SEC FORM 3

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

ZORICH ROBERT L

(Last)

(First)

(Middle)

1100 LOUISIANA, SUITE 3150

(Street)

HOUSTON

77002

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
06/16/2010

3. Issuer Name and Ticker or Trading Symbol
Oasis Petroleum Inc. [ OAS ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	61,630,000	D⁽¹⁾⁽²⁾⁽³⁾⁽⁴⁾⁽⁵⁾

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)

Explanation of Responses:

1. These securities are directly held by OAS Holding Company LLC ("OAS Holdco").

2. EnCap Energy Capital Fund VI, L.P. ("EnCap Fund VI"), EnCap VI-B Acquisitions, L.P. ("EnCap VI-B") and EnCap Energy Capital Fund VII, L.P. ("EnCap Fund VII" and, together with EnCap Fund VI and EnCap VI-B, the "EnCap Funds") collectively own a 61% interest in OAS Holdco. Therefore, the EnCap Funds may be deemed to beneficially own the reported securities.

3. The EnCap Funds are controlled indirectly by Messrs. Miller, Phillips, Petersen, and Zorich which are members of RNBD GP LLC ("RNBD") and any action taken by RNBD to dispose or acquire securities has to be unanimously approved by all four members. RNBD is the sole member of EnCap Investments GP, L.L.C. ("EnCap Investments GP"), which is the general partner of EnCap Investments L.P. ("EnCap Investments LP"), which is the general partner of EnCap Equity Fund VI GP, L.P. ("EnCap Fund VI GP") and EnCap Equity Fund VII GP, L.P. ("EnCap Fund VII GP"). EnCap Fund VI GP is the sole general partner of each of EnCap Fund VI and EnCap VI-B, and EnCap Fund VII GP is the sole general partner of EnCap Fund VII. Therefore, Messrs. Miller, Phillips, Petersen and Zorich, RNBD, EnCap Investments GP, EnCap Investments LP, EnCap Fund VI GP and EnCap Fund VII GP may be deemed to beneficially own the reported securities.

4. This report is filed in connection with the Form 3 filed jointly today by Messrs. Miller, Phillips and Petersen and RNBD and the Form 3 filed jointly today by the EnCap Funds, EnCap Investments GP, EnCap Investments LP, EnCap Fund VI GP, EnCap Fund VII GP.

5. The reporting person disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the reported securities for purposes of Section 16 or for any other purpose.

	/s/ Robert L. Zorich	06/16/2010
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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