amount of premium, if any paid in connection therewith), and

(2) if the Indebtedness being Refinanced was issued with any original issue discount, the accreted value of such Indebtedness (as determined in accordance with GAAP) at the time of such Refinancing.

Notwithstanding the preceding, no Indebtedness, Disqualified Stock or preferred stock will be deemed to be Permitted Refinancing Indebtedness, unless:

(1) such Indebtedness, Disqualified Stock or preferred stock has a final maturity date or redemption date, as applicable, no earlier than the final maturity date or redemption date, as applicable, of, and has a Weighted Average Life to Maturity equal to or greater than the Weighted Average Life to Maturity of, the Indebtedness, Disqualified Stock or preferred stock being Refinanced;

(2) if the Indebtedness, Disqualified Stock or preferred stock being Refinanced is contractually subordinated or otherwise junior in right of payment to the notes, such Indebtedness, Disqualified Stock or preferred stock has a final maturity date or redemption date, as applicable, no earlier than the final maturity date or redemption date, as applicable, of, and is contractually subordinated or otherwise junior in right of payment to, the notes, on terms at least as favorable to the holders of notes as those contained in the documentation governing the Indebtedness, Disqualified Stock or preferred stock being Refinanced at the time of the Refinancing; and

(3) such Indebtedness or Disqualified Stock is incurred or issued by Oasis or such Indebtedness, Disqualified Stock or preferred stock is incurred or issued by the Restricted Subsidiary who is the obligor on the Indebtedness being Refinanced or the issuer of the Disqualified Stock or preferred stock being Refinanced; provided that a Restricted Subsidiary that is also a Subsidiary Guarantor may guarantee Permitted Refinancing Indebtedness incurred by Oasis, regardless of whether such Restricted Subsidiary was an obligor or guarantor of the Indebtedness being Refinanced.

“Person” means any individual, corporation, partnership, joint venture, association, joint-stock company, trust, unincorporated organization, limited liability company, government or any agency or political subdivision thereof or any other entity.

“Prior Issue Date” means February 2, 2011, the date of initial issuance of the 2019 Notes.

“Production Payments” means Dollar-Denominated Production Payments and Volumetric Production Payments, collectively.

“Production Payments and Reserve Sales” means the grant or transfer by Oasis or a Subsidiary of Oasis to any Person of a royalty, overriding royalty, net profits interest, Production Payment, partnership or other interest in oil and gas properties, reserves or the right to receive all or a portion of the production or the proceeds from the sale of production attributable to such properties, including any such grants or transfers pursuant to incentive compensation programs on terms that are reasonably customary in the oil and gas business for geologists, geophysicists and other providers of technical services to Oasis or a Subsidiary of Oasis.

“Rating Agency” means each of S&P and Moody’s, or if (and only if) S&P or Moody’s or both shall not make a rating on the notes publicly available, a nationally recognized statistical rating agency or agencies, as the case may be, selected by Oasis, which shall be substituted for S&P or Moody’s, or both, as the case may be.

“Related Business” means any business which is the same as or related, ancillary or complementary to any of the businesses of Oasis and its Restricted Subsidiaries on the Issue Date, which includes (1) the acquisition, exploration, exploitation, development, production, operation and disposition of interests in oil, gas and other hydrocarbon properties, and the utilization of Oasis’ and its Restricted Subsidiaries’ properties, (2) the gathering, marketing, treating, processing, storage, refining, selling and transporting of any production from such interests or properties and products produced in association therewith, (3) any power generation and electrical transmission business, (4) oil field sales and services and related activities, (5) development, purchase and sale of real estate and interests therein, and (6) any business or activity relating to, arising from, or necessary, appropriate or incidental to the activities described in the foregoing clauses (1) through (5) of this definition.

“Reporting Failure” means the failure of Oasis to file with the SEC and make available or otherwise deliver to the trustee and each holder of notes, within the time periods specified in “—Covenants—Reports” (after giving effect to any grace period specified under Rule 12b-25 under the Exchange Act), the periodic reports, information, documents or other reports that Oasis may be required to file with the SEC pursuant to such provision.

“Restricted Investment” means any Investment other than a Permitted Investment.

“Restricted Subsidiary” means any Subsidiary of Oasis other than an Unrestricted Subsidiary.

“S&P” means Standard & Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.

“Senior Credit Agreement” means the Amended and Restated Credit Agreement dated as of February 26, 2010, as amended by the First through the Sixth Amendments thereto, among (i) OPNA, as borrower, (ii) Oasis and Oasis Petroleum LLC, a Delaware limited liability company

and a Subsidiary of Oasis, as guarantors, (iii) Wells Fargo Bank, National Association, as administrative agent and lender, and (iv) the lenders party thereto from time to time, and any related notes, Guarantees, collateral documents, instruments and agreements executed in connection therewith, and in each case as further amended, restated, modified, supplemented, increased, renewed, refunded, replaced (including replacement after the termination of such credit facility), supplemented, restructured or refinanced in whole or in part from time to time in one or more agreements or instruments.

(1) all Indebtedness of Oasis or any of its Restricted Subsidiaries outstanding under Credit Facilities and all Hedging Obligations with respect thereto;

(2) the notes and any other Indebtedness of Oasis or any of its Restricted Subsidiaries permitted to be incurred under the terms of the indenture, unless the instrument under which such Indebtedness is incurred expressly provides that it is subordinated in right of payment to the notes or any Subsidiary Guarantee; and

(3) all Obligations with respect to the items listed in the preceding clauses (1) and (2).

Notwithstanding anything to the contrary in the preceding sentence, Senior Debt will not include:

(a) any intercompany Indebtedness of Oasis or any of its Subsidiaries to Oasis or any of its Affiliates;

“Significant Subsidiary” means any Restricted Subsidiary that would be a “significant subsidiary” of Oasis within the meaning of Rule 1-02 under Regulation S-X under the Securities Act.

“Stated Maturity” means, with respect to any installment of interest or principal on any series of Indebtedness, the date on which the payment of interest or principal was scheduled to be paid in the documentation governing such Indebtedness as of its issue date, and will not include any contingent obligations to repay, redeem or repurchase any such interest or principal prior to the date originally scheduled for the payment thereof.

“Subordinated Debt” means Indebtedness of Oasis or a Subsidiary Guarantor that is contractually subordinated in right of payment (by its terms or the terms of any document or instrument relating thereto), to the notes or the Subsidiary Guarantee of such Subsidiary Guarantor, as applicable.

(1) any corporation, association or other business entity (other than a partnership) of which more than 50% of the total voting power of its Voting Stock is at the time owned or controlled, directly or indirectly, by that Person or one or more of the other Subsidiaries of that Person (or a combination thereof); and

(2) any partnership (a) the sole general partner or the managing general partner of which is such Person or a Subsidiary of such Person or (b) the only general partners of which are that Person or one or more Subsidiaries of that Person (or any combination thereof).

“Subsidiary Guarantee” means any Guarantee of the notes by any Subsidiary Guarantor in accordance with the provisions of the indenture described under the caption “—Covenants—Subsidiary guarantees.”

“Subsidiary Guarantor” means each Restricted Subsidiary that has become obligated under a Subsidiary Guarantee, in accordance with the terms of the guarantee provisions of the indenture, but only for so long as such Subsidiary remains so obligated pursuant to the terms of the indenture.

“Unrestricted Subsidiary” means any Subsidiary of Oasis (including any newly acquired or newly formed Subsidiary or a Person becoming a Subsidiary through merger or consolidation or Investment therein) that is designated by the Board of Directors of Oasis as an Unrestricted Subsidiary pursuant to a resolution of such Board of Directors, but only to the extent that such Subsidiary:

(2) is a Person with respect to which neither Oasis nor any of its Restricted Subsidiaries has any direct or indirect obligation (a) to subscribe for additional Equity Interests or (b) to maintain or preserve such Person’s financial condition or to cause such Person to achieve any specified levels of operating results; and

(3) has not guaranteed or otherwise directly or indirectly provided credit support for any Indebtedness of Oasis or any of its Restricted Subsidiaries, except to the extent such Guarantee or credit support would be released upon such designation.

Any Subsidiary of an Unrestricted Subsidiary shall also be an Unrestricted Subsidiary.

“Volumetric Production Payments” means production payment obligations recorded as deferred revenue in accordance with GAAP, together with all related undertakings and obligations.

“Voting Stock” of any specified Person as of any date means the Capital Stock of such Person that is at the time entitled (without regard to the occurrence of any contingency and after giving effect to any voting agreement or stockholders’ agreement that effectively transfers voting power) to vote in the election of the Board of Directors of such Person.

“Weighted Average Life to Maturity” means, when applied to any Indebtedness at any date, the number of years obtained by dividing:

(1) the sum of the products obtained by multiplying (a) the amount of each then remaining installment, sinking fund, serial maturity or other required payments of principal, including payment at final maturity, in respect of the Indebtedness, by (b) the number of years (calculated to the nearest one-twelfth) that will elapse between such date and the making of such payment; by

The following discussion summarizes certain U.S. federal income tax considerations, and in the case of a non-U.S. holder (as defined below), estate tax considerations, that may be relevant to the acquisition, ownership and disposition of the notes. This discussion is based upon the provisions of the Code, applicable U.S. Treasury Regulations promulgated thereunder, judicial authority and administrative interpretations, as of the date of this document, all of which are subject to change, possibly with retroactive effect, or are subject to different interpretations. We cannot assure you that the Internal Revenue Service, or IRS, will not challenge one or more of the tax consequences described in this discussion, and we have not obtained, nor do we intend to obtain, a ruling from the IRS or an opinion of counsel with respect to the U.S. federal tax consequences of acquiring, holding or disposing of the notes.

This discussion is limited to holders who purchase the notes in this offering for a price equal to the issue price of the notes (i.e., the first price at which a substantial amount of the notes is sold other than to bond houses, brokers or similar persons or organizations acting in the capacity of underwriters, placement agents or wholesalers) and who hold the notes as capital assets (generally, property held for investment). This discussion does not address the tax considerations arising under the laws of any foreign, state, local or other jurisdiction. In addition, this discussion does not address all tax considerations that may be important to a particular holder in light of the holder’s circumstances, or to certain categories of investors that may be subject to special rules, such as:

If an entity treated as a partnership for U.S. federal income tax purposes holds notes, the tax treatment of a partner generally will depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership acquiring the notes, we urge you to consult your own tax advisor about the U.S. federal income tax consequences of acquiring, holding and disposing of the notes.

INVESTORS CONSIDERING THE PURCHASE OF NOTES ARE URGED TO CONSULT THEIR OWN TAX ADVISORS REGARDING THE APPLICATION OF THE U.S. FEDERAL INCOME TAX LAWS TO THEIR PARTICULAR SITUATIONS AS WELL AS ANY TAX CONSEQUENCES OF THE PURCHASE, OWNERSHIP OR DISPOSITION OF THE NOTES UNDER U.S. FEDERAL ESTATE OR GIFT TAX LAWS OR UNDER THE LAWS OF ANY STATE, LOCAL OR FOREIGN JURISDICTION OR UNDER ANY APPLICABLE TAX TREATY.

In certain circumstances see “Description of notes—Repurchase at the option of holders—Change of control” and “Description of notes—Optional redemption,” we may be obligated to pay amounts on the notes that are in excess of interest or principal on the notes. These potential payments may implicate the provisions of the U.S. Treasury Regulations relating to “contingent payment debt instruments.” We do not intend to treat the possibility of paying such additional amounts as causing the notes to be treated as contingent payment debt instruments. However, additional income will be recognized if any such additional payment is made. It is possible that the IRS may take a different position, in which case a holder might be required to accrue interest income at a higher rate than the interest rate and to treat as ordinary interest income any gain realized on the taxable disposition of the note. The remainder of this discussion assumes that the notes will not be treated as contingent payment debt instruments. Investors should consult their own tax advisors regarding the possible application of the contingent payment debt instrument rules to the notes.

You are a “U.S. holder” for purposes of this discussion if you are a beneficial owner of a note and you are for U.S. federal income tax purposes:

Interest on the notes generally will be taxable to you as ordinary income at the time it is received or accrued in accordance with your regular method of accounting for U.S. federal income tax purposes.

You will generally recognize capital gain or loss on the sale, redemption, exchange, retirement or other taxable disposition of a note. This gain or loss will equal the difference between the proceeds you receive (excluding any proceeds attributable to accrued but unpaid interest which

will be recognized as ordinary interest income to the extent you have not previously included such amounts in income) and your adjusted tax basis in the note. The proceeds you receive will include the amount of any cash and the fair market value of any other property received for the note. Your adjusted tax basis in the note will generally equal the amount you paid for the note. The gain or loss will be long-term capital gain or loss if you held the note for more than one year at the time of the sale, redemption, exchange, retirement or other disposition. Long-term capital gains of individuals, estates and trusts currently are subject to a reduced rate of U.S. federal income tax. The deductibility of capital losses may be subject to limitation.

Information reporting will apply to payments of interest on, and the proceeds of the sale or other disposition (including a redemption or retirement) of, notes held by you, and backup withholding may apply to such payments unless you provide the appropriate intermediary with a taxpayer identification number, certified under penalties of perjury, as well as certain other information. Backup withholding is not an additional tax. Any amount withheld under the backup withholding rules is allowable as a credit against your U.S. federal income tax liability, if any, and a refund may be obtained if the amounts withheld exceed your actual U.S. federal income tax liability and you timely provide the required information or appropriate claim form to the IRS.

You are a “non-U.S. holder” for purposes of this discussion if you are a beneficial owner of notes that is an individual, corporation, estate or trust that is not a U.S. holder.

Payments to you of interest on the notes generally will be exempt from withholding of U.S. federal income tax under the “portfolio interest” exemption if you properly certify as to your foreign status, as described below, and:

The portfolio interest exemption and several of the special rules for non-U.S. holders described below generally apply only if you appropriately certify as to your foreign status. You can generally meet this certification requirement by providing a properly executed IRS Form W-8BEN or appropriate substitute form to the withholding agent. If you hold the notes through a financial institution or other agent acting on your behalf, you may be required to provide appropriate certifications to the agent. Your agent will then generally be required to provide appropriate certifications to the withholding agent, either directly or through other intermediaries. Special rules apply to foreign partnerships, estates and trusts, and in certain

circumstances certifications as to foreign status of partners, trust owners or beneficiaries may have to be provided to the withholding agent. In addition, special rules apply to qualified intermediaries that enter into withholding agreements with the IRS.

If you cannot satisfy the requirements described above, payments of interest made to you will be subject to U.S. federal withholding tax at a 30% rate, unless you provide the withholding agent with a properly executed IRS Form W-8BEN (or successor form) claiming an exemption from (or a reduction of) withholding under the benefit of a tax treaty, or the payments of interest are effectively connected with your conduct of a trade or business in the United States and you meet the certification requirements described below. (See “—Tax consequences to non-U.S. holders—Income or gain effectively connected with a U.S. trade or business.”)

You generally will not be subject to U.S. federal income tax on any gain realized on the sale, redemption, exchange, retirement or other taxable disposition of a note unless:

If you are a non-U.S. holder whose gain is described in the first bullet point above, you generally will be subject to U.S. federal income tax in the same manner as a U.S. holder (See “—Tax consequences to non-U.S. holders—Income or gain effectively connected with a U.S. trade or business”). If you are a non-U.S. holder described in the second bullet point above, you will be subject to U.S. federal income tax at a flat rate of 30% (or lower applicable treaty rate) on the gain derived from the sale or other disposition, which may be offset by U.S. source capital losses.

If any interest on the notes or gain from the sale, exchange or other taxable disposition of the notes is effectively connected with a U.S. trade or business conducted by you, then the income or gain will be subject to U.S. federal income tax at regular graduated income tax rates, unless an applicable income tax treaty provides otherwise. Effectively connected income will not be subject to U.S. withholding tax if you satisfy certain certification requirements by providing to the withholding agent a properly executed IRS Form W-8ECI (or IRS Form W-8BEN if a treaty exemption applies) or successor form. If you are a corporation, that portion of your earnings and profits that is effectively connected with your U.S. trade or business may also be subject to a “branch profits tax” at a 30% rate, although an applicable income tax treaty may provide for a lower rate.

If you are an individual and are not a resident of the United States (as specially defined for U.S. federal estate tax purposes) at the time of your death, the notes will not be included in your estate for U.S. federal estate tax purposes provided, at the time of your death, interest on the notes qualifies for the portfolio interest exemption under the rules described above in “—Consequences to non-U.S. holders—Interest on the notes” (without regard to the certification requirement).

Payments to you of interest on a note, and amounts withheld from such payments, if any, generally will be required to be reported to the IRS and to you. Copies of these information returns may also be made available to the tax authorities of the country in which you reside under the provisions of a specific treaty or agreement.

United States backup withholding generally will not apply to payments to you of interest on a note if the statement described in “—Tax consequences to non-U.S. holders—Interest on the notes” is duly provided or you otherwise establish an exemption, provided that we do not have actual knowledge or reason to know that you are a United States person.

Payment of the proceeds of a disposition (including a redemption or retirement) of a note effected by the U.S. office of a U.S. or foreign broker will be subject to information reporting requirements and backup withholding unless you properly certify under penalties of perjury as to your foreign status and certain other conditions are met or you otherwise establish an exemption. Information reporting requirements and backup withholding generally will not apply to any payment of the proceeds of the disposition of a note effected outside the United States by a foreign office of a broker. However, unless such a broker has documentary evidence in its records that you are a non-U.S. holder and certain other conditions are met, or you otherwise establish an exemption, information reporting will apply to a payment of the proceeds of the disposition of a note effected outside the United States by such a broker if it has certain relationships with the United States.

Backup withholding is not an additional tax. Any amount withheld under the backup withholding rules is allowable as a credit against your U.S. federal income tax liability, if any, and a refund may be obtained if the amounts withheld exceed your actual U.S. federal income tax liability and you timely provide the required information or appropriate claim form to the IRS.

For tax years beginning after December 31, 2012, a 3.8% tax is scheduled to be imposed on the “net investment income” of certain U.S. citizens and resident aliens, and on the undistributed “net investment income” of certain estates and trusts. Among other items, “net investment income” generally includes gross income from interest and net gain from the disposition of property, such as the notes, less certain deductions.

The Hiring Incentives to Restore Employment Act, enacted on March 18, 2010, would impose a 30% withholding tax on any payments on our obligations made to a foreign financial institution or non-financial foreign entity (including, in some cases, when such foreign financial institution or entity is acting as an intermediary), and on the gross proceeds of the sale or other disposition of our obligations, unless (i) in the case of a foreign financial institution, such institution enters into an agreement with the U.S. government to withhold on certain payments, and to collect and provide to the U.S. tax authorities substantial information regarding U.S. account holders of such institution (which includes certain equity and debt holders of such institution, as well as certain account holders that are foreign entities with U.S. owners), and (ii) in the case of a non-financial foreign entity, such entity provides the withholding agent with a certification identifying the direct and indirect U.S. owners of the entity. Under certain circumstances, a holder might be

eligible for refunds or credits of such taxes. Although this legislation currently applies to payments made after December 31, 2012, the Treasury and the IRS have issued administrative guidance indicating that they plan to issue Treasury Regulations that will delay the effective date of the withholding regime so that withholding will only apply to payments made after December 31, 2013 (in the case of interest payments) and December 31, 2014 (in the case of disposition proceeds). Proposed Treasury Regulations have been issued which, if finalized, would confirm the extension of the effective dates for withholding. Additionally, payments with respect to debt obligations that were outstanding on March 18, 2012 are not subject to these rules; however, proposed regulations not yet in effect would, if adopted, extend this grandfathering date to January 1, 2013. If these proposed regulations are adopted, withholding under these rules would not be required on the notes. You are encouraged to consult with your own tax advisors regarding the possible implications of this legislation on an investment in the notes.

THE PRECEDING DISCUSSION OF CERTAIN U.S. FEDERAL INCOME AND ESTATE TAX CONSIDERATIONS IS FOR GENERAL INFORMATION ONLY AND IS NOT TAX ADVICE. WE URGE EACH PROSPECTIVE INVESTOR TO CONSULT ITS OWN TAX ADVISOR REGARDING THE PARTICULAR FEDERAL, STATE, LOCAL AND FOREIGN TAX CONSEQUENCES OF PURCHASING, HOLDING AND DISPOSING OF OUR NOTES, INCLUDING THE CONSEQUENCES OF ANY PROPOSED CHANGE IN APPLICABLE LAWS.

Subject to the terms and conditions contained in the underwriting agreement between us, the guarantors and the underwriters, each underwriter named in the table below, for whom J.P. Morgan Securities LLC is acting as representative, has agreed to purchase, and we have agreed to sell to them the principal amount of notes set forth opposite such underwriter’s name in the table below:

The obligations of the underwriters to purchase the notes from us are several, and not joint. The underwriting agreement provides that the underwriters will purchase all of the notes sold pursuant to the underwriting agreement if any of them are purchased.

The underwriters initially propose to offer the notes to the public at the public offering price that appears on the cover page of this prospectus supplement. The underwriters may offer the notes to selected dealers at the public offering price minus a concession of up to 0.375% of the principal amount of the notes. In addition, the underwriters may allow, and those selected dealers may reallow, a concession of up to 0.25% of the principal amount of the notes to certain other dealers. After the initial offering, the underwriters may change the public offering price and any other selling terms. The underwriters may offer and sell notes through certain of their affiliates.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

The following table shows the underwriting discounts and commissions we will pay to the underwriters in connection with the offering (expressed as a percentage of the principal amount of the notes).

We estimate that our expenses in connection with the sale of the notes, other than underwriting discounts and commissions, will be approximately $1.0 million.

The notes are a new issue of securities with no established trading market. The notes will not be listed on any securities exchange. We have been advised by the underwriters that the underwriters intend to make a market in the notes, but are not obligated to do so and may discontinue market making at any time without notice. No assurance can be given as to the liquidity of the trading market for the notes.

We have agreed that we will not, for a period of up to 60 days after the date of the prospectus supplement, without first obtaining the prior written consent of J.P. Morgan Securities LLC, offer or sell any of our debt securities that are similar to the notes.

In connection with the offering of the notes, the underwriters may engage in overallotment, stabilizing transactions and syndicate covering transactions. Overallotment involves sales in excess of the offering size, which creates a short position for the underwriters. Stabilizing transactions involve bids to purchase the notes in the open market for the purpose of pegging, fixing or maintaining the price of the notes. Syndicate covering transactions involve purchases of the notes in the open market after the distribution has been completed in order to cover short positions. Stabilizing transactions and syndicate covering transactions may cause the price of the notes to be higher than it would otherwise be in the absence of those transactions. If the underwriters engage in stabilizing or syndicate covering transactions, they may discontinue them at any time.

Certain of the underwriters and affiliates of certain of the underwriters have provided, or may in the future provide, investment banking, commercial banking and other financial and advisory services to us and/or our affiliates, including underwriting and the provision of financial advice, and have received, or may in the future receive, customary fees and commissions for their services. Affiliates of certain of the underwriters are also lenders under our revolving credit facility.

In addition, in the ordinary course of their business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of us and/or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

In relation to each member state of the European Economic Area which has implemented the prospectus directive, as defined below (each, a “relevant member state”), with effect from and including the date on which the prospectus directive is implemented in that relevant member state (the “relevant implementation date”) the notes which are the subject of the offering contemplated in this prospectus supplement may not be offered to the public in that relevant member state other than:

(a) to any legal entity which is a qualified investor as defined in the prospectus directive;

(b) to fewer than 100 or, if the relevant member state has implemented the relevant provision of the 2010 PD Amending Directive, 150, natural or legal persons (other than

qualified investors as defined in the prospectus directive), subject to obtaining the prior consent of the representatives of the underwriter for any such offer; or

(c) in any other circumstances falling within Article 3(2) of the prospectus directive, provided that no such offer of notes shall require the Company or any underwriter to publish a prospectus pursuant to Article 3 of the prospectus directive or supplement a prospectus pursuant to Article 16 of the prospectus directive.

For the purposes of this provision, the expression “an offer of notes to the public” in relation to any notes in any relevant member state means the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or subscribe the notes, as the same may be varied in that member state by any measure implementing the prospectus directive in that member state and the expression “prospectus directive” means Directive 2003/71/EC (and amendments thereto, including the 2010 PD Amending Directive, to the extent implemented in the relevant member state), and includes any relevant implementing measure in each relevant member state and the expression “2010 PD Amending Directive” means Directive 2010/73/EU.

The notes may only be offered (a) in compliance with all applicable provisions of the Financial Services and Markets Act 2000 (“FSMA”) with respect to anything done in relation to the notes in, from or otherwise involving the United Kingdom and (b) where each underwriter has only communicated or caused to be communicated and will only communicate or cause to be communicated any invitation or inducement to engage in investment activity (within the meaning of Section 21 of the FSMA) received by it in connection with the issue or sale of notes in circumstances in which Section 21(1) of the FSMA does not apply to the Company. Without limitation to the other restrictions referred to herein, this prospectus supplement is directed solely at (1) persons outside the United Kingdom, (2) persons having professional experience in matters relating to investments who fall within the definition of “investment professionals” in Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended; (3) high net worth bodies corporate, unincorporated associations and partnerships and trustees of high value trusts as described in Article 49 of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended or (4) persons to whom an invitation or inducement to engage in investment banking activity (within the meaning of section 21 of the FSMA) in connection with the issue or sale of any securities may otherwise lawfully be communicated or caused to be communicated. Without limitation to the other restrictions referred to herein, any investment or investment activity to which this prospectus supplement relates is available only to, and will be engaged in only with, such persons, and persons within the United Kingdom who receive this communication (other than persons who fall within (1) to (4) above) should not rely or act upon this communication.

The validity of the notes will be passed upon for us by Vinson & Elkins L.L.P., Houston, Texas. Certain legal matters in connection with the notes will be passed upon for the underwriters by Andrews Kurth LLP, Houston, Texas.

The consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2011 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

Estimated quantities of proved reserves of Oasis Petroleum Inc., the future net revenues from those reserves and their present value is based, in part, on estimates of the proved reserves and present values of proved reserves as of December 31, 2009, 2010 and 2011. The reserve estimates at December 31, 2009, 2010 and 2011 are based on reports prepared by DeGolyer and MacNaughton, independent reserve engineers. We have incorporated these estimates in reliance on the authority of such firm as an expert in such matters.

The terms defined in this section are used throughout this prospectus supplement:

“Bbl.” One stock tank barrel, of 42 U.S. gallons liquid volume, used herein in reference to crude oil, condensate or natural gas liquids.

“Boe.” Barrels of oil equivalent, with 6,000 cubic feet of natural gas being equivalent to one barrel of oil.

“British thermal unit.” The heat required to raise the temperature of a one-pound mass of water from 58.5 to 59.5 degrees Fahrenheit.

“Basin.” A large natural depression on the earth’s surface in which sediments generally brought by water accumulate.

“Completion.” The process of treating a drilled well followed by the installation of permanent equipment for the production of natural gas or oil, or in the case of a dry hole, the reporting of abandonment to the appropriate agency.

“Developed acreage.” The number of acres that are allocated or assignable to productive wells or wells capable of production.

“Developed reserves.” Reserves of any category that can be expected to be recovered through existing wells with existing equipment and operating methods or for which the cost of required equipment is relatively minor when compared to the cost of a new well.

“Development well.” A well drilled within the proved area of a natural gas or oil reservoir to the depth of a stratigraphic horizon known to be productive.

“Dry hole.” A well found to be incapable of producing hydrocarbons in sufficient quantities such that proceeds from the sale of such production exceed production expenses and taxes.

“Economically producible.” A resource that generates revenue that exceeds, or is reasonably expected to exceed, the costs of the operation.

“Environmental assessment.” An environmental assessment, a study that can be required pursuant to federal law to assess the potential direct, indirect and cumulative impacts of a project.

“Exploratory well.” A well drilled to find and produce natural gas or oil reserves not classified as proved, to find a new reservoir in a field previously found to be productive of natural gas or oil in another reservoir or to extend a known reservoir.

“Field.” An area consisting of a single reservoir or multiple reservoirs all grouped on, or related to, the same individual geological structural feature or stratigraphic condition. The field name refers to the surface area, although it may refer to both the surface and the underground productive formations.

“Formation.” A layer of rock which has distinct characteristics that differ from nearby rock.

“Horizontal drilling.” A drilling technique used in certain formations where a well is drilled vertically to a certain depth and then drilled at a right angle within a specified interval.

“Infill wells.” Wells drilled into the same pool as known producing wells so that oil or natural gas does not have to travel as far through the formation.

“MBbl.” One thousand barrels of crude oil, condensate or natural gas liquids.

“MMBbl.” One million barrels of crude oil, condensate or natural gas liquids.

“Net acres.” The percentage of total acres an owner has out of a particular number of acres, or a specified tract. An owner who has 50% interest in 100 acres owns 50 net acres.

“PV-10.” When used with respect to oil and natural gas reserves, PV-10 means the estimated future gross revenue to be generated from the production of proved reserves, net of estimated production and future development and abandonment costs, using prices and costs in effect at the determination date, before income taxes, and without giving effect to non-property-related expenses, discounted to a present value using an annual discount rate of 10% in accordance with the guidelines of the Commission.

“Productive well.” A well that is found to be capable of producing hydrocarbons in sufficient quantities such that proceeds from the sale of the production exceed production expenses and taxes.

“Proved developed reserves.” Proved reserves that can be expected to be recovered through existing wells with existing equipment and operating methods.

“Proved reserves.” Under SEC rules for fiscal years ending on or after December 31, 2009, proved reserves are defined as:

Those quantities of oil and gas, which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically producible—from a given date forward, from known reservoirs, and under existing economic conditions, operating methods, and government regulations—prior to the time at which contracts providing the right to operate expire, unless evidence indicates that renewal is reasonably certain, regardless of whether deterministic or probabilistic methods are used for the estimation. The project to extract the hydrocarbons must have commenced or the operator must be reasonably certain that it will commence the project within a reasonable time. The area of the reservoir considered as proved includes (i) the area identified by drilling and limited by fluid contacts, if any, and (ii) adjacent undrilled portions of the reservoir that can, with reasonable certainty, be judged to be continuous with it and to contain economically producible oil or gas on the basis of available geoscience and engineering data. In the absence of data on fluid contacts, proved quantities in a reservoir are limited by the lowest known hydrocarbons, LKH, as seen in a well penetration unless geoscience, engineering, or performance data and reliable technology establishes a lower contact with reasonable certainty. Where direct observation from well penetrations has defined a

highest known oil, HKO, elevation and the potential exists for an associated gas cap, proved oil reserves may be assigned in the structurally higher portions of the reservoir only if geoscience, engineering, or performance data and reliable technology establish the higher contact with reasonable certainty. Reserves which can be produced economically through application of improved recovery techniques (including, but not limited to, fluid injection) are included in the proved classification when (i) successful testing by a pilot project in an area of the reservoir with properties no more favorable than in the reservoir as a whole, the operation of an installed program in the reservoir or an analogous reservoir, or other evidence using reliable technology establishes the reasonable certainty of the engineering analysis on which the project or program was based; and (ii) the project has been approved for development by all necessary parties and entities, including governmental entities. Existing economic conditions include prices and costs at which economic producibility from a reservoir is to be determined. The price shall be the average price during the 12-month period prior to the ending date of the period covered by the report, determined as an unweighted arithmetic average of the first-day-of-the-month price for each month within such period, unless prices are defined by contractual arrangements, excluding escalations based upon future conditions.

“Proved undeveloped reserves.” Proved reserves that are expected to be recovered from new wells on undrilled acreage or from existing wells where a relatively major expenditure is required for recompletion.

“Recompletion.” The process of re-entering an existing wellbore that is either producing or not producing and completing new reservoirs in an attempt to establish or increase existing production.

“Reserves.” Estimated remaining quantities of oil and natural gas and related substances anticipated to be economically producible as of a given date by application of development prospects to known accumulations.

“Reservoir.” A porous and permeable underground formation containing a natural accumulation of producible natural gas and/or oil that is confined by impermeable rock or water barriers and is separate from other reservoirs.

“Spacing.” The distance between wells producing from the same reservoir. Spacing is often expressed in terms of acres, e.g., 40-acre spacing, and is often established by regulatory agencies.

“Unit.” The joining of all or substantially all interests in a reservoir or field, rather than a single tract, to provide for development and operation without regard to separate property interests. Also, the area covered by a unitization agreement.

“Wellbore.” The hole drilled by the bit that is equipped for oil or gas production on a completed well. Also called well or borehole.

“Working interest.” The right granted to the lessee of a property to explore for and to produce and own oil, gas, or other minerals. The working interest owners bear the exploration, development, and operating costs on either a cash, penalty, or carried basis.

We may offer and sell the securities listed above from time to time in one or more offerings in one or more classes or series. Any debt securities we offer pursuant to this prospectus may be fully and unconditionally guaranteed by certain of our subsidiaries, including Oasis Petroleum LLC and Oasis Petroleum North America LLC.

This prospectus provides you with a general description of the securities that may be offered. Each time securities are offered, we may provide a prospectus supplement and attach it to this prospectus. The prospectus supplement will contain more specific information about the offering and the terms of the securities being offered, including any guarantees by our subsidiaries. A prospectus supplement may also add, update or change information contained in this prospectus. This prospectus may not be used to offer or sell securities without a prospectus supplement describing the method and terms of the offering.

We may sell these securities directly or through agents, underwriters or dealers, or through a combination of these methods. See “Plan of Distribution.” The prospectus supplement will list any agents, underwriters or dealers that may be involved and the compensation they will receive. The prospectus supplement will also show you the total amount of money that we will receive from selling the securities being offered, after the expenses of the offering. You should carefully read this prospectus and any accompanying prospectus supplement, together with the documents we incorporate by reference, before you invest in any of our securities.

Investing in any of our securities involves risk. Please read carefully the information included and incorporated by reference in this prospectus and in any applicable prospectus supplement for a discussion of the factors you should consider before deciding to purchase our securities. See “Risk Factors” beginning on page 5 of this prospectus.

Our common stock is listed on the New York Stock Exchange (“NYSE”) under the symbol “OAS.”

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

You should rely only on the information contained in or incorporated by reference into this prospectus and any prospectus supplement. We have not authorized any dealer, salesman or other person to provide you with additional or different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus and any prospectus supplement are not an offer to sell or the solicitation of an offer to buy any securities other than the securities to which they relate and are not an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make an offer or solicitation in that jurisdiction. You should not assume that the information contained in this prospectus is accurate as of any date other than the date on the front cover of this prospectus, or that the information contained in any document incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of a security.

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, which we refer to as the SEC, using a “shelf” registration process. Under this shelf registration process, we may offer and sell any combination of the securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide you with this prospectus and may provide you with a prospectus supplement that will contain specific information about the terms of the offering and the offered securities. That prospectus supplement may also add, update or change information contained in this prospectus. Any statement that we make in this prospectus will be modified or superseded by any inconsistent statement made by us in a prospectus supplement.

Additional information, including our financial statements and the notes thereto, is incorporated in this prospectus by reference to our reports filed with the SEC. Please read “Where You Can Find More Information” below. You are urged to read this prospectus carefully, including the “Risk Factors,” and our SEC reports in their entirety before investing in our securities.

Unless the context requires otherwise or unless otherwise noted, all references in this prospectus or any accompanying prospectus supplement to “Oasis,” “we” or “our” are to Oasis Petroleum Inc. and its subsidiaries.

We are an independent exploration and production company focused on the development and acquisition of unconventional oil and natural gas resources primarily in the Williston Basin. Since our inception, we have emphasized the acquisition of properties that provide current production and significant upside potential through further development. Our drilling activity is primarily directed toward projects that we believe can provide us with repeatable successes in the Bakken formation.

Our principal executive offices are located at 1001 Fannin Street, Suite 1500, Houston, Texas 77002, and our telephone number at that address is (281) 404-9500. Our common stock is listed on NYSE under the symbol “OAS.”

We file annual, quarterly and current reports and other information with the SEC (File No. 001-34776) pursuant to the Securities Exchange Act of 1934 (the “Exchange Act”). You may read and copy any documents that are filed at the SEC’s public reference room at 100 F Street, N.E., Washington, D.C. 20549. You may also obtain copies of these documents at prescribed rates from the public reference section of the SEC at its Washington address. Please call the SEC at 1-800-SEC-0330 for further information.

Our filings are also available to the public through the SEC’s website at http://www.sec.gov.

The SEC allows us to “incorporate by reference” information that we file with it, which means that we can disclose important information to you by referring you to documents previously filed with the SEC. The information incorporated by reference is an important part of this prospectus, and the information that we later file with the SEC will automatically update and supersede this information. The following documents we filed with the SEC pursuant to the Exchange Act are incorporated herein by reference:

These reports contain important information about us, our financial condition and our results of operations.

All future documents filed pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act (excluding any information furnished pursuant to Item 2.02 or Item 7.01 on any Current Report on Form 8-K) before the termination of each offering under this prospectus shall be deemed to be incorporated in this prospectus by reference and to be a part hereof from the date of filing of such documents. Any statement contained herein, or in a document incorporated or deemed to be incorporated by reference herein, shall be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained herein or in any subsequently filed document that also is or is deemed to be incorporated by reference herein, modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus.

You may request a copy of these filings at no cost by writing or telephoning us at the following address and telephone number:

We also maintain a website at http://www.oasispetroleum.com. However, the information on our website is not part of this prospectus.

This prospectus and the documents incorporated by reference contain forward-looking statements intended to qualify for the safe harbors from liability established by the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act and Section 21E of the Exchange Act. These forward-looking statements are subject to a number of risks and uncertainties, many of which are beyond our control. All statements, other than statements of historical fact included in this prospectus and the documents incorporated by reference, regarding our strategy, future operations, financial position, estimated revenues and losses, projected costs, prospects, plans and objectives of management are forward-looking statements. When used in this prospectus, the words “could,” “believe,” “anticipate,” “intend,” “estimate,” “expect,” “may,” “continue,” “predict,” “potential,” “project” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain such identifying words. When considering forward looking statements, you should keep in mind the risk factors and other cautionary statements described under the heading “Risk Factors” included in this prospectus, and the risk factors and other cautionary statements described under the headings “Risk Factors” included in our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and any subsequently filed Current Reports on Form 8-K, all of which are incorporated by reference in this prospectus.

These forward looking statements are based on management’s current belief, based on currently available information, as to the outcome and timing of future events. Without limiting the generality of the foregoing, certain statements incorporated by reference or included in this prospectus constitute forward looking statements.

All forward-looking statements speak only as of the date they are made. You should not place undue reliance on these forward-looking statements. Although we believe that our plans, intentions and expectations reflected in or suggested by the forward-looking statements we make in this prospectus and the documents incorporated by reference are reasonable, we can give no assurance that these plans, intentions or expectations will be achieved. We disclose important factors that could cause our actual results to differ materially from our expectations under “Risk Factors” beginning on page 5 of this prospectus and those risk factors incorporated by reference to our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and any subsequently filed Current Reports on Form 8-K. These cautionary statements qualify all forward-looking statements attributable to us or persons acting on our behalf.

All subsequent written and oral forward-looking statements attributable to us or to persons acting on our behalf are expressly qualified in their entirety by the foregoing. We undertake no obligation to publicly release the results of any revisions to any such forward-looking statements that may be made to reflect events or circumstances after the date of this prospectus or to reflect the occurrence of unanticipated events. See also “Where You Can Find More Information.”

An investment in our securities involves a significant degree of risk. Before you invest in our securities you should carefully consider those risk factors included in our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and any subsequently filed Current Reports on Form 8-K, which are incorporated herein by reference, and those risk factors that may be included in any applicable prospectus supplement, together with all of the other information included in this prospectus, any prospectus supplement and the documents we incorporate by reference, in evaluating an investment in our securities. If any of the risks discussed in the foregoing documents were to occur, our business, financial condition, results of operations and cash flows could be materially adversely affected. Please read “Cautionary Statement Regarding Forward-Looking Statements.”

The following table sets forth our ratios of consolidated earnings to fixed charges for the periods presented:

For purposes of computing the ratio of earnings to fixed charges, “earnings” consists of pre-tax income from continuing operations before fixed charges. “Fixed charges” consists of interest expense, amortized capital expenses related to indebtedness and an estimate of interest within rental expense.

We had no preferred stock outstanding for any period presented, and accordingly, the ratio of earnings to combined fixed charges and preferred stock dividends is the same as the ratio of earnings to fixed charges.

Except as may be stated in any applicable prospectus supplement, we intend to use the net proceeds from any sales of securities by us under this prospectus for general corporate purposes, which may include repayment or refinancing of borrowings, working capital, capital expenditures, investments and acquisitions. Pending any specific application, we may initially invest funds in short-term marketable securities or apply them to repayments of indebtedness.

The Debt Securities will be either our senior debt securities (“Senior Debt Securities”) or our subordinated debt securities (“Subordinated Debt Securities”). The Senior Debt Securities and the Subordinated Debt Securities will be issued under separate indentures among us, the Subsidiary Guarantors of such Debt Securities, if any, and a trustee to be determined (the “Trustee”). Senior Debt Securities will be issued under a “Senior Indenture” and Subordinated Debt Securities will be issued under a “Subordinated Indenture.” Together, the Senior Indenture and the Subordinated Indenture are called “Indentures.”

The Debt Securities may be issued from time to time in one or more series. The particular terms of each series that are offered by a prospectus supplement will be described in the prospectus supplement.

Unless the Debt Securities are guaranteed by our subsidiaries as described below, the rights of Oasis and our creditors, including holders of the Debt Securities, to participate in the assets of any subsidiary upon the latter’s liquidation or reorganization, will be subject to the prior claims of the subsidiary’s creditors, except to the extent that we may ourself be a creditor with recognized claims against such subsidiary.

We have summarized selected provisions of the Indentures below. The summary is not complete. The form of each Indenture has been filed with the SEC as an exhibit to the registration statement of which this prospectus is a part, and you should read the Indentures for provisions that may be important to you. Capitalized terms used in the summary have the meanings specified in the Indentures.

The Indentures provide that Debt Securities in separate series may be issued thereunder from time to time without limitation as to aggregate principal amount. We may specify a maximum aggregate principal amount for the Debt Securities of any series. We will determine the terms and conditions of the Debt Securities, including the maturity, principal and interest, but those terms must be consistent with the Indenture. The Debt Securities will be our unsecured obligations.

The Subordinated Debt Securities will be subordinated in right of payment to the prior payment in full of all of our Senior Debt (as defined) as described under “— Subordination of Subordinated Debt Securities” and in the prospectus supplement applicable to any Subordinated Debt Securities. If the prospectus supplement so indicates, the Debt Securities will be convertible into our common stock.

If specified in the prospectus supplement respecting a particular series of Debt Securities, certain subsidiaries of Oasis (each a “Subsidiary Guarantor”) will fully and unconditionally guarantee (the “Subsidiary Guarantee”) that series as described under “— Subsidiary Guarantee” and in the prospectus supplement. Each Subsidiary Guarantee will be an unsecured obligation of the Subsidiary Guarantor. A Subsidiary Guarantee of Subordinated Debt Securities will be subordinated to the Senior Debt of the Subsidiary Guarantor on the same basis as the Subordinated Debt Securities are subordinated to our Senior Debt.

The applicable prospectus supplement will set forth the price or prices at which the Debt Securities to be issued will be offered for sale and will describe the following terms of such Debt Securities:

(2) whether the Debt Securities are Senior Debt Securities or Subordinated Debt Securities and, if Subordinated Debt Securities, the related subordination terms;

(3) whether any Subsidiary Guarantor will provide a Subsidiary Guarantee of the Debt Securities;

(6) the interest rate that the Debt Securities will bear and the interest payment dates for the Debt Securities;

(8) any terms upon which the Debt Securities may be redeemed, in whole or in part, at our option;

(9) any sinking fund or other provisions that would obligate us to redeem or otherwise repurchase the Debt Securities;

(10) the portion of the principal amount, if less than all, of the Debt Securities that will be payable upon declaration of acceleration of the Maturity of the Debt Securities;

(13) whether the Debt Securities are convertible into our common stock and, if so, the terms and conditions upon which conversion will be effected, including the initial conversion price or conversion rate and any adjustments thereto and the conversion period;

(14) any addition to or change in the covenants in the Indenture applicable to the Debt Securities; and

(15) any other terms of the Debt Securities not inconsistent with the provisions of the Indenture.

Debt Securities, including any Debt Securities that provide for an amount less than the principal amount thereof to be due and payable upon a declaration of acceleration of the Maturity thereof (“Original Issue Discount Securities”), may be sold at a substantial discount below their principal amount. Special United States federal income tax considerations applicable to Debt Securities sold at an original issue discount may be described in the applicable prospectus supplement. In addition, special United States federal income tax or other considerations applicable to any Debt Securities that are denominated in a currency or currency unit other than United States dollars may be described in the applicable prospectus supplement.

The indebtedness evidenced by the Subordinated Debt Securities will, to the extent set forth in the Subordinated Indenture with respect to each series of Subordinated Debt Securities, be subordinated in right of payment to the prior payment in full of all of our Senior Debt, including the Senior Debt Securities, and it may also be senior in right of payment to all of our Subordinated Debt. The prospectus supplement relating to any Subordinated Debt Securities will summarize the subordination provisions of the Subordinated Indenture applicable to that series including:

The prospectus supplement will also describe as of a recent date the approximate amount of Senior Debt to which the Subordinated Debt Securities of that series will be subordinated.

The failure to make any payment on any of the Subordinated Debt Securities by reason of the subordination provisions of the Subordinated Indenture described in the prospectus supplement will not be construed as preventing the occurrence of an Event of Default with respect to the Subordinated Debt Securities arising from any such failure to make payment.

The subordination provisions described above will not be applicable to payments in respect of the Subordinated Debt Securities from a defeasance trust established in connection with any legal defeasance or

covenant defeasance of the Subordinated Debt Securities as described under “— Legal Defeasance and Covenant Defeasance.”

If specified in the prospectus supplement, one or more of the Subsidiary Guarantors will guarantee the Debt Securities of a series. Unless otherwise indicated in the prospectus supplement, the following provisions will apply to the Subsidiary Guarantee of the Subsidiary Guarantor.

Subject to the limitations described below and in the prospectus supplement, one or more of the Subsidiary Guarantors will jointly and severally, fully and unconditionally guarantee the punctual payment when due, whether at Stated Maturity, by acceleration or otherwise, of all our payment obligations under the Indentures and the Debt Securities of a series, whether for principal of, premium, if any, or interest on the Debt Securities or otherwise (all such obligations guaranteed by a Subsidiary Guarantor being herein called the “Guaranteed Obligations”). The Subsidiary Guarantors will also pay all expenses (including reasonable counsel fees and expenses) incurred by the applicable Trustee in enforcing any rights under a Subsidiary Guarantee with respect to a Subsidiary Guarantor.

In the case of Subordinated Debt Securities, a Subsidiary Guarantor’s Subsidiary Guarantee will be subordinated in right of payment to the Senior Debt of such Subsidiary Guarantor on the same basis as the Subordinated Debt Securities are subordinated to our Senior Debt. No payment will be made by any Subsidiary Guarantor under its Subsidiary Guarantee during any period in which payments by us on the Subordinated Debt Securities are suspended by the subordination provisions of the Subordinated Indenture.

Each Subsidiary Guarantee will be limited in amount to an amount not to exceed the maximum amount that can be guaranteed by the relevant Subsidiary Guarantor without rendering such Subsidiary Guarantee voidable under applicable law relating to fraudulent conveyance or fraudulent transfer or similar laws affecting the rights of creditors generally.

(1) remain in full force and effect until either (a) payment in full of all the applicable Debt Securities (or such Debt Securities are otherwise satisfied and discharged in accordance with the provisions of the applicable Indenture) or (b) released as described in the following paragraph;

(3) inure to the benefit of and be enforceable by the applicable Trustee, the Holders and their successors, transferees and assigns.

In the event that (a) a Subsidiary Guarantor ceases to be a Subsidiary, (b) either legal defeasance or covenant defeasance occurs with respect to the series or (c) all or substantially all of the assets or all of the Capital Stock of such Subsidiary Guarantor is sold, including by way of sale, merger, consolidation or otherwise, such Subsidiary Guarantor will be released and discharged of its obligations under its Subsidiary Guarantee without any further action required on the part of the Trustee or any Holder, and no other person acquiring or owning the assets or Capital Stock of such Subsidiary Guarantor will be required to enter into a Subsidiary Guarantee. In addition, the prospectus supplement may specify additional circumstances under which a Subsidiary Guarantor can be released from its Subsidiary Guarantee.

The Debt Securities of each series will be issuable only in fully registered form, without coupons, and, unless otherwise specified in the applicable prospectus supplement, only in denominations of $1,000 and integral multiples thereof.

At the option of the Holder, subject to the terms of the applicable Indenture and the limitations applicable to Global Securities, Debt Securities of each series will be exchangeable for other Debt Securities of the same series of any authorized denomination and of a like tenor and aggregate principal amount.

Subject to the terms of the applicable Indenture and the limitations applicable to Global Securities, Debt Securities may be presented for exchange as provided above or for registration of transfer (duly endorsed or with the form of transfer endorsed thereon duly executed) at the office of the Security Registrar or at the office of any transfer agent designated by us for such purpose. No service charge will be made for any registration of transfer or exchange of Debt Securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in that connection. Such transfer or exchange will be effected upon the Security Registrar or such transfer agent, as the case may be, being satisfied with the documents of title and identity of the person making the request. The Security Registrar and any other transfer agent initially designated by us for any Debt Securities will be named in the applicable prospectus supplement. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each Place of Payment for the Debt Securities of each series.

If the Debt Securities of any series (or of any series and specified tenor) are to be redeemed in part, we will not be required to (1) issue, register the transfer of or exchange any Debt Security of that series (or of that series and specified tenor, as the case may be) during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any such Debt Security that may be selected for redemption and ending at the close of business on the day of such mailing or (2) register the transfer of or exchange any Debt Security so selected for redemption, in whole or in part, except the unredeemed portion of any such Debt Security being redeemed in part.

Some or all of the Debt Securities of any series may be represented, in whole or in part, by one or more Global Securities that will have an aggregate principal amount equal to that of the Debt Securities they represent. Each Global Security will be registered in the name of a Depositary or its nominee identified in the applicable prospectus supplement, will be deposited with such Depositary or nominee or its custodian and will bear a legend regarding the restrictions on exchanges and registration of transfer thereof referred to below and any such other matters as may be provided for pursuant to the applicable Indenture.

Notwithstanding any provision of the Indentures or any Debt Security described in this prospectus, no Global Security may be exchanged in whole or in part for Debt Securities registered, and no transfer of a Global Security in whole or in part may be registered, in the name of any Person other than the Depositary for such Global Security or any nominee of such Depositary unless:

(1) the Depositary has notified us that it is unwilling or unable to continue as Depositary for such Global Security or has ceased to be qualified to act as such as required by the applicable Indenture, and in either case we fail to appoint a successor Depositary within 90 days;

(2) an Event of Default with respect to the Debt Securities represented by such Global Security has occurred and is continuing and the Trustee has received a written request from the Depositary to issue certificated Debt Securities;

(3) subject to the rules of the Depositary, we shall have elected to terminate the book-entry system through the Depositary; or

(4) other circumstances exist, in addition to or in lieu of those described above, as may be described in the applicable prospectus supplement.

All certificated Debt Securities issued in exchange for a Global Security or any portion thereof will be registered in such names as the Depositary may direct.

As long as the Depositary, or its nominee, is the registered holder of a Global Security, the Depositary or such nominee, as the case may be, will be considered the sole owner and Holder of such Global Security and the Debt Securities that it represents for all purposes under the Debt Securities and the applicable Indenture. Except in the limited circumstances referred to above, owners of beneficial interests in a Global Security will not be entitled to have such Global Security or any Debt Securities that it represents registered in their names, will not receive or be entitled to receive physical delivery of certificated Debt Securities in exchange for those interests

and will not be considered to be the owners or Holders of such Global Security or any Debt Securities that is represents for any purpose under the Debt Securities or the applicable Indenture. All payments on a Global Security will be made to the Depositary or its nominee, as the case may be, as the Holder of the security. The laws of some jurisdictions may require that some purchasers of Debt Securities take physical delivery of such Debt Securities in certificated form. These laws may impair the ability to transfer beneficial interests in a Global Security.

Ownership of beneficial interests in a Global Security will be limited to institutions that have accounts with the Depositary or its nominee (“participants”) and to persons that may hold beneficial interests through participants. In connection with the issuance of any Global Security, the Depositary will credit, on its book-entry registration and transfer system, the respective principal amounts of Debt Securities represented by the Global Security to the accounts of its participants. Ownership of beneficial interests in a Global Security will be shown only on, and the transfer of those ownership interests will be effected only through, records maintained by the Depositary (with respect to participants’ interests) or any such participant (with respect to interests of Persons held by such participants on their behalf). Payments, transfers, exchanges and other matters relating to beneficial interests in a Global Security may be subject to various policies and procedures adopted by the Depositary from time to time. None of us, the Subsidiary Guarantors, the Trustees or the agents of us, the Subsidiary Guarantors or the Trustees will have any responsibility or liability for any aspect of the Depositary’s or any participant’s records relating to, or for payments made on account of, beneficial interests in a Global Security, or for maintaining, supervising or reviewing any records relating to such beneficial interests.

Unless otherwise indicated in the applicable prospectus supplement, payment of interest on a Debt Security on any Interest Payment Date will be made to the Person in whose name such Debt Security (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest.

Unless otherwise indicated in the applicable prospectus supplement, principal of and any premium and interest on the Debt Securities of a particular series will be payable at the office of such Paying Agent or Paying Agents as we may designate for such purpose from time to time, except that at our option payment of any interest on Debt Securities in certificated form may be made by check mailed to the address of the Person entitled thereto as such address appears in the Security Register. Unless otherwise indicated in the applicable prospectus supplement, the corporate trust office of the Trustee under the Senior Indenture in The City of New York will be designated as sole Paying Agent for payments with respect to Senior Debt Securities of each series, and the corporate trust office of the Trustee under the Subordinated Indenture in The City of New York will be designated as the sole Paying Agent for payment with respect to Subordinated Debt Securities of each series. Any other Paying Agents initially designated by us for the Debt Securities of a particular series will be named in the applicable prospectus supplement. We may at any time designate additional Paying Agents or rescind the designation of any Paying Agent or approve a change in the office through which any Paying Agent acts, except that we will be required to maintain a Paying Agent in each Place of Payment for the Debt Securities of a particular series.

All money paid by us to a Paying Agent for the payment of the principal of or any premium or interest on any Debt Security which remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the Holder of such Debt Security thereafter may look only to us for payment.

Unless otherwise specified in the prospectus supplement, we may not consolidate with or merge into, or transfer, lease or otherwise dispose of all or substantially all of our assets to, any Person (a “successor Person”), and may not permit any Person to consolidate with or merge into us, unless:

(1) the successor Person (if not us) is a corporation, partnership, trust or other entity organized and validly existing under the laws of any domestic jurisdiction and assumes our obligations on the Debt Securities and under the Indentures;

(2) immediately before and after giving pro forma effect to the transaction, no Event of Default, and no event which, after notice or lapse of time or both, would become an Event of Default, has occurred and is continuing; and

(3) several other conditions, including any additional conditions with respect to any particular Debt Securities specified in the applicable prospectus supplement, are met.

The successor Person (if not us) will be substituted for us under the applicable Indenture with the same effect as if it had been an original party to such Indenture, and, except in the case of a lease, we will be relieved from any further obligations under such Indenture and the Debt Securities.

Unless otherwise specified in the prospectus supplement, each of the following will constitute an Event of Default under the applicable Indenture with respect to Debt Securities of any series:

(1) failure to pay principal of or any premium on any Debt Security of that series when due, whether or not, in the case of Subordinated Debt Securities, such payment is prohibited by the subordination provisions of the Subordinated Indenture;

(2) failure to pay any interest on any Debt Securities of that series when due, continued for 30 days, whether or not, in the case of Subordinated Debt Securities, such payment is prohibited by the subordination provisions of the Subordinated Indenture;

(3) failure to deposit any sinking fund payment, when due, in respect of any Debt Security of that series, whether or not, in the case of Subordinated Debt Securities, such deposit is prohibited by the subordination provisions of the Subordinated Indenture;

(4) failure to perform or comply with the provisions described under “— Consolidation, Merger and Sale of Assets”;

(5) failure to perform any of our other covenants in such Indenture (other than a covenant included in such Indenture solely for the benefit of a series other than that series), continued for 60 days after written notice has been given by the applicable Trustee, or the Holders of at least 25% in principal amount of the Outstanding Debt Securities of that series, as provided in such Indenture;

(6) any Debt of ourself, any Significant Subsidiary or, if a Subsidiary Guarantor has guaranteed the series, such Subsidiary Guarantor, is not paid within any applicable grace period after final maturity or is accelerated by its holders because of a default and the total amount of such Debt unpaid or accelerated exceeds $20.0 million;

(7) any judgment or decree for the payment of money in excess of $20.0 million is entered against us, any Significant Subsidiary or, if a Subsidiary Guarantor has guaranteed the series, such Subsidiary Guarantor, remains outstanding for a period of 60 consecutive days following entry of such judgment and is not discharged, waived or stayed;

(8) certain events of bankruptcy, insolvency or reorganization affecting us, any Significant Subsidiary or, if a Subsidiary Guarantor has guaranteed the series, such Subsidiary Guarantor; and

(9) if any Subsidiary Guarantor has guaranteed such series, the Subsidiary Guarantee of any such Subsidiary Guarantor is held by a final non-appealable order or judgment of a court of competent jurisdiction to be unenforceable or invalid or ceases for any reason to be in full force and effect (other than in accordance with the terms of the applicable Indenture) or any Subsidiary Guarantor or any Person acting on behalf of any Subsidiary Guarantor denies or disaffirms such Subsidiary Guarantor’s obligations under its Subsidiary Guarantee (other than by reason of a release of such Subsidiary Guarantor from its Subsidiary Guarantee in accordance with the terms of the applicable Indenture).

If an Event of Default (other than an Event of Default with respect to Oasis Petroleum Inc. described in clause (8) above) with respect to the Debt Securities of any series at the time Outstanding occurs and is continuing, either the applicable Trustee or the Holders of at least 25% in principal amount of the Outstanding

Debt Securities of that series by notice as provided in the Indenture may declare the principal amount of the Debt Securities of that series (or, in the case of any Debt Security that is an Original Issue Discount Debt Security, such portion of the principal amount of such Debt Security as may be specified in the terms of such Debt Security) to be due and payable immediately, together with any accrued and unpaid interest thereon. If an Event of Default with respect to Oasis Petroleum Inc. described in clause (8) above with respect to the Debt Securities of any series at the time Outstanding occurs, the principal amount of all the Debt Securities of that series (or, in the case of any such Original Issue Discount Security, such specified amount) will automatically, and without any action by the applicable Trustee or any Holder, become immediately due and payable, together with any accrued and unpaid interest thereon. After any such acceleration and its consequences, but before a judgment or decree based on acceleration, the Holders of a majority in principal amount of the Outstanding Debt Securities of that series may, under certain circumstances, rescind and annul such acceleration if all Events of Default with respect to that series, other than the non-payment of accelerated principal (or other specified amount), have been cured or waived as provided in the applicable Indenture. For information as to waiver of defaults, see “— Modification and Waiver” below.

Subject to the provisions of the Indentures relating to the duties of the Trustees in case an Event of Default has occurred and is continuing, no Trustee will be under any obligation to exercise any of its rights or powers under the applicable Indenture at the request or direction of any of the Holders, unless such Holders have offered to such Trustee reasonable security or indemnity. Subject to such provisions for the indemnification of the Trustees, the Holders of a majority in principal amount of the Outstanding Debt Securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the Trustee or exercising any trust or power conferred on the Trustee with respect to the Debt Securities of that series.

No Holder of a Debt Security of any series will have any right to institute any proceeding with respect to the applicable Indenture, or for the appointment of a receiver or a trustee, or for any other remedy thereunder, unless:

(1) such Holder has previously given to the Trustee under the applicable Indenture written notice of a continuing Event of Default with respect to the Debt Securities of that series;

(2) the Holders of at least 25% in principal amount of the Outstanding Debt Securities of that series have made written request, and such Holder or Holders have offered reasonable security or indemnity, to the Trustee to institute such proceeding as trustee; and

(3) the Trustee has failed to institute such proceeding, and has not received from the Holders of a majority in principal amount of the Outstanding Debt Securities of that series a direction inconsistent with such request, within 60 days after such notice, request and offer.

However, such limitations do not apply to a suit instituted by a Holder of a Debt Security for the enforcement of payment of the principal of or any premium or interest on such Debt Security on or after the applicable due date specified in such Debt Security or, if applicable, to convert such Debt Security.

We will be required to furnish to each Trustee annually a statement by certain of our officers as to whether or not we, to their knowledge, are in default in the performance or observance of any of the terms, provisions and conditions of the applicable Indenture and, if so, specifying all such known defaults.

We may modify or amend an Indenture without the consent of any holders of the Debt Securities in certain circumstances, including:

(1) to evidence the succession under the Indenture of another Person to us or any Subsidiary Guarantor and to provide for its assumption of our or such Subsidiary Guarantor’s obligations to holders of Debt Securities;

(2) to make any changes that would add any additional covenants of us or the Subsidiary Guarantors for the benefit of the holders of Debt Securities or that do not adversely affect the rights under the Indenture of the Holders of Debt Securities in any material respect;

(4) to provide for uncertificated notes in addition to or in place of certificated notes;

(7) to evidence and provide for the acceptance of appointment under the Indenture of a successor Trustee;

(10) in the case of any Subordinated Debt Security, to make any change in the subordination provisions that limits or terminates the benefits applicable to any Holder of Senior Debt.

Other modifications and amendments of an Indenture may be made by us, the Subsidiary Guarantors, if applicable, and the applicable Trustee with the consent of the Holders of a majority in principal amount of the Outstanding Debt Securities of each series affected by such modification or amendment; provided, however, that no such modification or amendment may, without the consent of the Holder of each Outstanding Debt Security affected thereby:

(1) change the Stated Maturity of the principal of, or any installment of principal of or interest on, any Debt Security;

(2) reduce the principal amount of, or any premium or interest on, any Debt Security;

(3) reduce the amount of principal of an Original Issue Discount Security or any other Debt Security payable upon acceleration of the Maturity thereof;

(4) change the place or currency of payment of principal of, or any premium or interest on, any Debt Security;

(5) impair the right to institute suit for the enforcement of any payment due on or any conversion right with respect to any Debt Security;

(6) modify the subordination provisions in the case of Subordinated Debt Securities, or modify any conversion provisions, in either case in a manner adverse to the Holders of the Subordinated Debt Securities;

(7) except as provided in the applicable Indenture, release the Subsidiary Guarantee of a Subsidiary Guarantor;

(8) reduce the percentage in principal amount of Outstanding Debt Securities of any series, the consent of whose Holders is required for modification or amendment of the Indenture;

(9) reduce the percentage in principal amount of Outstanding Debt Securities of any series necessary for waiver of compliance with certain provisions of the Indenture or for waiver of certain defaults;

(10) modify such provisions with respect to modification, amendment or waiver; or

(11) following the making of an offer to purchase Debt Securities from any Holder that has been made pursuant to a covenant in such Indenture, modify such covenant in a manner adverse to such Holder.

The Holders of a majority in principal amount of the Outstanding Debt Securities of any series may waive compliance by us with certain restrictive provisions of the applicable Indenture. The Holders of a majority in principal amount of the Outstanding Debt Securities of any series may waive any past default under the applicable Indenture, except a default in the payment of principal, premium or interest and certain covenants and provisions of the Indenture which cannot be amended without the consent of the Holder of each Outstanding Debt Security of such series.

Each of the Indentures provides that in determining whether the Holders of the requisite principal amount of the Outstanding Debt Securities have given or taken any direction, notice, consent, waiver or other action under such Indenture as of any date:

(1) the principal amount of an Original Issue Discount Security that will be deemed to be Outstanding will be the amount of the principal that would be due and payable as of such date upon acceleration of maturity to such date;

(2) if, as of such date, the principal amount payable at the Stated Maturity of a Debt Security is not determinable (for example, because it is based on an index), the principal amount of such Debt Security deemed to be Outstanding as of such date will be an amount determined in the manner prescribed for such Debt Security;

(3) the principal amount of a Debt Security denominated in one or more foreign currencies or currency units that will be deemed to be Outstanding will be the United States-dollar equivalent, determined as of such date in the manner prescribed for such Debt Security, of the principal amount of such Debt Security (or, in the case of a Debt Security described in clause (1) or (2) above, of the amount described in such clause); and

(4) certain Debt Securities, including those owned by us, any Subsidiary Guarantor or any of our other Affiliates, will not be deemed to be Outstanding.

Except in certain limited circumstances, we will be entitled to set any day as a record date for the purpose of determining the Holders of Outstanding Debt Securities of any series entitled to give or take any direction, notice, consent, waiver or other action under the applicable Indenture, in the manner and subject to the limitations provided in the Indenture. In certain limited circumstances, the Trustee will be entitled to set a record date for action by Holders. If a record date is set for any action to be taken by Holders of a particular series, only persons who are Holders of Outstanding Debt Securities of that series on the record date may take such action. To be effective, such action must be taken by Holders of the requisite principal amount of such Debt Securities within a specified period following the record date. For any particular record date, this period will be 180 days or such other period as may be specified by us (or the Trustee, if it set the record date), and may be shortened or lengthened (but not beyond 180 days) from time to time.

Each Indenture will be discharged and will cease to be of further effect as to all outstanding Debt Securities of any series issued thereunder, when:

(a) all outstanding Debt Securities of that series that have been authenticated (except lost, stolen or destroyed Debt Securities that have been replaced or paid and Debt Securities for whose payment money has theretofore been deposited in trust and thereafter repaid to us) have been delivered to the Trustee for cancellation; or

(b) all outstanding Debt Securities of that series that have been not delivered to the Trustee for cancellation have become due and payable or will become due and payable at their Stated Maturity within one year or are to be called for redemption within one year under arrangements satisfactory to the Trustee and in any case we have irrevocably deposited with the Trustee as trust funds money in an amount sufficient, without consideration of any reinvestment of interest, to pay the entire indebtedness of such Debt Securities not delivered to the Trustee for cancellation, for principal, premium, if any, and accrued interest to the Stated Maturity or redemption date;

(2) we have paid or caused to be paid all other sums payable by us under the Indenture with respect to the Debt Securities of that series; and

(3) we have delivered an Officers’ Certificate and an Opinion of Counsel to the Trustee stating that all conditions precedent to satisfaction and discharge of the Indenture with respect to the Debt Securities of that series have been satisfied.

To the extent indicated in the applicable prospectus supplement, we may elect, at our option at any time, to have our obligations discharged under provisions relating to defeasance and discharge of indebtedness, which we call “legal defeasance,” or relating to defeasance of certain restrictive covenants applied to the Debt Securities of any series, or to any specified part of a series, which we call “covenant defeasance”.

Legal Defeasance. The Indentures provide that, upon our exercise of our option (if any) to have the legal defeasance provisions applied to any series of Debt Securities, we and, if applicable, each Subsidiary Guarantor will be discharged from all our obligations, and, if such Debt Securities are Subordinated Debt Securities, the provisions of the Subordinated Indenture relating to subordination will cease to be effective, with respect to such Debt Securities (except for certain obligations to convert, exchange or register the transfer of Debt Securities, to replace stolen, lost or mutilated Debt Securities, to maintain paying agencies and to hold moneys for payment in trust) upon the deposit in trust for the benefit of the Holders of such Debt Securities of money or U.S. Government Obligations, or both, which, through the payment of principal and interest in respect thereof in accordance with their terms, will provide money in an amount sufficient (in the opinion of a nationally recognized firm of independent public accountants) to pay the principal of and any premium and interest on such Debt Securities on the respective Stated Maturities in accordance with the terms of the applicable Indenture and such Debt Securities. Such defeasance or discharge may occur only if, among other things:

(1) we have delivered to the applicable Trustee an Opinion of Counsel to the effect that we have received from, or there has been published by, the United States Internal Revenue Service a ruling, or there has been a change in tax law, in either case to the effect that Holders of such Debt Securities will not recognize gain or loss for federal income tax purposes as a result of such deposit and legal defeasance and will be subject to federal income tax on the same amount, in the same manner and at the same times as would have been the case if such deposit and legal defeasance were not to occur;

(2) no Event of Default or event that with the passing of time or the giving of notice, or both, shall constitute an Event of Default shall have occurred and be continuing at the time of such deposit or, with respect to any Event of Default described in clause (8) under “— Events of Default,” at any time until 121 days after such deposit;

(3) such deposit and legal defeasance will not result in a breach or violation of, or constitute a default under, any agreement or instrument (other than the applicable Indenture) to which we are a party or by which we are bound;

(4) in the case of Subordinated Debt Securities, at the time of such deposit, no default in the payment of all or a portion of principal of (or premium, if any) or interest on any Senior Debt shall have occurred and be continuing, no event of default shall have resulted in the acceleration of any Senior Debt and no other event of default with respect to any Senior Debt shall have occurred and be continuing permitting after notice or the lapse of time, or both, the acceleration thereof; and

(5) we have delivered to the Trustee an Opinion of Counsel to the effect that such deposit shall not cause the Trustee or the trust so created to be subject to the Investment Company Act of 1940.

Covenant Defeasance. The Indentures provide that, upon our exercise of our option (if any) to have the covenant defeasance provisions applied to any Debt Securities, we may fail to comply with certain restrictive covenants (but not with respect to conversion, if applicable), including those that may be described in the applicable prospectus supplement, and the occurrence of certain Events of Default, which are described above in clause (5) (with respect to such restrictive covenants) and clauses (6), (7) and (9) under “Events of Default” and any that may be described in the applicable prospectus supplement, will not be deemed to either be or result in an Event of Default and, if such Debt Securities are Subordinated Debt Securities, the provisions of the Subordinated Indenture relating to subordination will cease to be effective, in each case with respect to such Debt Securities. In order to exercise such option, we must deposit, in trust for the benefit of the Holders of such Debt Securities, money or U.S. Government Obligations, or both, which, through the payment of principal and interest in respect thereof in accordance with their terms, will provide money in an amount sufficient (in the opinion of a nationally recognized firm of independent public accountants) to pay the principal of and any premium and interest on such Debt Securities on the respective Stated Maturities in accordance with the terms of the applicable

Indenture and such Debt Securities. Such covenant defeasance may occur only if we have delivered to the applicable Trustee an Opinion of Counsel to the effect that Holders of such Debt Securities will not recognize gain or loss for federal income tax purposes as a result of such deposit and covenant defeasance and will be subject to federal income tax on the same amount, in the same manner and at the same times as would have been the case if such deposit and covenant defeasance were not to occur, and the requirements set forth in clauses (2), (3), (4) and (5) above are satisfied. If we exercise this option with respect to any series of Debt Securities and such Debt Securities were declared due and payable because of the occurrence of any Event of Default, the amount of money and U.S. Government Obligations so deposited in trust would be sufficient to pay amounts due on such Debt Securities at the time of their respective Stated Maturities but may not be sufficient to pay amounts due on such Debt Securities upon any acceleration resulting from such Event of Default. In such case, we would remain liable for such payments.

If we exercise either our legal defeasance or covenant defeasance option, any Subsidiary Guarantee will terminate.

No director, officer, employee, incorporator, stockholder, member, partner or trustee of the Company or any Subsidiary Guarantor, as such, shall have any liability for any obligations of the Company or any Subsidiary Guarantor under the Debt Securities, the Indentures or any Subsidiary Guarantees or for any claim based on, in respect of, or by reason of, such obligations or their creation. By accepting a Debt Security, each Holder shall be deemed to have waived and released all such liability. The waiver and release shall be a part of the consideration for the issue of the Debt Securities. The waiver may not be effective to waive liabilities under the federal securities laws, and it is the view of the SEC that such a waiver is against public policy.

Notices to Holders of Debt Securities will be given by mail to the addresses of such Holders as they may appear in the Security Register.

We, the Subsidiary Guarantors, the Trustees and any agent of us, the Subsidiary Guarantors or a Trustee may treat the Person in whose name a Debt Security is registered as the absolute owner of the Debt Security (whether or not such Debt Security may be overdue) for the purpose of making payment and for all other purposes.

The Indentures and the Debt Securities will be governed by, and construed in accordance with, the law of the State of New York.

We will enter into the Indentures with a Trustee that is qualified to act under the Trust Indenture Act of 1939, as amended, and with any other Trustees chosen by us and appointed in a supplemental indenture for a particular series of Debt Securities. We may maintain a banking relationship in the ordinary course of business with our Trustee and one or more of its affiliates.

Resignation or Removal of Trustee. If the Trustee has or acquires a conflicting interest within the meaning of the Trust Indenture Act, the Trustee must either eliminate its conflicting interest or resign, to the extent and in the manner provided by, and subject to the provisions of, the Trust Indenture Act and the applicable Indenture. Any resignation will require the appointment of a successor Trustee under the applicable Indenture in accordance with the terms and conditions of such Indenture.

The Trustee may resign or be removed by us with respect to one or more series of Debt Securities and a successor Trustee may be appointed to act with respect to any such series. The holders of a majority in aggregate principal amount of the Debt Securities of any series may remove the Trustee with respect to the Debt Securities of such series.

Limitations on Trustee if It Is Our Creditor. Each Indenture will contain certain limitations on the right of the Trustee, in the event that it becomes our creditor, to obtain payment of claims in certain cases, or to realize on certain property received in respect of any such claim as security or otherwise.

Certificates and Opinions to Be Furnished to Trustee. Each Indenture will provide that, in addition to other certificates or opinions that may be specifically required by other provisions of an Indenture, every application by us for action by the Trustee must be accompanied by an Officers’ Certificate and an Opinion of Counsel stating that, in the opinion of the signers, all conditions precedent to such action have been complied with by us.

The authorized capital stock of Oasis Petroleum Inc. consists of 300,000,000 shares of common stock, $0.01 par value per share, and 50,000,000 shares of preferred stock, $0.01 par value per share.

We adopted an amended and restated certificate of incorporation (the “Amended Charter”) and amended and restated bylaws (the “Amended Bylaws”) concurrently with the completion of our initial public offering. The following summary of the capital stock and Amended Charter and Amended Bylaws of Oasis Petroleum Inc. does not purport to be complete and is qualified in its entirety by reference to the provisions of applicable law and to our Amended Charter and Amended Bylaws, which are filed as exhibits to the registration statement filed in connection with our initial public offering.

As of June 30, 2011, we had 92,450,195 shares of common stock outstanding, all of which is voting common stock.

Except as provided by law or in a preferred stock designation, holders of common stock are entitled to one vote for each share held of record on all matters submitted to a vote of the stockholders, will have the exclusive right to vote for the election of directors and do not have cumulative voting rights. Except as otherwise required by law, holders of common stock, as such, are not entitled to vote on any amendment to the Amended Charter (including any certificate of designations relating to any series of preferred stock) that relates solely to the terms of any outstanding series of preferred stock if the holders of such affected series are entitled, either separately or together with the holders of one or more other such series, to vote thereon pursuant to the Amended Charter (including any certificate of designations relating to any series of preferred stock) or pursuant to the General Corporation Law of the State of Delaware. Subject to preferences that may be applicable to any outstanding shares or series of preferred stock, holders of common stock are entitled to receive ratably such dividends (payable in cash, stock or otherwise), if any, as may be declared from time to time by our board of directors out of funds legally available for dividend payments. All outstanding shares of common stock are fully paid and non-assessable, and the shares of common stock to be issued upon completion of this offering will be fully paid and non-assessable. The holders of common stock have no preferences or rights of conversion, exchange, pre-emption or other subscription rights. There are no redemption or sinking fund provisions applicable to the common stock. In the event of any liquidation, dissolution or winding-up of our affairs, holders of common stock will be entitled to share ratably in our assets that are remaining after payment or provision for payment of all of our debts and obligations and after liquidation payments to holders of outstanding shares of preferred stock, if any.

Our Amended Charter authorizes our board of directors, subject to any limitations prescribed by law, without further stockholder approval, to establish and to issue from time to time one or more classes or series of preferred stock, par value $0.01 per share, covering up to an aggregate of 50,000,000 shares of preferred stock. Each class or series of preferred stock will cover the number of shares and will have the powers, preferences, rights, qualifications, limitations and restrictions determined by the board of directors, which may include, among others, dividend rights, liquidation preferences, voting rights, conversion rights, preemptive rights and redemption rights. Except as provided by law or in a preferred stock designation, the holders of preferred stock will not be entitled to vote at or receive notice of any meeting of stockholders.

Anti-Takeover Effects of Provisions of Our Amended Charter, Our Amended Bylaws and Delaware Law

Some provisions of Delaware law, and our Amended Charter and our Amended Bylaws described below, contains provisions that could make the following transactions more difficult: acquisitions of us by means of a tender offer, a proxy contest or otherwise; or removal of our incumbent officers and directors. These provisions may also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that might result in a premium over the market price for our shares.

These provisions, summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with us. We believe that the benefits of increased protection and our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because, among other things, negotiation of these proposals could result in an improvement of their terms.

We are subject to the provisions of Section 203 of the Delaware General Corporation Law, or DGCL, regulating corporate takeovers. In general, those provisions prohibit a Delaware corporation, including those whose securities are listed for trading on the NYSE, from engaging in any business combination with any interested stockholder for a period of three years following the date that the stockholder became an interested stockholder, unless:

In general, Section 203 defines an interested stockholder as any entity or person beneficially owning 15% or more of the outstanding voting stock of the corporation and any entity or person affiliated with or controlling or controlled by any of these entities or persons.

A Delaware corporation may “opt out” of Section 203 with an express provision in its original certificate of incorporation or an express provision in its certificate of incorporation or bylaws resulting from amendments approved by the holders of at least a majority of the corporation’s outstanding voting shares. We did not “opt out” of the provisions of Section 203. The statute could prohibit or delay mergers or other takeover or change in control attempts and, accordingly, may discourage attempts to acquire us.

These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. Our Amended Bylaws specify the requirements as to form and content of all stockholders’ notices. These requirements may preclude stockholders from bringing matters before the stockholders at an annual or special meeting;

Our Amended Charter limits the liability of our directors for monetary damages for breach of their fiduciary duty as directors, except for liability that cannot be eliminated under the DGCL. Delaware law provides that

directors of a company will not be personally liable for monetary damages for breach of their fiduciary duty as directors, except for liabilities:

Any amendment, repeal or modification of these provisions will be prospective only and would not affect any limitation on liability of a director for acts or omissions that occurred prior to any such amendment, repeal or modification.

Our Amended Charter and Amended Bylaws also provide that we will indemnify our directors and officers to the fullest extent permitted by Delaware law. Our Amended Charter and Amended Bylaws also permit us to purchase insurance on behalf of any officer, director, employee or other agent for any liability arising out of that person’s actions as our officer, director, employee or agent, regardless of whether Delaware law would permit indemnification. We intend to enter into indemnification agreements with each of our current and future directors and officers. These agreements will require us to indemnify these individuals to the fullest extent permitted under Delaware law against liability that may arise by reason of their service to us, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified. We believe that the limitation of liability provision in our Amended Charter and the indemnification agreements will facilitate our ability to continue to attract and retain qualified individuals to serve as directors and officers.

Our Amended Charter provides that, to the fullest extent permitted by applicable law, we renounce any interest or expectancy in, or in being offered an opportunity to participate in, any business opportunity that may be from time to time presented to EnCap or its affiliates or any of their respective officers, directors, agents, shareholders, members, partners, affiliates and subsidiaries (other than us and our subsidiaries) or business opportunities that such parties participate in or desire to participate in, even if the opportunity is one that we might reasonably have pursued or had the ability or desire to pursue if granted the opportunity to do so, and no such person shall be liable to us for breach of any fiduciary or other duty, as a director or officer or controlling stockholder or otherwise, by reason of the fact that such person pursues or acquires any such business opportunity, directs any such business opportunity to another person or fails to present any such business opportunity, or information regarding any such business opportunity, to us unless, in the case of any such person who is our director or officer, any such business opportunity is expressly offered to such director or officer solely in his or her capacity as our director or officer.

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

We may issue warrants for the purchase of our common stock. Warrants may be issued independently or together with Debt Securities, preferred stock or common stock offered by any prospectus supplement and may be attached to or separate from any such offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent, all as set forth in the prospectus supplement relating to the particular issue of warrants. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders of warrants or beneficial owners of warrants. The following summary of certain provisions of the warrants does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all provisions of the warrant agreements.

You should refer to the prospectus supplement relating to a particular issue of warrants for the terms of and information relating to the warrants, including, where applicable:

(1) the number of shares of common stock purchasable upon exercise of the warrants and the price at which such number of shares of common stock may be purchased upon exercise of the warrants;

(2) the date on which the right to exercise the warrants commences and the date on which such right expires (the “Expiration Date”);

(4) the amount of the warrants outstanding as of the most recent practicable date; and

Warrants will be offered and exercisable for United States dollars only. Warrants will be issued in registered form only. Each warrant will entitle its holder to purchase such number of shares of common stock at such exercise price as is in each case set forth in, or calculable from, the prospectus supplement relating to the warrants. The exercise price may be subject to adjustment upon the occurrence of events described in such prospectus supplement. After the close of business on the Expiration Date (or such later date to which we may extend such Expiration Date), unexercised warrants will become void. The place or places where, and the manner in which, warrants may be exercised will be specified in the prospectus supplement relating to such warrants.

Prior to the exercise of any warrants, holders of the warrants will not have any of the rights of holders of common stock, including the right to receive payments of any dividends on the common stock purchasable upon exercise of the warrants, or to exercise any applicable right to vote.

We may sell the offered securities in and outside the United States (1) through underwriters or dealers, (2) directly to purchasers, including our affiliates and stockholders, (3) through agents or (4) through a combination of any of these methods. The prospectus supplement will include the following information:

If underwriters are used in the sale, the underwriters will acquire the securities for their own account for resale to the public, either on a firm commitment basis or a best efforts basis. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless we inform you otherwise in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions. The underwriters may change from time to time any offering price and any discounts or concessions allowed or reallowed or paid to dealers.

During and after an offering through underwriters, the underwriters may purchase and sell the securities in the open market. These transactions may include overallotment and stabilizing transactions and purchases to cover syndicate short positions created in connection with the offering. The underwriters may also impose a penalty bid, which means that selling concessions allowed to syndicate members or other broker-dealers for the offered securities sold for their account may be reclaimed by the syndicate if the offered securities are repurchased by the syndicate in stabilizing or covering transactions. These activities may stabilize, maintain or otherwise affect the market price of the offered securities, which may be higher than the price that might otherwise prevail in the open market. If commenced, the underwriters may discontinue these activities at any time.

If dealers are used, we will sell the securities to them as principals. The dealers may then resell that securities to the public at varying prices determined by the dealers at the time of resale. We will include in the prospectus supplement the names of the dealers and the terms of the transaction.

We may sell the securities directly. In this case, no underwriters or agents would be involved. We may also sell the securities through agents designated from time to time. In the prospectus supplement, we will name any agent involved in the offer or sale of the offered securities, and we will describe any commissions payable to the agent. Unless we inform you otherwise in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of securities. We will describe the terms of any such sales in the prospectus supplement.

Offered securities may also be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreements, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters, as that term is defined in the Securities Act, in connection with the securities remarketed.

If we so indicate in the prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The prospectus supplement will describe the commission payable for solicitation of those contracts.

We may have agreements with the agents, dealers, underwriters and remarketing firms to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the agents, dealers, underwriters or remarketing firms may be required to make. Agents, dealers, underwriters and remarketing firms may be customers of, engage in transactions with, or perform services for us in the ordinary course of their businesses.

Certain legal matters in connection with the securities will be passed upon by Vinson & Elkins L.L.P, Houston, Texas, as our counsel. Any underwriter or agent will be advised about other issues relating to any offering by its own legal counsel.

The consolidated financial statements of Oasis Petroleum Inc. and subsidiaries incorporated in this prospectus by reference to the Current Report on Form 8-K dated July 15, 2011 for the year ended December 31, 2010 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

Certain estimates of our net crude oil and natural gas reserves and related information included or incorporated by reference in this prospectus have been derived from reports prepared by W.D. Von Gonten & Co. and DeGolyer and MacNaughton. All such information has been so included or incorporated by reference on the authority of such firms as experts regarding the matters contained in their reports.



Title of Each Class of Securities Offered	Maximum Aggregate Offering Price	Amount of Registration Fee
6.875% Senior Notes due 2023	$400,000,000	$45,840


	Price to public(1)		Underwriting discounts and commissions		Proceeds, before expenses, to Oasis Petroleum Inc.(1)

Per note		100.00%		1.65%		98.35%
Total	$	400,000,000	$	6,600,000	$	393,400,000


		RBC Capital Markets		UBS Investment Bank
		RBS		Tudor, Pickering, Holt & Co.


Prospectus supplement

About this prospectus supplement			S-ii

Where you can find more information			S-ii

Cautionary statement regarding forward-looking statements			S-iv

Summary			S-1

Risk factors			S-16

Ratio of earnings to fixed charges			S-40

Use of proceeds			S-41

Capitalization			S-42

Description of other indebtedness			S-43

Description of notes			S-47

Certain United States federal income and estate tax considerations			S-109

Underwriting			S-115

Legal matters			S-118

Experts			S-118

Glossary of oil and natural gas terms			A-1

Prospectus

About this Prospectus			1

The Company			1

Where You Can Find More Information			2

Cautionary Statement Regarding Forward-Looking Statements			3

Risk Factors			5

Ratios of Earnings to Fixed Charges			5

Use of Proceeds			5

Description of Debt Securities			6

Description of Capital Stock			18

Description of Warrants			22

Plan of Distribution			23

Legal Matters			25

Experts			25


	As of March 31, 2012
(Dollars in thousands, except share amounts)	Actual			As adjusted for this offering

Cash, cash equivalents and short-term investments(1)	$	287,298		$	679,698


Long-term debt:
Revolving credit facility(2)	$	—		$	—
7.25% Senior Notes due 2019		400,000			400,000
6.5% Senior Notes due 2021		400,000			400,000
6.875% Senior Notes due 2023		—			400,000

Total long-term debt		800,000			1,200,000

Stockholders’ equity:
Common stock, $0.01 par value; 300,000,000 shares authorized; 93,136,773 issued and 93,074,949 outstanding		922			922
Treasury stock, at cost; 61,824 shares		(1,783	)		(1,783	)
Additional paid-in-capital		648,964			648,964
Retained earnings		2,986			2,986

Total stockholders’ equity		651,089			651,089

Total capitalization	$	1,451,089		$	1,851,089


	Period from February 26, 2007 (Inception) through December 31, 2007		Year ended December 31,								Three months ended March 31,
			2008		2009		2010		2011		2011		2012

Ratio of earnings to fixed charges(1)		—		—		—		9.72		4.74		—		2.72


Ratio of total outstanding borrowings to borrowing base	Applicable margin for LIBOR loans		Applicable margin for ABR loans

Less than .25 to 1		1.50%		0.00%
Greater than or equal to .25 to 1 but less than .50 to 1		1.75%		0.25%
Greater than or equal to .50 to 1 but less than .75 to 1		2.00%		0.50%
Greater than or equal to .75 to 1 but less than .90 to 1		2.25%		0.75%
Greater than .90 to 1 but less than or equal 1		2.50%		1.00%


Years	Redemption price

2017		103.438%
2018		102.292%
2019		101.146%
2020 and thereafter		100.000%


Name	Principal amount of notes

J.P. Morgan Securities LLC	$	128,000,000
Citigroup Global Markets Inc.		50,000,000
Wells Fargo Securities, LLC		50,000,000
RBC Capital Markets, LLC		34,000,000
UBS Securities LLC		34,000,000
RBS Securities Inc.		22,000,000
Tudor, Pickering, Holt & Co. Securities, Inc.		22,000,000
Johnson Rice & Company L.L.C.		20,000,000
Simmons & Company International		20,000,000
U.S. Bancorp Investments, Inc.		20,000,000

Total	$	400,000,000


	Per note		Total

Underwriting discounts and commissions paid by us		1.65%	$	6,600,000


ABOUT THIS PROSPECTUS			1
THE COMPANY			1
WHERE YOU CAN FIND MORE INFORMATION			2
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS			3
RISK FACTORS			5
RATIO OF EARNINGS TO FIXED CHARGES			5
USE OF PROCEEDS			5
DESCRIPTION OF DEBT SECURITIES			6
DESCRIPTION OF CAPITAL STOCK			18
DESCRIPTION OF WARRANTS			22
PLAN OF DISTRIBUTION			23
LEGAL MATTERS			25
EXPERTS			25


J.P. Morgan		Citigroup		Wells Fargo Securities