DEFM14A 1 a2234993zdefm14a.htm DEFM14A

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

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.          )

Filed by the Registrant ý

Filed by a Party other than the Registrant o

Check the appropriate box:

o

 

Preliminary Proxy Statement

o

 

Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

ý

 

Definitive Proxy Statement

o

 

Definitive Additional Materials

o

 

Soliciting Material under §240.14a-12

 

Archrock Partners, L.P.

(Name of Registrant as Specified In Its Charter)

 

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

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No fee required.

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Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11.
    (1)   Title of each class of securities to which transaction applies:
        
 
    (2)   Aggregate number of securities to which transaction applies:
        
 
    (3)   Per unit price or other underlying value of transaction computed pursuant to Exchange Act Rule 0-11 (set forth the amount on which the filing fee is calculated and state how it was determined):
        
 
    (4)   Proposed maximum aggregate value of transaction:
        
 
    (5)   Total fee paid:
        
 

o

 

Fee paid previously with preliminary materials.

o

 

Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

 

 

(1)

 

Amount Previously Paid:
        
 
    (2)   Form, Schedule or Registration Statement No.:
        
 
    (3)   Filing Party:
        
 
    (4)   Date Filed:
        
 

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LOGO
 
LOGO

MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT

           On January 1, 2018, Archrock, Inc., a Delaware corporation ("Archrock" or "AROC"), Archrock Partners, L.P., a Delaware limited partnership ("Archrock Partners" or "APLP"), Archrock General Partner, L.P., a Delaware limited partnership and the general partner of Archrock Partners (the "General Partner"), and Archrock GP LLC, a Delaware limited liability company and the general partner of the General Partner (the "Managing GP"), entered into an Agreement and Plan of Merger, which was amended on January 11, 2018 to add Amethyst Merger Sub LLC, a Delaware limited liability company and an indirect wholly owned subsidiary of Archrock ("Merger Sub"), as a party (as amended from time to time, the "merger agreement"), pursuant to which Archrock will acquire all of the outstanding common units representing limited partner interests in Archrock Partners (the "APLP common units," and such holders of APLP common units, "APLP common unitholders") that Archrock and its subsidiaries do not already own. Upon the terms and subject to the conditions set forth in the merger agreement, Merger Sub will be merged with and into Archrock Partners (the "merger"), with Archrock Partners surviving as an indirect wholly owned subsidiary of Archrock.

           The board of directors of Archrock (the "AROC board") has determined that the merger is in the best interests of its common stockholders and has unanimously approved the merger agreement and the merger. The conflicts committee of the board of directors of the Managing GP (the "APLP conflicts committee") and the board of directors of the Managing GP (the "APLP board") each has determined that the merger is in the best interests of Archrock Partners, including the APLP common unitholders other than Archrock and its affiliates (the "APLP unaffiliated unitholders"), and has unanimously approved the merger agreement and the merger.

           If the merger is completed, each outstanding APLP common unit not owned by Archrock or its subsidiaries will be converted into the right to receive 1.40 (the "exchange ratio") shares of common stock, par value $0.01 per share, of Archrock (the "AROC common stock," and such consideration, the "merger consideration"). Based on the closing price of AROC common stock on December 29, 2017, the last trading day before the public announcement of the merger, the aggregate value of the merger consideration was approximately $607 million. The exchange ratio is fixed and will not be adjusted on account of any change in price of either AROC common stock or APLP common units prior to completion of the merger. No fractional shares of AROC common stock will be issued in the merger; instead, all fractions of AROC common stock to which a holder of APLP common units otherwise would have been entitled will be aggregated and the resulting fraction will be rounded up to the nearest whole share of AROC common stock. Existing holders of shares of AROC common stock (the "AROC stockholders") will continue to own their existing AROC common stock. Upon the closing of the merger, former APLP common unitholders and current AROC stockholders will own approximately 44.9% and 55.1%, respectively, of the AROC common stock.

           Archrock will hold its annual meeting of stockholders and Archrock Partners will hold a special meeting of its unitholders in connection with the proposed merger. At the annual meeting of AROC stockholders (the "Archrock annual meeting"), the AROC stockholders will be asked to (i) vote on a proposal to approve the issuance of AROC common stock to APLP common unitholders pursuant to the merger agreement (the "AROC stock issuance proposal"), (ii) elect eight directors to the AROC board to serve until the next annual meeting of AROC stockholders or until their successors are duly elected or appointed and qualified, (iii) ratify the appointment of Deloitte & Touche LLP as Archrock's independent registered public accounting firm for the fiscal year ending December 31, 2018 (the "AROC ratification proposal"), (iv) approve, by a non-binding advisory vote, the compensation provided to Archrock's named executive officers for 2017 (the "AROC advisory compensation proposal") and (v) approve the adjournment of the Archrock annual meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies in the event there are not sufficient votes at the time of the Archrock annual meeting to approve AROC stock issuance proposal (the "AROC adjournment proposal"). Approval of the AROC stock issuance proposal requires the affirmative vote of a majority of the total votes cast on such proposal. The approval of each of the AROC ratification proposal, the AROC advisory compensation proposal and the AROC adjournment proposal requires the affirmative vote of a majority of the votes cast affirmatively or negatively on such proposal. Archrock's directors are elected by a plurality of the votes cast at the Archock annual meeting.

           At the special meeting of the APLP common unitholders (the "Archrock Partners special meeting"), the APLP common unitholders will be asked to (i) vote on the proposal to approve the merger agreement (the "Archrock Partners merger proposal") and (ii) approve the adjournment of the Archrock Partners special meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies in the event there are not sufficient votes at the time of the Archrock Partners special meeting to approve the Archrock Partners merger proposal (the "APLP adjournment proposal"). Approval of the Archrock Partners merger proposal requires the affirmative vote of holders of a majority of the outstanding APLP common units.

           We cannot complete the merger unless the AROC stockholders approve the AROC stock issuance proposal and the APLP common unitholders approve the Archrock Partners merger proposal. Accordingly, your vote is very important regardless of the number of shares of AROC common stock or APLP common units you own. Voting instructions are set forth inside this joint proxy statement/prospectus.

           The board of directors of Archrock recommends that the AROC stockholders vote FOR the AROC stock issuance proposal, FOR each of the eight nominees for election to the AROC board to serve until the next annual meeting of AROC stockholders or until their successors are duly elected or appointed and qualified, FOR the AROC ratification proposal, FOR the AROC advisory compensation proposal and FOR the AROC adjournment proposal. AROC stockholders should be aware that some of Archrock's directors and executive officers may have interests in the merger that are different from, or in addition to, the interests they may have as AROC stockholders. See "The Merger—Interests of Certain Persons in the Merger."

           The APLP conflicts committee and the APLP board each recommend that the APLP common unitholders vote FOR the Archrock Partners merger proposal. The APLP board recommends that the APLP common unitholders vote FOR the adjournment of the Archrock Partners special meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies in the event there are not sufficient votes at the time of the special meeting to approve the matters to be considered at the Archrock Partners special meeting. APLP common unitholders should be aware that some of Archrock Partners' directors and executive officers may have interests in the merger that are different from, or in addition to, the interests they may have as APLP common unitholders. See "The Merger—Interests of Certain Persons in the Merger."

           This joint proxy statement/prospectus provides you with detailed information about the proposed merger and related matters. You are encouraged to read the entire document carefully. In particular, please read "Risk Factors" beginning on page 25 of this joint proxy statement/prospectus for a discussion of risks relevant to the merger and Archrock's business following the merger.

           Shares of AROC common stock are listed on the New York Stock Exchange ("NYSE") under the symbol "AROC," and APLP common units are listed on the NASDAQ Global Select Market ("NASDAQ") under the symbol "APLP." The last reported sale price of AROC common stock on the NYSE on March 16, 2018 was $9.35. The last reported sale price of APLP common units on NASDAQ on March 16, 2018 was $13.00.


LOGO


D. Bradley Childers
President and Chief Executive Officer of
Archrock, Inc.
and
President, Chief Executive Officer and Chairman of
Archrock GP LLC

 

 

           Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued under this joint proxy statement/prospectus or has determined if this document is truthful or complete. Any representation to the contrary is a criminal offense.

           This joint proxy statement/prospectus is dated March 21, 2018 and is being first mailed to AROC stockholders and APLP common unitholders on or about March 21, 2018.


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LOGO
  Houston, Texas
March 21, 2018

 

 

9807 Katy Freeway, Suite 100
Houston, TX 77024

 

 

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To the Stockholders of Archrock, Inc.:

        An annual meeting (the "Archrock annual meeting") of stockholders (the "AROC stockholders") of Archrock, Inc. ("Archrock") will be held on Wednesday, April 25, 2018 at 9:30 a.m., local time, at 9807 Katy Freeway, Suite 100, Houston, TX 77024, for the following purposes:

    to consider and vote upon a proposal to approve the issuance (the "AROC stock issuance") of shares of common stock, par value $0.01 per share (the "AROC common stock"), in connection with the merger (the "merger") contemplated by the Agreement and Plan of Merger, dated as of January 1, 2018, and amended on January 11, 2018 to join Amethyst Merger Sub LLC, a Delaware limited liability company and indirect wholly owned subsidiary of Archrock, as a party thereto (as amended from time to time, the "merger agreement"), by and among Archrock, Archrock Partners, L.P., Archrock General Partner, L.P. and Archrock GP LLC (the "AROC stock issuance proposal");

    to consider and vote upon the election of eight directors to the board of directors of Archrock (the "AROC board") to serve until the next annual meeting of AROC stockholders or until their successors are duly elected or appointed and qualified;

    to consider and vote upon a proposal to ratify the appointment of Deloitte & Touche LLP as Archrock's independent registered public accounting firm for the fiscal year ending December 31, 2018 (the "AROC ratification proposal");

    to consider and vote upon a proposal to approve, by a non-binding advisory vote, the compensation provided to Archrock's named executive officers for 2017 (the "AROC advisory compensation proposal"); and

    to consider and vote on a proposal to approve the adjournment of the Archrock annual meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies in the event there are not sufficient votes at the time of the annual meeting to approve the above AROC stock issuance proposal (the "AROC adjournment proposal").

        Approval of the AROC stock issuance proposal requires the affirmative vote of a majority of the total votes cast on such proposal. The approval of each of the AROC ratification proposal, the AROC advisory compensation proposal and the AROC adjournment proposal requires the affirmative vote of a majority of the votes cast affirmatively or negatively on such proposal. Archrock's directors are elected by a plurality of the votes cast at the Archock annual meeting. Abstentions will have the same effect as votes against the AROC stock issuance proposal. Abstentions will have no effect on the AROC ratification proposal, the AROC advisory compensation proposal, the AROC adjournment proposal or the election of directors to the AROC board. Assuming there is a quorum, failures to vote and broker non-votes (if any) will have no effect on the AROC stock issuance proposal, the AROC advisory compensation proposal, the AROC adjournment proposal or the election of directors to the AROC board. Under applicable rules of the New York Stock Exchange, brokers are permitted to vote uninstructed shares at their discretion regarding the AROC ratification proposal, so broker non-votes are not expected on such proposal.

        We cannot complete the merger unless the AROC stockholders approve the AROC stock issuance proposal. Accordingly, your vote is very important regardless of the number of shares of AROC common stock you own.

        The AROC board has unanimously determined that the merger, the merger agreement and the transactions contemplated thereby, including the AROC stock issuance, are advisable, fair and reasonable to, and in the best interests of, Archrock and the AROC stockholders. The AROC board


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has unanimously approved the merger, the merger agreement and the transactions contemplated thereby, including the AROC stock issuance, and recommends that the AROC stockholders vote FOR the AROC stock issuance proposal, FOR each of the eight nominees for election to the AROC board to serve until the next annual meeting of AROC stockholders or until their successors are duly elected or appointed and qualified, FOR the AROC ratification proposal, FOR the AROC advisory compensation proposal and FOR the AROC adjournment proposal. For more information regarding the recommendation of the AROC board, see "The Merger—Recommendation of the AROC Board and its Reasons for the Merger."

        AROC stockholders should be aware that some of Archrock's directors and executive officers may have interests in the merger that are different from, or in addition to, the interests they may have as AROC stockholders. See "The Merger—Interests of Certain Persons in the Merger."

        Only AROC stockholders of record at the close of business on March 14, 2018, the record date for the Archrock annual meeting, are entitled to notice of and to vote at the Archrock annual meeting. A list of AROC stockholders entitled to vote at the Archrock annual meeting will be available for inspection at Archrock's offices in Houston, Texas for any purpose relevant to the Archrock annual meeting during normal business hours for a period of ten days before the meeting and at the Archrock annual meeting. References to the Archrock annual meeting in this joint proxy statement/prospectus are to such annual meeting as may be adjourned or postponed from time to time.

        YOUR VOTE IS IMPORTANT. WHETHER OR NOT YOU EXPECT TO ATTEND THE ARCHROCK ANNUAL MEETING, PLEASE SUBMIT YOUR PROXY IN ONE OF THE FOLLOWING WAYS:

    If you hold your AROC common stock in the name of a bank, broker or other nominee, you should follow the instructions provided by your bank, broker or other nominee when voting your AROC common stock.

    If you hold your AROC common stock in your own name, you may submit your proxy by:

    using the toll-free telephone number shown on the proxy card;

    using the Internet website shown on the proxy card; or

    marking, signing, dating and promptly returning the enclosed proxy card in the postage-paid envelope. It requires no postage if mailed in the United States.

        The enclosed joint proxy statement/prospectus provides a detailed description of the merger and the merger agreement as well as a description of the AROC stock issuance. You are urged to read this joint proxy statement/prospectus, including any documents incorporated by reference, and the Annexes carefully and in their entirety. If you have any questions concerning the merger or this joint proxy statement/prospectus, would like additional copies or need help voting your AROC common stock, please contact Archrock's proxy solicitor:

GRAPHIC

1407 Broadway, 27th Floor
New York, New York 10018
Call Toll-Free (800) 322-2885
(212) 929-5500 (Call Collect)
Email:
proxy@mackenziepartners.com

By order of the Board of Directors of
Archrock, Inc.
   

GRAPHIC


D. Bradley Childers
President and Chief Executive Officer of Archrock, Inc.

 

 

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LOGO
  Houston, Texas
March 21, 2018

 

 

9807 Katy Freeway, Suite 100
Houston, TX 77024

 

 

NOTICE OF SPECIAL MEETING OF COMMON UNITHOLDERS

To the Common Unitholders of Archrock Partners, L.P.:

        A special meeting (the "Archrock Partners special meeting") of common unitholders of Archrock Partners, L.P. ("Archrock Partners") will be held on Wednesday, April 25, 2018 at 9:00 a.m., local time, at 9807 Katy Freeway, Suite 100, Houston, TX 77024, for the following purposes:

    to consider and vote upon a proposal to approve the Agreement and Plan of Merger, dated as of January 1, 2018, and amended on January 11, 2018 to join Amethyst Merger Sub LLC, a Delaware limited liability company ("Merger Sub") (as amended from time to time, the "merger agreement"), by and among Archrock, Inc. ("Archrock"), Archrock Partners, Archrock General Partner, L.P., a Delaware limited partnership and the general partner of Archrock Partners (the "General Partner"), and Archrock GP LLC, a Delaware limited liability company and the general partner of the General Partner (the "Managing GP"), pursuant to which Merger Sub, an indirect wholly owned subsidiary of Archrock, will merge with and into Archrock Partners (the "merger") with Archrock Partners surviving as an indirect wholly owned subsidiary of Archrock (the "Archrock Partners merger proposal"); and

    to consider and vote on a proposal to approve the adjournment of the Archrock Partners special meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies in the event there are not sufficient votes at the time of the special meeting to approve the above proposal (the "APLP adjournment proposal").

        Approval of the Archrock Partners merger proposal requires the affirmative vote of holders of a majority of the outstanding common units representing limited partner interests in Archrock Partners ("APLP common units"). If a quorum is present at the Archrock Partners special meeting, the APLP adjournment proposal requires approval by the affirmative vote of holders of a majority of the outstanding APLP common units. If a quorum is not present, the APLP adjournment proposal requires approval by the affirmative vote of holders of a majority of the outstanding APLP common units represented either in person or by proxy at the Archrock Partners special meeting. Abstentions will have the same effect as votes against the Archrock Partners merger proposal and the APLP adjournment proposal. Assuming there is a quorum, failures to vote and broker non-votes (if any) will have the same effect as votes against the Archrock Partners merger proposal and the APLP adjournment proposal. If no quorum is present, broker non-votes (if any) will have the same effect as votes against the Archrock Partners merger proposal and the APLP adjournment proposal, but failures to vote will have no effect on the APLP adjournment proposal.

        We cannot complete the merger unless the APLP common unitholders approve the Archrock Partners merger proposal. Accordingly, your vote is very important regardless of the number of APLP common units you own.

        The conflicts committee—which consists of the three members of the board of directors of the Managing GP (the "APLP board") who are independent under Archrock Partners' governance guidelines and the listing standards of the NASDAQ Global Select Market and who are not also executive officers or members of the board of directors of Archrock—of the APLP Board (the "APLP conflicts committee") and the APLP Board each have determined that the merger is in the best interests of Archrock Partners, including the APLP common unitholders other than Archrock and its affiliates (the "APLP unaffiliated unitholders"), and have unanimously approved the merger agreement and the merger. The APLP conflicts committee and the APLP board each recommend that the APLP common unitholders vote FOR the Archrock Partners merger proposal. The APLP board recommends


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that the APLP common unitholders vote FOR the APLP adjournment proposal. For more information regarding the recommendation of the APLP conflicts committee and the APLP board, see "The Merger—Recommendation of the APLP Conflicts Committee and the APLP Board and Their Reasons for the Merger."

        APLP common unitholders should be aware that some of Archrock Partners' directors and executive officers may have interests in the merger that are different from, or in addition to, the interests they may have as APLP common unitholders. See "The Merger—Interests of Certain Persons in the Merger."

        Only APLP common unitholders of record at the close of business on March 14, 2018, the record date for the Archrock Partners special meeting, are entitled to notice of and to vote at the Archrock Partners special meeting. A list of unitholders entitled to vote at the Archrock Partners special meeting will be available for inspection at Archrock Partners' offices in Houston, Texas for any purpose relevant to the Archrock Partners special meeting during normal business hours for a period of ten days before the meeting and at the Archrock Partners special meeting. References to the Archrock Partners special meeting in this joint proxy statement/prospectus are to such special meeting as may be adjourned or postponed from time to time.

        YOUR VOTE IS IMPORTANT. WHETHER OR NOT YOU EXPECT TO ATTEND THE ARCHROCK PARTNERS SPECIAL MEETING, PLEASE SUBMIT YOUR PROXY IN ONE OF THE FOLLOWING WAYS:

    If you hold your APLP common units in the name of a bank, broker or other nominee, you should follow the instructions provided by your bank, broker or other nominee when voting your APLP common units.

    If you hold your APLP common units in your own name, you may submit your proxy by:

    using the toll-free telephone number shown on the proxy card;

    using the Internet website shown on the proxy card; or

    marking, signing, dating and promptly returning the enclosed proxy card in the postage-paid envelope. It requires no postage if mailed in the United States.

        The enclosed joint proxy statement/prospectus provides a detailed description of the merger and the merger agreement. You are urged to read this joint proxy statement/prospectus, including any documents incorporated by reference, and the Annexes carefully and in their entirety. If you have any questions concerning the merger or this joint proxy statement/prospectus, would like additional copies or need help voting your APLP common units, please contact Archrock Partners' proxy solicitor:

LOGO

1407 Broadway, 27th Floor
New York, New York 10018
Call Toll-Free (800) 322-2885
(212) 929-5500 (Call Collect)
Email: proxy@mackenziepartners.com

By order of the Board of Directors of
Archrock GP LLC
   

LOGO


D. Bradley Childers
President, Chief Executive Officer and Chairman of Archrock GP LLC

 

 

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IMPORTANT NOTE ABOUT THIS JOINT PROXY STATEMENT/PROSPECTUS

        This joint proxy statement/prospectus also constitutes a proxy statement of Archrock under Section 14(a) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), with respect to the solicitation of proxies for the Archrock annual meeting to, among other things, approve the AROC stock issuance proposal, and a prospectus of Archrock under Section 5 of the Securities Act of 1933, as amended (the "Securities Act"), for the shares of AROC common stock that will be issued to APLP common unitholders in the merger pursuant to the merger agreement.

        This joint proxy statement/prospectus, which forms part of a registration statement on Form S-4 filed with the Securities and Exchange Commission (the "SEC") constitutes a proxy statement of Archrock Partners under Section 14(a) of the Exchange Act with respect to the solicitation of proxies for the Archrock Partners special meeting to, among other things, approve the Archrock Partners merger proposal.

        As permitted under the rules of the SEC, this joint proxy statement/prospectus incorporates by reference important business and financial information about Archrock and Archrock Partners from other documents filed with the SEC that are not included in or delivered with this joint proxy statement/prospectus. See "Where You Can Find More Information" beginning on page 200. You can obtain any of the documents incorporated by reference into this document from Archrock or Archrock Partners, as the case may be, or from the SEC's website at http://www.sec.gov. This information is also available to you without charge upon your request in writing or by telephone from Archrock or Archrock Partners at the following addresses and telephone numbers:

Archrock, Inc.
Archrock Partners, L.P.
Attention: Investor Relations
9807 Katy Freeway, Suite 100
Houston, TX 77024
Telephone: (281) 836-8000

        Please note that copies of the documents provided to you will not include exhibits, unless the exhibits are specifically incorporated by reference into the documents or this joint proxy statement/prospectus.

        You may obtain certain of these documents at Archrock's and Archrock Partners' website, www.archrock.com. Information contained on Archrock's and Archrock Partners' websites is expressly not incorporated by reference into this joint proxy statement/prospectus.

        In order to receive timely delivery of requested documents in advance of the meetings, you must request them no later than five business days before the date of the meetings. This means your request should be received no later than April 17, 2018. If you request any documents, Archrock or Archrock Partners will mail them to you by first class mail, or another equally prompt means, after receipt of your request.

        Archrock and Archrock Partners have not authorized anyone to give any information or make any representation about the merger, Archrock or Archrock Partners that is different from, or in addition to, that contained in this joint proxy statement/prospectus or in any of the materials that have been incorporated by reference into this joint proxy statement/prospectus. Therefore, if anyone else distributes this type of information, you should not rely on it. If you are in a jurisdiction where offers to exchange or sell, or solicitations of offers to exchange or purchase, the securities offered by this joint proxy statement/prospectus or the solicitation of proxies are unlawful, or you are a person to whom it is unlawful to direct these types of activities, then the offer presented in this joint proxy statement/prospectus does not extend to you. The information contained in this joint proxy statement/prospectus speaks only as of the date of this joint proxy statement/prospectus, or in the case of information in a document incorporated by reference, as of the date of such document, unless the information specifically indicates that another date applies. All information in this document concerning Archrock has been furnished by Archrock. All information in this document concerning Archrock Partners has been furnished by Archrock Partners.


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JOINT PROXY STATEMENT/PROSPECTUS

TABLE OF CONTENTS

QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE MEETINGS

    ii  

SUMMARY

    1  

SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA OF ARCHROCK

    15  

SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA OF ARCHROCK PARTNERS

    17  

SELECTED UNAUDITED PRO FORMA CONSOLIDATED FINANCIAL INFORMATION

    20  

COMPARATIVE PER SHARE AND PER UNIT INFORMATION

    21  

MARKET PRICES, DIVIDEND AND DISTRIBUTION INFORMATION

    23  

RISK FACTORS

    25  

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

    32  

THE PARTIES

    34  

THE MERGER

    35  

THE MERGER AGREEMENT

    79  

COMPARISON OF RIGHTS OF AROC STOCKHOLDERS AND APLP COMMON UNITHOLDERS

    97  

DESCRIPTION OF AROC CAPITAL STOCK

    118  

THE ARCHROCK ANNUAL MEETING

    121  

THE AROC PROPOSALS

    125  

THE ARCHROCK PARTNERS SPECIAL MEETING

    139  

THE APLP PROPOSALS

    143  

ADDITIONAL INFORMATION ABOUT ARCHROCK

    146  

UNITED STATES FEDERAL INCOME TAX CONSEQUENCES

    194  

STOCKHOLDER AND UNITHOLDER PROPOSALS

    198  

LEGAL MATTERS

    200  

EXPERTS

    200  

WHERE YOU CAN FIND MORE INFORMATION

    200  

UNAUDITED PRO FORMA CONSOLIDATED FINANCIAL STATEMENTS

    203  

ANNEX A AGREEMENT AND PLAN OF MERGER

    A-1  

ANNEX B OPINION OF CITIGROUP GLOBAL MARKETS INC. 

    B-1  

ANNEX C OPINION OF EVERCORE GROUP L.L.C. 

    C-1  

i


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QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE MEETINGS

        Important Information and Risks.    The following are brief answers to some questions that you may have regarding the proposed merger, the Archrock annual meeting and Archrock Partners special meeting. You should read and consider carefully the remainder of this joint proxy statement/prospectus, including the Risk Factors beginning on page 25 and the attached Annexes, because the information in this section does not provide all of the information that might be important to you. Additional important information and descriptions of risk factors are also contained in the documents incorporated by reference in this joint proxy statement/prospectus. See "Where You Can Find More Information" beginning on page 200.

Q:
What is the proposed transaction and why am I receiving these materials?

A:
On January 1, 2018, Archrock, Inc., a Delaware corporation ("Archrock" or "AROC"), Archrock Partners, L.P., a Delaware limited partnership ("Archrock Partners" or "APLP"), Archrock General Partner, L.P., a Delaware limited partnership and the general partner of Archrock Partners (the "General Partner"), and Archrock GP LLC, a Delaware limited liability company and the general partner of the General Partner (the "Managing GP"), entered into an Agreement and Plan of Merger, which was amended on January 11, 2018 to join Amethyst Merger Sub LLC, a Delaware limited liability company and indirect wholly owned subsidiary of Archrock ("Merger Sub"), as a party (as amended from time to time, the "merger agreement"), pursuant to which Merger Sub will merge with and into Archrock Partners (the "merger"), with Archrock Partners surviving as a wholly owned indirect subsidiary of Archrock. The merger agreement is described in this joint proxy statement/prospectus and attached as Annex A. You are receiving this document because the merger cannot be completed without certain approvals of the AROC stockholders and the APLP common unitholders.

Q:
Why are Archrock and Archrock Partners proposing the merger?

A:
Archrock and Archrock Partners believe that the merger will benefit both AROC stockholders and APLP common unitholders. See "The Merger—Recommendation of the AROC Board and Its Reasons for the Merger" and "The Merger—Recommendation of the APLP Conflicts Committee and the APLP Board and Their Reasons for the Merger."

Q:
What will APLP common unitholders receive in the merger?

A:
If the merger is completed, each outstanding APLP common unit not owned by Archrock or its subsidiaries will be converted into the right to receive 1.40 shares of AROC common stock (such consideration, the "merger consideration," and such ratio, the "exchange ratio"). Based on the closing price of AROC common stock on December 29, 2017, the last trading day before the public announcement of the merger, the aggregate value of the merger consideration was approximately $607 million. The exchange ratio is fixed and will not be adjusted on account of any change in price of either AROC common stock or APLP common units prior to completion of the merger. If the exchange ratio would result in an APLP common unitholder being entitled to receive a fraction of a share of AROC common stock, all fractional shares to which such holder would otherwise have been entitled shall be aggregated and the resulting fraction will be rounded up to the nearest whole share of AROC common stock.

Q:
What will AROC stockholders receive in the merger?

A:
AROC stockholders will simply retain the AROC common stock they currently own. They will not receive any additional AROC common stock in the merger.

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Q:
Where will my shares or units trade after the merger?

A:
AROC common stock will continue to trade on the New York Stock Exchange ("NYSE") under the symbol "AROC." APLP common units will no longer be publicly traded after the completion of the merger.

Q:
What happens to my future distributions or dividends?

A:
If the date of the closing of the merger is prior to the record date set by the AROC board in connection with declared dividends to be paid by Archrock to its stockholders, former APLP common unitholders will receive dividends on the AROC common stock they receive in the merger at the discretion of the AROC board. If the date of the closing of the merger is after the record date set by the AROC board in connection with declared dividends to be paid by Archrock to its stockholders, a former APLP common unitholder will not receive dividends for that quarter on the AROC common stock it receives in the merger but will receive distributions for that quarter declared by Archrock Partners (if any) prior to the closing of the merger, if such former APLP common unitholder was a record holder of such common units on the record date with respect to such distribution. APLP common unitholders will not receive both distributions from Archrock Partners and dividends from Archrock for the same quarter. See "Market Prices, Dividend and Distribution Information."

    Current AROC stockholders will continue to receive dividends on their AROC common stock at the discretion of the AROC board. See "Comparison of Rights of AROC Stockholders and APLP Common Unitholders."

Q:
When and where will the meetings be held?

A:
AROC stockholders:    The Archrock annual meeting will be held at 9807 Katy Freeway, Suite 100, Houston, TX 77024, on April 25, 2018, at 9:30 a.m., local time.

    APLP common unitholders:    The Archrock Partners special meeting will be held at 9807 Katy Freeway, Suite 100, Houston, TX 77024, on April 25, 2018, at 9:00 a.m., local time.

Q:
Who is entitled to vote at the meetings?

A:
AROC stockholders:    The record date for the Archrock annual meeting is March 14, 2018. Only AROC stockholders of record as of the close of business on the record date are entitled to notice of, and to vote at, the Archrock annual meeting.

    APLP common unitholders:    The record date for the Archrock Partners special meeting is March 14, 2018. Only APLP common unitholders of record as of the close of business on the record date are entitled to notice of, and to vote at, the Archrock Partners special meeting.

Q:
What constitutes a quorum at the meetings?

A:
AROC stockholders:    The holders of a majority of the outstanding shares of AROC common stock, represented in person or by proxy (by submitting a properly executed proxy card or properly submitting your proxy by telephone or Internet), on the record date will constitute a quorum and will permit Archrock to conduct the proposed business at the Archrock annual meeting. Proxies received but marked as abstentions will be counted as shares of AROC common stock that are present and entitled to vote for purposes of determining the presence of a quorum. If a broker or nominee is permitted to vote the shares held on behalf of a beneficial owner, a "broker non-vote" on a particular proposal occurs with respect to those shares when the broker or nominee does not have discretionary authority to vote on the proposal and is not instructed by the beneficial owner to vote on the proposal. Broker non-votes (if any) would be considered present at the Archrock

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    annual meeting for purposes of determining a quorum. It is expected that each of the AROC stock issuance proposal, the AROC advisory compensation proposal, the AROC adjournment proposal and the election of directors to the AROC board are non-routine matters that brokers and nominees are not permitted to vote on absent specific instructions from the beneficial owner.

    APLP common unitholders:    The holders of a majority of the outstanding APLP common units represented in person or by proxy (by submitting a properly executed proxy card or properly submitting a proxy by telephone or Internet) will constitute a quorum and will permit Archrock Partners to conduct the proposed business at the Archrock Partners special meeting. Proxies received but marked as abstentions will be counted as units that are present and entitled to vote for purposes of determining the presence of a quorum. Broker non-votes (if any) would be considered present at the Archrock Partners special meeting for purposes of determining a quorum. It is expected that each of the Archrock Partners merger proposal and the APLP adjournment proposal are non-routine matters that brokers and nominees are not permitted to vote on absent specific instructions from the beneficial owner.

Q:
What is the vote required to approve each proposal?

A:
AROC stockholders:    Approval of the AROC stock issuance proposal requires the affirmative vote of a majority of the total votes cast on such proposal. Approval of each of the AROC ratification proposal, the AROC advisory compensation proposal and the AROC adjournment proposal requires the affirmative vote of a majority of the votes cast affirmatively or negatively on such proposal. Archrock's directors are elected by a plurality of the votes cast at the Archock annual meeting.

Abstentions will have the same effect as votes against the AROC stock issuance proposal. Abstentions will have no effect on the election of directors to the AROC board, the AROC ratification proposal, the AROC advisory compensation proposal and the AROC adjournment proposal. Assuming there is a quorum, failures to vote and broker non-votes (if any) will have no effect on the AROC stock issuance proposal, the election of directors to the AROC board, the AROC advisory compensation proposal and the AROC adjournment proposal. Under applicable rules of the NYSE, brokers are permitted to vote uninstructed shares at their discretion regarding the AROC ratification proposal, so broker non-votes are not expected on such proposal.

The directors and executive officers of Archrock beneficially owned, in the aggregate, approximately 2.9% of the outstanding AROC common stock as of the record date. Archrock believes that the directors and executive officers of Archrock will vote in favor of the AROC stock issuance proposal and the AROC adjournment proposal.

APLP common unitholders:    Approval of the Archrock Partners merger proposal requires the affirmative vote of holders of a majority of the outstanding APLP common units. If a quorum is present at the Archrock Partners special meeting, the APLP adjournment proposal requires approval by the affirmative vote of holders of a majority of the outstanding APLP common units. If no quorum is present, the APLP adjournment proposal requires approval by the affirmative vote of holders of a majority of the outstanding APLP common units represented either in person or by proxy at the Archrock Partners special meeting.

Abstentions will have the same effect as votes against the Archrock Partners merger proposal and the APLP adjournment proposal. Assuming there is a quorum, failures to vote and broker non-votes (if any) will have the same effect as votes against the Archrock Partners merger proposal and the APLP adjournment proposal. If no quorum is present, broker non-votes (if any) will have the same effect as votes against the Archrock Partners merger proposal and the APLP adjournment proposal, but failures to vote will have no effect on the APLP adjournment proposal.

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    Pursuant to the merger agreement, Archrock has agreed to vote or cause to be voted all APLP common units beneficially owned by Archrock and its affiliates in favor of the Archrock Partners merger proposal unless there is an APLP adverse recommendation change (see "The Merger Agreement—Managing GP Recommendation and APLP Adverse Recommendation Change"). As of the record date, Archrock and its affiliates other than its directors and executive officers beneficially owned approximately 41% of the outstanding APLP common units.

    The directors and executive officers of the Managing GP beneficially owned, in the aggregate, approximately 0.3% of the outstanding APLP common units as of the record date. Archrock and Archrock Partners believe that the directors and executive officers of the Managing GP will vote in favor of the Archrock Partners merger proposal and the APLP adjournment proposal.

Q:
How do I vote my AROC common stock or APLP common units if I hold them in my own name?

A:
AROC stockholders:    After you have read this joint proxy statement/prospectus carefully, please respond by completing, signing and dating your proxy card and returning it in the enclosed postage-paid envelope or by submitting your proxy by telephone or the Internet as soon as possible in accordance with the instructions provided under "The Archrock Annual Meeting—Voting Procedures—Voting by AROC Stockholders."

    APLP common unitholders:    After you have read this joint proxy statement/prospectus carefully, please respond by completing, signing and dating your proxy card and returning it in the enclosed postage-paid envelope or by submitting your proxy by telephone or the Internet as soon as possible in accordance with the instructions provided under "The Archrock Partners Special Meeting—Voting Procedures—Voting by APLP Common Unitholders."

Q:
If my AROC common stock or APLP common units are held in "street name" by my bank, broker or other nominee, will my bank, broker or other nominee vote them for me?

A:
AROC stockholders:    If your AROC common stock is held in "street name" in a stock brokerage account or by a broker, bank or other nominee, you must provide the record holder of your AROC common stock with instructions on how to vote your shares. Please follow the voting instructions provided by your broker, bank or other nominee. Please note that you may not vote AROC common stock held in street name by returning a proxy card directly to Archrock or by voting in person at the Archrock annual meeting unless you provide a "legal proxy," which you must obtain from your broker, bank or other nominee. Your broker, bank or other nominee is obligated to provide you with a voting instruction card for you to use. If you do not instruct your bank, broker or other nominee on how to vote your shares of AROC common stock, your bank, broker or other nominee cannot vote your shares of AROC common stock on any proposal other than the AROC ratification proposal, which will result in the absence of a vote for or against the AROC stock issuance proposal, the election of directors to the AROC board, the AROC advisory compensation proposal and the AROC adjournment proposal. You should therefore provide you bank, broker or other nominee with instructions as to how to vote your shares of AROC common stock.

APLP common unitholders:    If your APLP common units are held in "street name" in a stock brokerage account or by a broker, bank or other nominee, you must provide the record holder of your APLP common units with instructions on how to vote your units. Please follow the voting instructions provided by your broker, bank or other nominee. Please note that you may not vote APLP common units held in street name by returning a proxy card directly to Archrock Partners or by voting in person at the Archrock Partners special meeting unless you provide a "legal proxy," which you must obtain from your broker, bank or other nominee. Your broker, bank or other nominee is obligated to provide you with a voting instruction card for you to use. If you do not

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    instruct your bank, broker or other nominee on how to vote your APLP common units, your bank, broker or other nominee cannot vote your APLP common units, which will have the same effect as a vote against the Archrock Partners merger proposal and the APLP adjournment proposal. You should therefore provide you bank, broker or other nominee with instructions as to how to vote your APLP common units.

Q:
When do you expect the merger to be completed?

A:
We currently expect the merger to close in the second quarter of 2018. A number of conditions must be satisfied before Archrock and Archrock Partners can complete the merger, including the approval of the AROC stock issuance proposal by the AROC stockholders and the approval of the Archrock Partners merger proposal by the APLP common unitholders. Although Archrock and Archrock Partners cannot be sure when all of the conditions to the merger will be satisfied, Archrock and Archrock Partners expect to complete the merger as soon as practicable following the Archrock annual meeting and Archrock Partners special meeting (assuming the AROC stock issuance proposal and the Archrock Partners merger proposal are approved by the AROC stockholders and APLP common unitholders, respectively), subject to, among other things, the registration statement of which this joint proxy statement/prospectus forms a part having been declared effective under the Securities Act. See "The Merger Agreement—Conditions to Completion of the Merger" and "Risk Factors—Risks Related to the Merger." The merger is subject to conditions, including some conditions that may not be satisfied on a timely basis, if at all. Failure to complete the merger, or significant delays in completing the merger, could negatively affect each party's future business and financial results and the trading prices of AROC common stock and APLP common units.

Q:
How does the AROC board recommend that the AROC stockholders vote?

A:
The AROC board recommends that AROC stockholders vote FOR the AROC stock issuance proposal, FOR each of the eight nominees for election to the AROC board to serve until the next annual meeting of AROC stockholders or until their successors are duly elected or appointed and qualified, FOR the AROC ratification proposal, FOR the AROC advisory compensation proposal and FOR the AROC adjournment proposal.

On January 1, 2018, the AROC board unanimously determined that the merger, the merger agreement and the transactions contemplated thereby, including the AROC stock issuance, are in the best interests of Archrock and the AROC stockholders. The AROC board unanimously approved the merger, the merger agreement and the transactions contemplated thereby, including the AROC stock issuance, and recommends that the AROC stockholders vote FOR the AROC stock issuance proposal.

AROC stockholders should be aware that some of Archrock's directors and executive officers may have interests in the merger that are different from, or in addition to, the interests they may have as AROC stockholders. See "The Merger—Interests of Certain Persons in the Merger."

Q:
How do the APLP conflicts committee and the APLP board recommend that the APLP common unitholders vote?

A:
The APLP conflicts committee and the APLP board each recommend that the APLP common unitholders vote FOR the Archrock Partners merger proposal. The APLP board recommends that the APLP common unitholders vote FOR the APLP adjournment proposal.

On January 1, 2018, the APLP conflicts committee—which consists of the three members of APLP board who are independent under Archrock Partners' governance guidelines and the listing standards of the NASDAQ Global Select Market ("NASDAQ") and who are not also executive

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    officers or members of the AROC board—and the APLP board each unanimously determined that the merger is in the best interests of Archrock Partners, including the APLP common unitholders other than Archrock and its affiliates (the "APLP unaffiliated unitholders"), and unanimously approved the merger agreement and the merger. The APLP conflicts committee and the APLP board each unanimously recommend that the APLP common unitholders vote FOR the Archrock Partners merger proposal. The APLP conflicts committee's approval constitutes "Special Approval," as such term is defined by the First Amended and Restated Agreement of Limited Partnership of Archrock Partners, dated as of October 20, 2006, as amended or supplemented from time to time (the "Archrock Partners partnership agreement").

    For more information regarding the recommendation of the APLP conflicts committee in making such determination under the Archrock Partners partnership agreement, see "The Merger—Recommendation of the APLP Conflicts Committee and the APLP Board and Their Reasons for the Merger."

    APLP common unitholders should be aware that some of Archrock Partners' directors and executive officers may have interests in the merger that are different from, or in addition to, the interests they may have as APLP common unitholders. See "The Merger—Interests of Certain Persons in the Merger."

Q:
What are the U.S. federal income tax consequences to an APLP common unitholder as a result of the merger?

A:
The receipt of AROC common stock in exchange for APLP common units pursuant to the merger agreement will be a taxable transaction to U.S. Holders (as defined in "United States Federal Income Tax Consequences") for U.S. federal income tax purposes. In such case, a U.S. Holder will generally recognize capital gain or loss on the receipt of AROC common stock in exchange for APLP common units. However, a portion of this gain or loss, which could be substantial, will be separately computed and taxed as ordinary income or loss to the extent attributable to "unrealized receivables," including depreciation recapture, or to "inventory items" owned by Archrock Partners and its subsidiaries. Passive losses that were not deductible by a U.S. Holder in prior taxable periods because they exceeded a U.S. Holder's share of Archrock Partners' income may become available to offset a portion of the gain recognized by such U.S. Holder. A U.S. Holder's tax basis in the shares of AROC common stock received in the merger will equal the fair market value of such shares. See "United States Federal Income Tax Consequences" for a more complete discussion of the U.S. federal income tax consequences of the merger.

Q:
What are the U.S. federal income tax consequences for an APLP common unitholder of the ownership of AROC common stock after the merger is completed?

A:
Archrock is classified as a corporation for U.S. federal income tax purposes and is subject to U.S. federal income tax on its taxable income. A distribution of cash by Archrock to a stockholder who is a U.S. Holder will generally be included in such U.S. Holder's income as ordinary dividend income to the extent of Archrock's current or accumulated "earnings and profits" as determined under U.S. federal income tax principles. A portion of the cash distributed to AROC stockholders by Archrock after the merger may exceed Archrock's current and accumulated earnings and profits. Distributions of cash in excess of Archrock's current and accumulated earnings and profits will be treated as a non-taxable return of capital reducing a U.S. Holder's adjusted tax basis in such U.S. Holder's AROC common stock and, to the extent the distribution exceeds such stockholder's adjusted tax basis, as capital gain from the sale or exchange of such AROC common stock. See "United States Federal Income Tax Consequences" for a more complete discussion of the U.S. federal income tax consequences of owning and disposing of AROC common stock received in the merger.

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Q:
Are AROC stockholders or APLP common unitholders entitled to appraisal rights?

A:
No. Neither AROC stockholders nor APLP common unitholders are entitled to appraisal rights in connection with the merger under applicable law or contractual appraisal rights under Archrock's organizational documents, the Archrock Partners partnership agreement or the merger agreement.

Q:
What if I do not specify an instruction?

A:
If you sign and return your proxy or voting instruction card without indicating how to vote on any particular proposal, the AROC common stock represented by your proxy will be voted as recommended by the AROC board with respect to that proposal or the APLP common units represented by your proxy will be voted as recommended by the APLP board with respect to that proposal. Unless an AROC stockholder or APLP common unitholder, as applicable, checks the box on its proxy card to withhold discretionary authority, the applicable proxy holders may use their discretion to vote on other matters relating to the Archrock annual meeting or Archrock Partners special meeting, as applicable.

For purposes of each of the Archrock annual meeting and the Archrock Partners special meeting, an abstention occurs when a stockholder or unitholder, as applicable, attends the applicable special meeting in person and does not vote or returns a proxy with an "abstain" instruction.

    Archrock

    AROC Stock Issuance Proposal:    An abstention will have the same effect as a vote cast "AGAINST" the AROC stock issuance proposal. If an AROC stockholder is not present in person at the Archrock annual meeting and does not submit a proxy, it will have no effect on the vote count for the AROC stock issuance proposal (assuming a quorum is present).

    Election of Directors to the AROC Board:    Archrock's directors are elected by a plurality of the votes cast at the Archock annual meeting. Therefore, an abstention will have no effect on the election of directors to the AROC board. If an AROC stockholder is not present in person at the Archrock annual meeting and does not submit a proxy, it will have no effect on the vote count for the election of directors to the AROC board.

    AROC Ratification Proposal:    An abstention will have no effect on the AROC ratification proposal. If an AROC stockholder is not present in person at the Archrock annual meeting and does not submit a proxy, it will have no effect on the vote count for the AROC ratification proposal.

    AROC Advisory Compensation Proposal:    An abstention will have no effect on the AROC advisory compensation proposal. If an AROC stockholder is not present in person at the Archrock annual meeting and does not submit a proxy, it will have no effect on the vote count for the AROC advisory compensation proposal.

    AROC Adjournment Proposal:    An abstention will have no effect on the AROC adjournment proposal. If an AROC stockholder is not present in person at the Archrock annual meeting and does not submit a proxy, it will have no effect on the vote count for the AROC adjournment proposal.

    Archrock Partners

    Archrock Partners Merger Proposal:    An abstention will have the same effect as a vote cast "AGAINST" the Archrock Partners merger proposal. If an APLP common unitholder is not present in person at the Archrock Partners special meeting and does not submit a proxy, it will have the same effect as a vote cast "AGAINST" the Archrock Partners merger proposal.

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    APLP Adjournment Proposal:    An abstention will have the same effect as a vote "AGAINST" the APLP adjournment proposal. APLP common units not in attendance at the Archrock Partners special meeting and for which no proxy has been submitted will have no effect on the outcome of any vote to adjourn the Archrock Partners special meeting if a quorum is not present. If a quorum is present, APLP common units not in attendance at the Archrock Partners special meeting and for which no proxy has been submitted will have the same effect as a vote "AGAINST" the APLP adjournment proposal.

Q:
If I am planning to attend a meeting in person, should I still vote by proxy?

A:
Yes. Whether or not you plan to attend the Archrock annual meeting or the Archrock Partners special meeting, as applicable, you should vote by proxy. Your AROC common stock or APLP common units will not be voted if you do not vote by proxy and do not vote in person at the Archrock annual meeting or the Archrock Partners special meeting, as applicable.

Q:
Who may attend the Archrock annual meeting and the Archrock Partners special meeting?

A:
AROC stockholders as of the record date (or their authorized representatives) and Archrock's invited guests may attend the Archrock annual meeting. APLP common unitholders as of the record date (or their authorized representatives) and Archrock Partners' invited guests may attend the Archrock Partners special meeting. All attendees should be prepared to present government-issued photo identification (such as a driver's license or passport) for admittance.

Q:
Can I change my vote after I have submitted my proxy?

A:
Yes. If you own your AROC common stock or APLP common units in your own name, you may revoke your proxy at any time prior to its exercise by:

giving written notice of revocation that is received by the Secretary of the Managing GP or the Secretary of Archrock, as applicable, at or before the Archrock annual meeting or the Archrock Partners special meeting, as applicable;

appearing and voting in person at the Archrock annual meeting or the Archrock Partners special meeting, as applicable; or

properly completing and executing a later dated proxy and delivering it, or properly completing and submitting a later dated proxy by internet or telephone, to the Secretary of the Managing GP or the Secretary of Archrock, as applicable, at or before the Archrock annual meeting or the Archrock Partners special meeting, as applicable.

Your presence without voting at the Archrock annual meeting or the Archrock Partners special meeting, as applicable, will not automatically revoke your proxy, and any revocation during the meeting will not affect votes previously taken.

Q:
What should I do if I receive more than one set of voting materials for the Archrock annual meeting or the Archrock Partners special meeting?

A:
You may receive more than one set of voting materials for the Archrock annual meeting or the Archrock Partners special meeting and the materials may include multiple proxy cards or voting instruction cards. For example, you will receive a separate voting instruction card for each brokerage account in which you hold AROC common stock or APLP common units. Additionally, if you are a holder of record registered in more than one name, you will receive more than one proxy card. Finally, if you hold both AROC common stock and APLP common units, you will receive two separate packages of proxy materials. Please complete, sign, date and return each proxy card and voting instruction card that you receive according to the instructions on it.

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Q:
Whom do I call if I have further questions about voting, the meetings or the merger?

A:
AROC stockholders and APLP common unitholders who have questions about the merger, including the procedures for voting their shares or units, or who desire additional copies of this joint proxy statement/prospectus or additional proxy cards should contact:
AROC Stockholders   APLP Common Unitholders

Banks and Brokers Call: (212) 929-5500
All Others Call Toll Free: (800) 322-2885
Email:
proxy@mackenziepartners.com

 

Banks and Brokers Call: (212) 929-5500
All Others Call Toll Free: (800) 322-2885
Email:
proxy@mackenziepartners.com

or

 

or

Archrock, Inc.
9807 Katy Freeway, Suite 100
Houston, TX 77024
Telephone: (281) 836-8000

 

Archrock Partners, L.P.
9807 Katy Freeway, Suite 100
Houston, TX 77024
Telephone: (281) 836-8000

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SUMMARY

        This summary highlights selected information contained in this joint proxy statement/prospectus and does not contain all the information that may be important to you. Archrock and Archrock Partners urge you to read carefully this joint proxy statement/prospectus in its entirety, including the Annexes. Additionally, important information, which Archrock and Archrock Partners also urge you to read, is contained in the documents incorporated by reference into this joint proxy statement/prospectus. See "Where You Can Find More Information" beginning on page 200. Unless stated otherwise, all references in this joint proxy statement/prospectus to Archrock are to Archrock, Inc., all references to Archrock Partners are to Archrock Partners, L.P. and all references to the merger agreement are to the Agreement and Plan of Merger, dated as of January 1, 2018, by and among Archrock, the General Partner, the Managing GP and Archrock Partners, as amended by Amendment No. 1 to the Agreement and Plan of Merger, dated as of January 11, 2018, by and among Archrock, Merger Sub, the General Partner, the Managing GP and Archrock Partners, copies of which are attached as Annex A to this joint proxy statement/prospectus and incorporated by reference herein.

The Parties

    Archrock, Inc.

        Archrock is a corporation incorporated under the laws of the State of Delaware, and Archrock's common stock is listed on the NYSE under the trading symbol "AROC." Archrock is a pure play U.S. natural gas contract operations services business and the leading provider of natural gas compression services to customers in the oil and natural gas industry throughout the U.S. and a leading supplier of aftermarket services to customers that own compression equipment in the U.S. Archrock operates in two primary business lines: contract operations and aftermarket services. In its contract operations business line, Archrock uses its fleet of natural gas compression equipment to provide operations services to its customers. In its aftermarket services business line, Archrock sells parts and components and provides operations, maintenance, overhaul and reconfiguration services to customers who own compression equipment.

        Archrock's principal executive offices are located at 9807 Katy Freeway, Suite 100, Houston, TX 77024 and its telephone number is (281) 836-8000.

    Archrock Partners, L.P.

        Archrock Partners is a publicly traded master limited partnership organized under the laws of the State of Delaware that was formed in June 2006. Archrock Partners' common units are listed on NASDAQ under the trading symbol "APLP." Archrock Partners is the U.S. market leader in the full-service natural gas compression industry. Archrock Partner's contract operations services primarily include designing, sourcing, owning, installing, operating, servicing, repairing and maintaining equipment to provide natural gas compression services to its customers.

        Archrock Partners' principal executive offices are located at 9807 Katy Freeway, Suite 100, Houston, TX 77024 and its telephone number is (281) 836-8000.

    Amethyst Merger Sub LLC

        Merger Sub, an indirect wholly owned subsidiary of Archrock, is a Delaware limited liability company formed on January 10, 2018, for the purpose of effecting the merger. Upon completion of the merger, Merger Sub will merge with and into Archrock Partners, with Archrock Partners continuing as the surviving entity and a wholly owned indirect subsidiary of Archrock. Merger Sub has not conducted any activities other than those incidental to its formation and the matters contemplated by the merger agreement.

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    Relationships Between the Parties

        Archrock has a significant equity interest in Archrock Partners. As of March 14, 2018, Archrock's interests in Archrock Partners consisted of the following:

    an approximate 2% general partner interest, which Archrock holds through its indirect 100% ownership interest in the Managing GP;

    all of the outstanding incentive distribution rights ("IDRs"); and

    29.1 million (approximately 41%) of the 70.2 million outstanding APLP common units.

        The outstanding common units (including common units held by Archrock and the Managing GP) account for approximately 98% of the total ownership interest in Archrock Partners, with the remaining 2% of the total ownership interest in Archrock Partners being composed of the general partner interest in Archrock Partners.

        Certain of the executive officers and directors of the Managing GP are also executive officers and directors of Archrock. See "The Merger—Interests of Certain Persons in the Merger—Common Directors and Executive Officers."

The Merger

        Subject to the terms and conditions of the merger agreement and in accordance with Delaware law, at the effective time of the merger, Merger Sub, an indirect wholly owned subsidiary of Archrock, will merge with and into Archrock Partners, with Archrock Partners continuing as the surviving entity and an indirect wholly owned subsidiary of Archrock.

The Merger Consideration

        At the effective time of the merger, each APLP common unit issued and outstanding will be converted into the right to receive 1.40 shares of AROC common stock, other than (i) APLP common units that are owned immediately prior to the effective time of the merger by Archrock Partners, which will be automatically cancelled and will cease to exist, and (ii) APLP common units owned immediately prior to the effective time of the merger by Archrock MLP LP LLC, an indirect wholly owned subsidiary of Archrock, which will remain outstanding and unaffected by the merger. The General Partner Interest (as defined in the Archrock Partners partnership agreement) will also remain outstanding, unaffected by the merger.

        Archrock will not issue any fractional shares of AROC common stock in the merger; instead, all fractions of AROC common stock to which a holder of APLP common units would otherwise have been entitled shall be aggregated and the resulting fraction will be rounded up to the nearest whole share of AROC common stock.

Treatment of Phantom Units

        At the effective time of the merger, each award of phantom units of Archrock Partners ("APLP phantom units") (whether vested or unvested) that is outstanding as of immediately prior to the effective time will be assumed by Archrock and converted into an award of restricted stock units of Archrock ("AROC RSUs") granted under Archrock's 2013 Stock Incentive Plan representing a number of shares of AROC common stock equal to (i) the number of APLP phantom units subject to such award as of immediately prior to the effective time, multiplied by (ii) 1.40, rounded down to the nearest whole AROC RSU. Each such award of AROC RSUs shall be subject to the same vesting, forfeiture and other terms and conditions (including form(s) of payment and distribution equivalent rights, if any) applicable to the converted award of APLP phantom units as of immediately prior to the effective time.

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Archrock Annual Meeting

        Where and when:    The Archrock annual meeting will take place at 9807 Katy Freeway, Suite 100, Houston, TX 77024, on April 25, 2018 at 9:30 a.m., local time.

        What you are being asked to vote on:    At the Archrock annual meeting, AROC stockholders will vote on the AROC stock issuance proposal, the AROC ratification proposal, the AROC advisory compensation proposal and the AROC adjournment proposal. AROC stockholders may also be asked to consider other matters as may properly come before the Archrock annual meeting. At this time, Archrock knows of no other matters that will be presented for the consideration of the AROC stockholders at the Archrock annual meeting.

        Who may vote:    You may vote at the Archrock annual meeting if you owned AROC common stock at the close of business on the record date of March 14, 2018. On that date, there were 71,712,997 shares of AROC common stock outstanding. You may cast one vote for each outstanding share of AROC common stock that you owned on the record date.

        What vote is needed:    Approval of the AROC stock issuance proposal requires the affirmative vote of a majority of the total votes cast on such proposal. Approval of each of the AROC ratification proposal, the AROC advisory compensation proposal and the AROC adjournment proposal requires the affirmative vote of a majority of the votes cast affirmatively or negatively on such proposal. Archrock's directors are elected by a plurality of the votes cast at the Archock annual meeting.

        All of the directors and executive officers of Archrock beneficially owned, in the aggregate, approximately 2.9% of the outstanding AROC common stock as of the record date. Archrock believes that the directors and executive officers of Archrock will vote in favor of the AROC stock issuance proposal and the AROC adjournment proposal.

Archrock Partners Special Meeting

        Where and when:    The Archrock Partners special meeting will take place at 9807 Katy Freeway, Suite 100, Houston, TX 77024, on April 25, 2018 at 9:00 a.m., local time.

        What you are being asked to vote on:    At the Archrock Partners special meeting, APLP common unitholders will vote on the Archrock Partners merger proposal and the APLP adjournment proposal. APLP common unitholders also may be asked to consider other matters as may properly come before the Archrock Partners special meeting. At this time, Archrock Partners knows of no other matters that will be presented for the consideration of the APLP common unitholders at the Archrock Partners special meeting.

        Who may vote:    You may vote at the Archrock Partners special meeting if you owned APLP common units at the close of business on the record date of March 14, 2018. On that date, there were 70,231,036 APLP common units outstanding. You may cast one vote for each outstanding APLP common unit that you owned on the record date.

        What vote is needed:    Approval of the Archrock Partners merger proposal requires the affirmative vote of holders of a majority of the outstanding APLP common units. If a quorum is present, the APLP adjournment proposal requires approval by the affirmative vote of holders of a majority of the outstanding APLP common units. If no quorum is present, the APLP adjournment proposal requires approval of the affirmative vote of holders of a majority of the outstanding APLP common units represented either in person or by proxy at the Archrock Partners special meeting.

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        Pursuant to the merger agreement, Archrock has agreed to vote or cause to be voted all Archrock Partners units beneficially owned by Archrock and its affiliates in favor of the Archrock Partners merger proposal unless there is an Archrock Partners adverse recommendation change. As of the record date, Archrock and its affiliates other than its directors and executive officers beneficially owned approximately 29.1 million APLP common units which represent, in the aggregate, 41% of the total outstanding APLP common units.

        All of the directors and executive officers of the Managing GP beneficially owned, in the aggregate, approximately 0.3% of the outstanding APLP common units as of the record date. Archrock and Archrock Partners believe that the directors and executive officers of the Managing GP will vote in favor of the Archrock Partners merger proposal and the APLP adjournment proposal.

Recommendation of the AROC Board and Its Reasons for the Merger

        At a meeting held on January 1, 2018, the AROC board unanimously determined that the merger, the merger agreement and the transactions contemplated thereby, including the AROC stock issuance are in the best interests of Archrock and the AROC stockholders. The AROC board unanimously approved the merger, the merger agreement, the exchange ratio of 1.40 shares of AROC common stock for each APLP common unit and the transactions contemplated by the merger agreement, including the AROC stock issuance, and recommends that the AROC stockholders vote FOR the AROC stock issuance proposal. In the course of reaching its decision, the AROC board considered a number of factors in its deliberations. See "The Merger—Recommendation of the AROC board and its Reasons for the Merger."

        AROC stockholders should be aware that some of Archrock's directors and executive officers may have interests in the transactions that are different from, or in addition to, the interests they may have as AROC stockholders. See "The Merger—Interests of Certain Persons in the Merger."

        The AROC board recommends that the AROC stockholders vote FOR each of the eight nominees for election to the AROC board to serve until the next annual meeting of AROC stockholders or until their successors are duly elected or appointed and qualified, FOR the AROC ratification proposal, FOR the AROC advisory compensation proposal and FOR the AROC adjournment proposal.

Recommendation of the APLP Conflicts Committee and the APLP Board and Their Reasons for the Merger

        At a meeting of the APLP conflicts committee held on January 1, 2018, the APLP conflicts committee (a) determined that the merger and the merger agreement are in the best interests of Archrock Partners, including the APLP unaffiliated unitholders; (b) approved the merger and the execution, delivery and performance by Archrock Partners of the merger agreement, which approval constitutes "Special Approval," as such term is defined by the Archrock Partners partnership agreement; (c) determined to recommend that the APLP board approve the merger and the merger agreement; (d) determined to recommend that the APLP board submit the merger agreement to a vote of the Limited Partners (as defined in the Archrock Partners partnership agreement); and (e) determined to recommend that the APLP common unitholders vote in favor of and approving and adopting the merger agreement.

        Later on January 1, 2018, at a meeting of the APLP board, the APLP board (based upon the recommendation of the APLP conflicts committee) unanimously determined that the merger and the merger agreement, including the transactions contemplated thereby, are in the best interests of Archrock Partners, including the APLP unaffiliated unitholders, approved the execution, delivery and performance of the merger agreement and the transactions contemplated thereby, including the merger, and resolved to submit the merger and the merger agreement to a vote of the APLP common unitholders and recommend approval of the merger agreement by the APLP common unitholders. For

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more information regarding the recommendation of the APLP conflicts committee and the APLP board, see "The Merger—Recommendation of the APLP Conflicts Committee and the APLP Board and Their Reasons for the Merger."

        APLP common unitholders should be aware that some of Archrock Partners' directors and executive officers may have interests in the transactions that are different from, or in addition to, the interests they may have as APLP common unitholders. See "The Merger—Interests of Certain Persons in the Merger."

        The APLP conflicts committee and the APLP board each recommend that the APLP common unitholders vote FOR the Archrock Partners merger proposal. The APLP board recommends that the APLP common unitholders vote FOR the APLP adjournment proposal.

Opinion of the Financial Advisor to Archrock

        In connection with the merger, Archrock's financial advisor, Citigroup Global Markets Inc. ("Citi") delivered a written opinion, dated January 1, 2018, to the AROC board as to the fairness, from a financial point of view and as of the date of the opinion, to Archrock of the exchange ratio provided for pursuant to the merger agreement. The full text of Citi's written opinion, dated January 1, 2018, which describes the assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken, is attached as Annex B to this joint proxy statement/prospectus and is incorporated into this joint proxy statement/prospectus by reference. The description of Citi's opinion set forth below is qualified in its entirety by reference to the full text of Citi's opinion. Citi's opinion was provided for the information of the AROC board (in its capacity as such) in connection with its evaluation of the exchange ratio from a financial point of view to Archrock and did not address any other terms, aspects or implications of the merger. Citi expressed no view as to, and its opinion did not address, the underlying business decision of Archrock to effect or enter into the merger, the relative merits of the merger as compared to any alternative business strategies that might exist for Archrock or the effect of any other transaction which Archrock might engage in or consider. Citi's opinion is not intended to be and does not constitute a recommendation to any securityholder as to how such securityholder should vote or act on any matters relating to the proposed merger or otherwise.

Opinion of the Financial Advisor to the APLP Conflicts Committee

        In connection with the proposed merger, Evercore Group L.L.C. ("Evercore") delivered a written opinion, dated January 1, 2018, to the APLP conflicts committee as to the fairness, from a financial point of view and as of the date of the opinion, to the APLP unaffiliated unitholders of the exchange ratio provided for pursuant to the merger agreement. The full text of Evercore's written opinion, dated January 1, 2018, to the APLP conflicts committee, which describes the assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken, is attached as Annex C to this joint proxy statement/prospectus and is incorporated herein by reference. The description of Evercore's opinion set forth in this joint proxy statement/prospectus is qualified in its entirety by reference to the full text of Evercore's opinion. Evercore's opinion was prepared at the request and for the benefit and use of the APLP conflicts committee (in its capacity as such) in connection with its evaluation of the exchange ratio from a financial point of view, and Evercore did not express any opinion on any other terms or aspects of the merger or any other matter. Evercore expressed no opinion as to the relative merits of the merger or any other transactions or business strategies discussed by the APLP conflicts committee as alternatives to the merger or the decision of the APLP conflicts committee to proceed with the merger. Evercore's opinion did not constitute and is not a recommendation to the APLP conflicts committee as to any action taken on any aspect of the merger or any other matter. Neither Evercore's written opinion, nor the summary of such opinion and the related analyses set forth in this joint proxy statement/prospectus are intended to be, and they do

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not constitute, a recommendation as to how unitholders of Archrock Partners or any other person should act or vote with respect to the merger or any other matter.

Interests of Certain Persons in the Merger

        APLP common unitholders should be aware that some of the executive officers and directors of the Managing GP have interests in the transaction that may differ from, or may be in addition to, the interests of APLP common unitholders generally. These interests include:

    Certain of the executive officers and directors of the Managing GP are also executive officers and directors of Archrock.

    The directors and officers of the Managing GP are entitled to continued indemnification and insurance coverage under the merger agreement.

    Certain of the directors and executive officers of the Managing GP beneficially own APLP common units and/or phantom units and will receive the applicable merger consideration upon completion of the merger.

    Certain of the executive officers and certain of the directors of the Managing GP beneficially own AROC common stock and/or AROC equity awards.

        AROC stockholders should be aware that some of the executive officers and directors of Archrock have interests in the transaction that may differ from, or may be in addition to, the interests of AROC stockholders generally. These interests include:

    Certain of the executive officers and directors of Archrock are also executive officers and directors of the Managing GP.

    Certain of the executive officers and certain of the directors of Archrock beneficially own APLP common units and/or phantom units, and these directors and executive officers will receive the applicable merger consideration upon completion of the merger.

Conditions to Completion of the Merger

        Archrock and Archrock Partners may not complete the merger unless each of the following conditions is satisfied or, if applicable, waived:

    the merger agreement must have been approved by the affirmative vote or consent of holders of a majority of the outstanding APLP common units at the Archrock Partners special meeting (the "APLP common unitholder approval");

    the AROC stock issuance must have been approved by the affirmative vote of the holders of a majority of the total votes cast on such proposal (the "AROC stockholder approval");

    any waiting period applicable to the transactions contemplated by the merger agreement under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and the rules and regulations promulgated thereunder (the "HSR Act") shall have been terminated or must have expired (early termination of the waiting period under the HSR Act was granted on February 9, 2018);

    no law, injunction, judgment or ruling enacted, promulgated, issued, entered, amended or enforced by any governmental authority (each a "restraint") is in effect enjoining, restraining, preventing or prohibiting the completion of the transactions contemplated by the merger agreement or making the completion of the transactions contemplated by the merger agreement illegal;

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    the registration statement of which this joint proxy statement/prospectus forms a part must have been declared effective under the Securities Act and no stop order suspending the effectiveness of the registration statement will have been issued and no proceedings for that purpose will have been initiated or threatened by the SEC; and

    the AROC common stock deliverable to the APLP common unitholders as contemplated by the merger agreement must have been approved for listing on the NYSE, subject to official notice of issuance.

        The obligations of Archrock and Merger Sub to effect the merger are subject to the satisfaction or waiver of the following additional conditions:

    the representations and warranties in the merger agreement of Archrock Partners, the General Partner and the Managing GP being true and correct as of January 1, 2018 and as of the closing date of the merger, subject to certain standards, including materiality and material adverse effect qualifications, as described "The Merger Agreement—Conditions to Completion of the Merger";

    Archrock Partners, the General Partner and the Managing GP having performed in all material respects all obligations required to be performed by each of them under the merger agreement; and

    the receipt by Archrock of an officer's certificate signed on behalf of Archrock Partners, the General Partner and the Managing GP by an executive officer of the Managing GP certifying that the preceding conditions have been satisfied.

        The obligation of Archrock Partners to effect the merger is subject to the satisfaction or waiver of the following additional conditions:

    the representations and warranties in the merger agreement of Archrock being true and correct as of January 1, 2018 and as of the closing date of the merger, subject to certain standards, including materiality and material adverse effect qualifications, as described "The Merger Agreement—Conditions to Completion of the Merger";

    Archrock and Merger Sub having performed in all material respects all obligations required to be performed by each of them under the merger agreement; and

    the receipt by Archrock Partners of an officer's certificate signed on behalf of Archrock by an executive officer of Archrock certifying that the preceding conditions have been satisfied.

The Managing GP Recommendation and Archrock Partners Adverse Recommendation Change

        The merger agreement generally provides that, subject to the exceptions described below, neither the APLP conflicts committee nor the APLP board will make an Archrock Partners adverse recommendation change (as described under "The Merger Agreement—the Managing GP Recommendation and Archrock Partners Adverse Recommendation Change").

        The APLP conflicts committee and the APLP board may, however, make an Archrock Partners adverse recommendation change only if the APLP board or the APLP conflicts committee, as applicable, after consultation with its financial advisor and outside legal counsel, determines in good faith that the failure to take such action would be inconsistent with its duties under the Archrock Partners partnership agreement and applicable law; provided, however, that the APLP board or the APLP conflicts committee, as applicable, may not take such action pursuant to the foregoing unless it complies with certain provisions of the merger agreement as described under "The Merger Agreement—the Managing GP Recommendation and Archrock Partners Adverse Recommendation Change."

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APLP Common Unitholder Approval

        Archrock Partners has agreed to hold a special meeting of the APLP common unitholders as promptly as practicable (which shall be no later than 35 days after the date that the registration statement of which this joint proxy statement/prospectus forms a part is declared effective under the Securities Act) for purposes of obtaining the APLP common unitholder approval. See "—The Archrock Partners Special Meeting." This obligation is not affected by the withdrawal or modification by the APLP board or the APLP conflicts committee of its recommendation or any other action by the APLP board or the APLP conflicts committee, as the case may be, with respect to the merger agreement or the transactions contemplated by the merger agreement.

        The merger agreement also requires Archrock Partners, through the APLP board and the APLP conflicts committee, to recommend to the limited partners of Archrock Partners approval of the merger agreement (subject to the ability of the APLP board or the APLP conflicts committee to change such recommendation as described herein) and to use reasonable best efforts to obtain from the limited partners of Archrock Partners the APLP common unitholder approval.

Archrock Recommendation and Archrock Adverse Recommendation Change

        The merger agreement generally provides that, subject to the exceptions described below, the AROC board will not make an Archrock adverse recommendation change (as described under "The Merger Agreement—Archrock Recommendation and Archrock Adverse Recommendation Change").

        The AROC board may, however, make an Archrock adverse recommendation change in connection with a superior proposal only if Archrock has received a written alternative proposal that the AROC board believes is bona fide and the AROC board, after consultation with Archrock's financial advisors and outside legal counsel, has determined in good faith that such alternative proposal constitutes a superior proposal and, after consultation with Archrock's outside legal counsel, that failure to take such action would be inconsistent with its duties under applicable law; provided, however, that the AROC board may not take such action pursuant to the foregoing unless it complies with certain provisions of the merger agreement as described under "The Merger Agreement—Archrock Recommendation and Archrock Adverse Recommendation Change."

AROC Stockholder Approval

        Archrock has agreed to hold a special meeting of the AROC stockholders as promptly as practicable (which shall be no later than 35 days after the date that the registration statement of which this joint proxy statement/prospectus forms a part is declared effective under the Securities Act) for the purpose of obtaining the AROC stockholder approval. See "—The Archrock Annual Meeting." This obligation is not affected by any action by the AROC board with respect to the merger agreement or the transactions contemplated by the merger agreement. See "—The Archrock Annual Meeting."

        The merger agreement also requires Archrock, through the AROC board, to recommend to the AROC stockholders' approval of the AROC stock issuance (subject to the ability of the AROC board to change such recommendation as described herein) and use reasonable best efforts to obtain from the AROC stockholders the AROC stockholder approval.

No Solicitation by Archrock of Alternative Proposals

        The merger agreement contains provisions prohibiting Archrock from seeking an alternative proposal. Under these "no solicitation" covenants, Archrock has agreed that it will not, and will cause

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its subsidiaries and use reasonable best efforts to cause its and its subsidiaries' respective representatives not to, directly or indirectly, except as permitted by the merger agreement:

    solicit, initiate, knowingly facilitate or knowingly encourage the submission of an alternative proposal (including any acquisition structured as a merger, consolidation or share exchange);

    participate in any discussions or negotiations regarding, or furnish any information with respect to, any proposal or offer from any person relating to, or that could reasonably be expected to lead to, an alternative proposal;

    knowingly assist, participate in or facilitate in any other manner any effort or attempt by any Person to do or seek any of the foregoing;

    enter into any acquisition agreement with respect to any alternative proposal (other than a confidentiality agreement containing customary provisions); or

    make an Archrock adverse recommendation change.

        Archrock has agreed that it will, and will cause its subsidiaries and use reasonable best efforts to cause its and its subsidiaries' respective representatives to, cease and cause to be terminated any discussions or negotiations with any persons conducted prior to the execution of the merger agreement with respect to an alternative proposal and immediately prohibit any access by any person to confidential information relating to a possible alternative proposal.

        After the date of the merger agreement and before Archrock obtains its stockholders' approval, if (i) Archrock has received a written alternative proposal that the AROC board believes is bona fide, (ii) the AROC board, after consultation with Archrock's financial advisors and outside legal counsel, determines in good faith that such alternative proposal constitutes or could reasonably be expected to lead to or result in a superior proposal and, after consultation with Archrock's outside legal counsel, failure to take such action would be inconsistent with its duties under applicable laws and (iii) such alternative proposal did not result from a material breach of the "no solicitation" covenants in the merger agreement, then Archrock may (x) furnish information, including confidential information, with respect to Archrock and its subsidiaries to the person making such alternative proposal and (y) participate in discussions or negotiations regarding such alternative proposal; provided, however, that (A) Archrock and its respective subsidiaries will not, and will use their reasonable best efforts to cause their respective representatives not to, disclose any non-public information to such person unless Archrock has, or first enters into, a confidentiality agreement with such person and (B) Archrock will provide to Archrock Partners, the General Partner and the Managing GP non-public information with respect to Archrock Partners and its subsidiaries that was not previously provided or made available to Archrock Partners, the General Partner and the Managing GP prior to or substantially concurrently with providing or making available such non-public information to such other person.

Termination of the Merger Agreement

        The merger agreement may be terminated prior to the closing of the merger:

    by the mutual written consent of Archrock and Archrock Partners duly authorized by the AROC board and the APLP conflicts committee, respectively.

    by either of Archrock Partners or Archrock:

    if the closing does not occur on or before September 30, 2018; provided that this termination right will not be available to a party whose failure to perform and comply in all material respects with its covenants and agreements is the cause of the failure of the closing and this termination right will not be available to Archrock Partners or Archrock,

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        respectively, if the other party has filed and is pursuing an action seeking specific performance;

      if any restraint by a government authority is in effect and has become final and nonappealable; provided, however, that this termination right is not available to Archrock Partners or Archrock if such restraint was due to the failure of, in the case of Archrock Partners, Archrock Partners, the General Partner or the Managing GP and, in the case of Archrock, Archrock or Merger Sub, to perform any of its obligations under the merger agreement;

      if the Archrock Partners special meeting has occurred and the APLP common unitholder approval has not been obtained; or

      if the AROC stockholder meeting has occurred and the AROC stockholder approval has not been obtained.

    by Archrock:

    if the APLP board or the APLP conflicts committee makes an Archrock Partners adverse recommendation change, unless the APLP common unitholder approval has been obtained;

    if Archrock Partners, the General Partner or the Managing GP has breached or failed to perform any of its covenants or agreements in the merger agreement, or any representations or warranties become untrue, in a way that the related condition to closing would not be satisfied, and such breach is either incurable or not cured within 30 days (unless Archrock or Merger Sub is also in material breach of any representations, warranties, covenants or agreements in the merger agreement); or

    if Archrock is terminating the merger agreement to enter into a definitive agreement relating to a superior proposal in accordance with the terms of the merger agreement, so long as Archrock has complied in all material respects with the "no solicitation" covenants in the merger agreement.

    by Archrock Partners (which may be effected by the APLP conflicts committee):

    if Archrock has breached or failed to perform the "no-solicitation" covenant in the merger agreement; or

    if Archrock has breached or failed to perform any of its covenants or agreements in the merger agreement, or any representations or warranties become untrue, in a way that the related condition to closing would not be satisfied, and such breach is either incurable or not cured within 30 days (unless Archrock Partners, the General Partner or the Managing GP is in material breach of any representations, warranties, covenants or agreements in the merger agreement).

Effect of Termination; Termination Fees

        If the merger agreement is validly terminated, then, except as described below, each of the parties will be relieved of its duties and obligations and such termination will be without liability to either party. However, termination will not relieve either party of any liability for failure to consummate the merger and other transactions contemplated by the merger agreement when required under the agreement or for intentional fraud or any "willful breach" (as defined in the merger agreement).

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        The merger agreement contains various amounts payable under the circumstances described below:

    if the merger agreement is terminated by Archrock Partners or Archrock due to the failure of the closing of the merger to occur prior to September 30, 2018, then Archrock shall reimburse Archrock Partners for its reasonable expenses (up to $2 million);

    if the merger agreement is terminated by Archrock Partners or Archrock due to the failure to obtain the required AROC stockholder approval, then Archrock shall reimburse Archrock Partners for its reasonable expenses (up to $2 million);

    if the merger agreement is terminated by Archrock Partners due to a material uncured breach by Archrock of any of its covenants, agreements, representations or warranties, then Archrock shall pay to Archrock Partners an amount equal to $10 million;

    if the merger agreement is terminated by Archrock due to a material uncured breach by Archrock Partners of any of its covenants, agreements, representations or warranties, then Archrock Partners shall reimburse Archrock for its reasonable expenses (up to $2 million);

    if the merger agreement is terminated by Archrock to enter into a definitive agreement relating to a superior proposal, then Archrock shall pay to Archrock Partners an amount equal to $10 million; or

    if an alternative proposal is publicly made prior to the AROC stockholders meeting and the merger agreement is terminated by Archrock Partners or Archrock due to the failure of the closing of the merger to occur prior to September 30, 2018 or the failure to obtain the required AROC stockholder approval, and, within twelve months after termination, Archrock (or any of its subsidiaries) has entered into a definitive agreement with respect to an alternative proposal or consummated an alternative proposal (whether or not such proposal is the same proposal made prior to the AROC stockholders meeting), then Archrock shall pay to Archrock Partners an amount equal to $10 million.

        If a $10 million fee is paid to Archrock Partners in one of the preceding circumstances, that fee (less certain unreimbursed out-of-pocket expenses) received by Archrock Partners will be distributed to the APLP common unitholders as a special distribution, and Archrock and its affiliates will waive any rights to receive such distribution.

APLP Conflicts Committee

        Archrock has agreed, until the effective time of the merger or the termination of the merger agreement, not to, without the consent of holders of a majority of the then existing APLP conflicts committee, take any action (or allow its subsidiaries to take any action) intended to cause the Managing GP to eliminate the APLP conflicts committee, revoke or diminish the authority of the APLP conflicts committee or remove or cause the removal of any director of the APLP board that is a member of the APLP conflicts committee either as a director or member of such committee.

United States Federal Income Tax Consequences of the Merger

        The receipt of AROC common stock in exchange for APLP common units pursuant to the merger agreement will be a taxable transaction for U.S. federal income tax purposes to U.S. Holders (as defined in "United States Federal Income Tax Consequences"). In such case, a U.S. Holder who receives AROC common stock in exchange for APLP common units pursuant to the merger agreement will recognize gain or loss in an amount equal to the difference between:

    the sum of (i) the fair market value of the AROC common stock received and (ii) such U.S. Holder's share of Archrock Partners' nonrecourse liabilities immediately prior to the merger; and

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    such U.S. Holder's adjusted tax basis in the APLP common units exchanged therefor (which includes such U.S. Holder's share of Archrock Partners' nonrecourse liabilities immediately prior to the merger).

        Gain or loss recognized by a U.S. Holder will generally be taxable as capital gain or loss. However, a portion of this gain or loss, which could be substantial, will be separately computed and taxed as ordinary income or loss under Section 751 of the Code to the extent attributable to "unrealized receivables," including depreciation recapture, or to "inventory items" owned by Archrock Partners and its subsidiaries. Passive losses that were not deductible by a U.S. Holder in prior taxable periods because they exceeded a U.S. Holder's share of Archrock Partners' income may become available to offset a portion of the gain recognized by such U.S. Holder.

        The U.S. federal income tax consequences of the merger to an APLP common unitholder will depend on such common unitholder's own personal tax situation. Accordingly, you are strongly urged to consult your tax advisor for a full understanding of the particular tax consequences of the merger to you.

        See "United States Federal Income Tax Consequences" for a more complete discussion of U.S. federal income tax consequences of the merger.

No Appraisal Rights

        Neither AROC stockholders nor APLP common unitholders are entitled to appraisal rights in connection with the merger under applicable law or contractual appraisal rights under Archrock's organizational documents, the Archrock Partners partnership agreement or the merger agreement.

Listing of AROC Common Stock to be Issued in the Merger; Delisting and Deregistration of APLP Common Units

        Archrock expects to obtain approval to list on the NYSE the AROC common stock to be issued pursuant to the merger agreement, which approval is a condition to the merger. Upon completion of the merger, APLP common units currently listed on NASDAQ will cease to be listed on NASDAQ and will be subsequently deregistered under the Exchange Act.

Accounting Treatment of the Merger

        The merger will be accounted for in accordance with Financial Accounting Standards Board Accounting Standards Codification (ASC) 810, Consolidation (ASC 810). Because Archrock controls Archrock Partners both before and after the merger, the changes in Archrock's ownership interest in Archrock Partners resulting from the merger will be accounted for as an equity transaction, and no gain or loss will be recognized in Archrock's consolidated statement of operations. In addition, the tax effects of the merger are reported as adjustments to long-term assets associated with discontinued operations, deferred income taxes, additional paid-in capital and accumulated other comprehensive income consistent with ASC 740, Income Taxes (ASC 740).

Timing of the Merger

        The merger is expected to close in the second quarter of 2018, subject to the receipt of stockholder and unitholder approvals and the satisfaction or waiver of the other closing conditions. For a discussion of the timing of the merger, see "The Merger Agreement—The Merger; Effective Time; Closing" beginning on page 79.

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Comparison of the Rights of AROC Stockholders and APLP Common Unitholders

        A limited partnership is inherently different from a corporation. Ownership interests in a limited partnership are therefore fundamentally different from ownership interests in a corporation. APLP common unitholders will own AROC common stock following the completion of the merger, and their rights associated with the AROC common stock will be governed by Archrock's organizational documents and the Delaware General Corporation Law (the "DGCL"), which differ in a number of respects from the Archrock Partners partnership agreement and Delaware Revised Uniform Limited Partnership Act (the "Delaware LP Act").

Summary of Risk Factors

        You should consider carefully all the risk factors together with all of the other information included in this joint proxy statement/prospectus before deciding how to vote. The risks related to the merger and the related transactions, Archrock's business, AROC common stock and risks resulting from Archrock's organizational structure are described under "Risk Factors" beginning on page 25. Some of these risks include, but are not limited to, those described below:

    The merger is subject to conditions, including some conditions that may not be satisfied on a timely basis, if at all. Failure to complete the merger, or significant delays in completing the merger, could negatively affect each party's future business and financial results and the trading prices of AROC common stock and APLP common units.

    Because the exchange ratio is fixed and because the market price of AROC common stock will fluctuate prior to the completion of the merger, APLP common unitholders cannot be sure of the market value of the AROC common stock they will receive as merger consideration relative to the value of APLP common units they exchange.

    The date APLP common unitholders will receive the merger consideration depends on the completion date of the merger, which is uncertain.

    Archrock and Archrock Partners may incur substantial transaction-related costs in connection with the merger.

    Each of Archrock and Archrock Partners is subject to provisions that limit its ability to pursue alternatives to the merger and could discourage a potential competing acquirer from making a favorable alternative transaction proposal.

    Archrock is subject to provisions under the merger agreement that, in specified circumstances, could require Archrock to pay a fee to Archrock Partners of $10 million. In addition, each of Archrock and Archrock Partners may, under certain specified circumstances, be responsible for the other party's expenses in an amount up to $2 million.

    Certain executive officers and directors of the Managing GP and Archrock have interests in the merger that are different from, or in addition to, the interests they may have as APLP common unitholders or AROC stockholders, respectively, which could have influenced their decision to support or approve the merger.

    Financial projections by Archrock and Archrock Partners may not prove to be reflective of actual future results.

    Archrock and Archrock Partners may be unable to obtain the regulatory clearances required to complete the merger or, in order to do so, Archrock and Archrock Partners may be required to comply with material restrictions or satisfy material conditions.

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    The unaudited pro forma financial statements included in this joint proxy statement/prospectus are presented for illustrative purposes only and may not be an indication of the combined entity's financial condition or results of operations following the merger.

    Shares of AROC common stock to be received by APLP common unitholders as a result of the merger have different rights from APLP common units.

    The merger will be a taxable transaction to APLP common unitholders and, in such case, the resulting tax liability of an APLP common unitholder, if any, will depend on the unitholder's particular situation. The tax liability of an APLP common unitholder as a result of the merger could be more than expected.

    The U.S. federal income tax treatment of owning and disposing of AROC common stock received in the merger will be different than the U.S. federal income tax treatment of owning and disposing of APLP common units.

    Archrock's future tax liability may be greater than expected if it does not generate net operating losses ("NOLs") sufficient to offset taxable income or if tax authorities challenge certain of its tax positions.

    Archrock's ability to use NOLs to offset future income may be limited.

    The recently passed comprehensive tax reform bill could adversely affect our business and financial condition.

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SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA OF ARCHROCK

        The following selected historical consolidated financial data as of December 31, 2017 and 2016 and for each of the years ended December 31, 2017, 2016 and 2015 are derived from Archrock's audited consolidated financial statements incorporated by reference into this joint proxy statement/prospectus. Historical consolidated financial data as of December 31, 2015, 2014 and 2013 and for the years ended December 31, 2014 and 2013 are derived from Archrock's consolidated financial statements not incorporated by reference into this joint proxy statement/prospectus. The following data should be read in conjunction with "Management's Discussion and Analysis of Financial Condition and Results of Operations" and the consolidated financial statements and the related notes thereto set forth in Archrock's Annual Report on Form 10-K for the year ended December 31, 2017, which is incorporated by reference into this joint proxy statement/prospectus. It should not be assumed the results of operations for any past period indicate results for any future period. For more information, see "Where You Can Find More Information" beginning on page 200.

 
  Year Ended December 31,  
Archrock, Inc.
  2017   2016   2015   2014   2013  
 
  (In thousands, except per share amounts)
 

Statement of Operations Data:

                               

Revenue

  $ 794,655   $ 807,069   $ 998,108   $ 959,153   $ 862,772  

Selling, general and administrative

    111,483     114,470     131,919     132,651     118,851  

Depreciation and amortization

    188,563     208,986     229,127     212,268     187,476  

Long-lived asset impairment

    29,142     87,435     124,979     42,828     16,696  

Restatement and other charges

    4,370     13,470              

Restructuring and other charges

    1,386     16,901     4,745     5,394      

Goodwill impairment

            3,738          

Interest expense

    88,760     83,899     107,617     112,273     112,194  

Debt extinguishment costs

    291         9,201          

Other income, net

    (5,643 )   (8,590 )   (2,079 )   (5,475 )   (22,535 )

Loss before income taxes

    (42,619 )   (89,421 )   (106,185 )   (45,179 )   (20,888 )

Provision for (benefit from) income taxes

    (61,083 )   (24,604 )   53,189     (28,066 )   (17,840 )

Income (loss) from continuing operations

    18,464     (64,817 )   (159,374 )   (17,113 )   (3,048 )

Net income (loss) from discontinued operations, net of tax

    (54 )   (426 )   33,677     105,774     129,654  

Net income (loss) attributable to noncontrolling interest

    (543 )   (10,688 )   6,852     27,716     32,578  

Net income (loss) attributable to AROC stockholders

    18,953     (54,555 )   (132,549 )   60,945     94,028  

Income (loss) from continuing operations attributable to AROC stockholders per common share:

                               

Basic and diluted

  $ 0.26   $ (0.79 ) $ (2.44 ) $ (0.68 ) $ (0.55 )

Weighted average common shares outstanding used in income (loss) per common share:

                               

Basic

    69,552     68,993     68,433     66,234     64,454  

Diluted

    69,664     68,993     68,433     66,234     64,454  

Other Financial Data:

                               

Gross margin(a)

  $ 375,733   $ 427,150   $ 503,062   $ 454,760   $ 391,794  

Capital expenditures

  $ 221,693   $ 117,572   $ 256,142   $ 383,841   $ 291,530  

Dividends declared and paid per common share

  $ 0.4800   $ 0.4975   $ 0.6000   $ 0.6000   $  

Balance Sheet Data:

                               

Cash and cash equivalents

  $ 10,536   $ 3,134   $ 1,563   $ 378   $ 471  

Working capital

    90,307     109,157     150,199     508,531     434,577  

Property, plant and equipment, net

    2,076,927     2,079,099     2,267,788     2,372,081     1,855,076  

Total assets

    2,408,007     2,414,779     2,695,180     4,875,835     4,204,409  

Long-term debt

    1,417,053     1,441,724     1,576,882     2,008,311     1,486,605  

Total AROC stockholders' equity

    777,049     718,966     733,910     1,710,021     1,609,571  

(a)
Archrock defines gross margin, a non-GAAP financial measure, as total revenue less cost of sales (excluding depreciation and amortization expense). Gross margin is included as a supplemental disclosure because it is a primary measure used by Archrock management to evaluate the results of revenue and cost of sales (excluding depreciation and amortization expense), which are key components of Archrock's operations. AROC management believes gross margin is important

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    because it focuses on the current operating performance of Archrock's operations and excludes the impact of the prior historical costs of the assets acquired or constructed that are utilized in those operations, the indirect costs associated with Archrock's selling, general and administrative ("SG&A") activities, the impact of Archrock's financing methods and income taxes. Depreciation and amortization expense may not accurately reflect the costs required to maintain and replenish the operational usage of Archrock's assets and therefore may not portray the costs of current operating activity. As an indicator of Archrock's operating performance, gross margin should not be considered an alternative to, or more meaningful than, net income (loss) as determined in accordance with GAAP. Archrock's gross margin may not be comparable to a similarly titled measure of another company because other entities may not calculate gross margin in the same manner. Gross margin has certain material limitations associated with its use as compared to net income (loss). These limitations are primarily due to the exclusion of interest expense, depreciation and amortization expense, SG&A expense, impairment charges, restatement and other charges, restructuring and other charges, debt extinguishment costs, provision for (benefit from) income taxes and other (income) loss, net. Because Archrock intends to finance a portion of its operations through borrowings, interest expense is a necessary element of its costs and its ability to generate revenue. Additionally, because Archrock uses capital assets, depreciation expense is a necessary element of its costs and its ability to generate revenue and SG&A expense is necessary to support its operations and required corporate activities. To compensate for these limitations, Archrock management uses this non-GAAP measure as a supplemental measure to other GAAP results to provide a more complete understanding of Archrock's performance.

    The following table reconciles Archrock's net income (loss) to gross margin (in thousands):

 
  Year Ended December 31,  
Archrock, Inc.
  2017   2016   2015   2014   2013  

Net income (loss)

  $ 18,410   $ (65,243 ) $ (125,697 ) $ 88,661   $ 126,606  

Selling, general and administrative

    111,483     114,470     131,919     132,651     118,851  

Depreciation and amortization

    188,563     208,986     229,127     212,268     187,476  

Long-lived asset impairment

    29,142     87,435     124,979     42,828     16,696  

Restatement and other charges

    4,370     13,470              

Restructuring and other charges

    1,386     16,901     4,745     5,394      

Goodwill impairment

            3,738          

Interest expense

    88,760     83,899     107,617     112,273     112,194  

Debt extinguishment costs

    291         9,201          

Other income, net

    (5,643 )   (8,590 )   (2,079 )   (5,475 )   (22,535 )

Provision for (benefit from) income taxes

    (61,083 )   (24,604 )   53,189     (28,066 )   (17,840 )

(Income) loss from discontinued operations, net of tax

    54     426     (33,677 )   (105,774 )   (129,654 )

Gross margin

  $ 375,733   $ 427,150   $ 503,062   $ 454,760   $ 391,794  

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SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA OF ARCHROCK PARTNERS

        The following selected historical consolidated financial data as of December 31, 2017 and 2016 and for each of the years ended December 31, 2017, 2016 and 2015 are derived from Archrock Partners' audited consolidated financial statements incorporated by reference into this joint proxy statement/prospectus. Historical consolidated financial data as of December 31, 2015, 2014 and 2013 and for each of the years ended December 31, 2014 and 2013 are derived from Archrock Partners' consolidated financial statements not incorporated by reference into this joint proxy statement/prospectus. The following data should be read in conjunction with "Management's Discussion and Analysis of Financial Condition and Results of Operations" and the consolidated financial statements and the related notes thereto set forth in Archrock Partners' Annual Report on Form 10-K for the year ended December 31, 2017, which is incorporated by reference into this joint proxy statement/prospectus. It should not be assumed the results of operations for any past period indicate results for any future period. For more information, see "Where You Can Find More Information" beginning on page 200.

 
  Year Ended December 31,  
Archrock Partners, L.P.
  2017   2016   2015   2014   2013  
 
  (In thousands, except per unit amounts)
 

Statement of Operations Data:

                               

Revenue

  $ 557,503   $ 562,360   $ 656,808   $ 581,036   $ 466,193  

Selling, general and administrative

    82,035     79,717     85,586     80,521     61,971  

Depreciation and amortization

    143,848     153,741     155,786     128,196     103,711  

Long-lived asset impairment

    19,106     46,258     38,987     12,810     5,350  

Restructuring charges

        7,309         702      

Goodwill impairment

            127,757          

Interest expense

    84,291     77,863     74,581     57,811     37,068  

Debt extinguishment costs

    291                  

Other income, net

    (4,384 )   (2,594 )   (1,391 )   (74 )   (9,481 )

Provision for income taxes

    3,382     1,412     1,035     1,313     1,506  

Net income (loss)

  $ (421 ) $ (10,757 ) $ (84,025 ) $ 61,719   $ 64,023  

Income (loss) per common unit:

                               

Basic and diluted

  $ (0.01 ) $ (0.18 ) $ (1.71 ) $ 0.89   $ 1.18  

Weighted average common units outstanding:

                               

Basic

    67,237     60,450     58,539     54,107     47,651  

Diluted

    67,237     60,450     58,539     54,109     47,667  

Other Financial Data:

                               

Gross margin(a)

  $ 328,148   $ 352,949   $ 398,316   $ 342,998   $ 264,148  

Distributable cash flow(b)

    137,139     175,696     190,690     177,628     152,976  

Cash capital expenditures

    179,319     62,345     229,202     303,952     168,036  

Distributions declared and paid per common unit

    1.1400     1.4275     2.2600     2.1650     2.0800  

Balance Sheet Data:

                               

Cash

  $ 8,078   $ 217   $ 472   $ 295   $ 182  

Working capital

    30,925     39,216     55,928     60,256     46,802  

Total assets

    1,930,202     1,903,374     1,994,653     1,995,713     1,359,460  

Long-term debt, net

    1,361,053     1,342,724     1,410,382     1,286,564     749,352  

Partners' capital

    514,740     522,173     547,996     683,341     591,755  

(a)
Archrock Partners defines gross margin, a non-GAAP financial measure, as total revenue less cost of sales (excluding depreciation and amortization expense). Gross margin is included as a supplemental disclosure because it is a primary measure used by APLP management to evaluate the results of revenue and cost of sales (excluding depreciation and amortization expense), which are key components of APLP's operations. Archrock Partners believes gross margin is important because it focuses on the current operating performance of APLP's operations and excludes the impact of the prior historical costs of the assets acquired or constructed that are utilized in those operations, the indirect costs associated with APLP's SG&A activities, the impact of APLP's financing methods and income taxes. Depreciation and amortization expense may not accurately reflect the costs required to maintain and replenish the operational usage of APLP's assets and therefore may not portray the costs of current operating

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    activity. As an indicator of APLP's operating performance, gross margin should not be considered an alternative to, or more meaningful than, net income (loss) as determined in accordance with GAAP. APLP's gross margin may not be comparable to a similarly titled measure of another company because other entities may not calculate gross margin in the same manner.

    Gross margin has certain material limitations associated with its use as compared to net income (loss). These limitations are primarily due to the exclusion of interest expense, depreciation and amortization expense, SG&A expense, impairments, restructuring charges, debt extinguishment costs, provision for (benefit from) income taxes and other (income) loss, net. Because Archrock Partners intends to finance a portion of its operations through borrowings, interest expense is a necessary element of APLP's costs and APLP's ability to generate revenue. Additionally, because Archrock Partners uses capital assets, depreciation expense is a necessary element of its costs and ability to generate revenue and SG&A expense is necessary to support our operations and required partnership activities. To compensate for these limitations, APLP management uses this non-GAAP measure as a supplemental measure to other GAAP results to provide a more complete understanding of our performance.

    The following table reconciles Archrock Partners' net income (loss) to gross margin (in thousands):

 
  Year Ended December 31,  
Archrock Partners, L.P.
  2017   2016   2015   2014   2013  

Net income (loss)

  $ (421 ) $ (10,757 ) $ (84,025 ) $ 61,719   $ 64,023  

Selling, general and administrative—affiliates

    82,035     79,717     85,586     80,521     61,971  

Depreciation and amortization

    143,848     153,741     155,786     128,196     103,711  

Long-lived asset impairment

    19,106     46,258     38,987     12,810     5,350  

Restructuring charges

        7,309         702      

Goodwill impairment

            125,757          

Interest expense

    84,291     77,863     74,581     57,811     37,068  

Debt extinguishment costs

    291                  

Other income, net

    (4,384 )   (2,594 )   (1,391 )   (74 )   (9,481 )

Provision for income taxes

    3,382     1,412     1,035     1,313     1,506  

Gross margin

  $ 328,148   $ 352,949   $ 398,316   $ 342,998   $ 264,148  
(b)
APLP defines distributable cash flow, a non-GAAP financial measure, as net income (loss) (i) plus depreciation and amortization expense, impairment charges, restructuring charges, non-cash SG&A costs, interest expense, expensed acquisition costs, debt extinguishment costs and any amounts reimbursed to us by AROC as a result of the caps on cost of sales and SG&A costs provided in the Omnibus Agreement (as defined in the Archrock Partners partnership agreement), which amounts are treated as capital contributions from AROC for accounting purposes (ii) less cash interest expense (excluding amortization of deferred financing fees, amortization of debt discount and non-cash transactions related to interest rate swaps) and maintenance capital expenditures and (iii) excluding gains or losses on asset sales and other items. Distributable cash flow is a supplemental financial measure that APLP management and, Archrock Partners believes, external users of its consolidated financial statements, such as industry analysts, investors, lenders and rating agencies, may use to assess its operating performance as compared to other publicly traded partnerships without regard to historical cost basis. Archrock Partners also believes distributable cash flow is an important liquidity measure because it allows APLP management and external users of our financial statements the ability to compute the ratio of distributable cash flow to the cash distributions declared to all unitholders, including incentive distribution rights, to determine the rate at which the distributable cash flow covers the distribution. Archrock Partners' distributable cash flow may not be comparable to a similarly titled measure of another company because other entities may not calculate distributable cash flow in the same manner. Distributable cash flow is not a measure of financial performance under GAAP and should not be considered in isolation or as an alternative to net income (loss), cash flows from operating activities and other measures determined in accordance with GAAP. Items excluded from distributable cash flow are significant and necessary components to the operations of APLP's business, and, therefore, distributable cash flow should only be used as a supplemental measure of APLP's operating performance.

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    The following table reconciles Archrock Partners' net income (loss) to distributable cash flow (in thousands):

 
  Year Ended December 31,  
Archrock Partners, L.P.
  2017   2016   2015   2014   2013  

Net income (loss)

  $ (421 ) $ (10,757 ) $ (84,025 ) $ 61,719   $ 64,023  

Depreciation and amortization

    143,848     153,741     155,786     128,196     103,711  

Long-lived asset impairment

    19,106     46,258     38,987     12,810     5,350  

Restructuring charges

        7,309         702      

Goodwill impairment

            127,757          

Cap on operating and selling, general and administrative costs provided by Archrock

                13,850     25,180  

Non-cash selling, general and administrative—affiliates

    1,062     1,203     1,059     1,376     1,174  

Interest expense

    84,291     77,863     74,581     57,811     37,068  

Expensed acquisition costs

        523     302     2,471     821  

Debt extinguishment costs

    291                  

Less: Gain on sale of property, plant and equipment

    (4,262 )   (3,585 )   (1,747 )   (2,466 )   (10,140 )

Less: Loss on non-cash consideration in March 2016 acquisition

        635              

Less: Cash interest expense

    (76,505 )   (73,594 )   (70,181 )   (53,525 )   (32,810 )

Less: Maintenance capital expenditures

    (30,271 )   (23,900 )   (51,829 )   (45,316 )   (41,401 )

Distributable cash flow

  $ 137,139   $ 175,696   $ 190,690   $ 177,628   $ 152,976  

    The following table reconciles Archrock Partners' net cash provided by operating activities to distributable cash flow (in thousands):

 
  Year Ended December 31,  
Archrock Partners, L.P.
  2017   2016   2015   2014   2013  

Net cash provided by operating activities

  $ 179,333   $ 213,029   $ 241,166   $ 185,764   $ 158,286  

(Provision for) benefit from doubtful accounts

    (4,104 )   (2,672 )   (2,255 )   (1,060 )   25  

Restructuring charges

        7,309         702      

Cap on operating and selling, general and administrative costs provided by Archrock

                13,850     25,180  

Expensed acquisition costs

        523     302     2,471     821  

Deferred income tax (provision) benefit

    (3,384 )   (1,444 )   160     (1,402 )   (356 )

Payments for settlement of interest rate swaps that include financing elements

    (1,785 )   (3,058 )   (3,728 )   (3,793 )   (2,207 )

Maintenance capital expenditures

    (30,271 )   (23,900 )   (51,829 )   (45,316 )   (41,401 )

Changes in assets and liabilities

    (2,650 )   (14,091 )   6,874     26,412     12,628  

Distributable cash flow

  $ 137,139   $ 175,696   $ 190,690   $ 177,628   $ 152,976  

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SELECTED UNAUDITED PRO FORMA CONSOLIDATED FINANCIAL INFORMATION

        The following table sets forth selected unaudited pro forma consolidated financial information for Archrock after giving effect to the merger. The selected unaudited pro forma consolidated financial information is derived from the unaudited pro forma consolidated financial statements included in this joint proxy statement/prospectus and should be read in conjunction with the section entitled "Unaudited Pro Forma Consolidated Financial Statements" and related notes included in this joint proxy statement/prospectus beginning on page 203.

 
  Year Ended
December 31, 2017
 
 
  (In thousands,
except per share
amounts)

 

Pro forma statement of operations data

       

Total revenue

  $ 794,655  

Income from continuing operations

    17,288  

Income from continuing operations per common share—basic and diluted

    0.13  

Pro forma balance sheet data

       

Total assets

  $ 2,401,165  

Long-term debt, including current maturities

    1,417,053  

Total Archrock stockholders' equity

    815,494  

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COMPARATIVE PER SHARE AND PER UNIT INFORMATION

        The following table sets forth (i) historical per share information of Archrock, (ii) the unaudited pro forma per share information of Archrock after giving pro forma effect to the proposed merger and the transactions contemplated thereby, including Archrock's issuance of 1.40 of a share of AROC common stock for each outstanding APLP common unit not owned by Archrock or its subsidiaries, and (iii) the historical and equivalent pro forma per share information for Archrock Partners.

        This information should be read in conjunction with (i) the summary historical financial information included elsewhere in this joint proxy statement/prospectus, (ii) the historical consolidated financial statements of Archrock and Archrock Partners and related notes that are incorporated by reference in this joint proxy statement/prospectus and (iii) the "Unaudited Pro Forma Consolidated Financial Statements" and related notes included elsewhere in this joint proxy statement/prospectus. The unaudited pro forma per share and unit information does not purport to represent what the actual results of operations of Archrock and Archrock Partners would have been had the proposed merger been completed in another period or to project Archrock's and Archrock Partners' results of operations that may be achieved if the proposed merger is completed.

Archrock, Inc.
  Year Ended
December 31, 2017
 

Historical—Archrock

       

Income (loss) from continuing operations per common share attributable to Archrock common stockholders—basic and diluted

  $ 0.26  

Dividends declared and paid per common share

  $ 0.4800  

Book value per share(a)

  $ 10.95  

Historical—Archrock Partners

       

Limited partners' net loss per unit—basic and diluted

  $ (0.01 )

Distributions per unit declared in the period

  $ 1.1400  

Book value per unit(a)

  $ 7.33  

Pro forma combined—Archrock

       

Income from continuing operations per common share—basic and diluted(b)

  $ 0.13  

Dividends per share declared in the period(c)

  $ 0.6108  

Book value per share(d)

  $ 6.34  

Equivalent pro forma combined—Archrock Partners(e)

       

Income from continuing operations per common share—basic and diluted

  $ 0.18  

Dividends per share declared in the period

  $ 0.8551  

Book value per share

  $ 8.88  

(a)
The historical book value per share or unit was calculated as follows (in thousands, except per share or unit amounts):


 
  As of
December 31, 2017
 
 
  Archrock   Archrock
Partners
 

Equity or capital, as applicable, before noncontrolling interests

  $ 777,049   $ 514,740  

Divided by: Number of shares or units outstanding as of end of period

    70,951     70,197  

Book value per share or unit outstanding

  $ 10.95   $ 7.33  
(b)
Amount is from the unaudited pro forma consolidated financial statements included under "Unaudited Pro Forma Consolidated Financial Statements."

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(c)
The pro forma combined—Archrock dividends declared amount was calculated as follows (in thousands, except per share or unit amounts):
 
  Year Ended
December 31, 2017
 
 
  Archrock   Archrock
Partners
  Total  

Declared dividends or distributions, as applicable, in the period to the public (historical)

  $ 34,063   $ 44,449   $ 78,512  

Divided by: Pro forma combined number of shares outstanding as of date of record(f)

                128,536  

Dividends per share declared in the period (pro forma)

              $ 0.6108  
(d)
The pro forma combined—Archrock, book value per share was calculated as follows (in thousands, except per share amounts):
 
  As of
December 31,
2017
 

Pro forma equity before noncontrolling interests

  $ 815,494  

Divided by: Pro forma combined number of shares outstanding(f)

    128,536  

Book value per share

  $ 6.34  
(e)
Equivalent pro forma amounts are calculated by multiplying pro forma combined Archrock amounts by the exchange ratio of 1.40.

(f)
Pro forma combined number of shares calculated as follows (in thousands, except exchange ratio):
 
  As of
December 31, 2017
 
 
  Archrock   Archrock
Partners
  Total  

Number of public shares outstanding

    70,951     41,132        

Exchange ratio

          1.40        

Number of public shares outstanding (pro forma)

    70,951     57,585     128,536  

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MARKET PRICES, DIVIDEND AND DISTRIBUTION INFORMATION

        Shares of AROC common stock are traded on the NYSE under the ticker symbol "AROC" and the APLP common units are traded on the NASDAQ under the ticker symbol "APLP." The following table sets forth, for the periods indicated, the range of high and low sales prices for AROC common stock and APLP common units, on the NYSE and NASDAQ composite tapes, as well as information concerning quarterly cash dividends declared and paid on the AROC common stock and cash distributions declared and paid on the APLP common units. The sales prices are as reported in published financial sources.

 
  AROC Common Stock   APLP Common Units  
 
  High   Low   Dividend(1)   High   Low   Distribution(2)  

2014

                                     

First quarter

  $ 44.66   $ 33.42   $ 0.15   $ 31.00   $ 27.75   $ 0.5325  

Second quarter

  $ 45.90   $ 40.81   $ 0.15   $ 30.17   $ 26.25   $ 0.5375  

Third quarter

  $ 47.01   $ 41.16   $ 0.15   $ 30.64   $ 27.15   $ 0.5425  

Fourth quarter

  $ 45.35   $ 30.58   $ 0.15   $ 30.14   $ 19.01   $ 0.5525  

2015

                                     

First quarter

  $ 34.23   $ 26.24   $ 0.15   $ 26.00   $ 20.58   $ 0.5575  

Second quarter

  $ 37.71   $ 30.14   $ 0.15   $ 27.93   $ 22.07   $ 0.5625  

Third quarter

  $ 32.94   $ 16.68   $ 0.15   $ 24.16   $ 11.65   $ 0.5675  

Fourth quarter(3)

  $ 24.17   $ 7.12   $ 0.15   $ 20.96   $ 10.58   $ 0.5725  

2016

                                     

First quarter

  $ 8.18   $ 3.41   $ 0.1875   $ 13.12   $ 5.36   $ 0.5725  

Second quarter

  $ 10.13   $ 5.60   $ 0.095   $ 16.00   $ 9.61   $ 0.285  

Third quarter

  $ 13.18   $ 8.28   $ 0.095   $ 15.64   $ 12.79   $ 0.285  

Fourth quarter

  $ 14.90   $ 10.80   $ 0.12   $ 17.47   $ 13.43   $ 0.285  

2017

                                     

First quarter

  $ 16.40   $ 11.56   $ 0.12   $ 18.55   $ 15.66   $ 0.285  

Second quarter

  $ 13.65   $ 9.60   $ 0.12   $ 17.14   $ 12.43   $ 0.285  

Third quarter

  $ 12.85   $ 8.30   $ 0.12   $ 15.64   $ 12.69   $ 0.285  

Fourth quarter

  $ 13.01   $ 9.25   $ 0.12   $ 14.60   $ 10.58   $ 0.285  

2018

                                     

First Quarter (through March 9, 2018)

  $ 10.95   $ 8.48     N/A   $ 15.10   $ 11.94     N/A  

(1)
Represents cash dividends per share of AROC common stock declared and paid in the quarter presented.

(2)
Represents cash distributions per APLP common unit declared with respect to the quarter presented and paid in the following quarter.

(3)
In November 2015, Archrock completed the spin-off of its international contract operations, international aftermarket services operations and global fabrication businesses into an independent, publicly traded company.

        As of March 14, 2018, the record date for the Archrock annual meeting, there were 71,712,997 shares of AROC common stock outstanding held by holders of record. Archrock intends to pay to the AROC stockholders, on a quarterly basis, dividends based on the cash it receives from its Archrock Partners distributions in accordance with the Archrock Partners partnership agreement, less reserves for expenses, future dividends and other uses of cash. If Archrock Partners is successful in implementing its business strategy and increasing distributions to its partners, Archrock would generally expect to increase dividends to the AROC stockholders, although the timing and amount of any such increased

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dividends may not necessarily be comparable to any increased Archrock Partners distributions. Archrock cannot guarantee that any dividends will be declared or paid in the future.

        As of March 14, 2018, the record date for the Archrock Partners special meeting, there were 70,231,036 APLP common units outstanding held by holders of record. The Archrock Partners partnership agreement requires, within 45 days after the end of each quarter, Archrock Partners to distribute all of its "available cash," as defined in the Archrock Partners partnership agreement, to APLP common unitholders of record on the applicable record date. The payment of quarterly cash distributions by Archrock Partners in the future will depend on the amount of its "available cash" at the end of each quarter. APLP common unitholders will not receive both distributions from Archrock Partners and dividends from Archrock for the same quarter.

        The following table presents per share or unit closing prices for AROC common stock and APLP common units, respectively, on December 29, 2017, the last trading day before the public announcement of the merger as reported on the NYSE and NASDAQ, respectively. This table also presents the equivalent market value per APLP common unit on such dates. The equivalent market value for APLP common units has been determined by multiplying the closing price of AROC common stock on those dates by the exchange ratio.

 
  Archrock
Shares
  Archrock Partners
Common Units
  Equivalent
Market Value
per Archrock
Partners
Common
Unit
 

December 29, 2017

  $ 10.50   $ 11.91   $ 14.70  

        Because the exchange ratio is fixed and because the market price of AROC common stock will fluctuate prior to the completion of the merger, APLP common unitholders cannot be sure of the market value of the AROC common stock they will receive as merger consideration relative to the value of APLP common units they exchange. See "Risk Factors" beginning on page 25.

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RISK FACTORS

        In addition to the other information included and incorporated by reference into this joint proxy statement/prospectus, including the matters addressed in the section titled "Cautionary Statement Regarding Forward-Looking Statements," you should carefully consider the following risks before deciding whether to vote for the approval of the applicable proposals described in this joint proxy statement/prospectus. In addition, you should read and carefully consider the risks associated with each of Archrock and Archrock Partners and their respective businesses. These risks can be found in Archrock's and Archrock Partners' respective Annual Reports on Form 10-K for the year ended December 31, 2017, all of which are filed with the SEC and incorporated by reference into this joint proxy statement/prospectus. For further information regarding the documents incorporated into this joint proxy statement/prospectus by reference, please see the section titled "Where You Can Find More Information" beginning on page 200. Realization of any of the risks described below, any of the events described under "Cautionary Statement Regarding Forward-Looking Statements" or any of the risks or events described in the documents incorporated by reference could have a material adverse effect on Archrock's, Archrock Partners' or the combined organization's businesses, financial condition, cash flows and results of operations and could result in a decline in the trading prices of the AROC common stock or the APLP common units.

Risks Related to the Merger

The merger is subject to conditions, including some conditions that may not be satisfied on a timely basis, if at all. Failure to complete the merger, or significant delays in completing the merger, could negatively affect each party's future business and financial results and the trading prices of AROC common stock and APLP common units.

        The completion of the merger is subject to a number of conditions. The completion of the merger is not assured and is subject to risks, including the risk that AROC stockholder approval or APLP common unitholder approval is not obtained. Further, the merger may not be completed even if the AROC stockholder approval and the APLP common unitholder approval are obtained. The merger agreement contains conditions, some of which are beyond the parties' control, that, if not satisfied or waived, may prevent, delay or otherwise result in the merger not occurring. See "The Merger Agreement—Conditions to Completion of the Merger."

        If the merger is not completed, or if there are significant delays in completing the merger, Archrock's and Archrock Partners' future business and financial results and the trading prices of AROC common stock and APLP common units could be negatively affected, and each of the parties will be subject to several risks, including the following:

    the parties may be liable for fees or expenses to one another under the terms and conditions of the merger agreement;

    there may be negative reactions from the financial markets due to the fact that current prices of AROC common stock and APLP common units may reflect a market assumption that the merger will be completed; and

    the attention of management will have been diverted to the merger rather than their own operations and pursuit of other opportunities that could have been beneficial to their respective businesses.

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Because the exchange ratio is fixed and because the market price of AROC common stock will fluctuate prior to the completion of the merger, APLP common unitholders cannot be sure of the market value of the AROC common stock they will receive as merger consideration relative to the value of APLP common units they exchange.

        The market value of the consideration that APLP common unitholders will receive in the merger will depend on the trading price of AROC common stock at the closing of the merger. The exchange ratio that determines the number of shares of AROC common stock that APLP common unitholders will receive in the merger is fixed at 1.40 shares of AROC common stock for each APLP common unit. This means that there is no mechanism contained in the merger agreement that would adjust the number of shares of AROC common stock that APLP common unitholders will receive based on any decreases or increases in the trading price of AROC common stock. Stock or unit price changes may result from a variety of factors (many of which are beyond Archrock's and Archrock Partners' control), including:

    changes in Archrock's or Archrock Partners' business, operations and prospects;

    changes in market assessments of Archrock's or Archrock Partners' business, operations and prospects;

    changes in market assessments of the likelihood that the merger will be completed;

    interest rates, commodity prices, general market, industry and economic conditions and other factors generally affecting the price of AROC common stock or APLP common units; and

    federal, state and local legislation, governmental regulation and legal developments in the businesses in which Archrock and Archrock Partners operate.

        If the price of AROC common stock at the closing of the merger is less than the price of AROC common stock on the date that the merger agreement was signed, then the market value of the merger consideration will be less than contemplated at the time the merger agreement was signed.

The date APLP common unitholders will receive the merger consideration depends on the completion date of the merger, which is uncertain.

        As described in this joint proxy statement/prospectus, completing the proposed merger is subject to several conditions, not all of which are controllable by Archrock or Archrock Partners. Accordingly, even if the proposed merger is approved by APLP common unitholders, the date on which common unitholders will receive merger consideration depends on the completion date of the merger, which is uncertain and subject to several other closing conditions.

Archrock and Archrock Partners may incur substantial transaction-related costs in connection with the merger.

        Archrock and Archrock Partners expect to incur substantial expenses in connection with completing the merger, including fees paid to legal, financial and accounting advisors, filing fees, proxy solicitation costs and printing costs. Many of the expenses that will be incurred, by their nature, are difficult to estimate accurately at the present time.

Each of Archrock and Archrock Partners is subject to provisions that limit its ability to pursue alternatives to the merger and could discourage a potential competing acquirer from making a favorable alternative transaction proposal.

        Under the merger agreement, Archrock is restricted from pursuing alternative proposals. Under certain "no solicitation" covenants, Archrock has agreed that it will not, and will cause its subsidiaries

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and use reasonable best efforts to cause its representatives not to, directly or indirectly, except as permitted by the merger agreement:

    solicit, initiate, knowingly facilitate or knowingly encourage the submission of an alternative proposal (including any acquisition structured as a merger, consolidation or share exchange);

    participate in any discussions or negotiations regarding, or furnish any information with respect to, any proposal or offer from any person relating to, or that could reasonably be expected to lead to, an alternative proposal;

    knowingly assist, participate in or facilitate in any other manner any effort or attempt by any Person to do or seek any of the foregoing;

    enter into any acquisition agreement with respect to any alternative proposal (other than a confidentiality agreement containing customary provisions); or

    make an Archrock adverse recommendation change.

        Archrock has agreed that it will, and will cause its subsidiaries and use reasonable best efforts to cause its representatives to, cease and cause to be terminated any discussions or negotiations with any persons conducted prior to the execution of the merger agreement with respect to an alternative proposal and immediately prohibit any access by any person to confidential information relating to a possible alternative proposal.

        In addition, each of Archrock and Archrock Partners has agreed not to make an adverse recommendation change, except as provided in the merger agreement. Under the merger agreement, in the event of a potential APLP adverse recommendation change or a potential Archrock adverse recommendation change (as defined under "The Merger Agreement—the Managing GP Recommendation and APLP Adverse Recommendation Change" and under "The Merger Agreement—Archrock Recommendation and Archrock Adverse Recommendation Change"), each party must provide the other party with three days' notice to allow the other party to propose an adjustment to the terms and conditions of the merger agreement.

        These provisions could discourage a third party that may have an interest in acquiring all or a significant part of Archrock or Archrock Partners from considering or proposing that acquisition. See "The Merger Agreement—No Solicitation by Archrock of Alternative Proposals," "The Merger Agreement—Archrock Recommendation and Archrock Adverse Recommendation Change" and "The Merger Agreement—the Managing GP Recommendation and Archrock Partners Adverse Recommendation Change."

Archrock is subject to provisions under the merger agreement that, in specified circumstances, could require Archrock to pay a fee to Archrock Partners of $10 million. In addition, each of Archrock and Archrock Partners may, under certain specified circumstances, be responsible for the other party's expenses in an amount up to $2 million.

        If the merger agreement (i) is terminated by Archrock Partners due to a material uncured breach by Archrock of any of its covenants, representations or warranties, (ii) by Archrock to enter into a definitive agreement relating to a superior proposal or (iii) by Archrock Partners or Archrock due to the failure to obtain the required Archrock stockholder approval and an alternative proposal has been made publicly prior to the Archrock stockholder meeting and within twelve months of termination Archrock has entered into a definitive agreement with respect to, or consummated, an alternative proposal, Archrock will be required to pay a fee to Archrock Partners in the amount of $10 million. If a $10 million fee is paid to Archrock Partners in one of the preceding circumstances, that fee (less certain unreimbursed out-of-pocket expenses) received by Archrock Partners will be distributed to the APLP common unitholders as a special distribution, and Archrock and its affiliates will waive any rights

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to receive such distribution. Alternatively, if the merger agreement is terminated under specified circumstances, either Archrock or Archrock Partners may be required to make a payment of up to $2 million in respect of the other party's expenses. See "The Merger Agreement—Termination of the Merger Agreement" and "The Merger Agreement—Effect of Termination; Termination Fees." If such termination fee or expenses are payable, the payment of such termination fee or expenses could have material and adverse consequences to the financial condition and operations of the party responsible for such payment.

Certain executive officers and directors of the Managing GP and Archrock have interests in the merger that are different from, or in addition to, the interests they may have as APLP common unitholders or AROC stockholders, respectively, which could have influenced their decision to support or approve the merger.

        Certain executive officers and directors of the Managing GP own equity interests in Archrock, receive fees and other compensation from Archrock, and will have rights to ongoing indemnification and insurance coverage by the surviving company that give them interests in the merger that may be different from, or be in addition to, interests of an APLP unaffiliated unitholder.

        Additionally, certain executive officers and directors of Archrock beneficially own APLP common units and will receive the applicable merger consideration upon completion of the merger, receive fees and other compensation from Archrock, and are entitled to indemnification arrangements with Archrock that give them interests in the merger that may be different from, or be in addition to, interests a holder of AROC common stock may have as an AROC stockholder.

        These different interests are described in "The Merger—Interests of Certain Persons in the Merger."

Financial projections by Archrock and Archrock Partners may not prove to be reflective of actual future results.

        In connection with the merger, Archrock and Archrock Partners prepared and considered, among other things, internal financial forecasts for Archrock and Archrock Partners, respectively. These forecasts speak only as of the date made and will not be updated. These financial projections were not provided with a view to public disclosure, are subject to significant economic, competitive, industry and other uncertainties and may not be achieved in full, at all or within projected timeframes. In addition, the failure of businesses to achieve projected results could have a material adverse effect on Archrock's share price, financial position and ability to maintain or increase its dividends following the merger.

Archrock and Archrock Partners may be unable to obtain the regulatory clearances required to complete the merger or, in order to do so, Archrock and Archrock Partners may be required to comply with material restrictions or satisfy material conditions.

        The merger is subject to review by the Antitrust Division and the FTC, under the HSR Act. On February 9, 2018, the Antitrust Division and the Federal Trade Commission granted early termination of the waiting period under the HSR Act. The closing of the merger is subject to the condition precedent that there is no law, injunction, judgment or ruling by a governmental authority in effect enjoining, restraining, preventing or prohibiting the consummation of the transactions contemplated by the merger agreement or making the consummation of the transactions contemplated by the merger agreement illegal. See "The Merger—Regulatory Matters."

        Additionally, state attorneys general could seek to block or challenge the merger as they deem necessary or desirable in the public interest at any time, including after completion of the transaction. In addition, in some circumstances, a third party could initiate a private action under antitrust laws challenging or seeking to enjoin the merger, before or after it is completed. Archrock may not prevail and may incur significant costs in defending or settling any action under the antitrust laws.

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The unaudited pro forma financial statements included in this joint proxy statement/prospectus are presented for illustrative purposes only and may not be an indication of the combined entity's financial condition or results of operations following the merger.

        The unaudited pro forma financial statements contained in this joint proxy statement/prospectus are presented for illustrative purposes only, are based on various adjustments, assumptions and preliminary estimates and may not be an indication of the financial condition or results of operations of the combined entity following the merger for several reasons. The actual financial condition and results of operations of the combined entity following the merger may not be consistent with, or evident from, these pro forma financial statements. In addition, the assumptions used in preparing the pro forma financial information may not prove to be accurate, and other factors may affect the financial condition or results of operations of the combined entity following the merger. Any potential decline in the financial condition or results of operations of the combined entity may cause significant variations in the price of AROC common stock after completion of the merger. See "Unaudited Pro Forma Consolidated Financial Statements."

Shares of AROC common stock to be received by APLP common unitholders as a result of the merger have different rights from APLP common units.

        Following completion of the merger, APLP common unitholders will no longer hold APLP common units, but will instead be AROC stockholders. There are important differences between the rights of APLP common unitholders and the rights of AROC stockholders. Ownership interests in a limited partnership are fundamentally different from ownership interests in a corporation. APLP common unitholders will own AROC common stock following the completion of the merger, and their rights associated with the AROC common stock will be governed by Archrock's organizational documents and the DGCL, which differ in a number of respects from the Archrock Partners partnership agreement and the Delaware LP Act. See "Comparison of Rights of AROC Stockholders and APLP Common Unitholders."

Tax Risks Related to the Merger and the Ownership of AROC Common Stock Received in the Merger

        In addition to reading the following risk factors, you are urged to read "United States Federal Income Tax Consequences" for a more complete discussion of the expected U.S. federal income tax consequences of the merger and owning and disposing of AROC common stock received in the merger.

The merger will be a taxable transaction and, in such case, the resulting tax liability of an APLP common unitholder, if any, will depend on the unitholder's particular situation. The tax liability of an APLP common unitholder as a result of the merger could be more than expected.

        APLP common unitholders will receive AROC common stock as the merger consideration. Although Archrock Partners' common unitholders will receive no cash consideration, the merger will be treated as a taxable sale by U.S. Holders (as defined in "United States Federal Income Tax Consequences") of APLP common units for U.S. federal income tax purposes. In such case, as a result of the merger, an APLP common unitholder will recognize gain or loss for U.S. federal income tax purposes equal to the difference between such unitholder's amount realized and the unitholder's adjusted tax basis in the APLP common units. The amount of gain or loss recognized by each APLP common unitholder in the merger will vary depending on each unitholder's particular situation, including the value of the shares of AROC common stock received by each unitholder in the merger, the adjusted tax basis of the APLP common units exchanged by each unitholder in the merger, and the amount of any suspended passive losses that may be available to a particular unitholder to offset a portion of the gain recognized by the unitholder.

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        Because the value of any AROC common stock received in the merger will not be known until the effective time of the merger, an APLP common unitholder will not be able to determine its amount realized, and therefore its taxable gain or loss, until such time. In addition, because prior distributions in excess of an APLP common unitholder's allocable share of Archrock Partners' net taxable income decrease the unitholder's tax basis in its common units, the amount, if any, of the prior excess distributions with respect to such APLP common units will, in effect, become taxable income to a unitholder if the aggregate value of the consideration received in the merger is greater than the unitholder's adjusted tax basis in its common units, even if the aggregate value of the consideration received in the merger is less than the unitholder's original cost basis in its common units. Furthermore, a portion of this gain or loss, which could be substantial, will be separately computed and taxed as ordinary income or loss to the extent attributable to "unrealized receivables," including depreciation recapture, or to "inventory items" owned by Archrock Partners and its subsidiaries.

        For a more complete discussion of U.S. federal income tax consequences of the merger, see "United States Federal Income Tax Consequences."

The U.S. federal income tax treatment of owning and disposing of AROC common stock received in the merger will be different than the U.S. federal income tax treatment of owning and disposing of APLP common units.

        Archrock Partners is classified as a partnership for U.S. federal income tax purposes and, generally, is not subject to entity-level U.S. federal income taxes. Instead, each APLP common unitholder is required to take into account its respective share of Archrock Partners' items of income, gain, loss and deduction in computing its federal income tax liability, even if no cash distributions are made by Archrock Partners to the unitholder. A pro rata distribution of cash by Archrock Partners to an APLP common unitholder who is a U.S. Holder is generally not taxable for U.S. federal income tax purposes unless the amount of cash distributed is in excess of the unitholder's adjusted tax basis in its APLP common units.

        In contrast, Archrock is classified as a corporation for U.S. federal income tax purposes and is subject to U.S. federal income tax on its taxable income. A distribution of cash by Archrock to a stockholder who is a U.S. Holder will generally be included in such stockholder's income as ordinary dividend income to the extent of Archrock's current or accumulated "earnings and profits," as determined under U.S. federal income tax principles. A portion of the cash distributed to AROC stockholders by Archrock after the merger may exceed Archrock's current and accumulated earnings and profits. Cash distributions to an AROC stockholder who is a U.S. Holder in excess of Archrock's current and accumulated earnings and profits will be treated as a non-taxable return of capital, reducing the adjusted tax basis in the holder's AROC common stock and, to the extent the cash distribution exceeds the holder's adjusted tax basis, as capital gain from the sale or exchange of such AROC common stock. See "United States Federal Income Tax Consequences."

Archrock's future tax liability may be greater than expected if it does not generate NOLs sufficient to offset taxable income or if tax authorities challenge certain of its tax positions.

        Archrock expects to generate deductions and NOL carryforwards that it can use to offset taxable income. As a result, Archrock does not expect to pay meaningful U.S. federal income tax through at least 2023. This estimate is based upon assumptions Archrock has made regarding, among other things, income, capital expenditures and net working capital. The Internal Revenue Service (the "IRS") or other tax authorities, including state and local tax authorities, could challenge one or more tax positions Archrock takes, such as the classification of assets under the income tax depreciation rules or the characterization of expenses for income tax purposes. Further, any change in law may affect Archrock's tax position. While Archrock expects that its deductions and NOL carryforwards will be available to it as a future benefit, in the event that they are not generated as expected, are successfully challenged by

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the IRS (in a tax audit or otherwise) or are subject to future limitations as described below, Archrock's ability to realize these benefits may be limited.

Archrock's ability to use NOLs to offset future income may be limited.

        Archrock's ability to use any NOLs generated by it could be substantially limited if Archrock were to experience an "ownership change" as defined under Section 382 of the Code. In general, an "ownership change" would occur if Archrock's "5-percent stockholders," as defined under Section 382 of the Code, including certain groups of persons treated as "5-percent stockholders," collectively increased their ownership in Archrock by more than 50 percentage points over a rolling three-year period. An ownership change can occur as a result of a public offering of Archrock's common stock, as well as through secondary market purchases of our common stock and certain types of reorganization transactions. A corporation that experiences an ownership change will generally be subject to an annual limitation on the use of its pre-ownership change NOLs (and certain other losses and/or credits) equal to the equity value of the corporation immediately before the ownership change, multiplied by the long-term tax-exempt rate for the month in which the ownership change occurs. Though the merger is not expected to result in an ownership change, such a limitation could result from future transactions and could, for any given year, have the effect of increasing the amount of Archrock's U.S. federal income tax liability, which would negatively impact the amount of after-tax cash available for distribution to holders of AROC common stock and Archrock's financial condition.

The recently passed comprehensive tax reform bill could adversely affect our business and financial condition.

        On December 22, 2017, President Trump signed into law Public Law No. 115-97, a comprehensive tax reform bill (the "Tax Cuts and Jobs Act" or the "TCJA"), that significantly reforms the Internal Revenue Code of 1986, as amended (the "Code"). The TCJA, among other things, contains significant changes to corporate taxation, including a permanent reduction of the corporate income tax rate, a partial limitation on the deductibility of business interest expense, limitation of the deduction for certain net operating losses to 80% of current year taxable income, an indefinite net operating loss carryforward, immediate deductions for certain new investments instead of deductions for depreciation expense over time and the modification or repeal of many business deductions and credits. Archrock continues to examine the impact of this tax reform legislation, and as its overall impact is uncertain, Archrock notes that the TCJA could adversely affect its business and financial condition, including the determination that Archrock does not expect to pay meaningful U.S. federal income tax through at least 2023. The impact of this tax reform legislation on holders of AROC common stock is also uncertain and could be adverse.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

        Some of the statements contained and incorporated in this joint proxy statement/prospectus are forward-looking statements as defined under federal securities laws. The forward-looking statements relate to Archrock's or Archrock Partners' anticipated financial performance (including projected operating income, net income, capital expenditures, cash flow and projected levels of dividends and distributions), liquidity, management's plans and objectives for Archrock's or Archrock Partners' future growth projects and other future operations (including plans to construct additional natural gas and natural gas liquids pipelines and processing facilities and related cost estimates), Archrock's or Archrock Partners' business prospects, the outcome of regulatory and legal proceedings, market conditions and other matters. Archrock and Archrock Partners make these forward-looking statements in reliance on the safe harbor protections provided under federal securities legislation and other applicable laws. The following discussion is intended to identify important factors that could cause future outcomes to differ materially from those set forth in the forward-looking statements.

        Forward-looking statements include the items identified in the preceding paragraph, the information concerning possible or assumed future results of Archrock's or Archrock Partners' operations and other statements contained or incorporated in this joint proxy statement/prospectus identified by words such as "anticipate," "estimate," "expect," "project," "intend," "plan," "believe," "should," "goal," "forecast," "guidance," "could," "may," "continue," "might," "potential," "scheduled" and other words and terms of similar meaning.

        One should not place undue reliance on forward-looking statements. Known and unknown risks, uncertainties and other factors may cause Archrock's or Archrock Partners' actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by forward-looking statements. Those factors may affect Archrock's or Archrock Partners' operations, markets, products, services and prices. In addition to any assumptions and other factors referred to specifically in connection with the forward-looking statements, factors that could cause Archrock's or Archrock Partners' actual results to differ materially from those contemplated in any forward-looking statement include, among others, the following:

    the ability to obtain the requisite approvals from Archrock's stockholders or Archrock Partners' unitholders relating to the merger;

    the risk that Archrock or Archrock Partners may be unable to obtain governmental and regulatory approvals required for the merger or required governmental and regulatory approvals may delay the transaction or result in the imposition of conditions that could cause the parties to abandon the merger (early termination of the waiting period under the HSR Act was granted on February 9, 2018);

    the risk that a condition to closing of the merger may not be satisfied;

    the timing to complete the merger;

    the risk that cost savings, tax benefits and any other synergies from the merger may not be fully realized or may take longer to realize than expected;

    disruption from the merger may make it more difficult to maintain relationships with customers, employees or suppliers;

    the possible diversion of management time on merger-related issues;

    the impact and outcome of pending and future litigation, including litigation, if any, relating to the merger;

    conditions in the oil and natural gas industry, including a sustained decrease in the level of supply or demand for oil or natural gas or a sustained low price of oil or natural gas;

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    reduced profit margins or the loss of market share resulting from competition or the introduction of competing technologies by other companies;

    changes in economic or political conditions, including terrorism and legislative changes;

    the inherent risks associated with the operations of Archrock and Archrock Partners, such as equipment defects, impairments, malfunctions and natural disasters;

    the loss of Archrock Partners' status as a partnership for U.S. federal income tax purposes;

    the risk that counterparties will not perform their obligations under financial instruments of Archrock and Archrock Partners;

    the financial condition of customers of Archrock and Archrock Partners;

    Archrock's and Archrock Partners' ability to timely and cost-effectively obtain components necessary to conduct their respective businesses;

    employment and workforce factors, including Archrock's and Archrock Partners' respective abilities to hire, train and retain key employees;

    Archrock's and Archrock Partners' ability to implement certain business and financial objectives, such as:

    winning profitable new business;

    growing their respective asset bases and enhancing asset utilization;

    integrating acquired businesses;

    generating sufficient cash; and

    accessing the capital markets at an acceptable cost;

    liability related to the use of Archrock's and Archrock Partners' services;

    changes in governmental safety, health, environmental or other regulations, which could require Archrock and Archrock Partners to make significant expenditures;

    the effectiveness of Archrock's and Archrock Partners' respective control environments, including the identification of additional control deficiencies;

    the results of any reviews, investigations or other proceedings by government authorities;

    Archrock's and Archrock Partners' level of indebtedness and ability to fund their respective businesses; and

    the risk factors listed in the reports Archrock and Archrock Partners have filed and may file with the SEC, which are incorporated by reference.

        These factors are not necessarily all of the important factors that could cause actual results to differ materially from those expressed in any of Archrock's or Archrock Partners' forward-looking statements. Other factors could also have material adverse effects on Archrock's or Archrock Partners' future results. These and other risks are described in greater detail in "Risk Factors" in this joint proxy statement/prospectus and in Archrock's and Archrock Partners' other filings made with the SEC, which are available via the SEC's website at www.sec.gov, Archrock's and Archrock Partners' website at www.archrock.com. All forward-looking statements attributable to Archrock or Archrock Partners or persons acting on their behalf are expressly qualified in their entirety by these factors. Any such forward-looking statement speaks only as of the date on which such statement is made, and other than as required under securities laws, neither Archrock nor Archrock Partners undertakes any obligation to update publicly any forward-looking statement whether as a result of new information, subsequent events or change in circumstances, expectations or otherwise.

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THE PARTIES

Archrock, Inc.

        Archrock is a corporation incorporated under the laws of the State of Delaware, and Archrock's common stock is listed on the NYSE under the trading symbol "AROC." Archrock is a pure play U.S. natural gas contract operations services business and the leading provider of natural gas compression services to customers in the oil and natural gas industry throughout the U.S. and a leading supplier of aftermarket services to customers that own compression equipment in the U.S. Archrock operates in two primary business lines: contract operations and aftermarket services. In its contract operations business line, Archrock uses its fleet of natural gas compression equipment to provide operations services to its customers. In its aftermarket services business line, Archrock sells parts and components and provides operations, maintenance, overhaul and reconfiguration services to customers who own compression equipment.

        Archrock's principal executive offices are located at 9807 Katy Freeway, Suite 100, Houston, TX 77024 and its telephone number is (281) 836-8000.

Archrock Partners, L.P.

        Archrock Partners is a publicly traded master limited partnership organized under the laws of the State of Delaware that was formed in June 2006. Archrock Partners' common units are listed on NASDAQ under the trading symbol "APLP." Archrock Partners is the U.S. market leader in the full-service natural gas compression industry. Archrock Partner's contract operations services primarily include designing, sourcing, owning, installing, operating, servicing, repairing and maintaining equipment to provide natural gas compression services to its customers.

        Archrock Partners' principal executive offices are located at 9807 Katy Freeway, Suite 100, Houston, TX 77024 and its telephone number is (281) 836-8000.

Amethyst Merger Sub LLC

        Merger Sub, an indirect wholly owned subsidiary of Archrock, is a Delaware limited liability company formed on January 10, 2018, for the purpose of effecting the merger. Upon completion of the merger, Merger Sub will merge with and into Archrock Partners, with Archrock Partners continuing as the surviving entity and a wholly owned indirect subsidiary of Archrock. Merger Sub has not conducted any activities other than those incidental to its formation and the matters contemplated by the merger agreement.

Relationship Between the Parties

        Archrock has a significant equity interest in Archrock Partners. As of March 14, 2018, Archrock's interests in Archrock Partners consisted of the following:

    an approximate 2% general partner interest, which Archrock holds through its indirect 100% ownership interest in the Managing GP;

    all of the outstanding IDRs; and

    29.1 million (approximately 41%) of the 70.2 million outstanding APLP common units.

        The outstanding APLP common units (including common units held by Archrock and the General Partner) account for approximately 98% of the total ownership interest in Archrock Partners, with the remaining 2% of the total ownership interest in Archrock Partners being composed of the general partner interest in Archrock Partners.

        Certain of the executive officers and directors of the Managing GP are also executive officers and directors of Archrock. See "The Merger—Interests of Certain Persons in the Merger—Common Directors and Executive Officers."

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THE MERGER

        The following discussion of the merger is qualified in its entirety by reference to the Agreement and Plan of Merger, dated as of January 1, 2018, by and among Archrock, the General Partner, the Managing GP and Archrock Partners, as amended by Amendment No. 1 to the Agreement and Plan of Merger, dated as of January 11, 2018, by and among Archrock, Merger Sub, the General Partner, the Managing GP and Archrock Partners. You are urged to read carefully the merger agreement and the amendment thereto, copies of which are attached as Annex A to this joint proxy statement/prospectus and incorporated by reference herein.

Overview

        On January 1, 2018, Archrock, Archrock Partners, the General Partner and the Managing GP entered into the merger agreement, which was amended on January 11, 2018 to add Merger Sub as a party, pursuant to which Archrock will acquire all of the outstanding APLP common units that Archrock and its subsidiaries do not already own. Upon the terms and subject to the conditions set forth in the merger agreement, Merger Sub will be merged with and into Archrock Partners, with Archrock Partners surviving as a wholly owned indirect subsidiary of Archrock.

Background of the Merger

        As part of their ongoing evaluation of Archrock's business, the AROC board and senior management regularly review and assess opportunities to increase stockholder value and achieve long-term strategic goals, including, among other things, potential opportunities for acquisitions, sales and business combinations, capital projects, improvements to cost structure, operational improvements, capital raises and other strategic alternatives. In this regard, Archrock management has considered and discussed with the AROC board numerous potential strategic alternatives with respect to Archrock to enhance value for AROC stockholders. These alternatives have included potential acquisitions or business combination transactions with third parties, potential acquisitions or business combination transactions involving Archrock and Archrock Partners, potential sales of assets from Archrock to Archrock Partners and potential strategic alternatives regarding Archrock Partners' businesses, including a potential reset or elimination of the incentive distribution rights, or IDRs, in Archrock Partners.

        On October 20, 2017, at a regularly scheduled meeting of the AROC board, the AROC board met with members of Archrock management and representatives of Citi, who had been invited to attend the board meeting to provide an overview of the midstream market and industry trends both generally and specifically in the context of master limited partnerships. Citi discussed with the AROC board, among other things, the historical performance of AROC common stock and APLP common units over the prior year and certain other market indicators relative to certain other companies as well as various potential strategic transaction alternatives for Archrock, including, among other things, a combination of Archrock and Archrock Partners, a restructuring of Archrock's IDRs in Archrock Partners, and potential merger and acquisition transactions. After discussion, the AROC board directed Archrock management to review further a possible acquisition of the publicly held APLP common units by Archrock, including the potential benefits of the transaction, Archrock's ability to execute the transaction on economically acceptable terms for both Archrock and Archrock Partners, and strategic alternatives to such a transaction, and to present its findings to the AROC board.

        Throughout November 2017, Archrock management continued to evaluate possible strategic alternatives with Archrock's advisors. During this period, Archrock management concluded that an acquisition by Archrock of the common units of Archrock Partners not already owned by Archrock and its subsidiaries (the "Potential Transaction") would be beneficial to Archrock, as well as to Archrock's stockholders and Archrock Partners' common unitholders, and could be executed on terms

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economically acceptable for both parties. Archrock management based its conclusion on several factors, including that the Potential Transaction provided an improved long-term financial outlook for the combined entities based on decreasing near-term leverage, over two times pro forma cash available for dividend coverage through 2020, anticipated 10% to 15% annual dividend growth, a simplified corporate governance structure, enhanced access to capital markets, a broader anticipated investor base, and anticipated cost savings. Archrock management determined that the expected advantages of a combination of the two entities could significantly improve the combined company's financial profile and position the combined company to compete even more effectively in the market for outsourced compression services.

        On November 28, 2017, a meeting of the AROC board was convened to discuss Archrock management's conclusion that Archrock's acquisition of the common units of Archrock Partners not already owned by Archrock and its subsidiaries was in the best interest of Archrock, as well as Archrock's stockholders and Archrock Partners' common unitholders. At that meeting, the AROC board met with members of Archrock management and representatives of Citi and Latham & Watkins LLP ("Latham & Watkins"), Archrock's external counsel. Citi discussed with the AROC board certain financial and market considerations in the context of the Potential Transaction. The AROC board also discussed with Archrock's management and advisors, among other things, the rationale for the Potential Transaction, which would take the form of an all-equity share-for-unit exchange, including with respect to leverage, dividend growth, access to capital markets, synergies and other potential benefits, and the possible terms under which Archrock could propose to acquire the APLP common units it did not already own. After discussion, the AROC board directed Archrock management to make an offer to the APLP board on the terms approved by the AROC board, and further directed Archrock management to negotiate with the APLP board any counterproposal which may be subsequently received. Later that day, D. Bradley Childers notified Stephen Finley, chairman of the APLP conflicts committee, that a transaction proposal would be forthcoming. Mr. Finley in turn notified the other members of the APLP conflicts committee, James G. Crump and Edmund P. Segner III, that Archrock management had informed him that a proposal would be forthcoming.

        On November 29, 2017, Archrock management, on behalf of the AROC board, provided an initial written proposal regarding the Potential Transaction to the APLP board. The proposal contemplated an all-equity share-for-unit exchange at an exchange ratio of 1.32 shares of AROC common stock for each outstanding publicly held APLP common unit, representing a 15% premium based on the closing prices of APLP common units and AROC common stock on November 28, 2017.

        On December 4, 2017, the APLP conflicts committee held a meeting with representatives of Akin Gump Strauss Hauer & Feld LLP ("Akin Gump"), counsel to the APLP conflicts committee. At that meeting, the APLP conflicts committee discussed the process for evaluating the proposed merger and interviewed a potential financial advisor to assist the APLP conflicts committee in evaluating the Proposed Transaction. The APLP conflicts committee also determined to engage special Delaware counsel to assist with its review of the Proposed Transaction; the APLP conflicts committee engaged Morris, Nichols, Arsht & Tunnell LLP ("MNAT").

        On December 5, 2017, the APLP conflicts committee met again to interview two additional potential financial advisors. Representatives of Akin Gump were also present at the meeting. Following the interviews, the APLP conflicts committee resolved to engage Evercore Group L.L.C. ("Evercore") as its financial advisor, subject to the negotiation of a mutually acceptable engagement letter, after determining that Evercore, based on its presentation at the interview and its reputation, experience and familiarity with Archrock, Archrock Partners and their businesses, had the professional ability and competence to serve as the financial advisor to the APLP conflicts committee in connection with the Proposed Transaction.

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        On December 8, 2017, the APLP board formally delegated authority to the APLP conflicts committee, consisting of Messrs. Crump, Finley and Segner, all of whom are independent members of the APLP board, to consider, review, evaluate, analyze and negotiate the Potential Transaction and related agreements and arrangements for the purpose of determining whether to approve and, if so approved, whether to recommend that the APLP board approve, the Potential Transaction and related agreements and arrangements.

        Also on December 8, 2017, the APLP conflicts committee met in person and by telephone at Archrock's offices in Houston, Texas. Representatives of Archrock management, Latham & Watkins, Akin Gump, MNAT, Citi and Evercore also were present at the meeting. At the meeting, Archrock management explained to the APLP conflicts committee and its advisors the background to and strategic rationale for the Proposed Transaction, and provided an overview of, among other things, certain potential strategic alternatives considered by Archrock, management's financial forecasts for both Archrock and Archrock Partners and the expected benefits of the Proposed Transaction to the combined company. After discussion, the members of the APLP conflicts committee met separately with representatives of Akin Gump, MNAT and Evercore to discuss their initial impressions of the Proposed Transaction and related matters and the process for evaluating and negotiating the Proposed Transaction. In addition, representatives of Akin Gump reviewed with the members of the APLP conflicts committee their duties and obligations under the APLP partnership agreement in connection with their review and consideration of the Proposed Transaction.

        On December 13, 2017, at the direction of Archrock management, representatives of Citi delivered to representatives of Evercore Archrock's financial projections for Archrock and Archrock Partners. The financial projections outlined, among other things, (i) projected cash flows of each of Archrock and Archrock Partners, (ii) projected dividends by Archrock and (iii) projected distributions by Archrock Partners.

        On December 15, 2017, representatives of Latham & Watkins, on behalf of Archrock, sent a draft merger agreement to Akin Gump. The draft merger agreement, among other things, (i) provided that the obligations of Archrock and Archrock Partners to consummate the merger would be conditioned on, among other things, the approval of the merger by the affirmative vote of a majority of the outstanding APLP common units and the approval of the issuance of the merger consideration by the affirmative vote of holders of a majority of the outstanding shares of AROC common stock present in person or represented by proxy at the Archrock annual meeting and entitled to vote thereon, (ii) included substantially reciprocal representations and warranties, (iii) included substantially reciprocal restrictions on each party's business during the period between execution of the merger agreement and closing of the merger (the "interim period"), (iv) included a "force the vote" provision that would require Archrock Partners to submit the transaction for approval by the APLP common unitholders regardless of any change of recommendation by the APLP board or the APLP conflicts committee, (v) included restrictions on the ability of the APLP board and the APLP conflicts committee to effect an Archrock Partners adverse recommendation change, other than in response to an intervening event, (vi) provided for expense reimbursement fees and termination fees in unspecified amounts payable by each of Archrock and Archrock Partners under specified circumstances, and (vii) specified that APLP's quarterly distribution with respect to any quarter during the interim period would not exceed $0.285 per APLP common unit.

        On December 19, 2017, the APLP conflicts committee held a telephonic meeting, also attended by representatives of Akin Gump and Evercore. At the meeting, representatives of Evercore presented to the committee Evercore's preliminary analysis of the financial terms of the Proposed Transaction, based on the financial projections received from Archrock management, and noting that certain items were subject to change pending receipt from Archrock management of sensitivities to the projections. During the presentation Evercore provided, among other things: (i) a summary of the terms of the Proposed Transaction, (ii) a situational overview for Archrock and Archrock Partners, including their operational

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status and the financial projections for each of them provided by Archrock management, (iii) an indicative valuation of Archrock Partners, including a discounted cash flow analysis, a precedent transactions analysis, a peer group trading analysis and a premiums paid analysis, (iv) an indicative valuation analysis for the proposed consideration to be received by the APLP unaffiliated unitholders in the Proposed Transaction, and (v) an analysis of the proposed exchange ratio for the Proposed Transaction on Archrock and Archrock Partners on a combined pro forma basis. At the end of the meeting, after discussing Evercore's presentation and the Proposed Transaction, the APLP conflicts committee members agreed to defer consideration of any potential counterproposal until after Evercore received certain additional financial and other information from Archrock.

        On December 20, 2017, at the direction of Archrock management, representatives of Citi delivered to representatives of Evercore Archrock's overview of the tax basis of APLP unaffiliated unitholders and on December 21, 2017 delivered to representatives of Evercore Archrock's sensitivity case financial projections for Archrock and Archrock Partners.

        On December 26, 2017, the APLP conflicts committee held a telephonic meeting, also attended by representatives of Akin Gump, MNAT and Evercore. At the meeting, representatives of Evercore reviewed with the committee a revised presentation with their financial analysis of the Proposed Transaction, which had been updated to include the sensitivity case projections and information on the potential U.S. federal tax effects of the Proposed Transaction on the APLP unaffiliated unitholders provided on behalf of Archrock management. Following the presentation, the APLP conflicts committee and its advisors engaged in a discussion regarding a potential response to Archrock management's initial proposal. Following the discussion, the APLP conflicts committee unanimously directed Evercore to deliver a responsive proposal to Archrock management that included an exchange ratio of 1.49 shares of AROC common stock per APLP common unit (representing an effective 31% premium to the APLP common unitholders, based on closing trading prices on December 22, 2017). Representatives of Akin Gump then provided the APLP conflicts committee with an overview of the terms of the initial draft of the merger agreement and discussed with the committee a number of potential negotiation points and suggested revisions to the draft merger agreement. Following the discussions, the APLP conflicts committee directed Akin Gump to provide a revised draft of the merger agreement to Latham & Watkins. The APLP conflicts committee also instructed Evercore to communicate to Citi that the committee reserved the right to include additional comments to the merger agreement depending on Archrock management's response to the APLP conflicts committee's proposal regarding the exchange ratio for the Proposed Transaction.

        On December 27, 2017, at the direction of the APLP conflicts committee, representatives of Evercore communicated Archrock Partners' responsive proposal, including an exchange ratio of 1.49 shares of AROC common stock per APLP common unit (representing a 35% premium based on closing trading prices on December 26, 2017), to representatives of Citi.

        On December 28, 2017, Archrock management discussed the revised proposal with representatives of Citi. At the direction of AROC management, representatives of Citi communicated Archrock's revised proposal, including an exchange ratio of 1.38 shares of AROC common stock per APLP common unit (representing a 24% premium based on closing trading prices on December 28, 2017), to representatives of Evercore, who delivered the revised proposal to the APLP conflicts committee.

        The following morning, on December 29, 2017, the APLP conflicts committee held a telephonic meeting to discuss the revised proposal with representatives of Akin Gump, MNAT and Evercore. After considering and discussing Archrock's revised proposal with its advisors, the APLP conflicts committee instructed representatives of Evercore to communicate to Citi a responsive proposed exchange ratio of 1.40 shares of AROC common stock per APLP common unit (representing a 26% premium based on closing trading prices on December 28, 2017). Later on December 29, 2017, representatives of Evercore communicated the revised proposal to representatives of Citi.

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        Also on December 29, 2017, representatives of Akin Gump sent a revised draft merger agreement to Latham & Watkins. The revised draft merger agreement, among other things, (i) included a "non-solicitation" covenant restricting Archrock's ability to pursue an alternative proposal except as required by applicable law, (ii) eliminated Archrock Partners' obligation to pay Archrock a termination fee under any circumstances, (iii) specified that amendments of, and extensions of time and waivers relating to, the merger agreement would require approval by the APLP conflicts committee, (iv) imposed certain additional limitations on the conduct of Archrock's business during the interim period, and (vi) provided that the APLP board would determine and declare quarterly distributions in the ordinary course and consistent with past practice during the interim period.

        On December 30, 2017, Archrock management discussed the APLP conflicts committee's revised exchange ratio proposal with representatives of Citi and determined that the proposed 1.40x exchange ratio should be presented to the AROC board. Also on that day, members of Archrock management participated in various discussions with Archrock's advisors regarding the revised merger proposal and the revised draft of the merger agreement.

        On December 31, 2017, representatives of Latham & Watkins sent a revised draft of the merger agreement to Akin Gump. The revised draft merger agreement, among other things, (i) revised the "no solicitation" restriction on Archrock to permit the AROC board to terminate the agreement to pursue a superior proposal (upon payment of the termination fee to Archrock Partners), (ii) specified a $10 million termination fee payable by Archrock to Archrock Partners in certain circumstances, which fee (less certain unreimbursed out-of-pocket expenses) would be distributed to the APLP common unitholders as a special distribution, and Archrock and its affiliates would waive any rights to receive such distribution, (iii) capped the mutual expense reimbursements payable in certain circumstances at $2 million, and (iv) eliminated certain of the proposed additional limitations on the conduct of Archrock's business during the interim period and added a restriction on the conduct of Archrock Partners' business during the interim period.

        Later on December 31, 2017, a special meeting of the AROC board was convened. Members of AROC management and representatives of Citi and Latham & Watkins also were in attendance. During this meeting, the AROC board discussed the Potential Transaction, in which Archrock would acquire all of the public outstanding common units of Archrock Partners that Archrock does not already own in an all stock-for-unit transaction at a ratio of 1.40 shares of AROC common stock per APLP common unit, as well as the expected leverage and coverage ratios and dividend growth rate of the combined company. Citi updated the AROC board regarding various matters relating to the Proposed Transaction, including the implied premium as originally proposed by Archrock, the APLP conflicts committee's most recent counterproposal and Citi's preliminary financial perspectives regarding the proposed 1.40 exchange ratio. Archrock management then discussed the potential tax impact of the Potential Transaction. Representatives of Latham & Watkins reviewed the directors' duties in considering the Potential Transaction and the principal legal terms of the merger agreement. After discussion, the AROC board determined to convene the following evening once the terms of the merger agreement were substantially final.

        On January 1, 2018, AROC management notified Standard & Poor's and Moody's of the Potential Transaction.

        Over the course of January 1, 2018, representatives of Latham & Watkins, in consultation with Archrock management, and representatives of Akin Gump and MNAT, in consultation with the APLP conflicts committee, participated in multiple conference calls and negotiated and finalized the terms of the proposed merger agreement.

        On January 1, 2018, the APLP conflicts committee held a telephonic meeting, which was attended by representatives of Akin Gump, MNAT and Evercore. Akin Gump provided the APLP conflicts committee with an overview of various matters relating to the proposed merger and the terms of the

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revised merger agreement. Also at this meeting, Evercore reviewed its financial analysis of the proposed exchange ratio with the APLP conflicts committee and, at the request of the APLP conflicts committee, rendered an oral opinion to the APLP conflicts committee, which was subsequently confirmed by delivery of a written opinion dated as of January 1, 2018, to the effect that, as of such date and based upon and subject to the assumptions, procedures, qualifications, limitations and other matters considered by Evercore in connection with the preparation of its opinion, the exchange ratio provided for pursuant to the merger agreement is fair, from a financial point of view, to the APLP unaffiliated unitholders. Evercore also reiterated to the APLP conflicts committee the nature of its relationship and engagements for Archrock, Archrock Partners and their affiliates since January 1, 2015 and the amount and nature of the fees it received from such parties in its presentation dated January 1, 2018. At this meeting, the APLP conflicts committee determined that the merger agreement and the merger are in the best interests of Archrock Partners, including the APLP unaffiliated unitholders, (ii) approved the merger and the execution, delivery and performance by Archrock Partners of the merger agreement, which approval constitutes "Special Approval" under the Archrock Partners partnership agreement, and (iii) recommended that (A) the APLP board approve the merger agreement and the merger and submit the merger agreement to a vote of the APLP common unitholders for approval at a special meeting of the APLP common unitholders, and (B) the APLP common unitholders vote in favor of approving and adopting the merger agreement. See "—Recommendation of the APLP Conflicts Committee and the APLP Board and Their Reasons for the Merger."

        Later on January 1, 2018, a meeting of the APLP board was held. In addition to members of Archrock management, the meeting was attended by representatives of Latham & Watkins. The APLP conflicts committee provided a report to the full APLP board as to its determinations, and as to its receipt of the oral opinion of Evercore described above. The full APLP board discussed the report and the proposed transaction with the APLP conflicts committee. At this meeting, the APLP board (acting based upon the recommendation of the APLP conflicts committee) unanimously (i) determined that the consummation of the merger and the other transactions contemplated by the merger agreement are in the best interests of Archrock Partners, including the APLP unaffiliated unitholders, (ii) approved the merger and the execution, delivery and performance of the merger agreement and the transactions contemplated by the merger agreement, (iii) determined to submit the merger agreement to the APLP common unitholders for approval, and (iv) resolved to recommend approval of the merger agreement by the APLP common unitholders.

        Also on January 1, 2018, a special telephonic meeting of the AROC board was convened. Members of Archrock management and representatives of Citi and Latham & Watkins also were in attendance. At this meeting, representatives of Latham & Watkins reviewed the principal legal terms of the merger agreement, focusing primarily on the updates from the draft reviewed with the AROC board the day before. Citi updated the AROC board as to certain information previously provided to the AROC board regarding Citi's material investment banking relationships with Archrock and Archrock Partners. At the request of the AROC board, Citi reviewed with the AROC board its financial analysis of the exchange ratio and rendered an oral opinion, confirmed by delivery of a written opinion dated January 1, 2018, to the AROC board to the effect that, as of such date and based on and subject to various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken, the exchange ratio provided for pursuant to the merger agreement was fair, from a financial point of view, to Archrock. The AROC board also discussed the potential market reaction to the transaction as well as perceived benefits of, and other considerations relating to, the merger. After discussion, the AROC board unanimously (i) determined that the transactions contemplated by the merger agreement were in the best interests of Archrock and its stockholders, (ii) approved the execution, delivery and performance of the merger agreement and the transactions contemplated thereby, including the AROC common stock issuance, and

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(iii) recommended that AROC stockholders vote in favor of approving the AROC common stock issuance contemplated by the merger agreement.

        Later on January 1, 2018, Archrock and Archrock Partners executed the merger agreement.

        On January 2, 2018, Archrock and Archrock Partners issued a joint press release announcing the execution of the merger agreement.

Recommendation of the AROC Board and Its Reasons for the Merger

        At a telephonic meeting held on January 1, 2018, the AROC board unanimously determined that the merger, the merger agreement and the transactions contemplated thereby, including the AROC stock issuance, are in the best interests of Archrock and the AROC stockholders. The AROC board unanimously approved the merger, the merger agreement and the transactions contemplated thereby, including the AROC stock issuance, and recommended that the AROC stockholders vote FOR the AROC stock issuance proposal and FOR the AROC adjournment proposal.

        In evaluating the merger and the merger agreement, the AROC board consulted with Archrock's management and legal and financial advisors and considered a number of factors. In view of the variety of factors and the quality and amount of information considered, Archrock did not find it practicable to and did not quantify or otherwise assign relative weights to the specific factors considered in reaching its determination but conducted an overall review of the merger. In addition, individual members of the AROC board may have given different weight to different factors. The AROC board considered this information and these factors, as a whole and, overall, considered the relevant information and factors to be favorable to, and in support of, its determinations and recommendation.

        The decision of the AROC board was based upon a number of potential benefits of the transaction and other factors that it believed would contribute to the success of the combined company, and thus benefit the AROC stockholders, including the factors mentioned below, the order of which does not necessarily reflect their relative significance.

        The AROC board considered the following factors as generally supporting its decision to enter into the merger agreement:

    The merger is expected to increase the financial stability of Archrock and accelerate Archrock's de-leveraging process through increased retained cash flow.

    The merger simplifies the capital structure of Archrock, as well as eliminates the IDRs in Archrock Partners. The elimination of the IDRs is expected to result in a more competitive cost of capital over the long-term. The simplified structure is also expected to result in $2 million to $3 million of ongoing annual cost savings.

    The merger will result in a larger market capitalization, which, coupled with the simplified corporate structure, is expected to attract a broader universe of investors and increase equity trading liquidity, in turn allowing Archrock to access a deeper pool of capital to finance future growth if necessary.

    The merger is expected to result in over 2.00x cash available for dividend coverage through 2020.

    The merger is expected to be immediately accretive to Archrock's cash available for dividend per share, and Archrock expects to increase its cash dividend per share as a result.

    The merger results in a step-up in tax basis on Archrock Partners' assets. Given this step-up in basis and expected capital expenditure levels, Archrock expects not to pay federal cash income taxes through 2023.

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    The merger does not require the immediate refinancing of the parties' existing indebtedness, and any future refinancing indebtedness is expected to be obtained on suitable terms.

    AROC common stock rather than cash will be the form of consideration to be paid to APLP unitholders, which does not require Archrock to make any additional borrowings or cash outlays (other than to pay transaction costs).

    Archrock's management was supportive of the merger.

    The AROC board took into account the requirement that AROC stockholder approval be obtained as a condition to the AROC stock issuance in connection with the merger.

    The AROC board took into account the opinion, dated January 1, 2018, of Citi to the AROC board as to the fairness, from a financial point of view and as of the date of the opinion, to Archrock of the exchange ratio provided for pursuant to the merger agreement, which opinion was based on and subject to various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken as more fully described below under the caption "—Opinion of the Financial Advisor to Archrock."

        In addition, Archrock also identified and considered various potential risks of the merger, including the following, the order of which does not necessarily reflect their relative significance:

    The pendency of the merger for an extended period following the announcement of the execution of the merger agreement could have an adverse impact on Archrock and Archrock Partners.

    One or more of the conditions to the merger may not be satisfied.

    The attention of management and employees may be diverted during the period prior to completion of the merger, which may negatively affect Archrock's and Archrock Partners' businesses.

    Archrock shares may not trade at the expected valuations.

    The potential benefits sought in the merger may not be realized or may not be realized within the expected period.

    The merger agreement restricts the conduct of Archrock's and Archrock Partners' businesses, including Archrock's ability to solicit or consider other proposals to acquire Archrock or a portion of its business in certain circumstances, during the period between execution of the merger agreement and the consummation of the merger.

    Litigation may be commenced in connection with the merger, and that litigation may increase costs and result in a diversion of management focus.

    The payment of expenses or a termination fee by Archrock to Archrock Partners in connection with the termination of the merger agreement in certain circumstances (as described under "The Merger Agreement—Effect of Termination; Termination Fee and Expenses") could have a negative impact on the financial condition and results of operations of Archrock.

    The resulting combined company might not achieve its projected financial results.

        The AROC board also considered that the fixed exchange ratio will not adjust upward or downward to compensate for changes in the price of either AROC common stock or APLP common units prior to the consummation of the merger, and the terms of the merger agreement do not include termination rights triggered expressly by a decrease in value of either party as a result of a decline in the market price of that company's common equity. The AROC board determined that this structure was appropriate and the risk acceptable in view of the reciprocal nature of the fixed exchange ratio, the

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AROC board's focus on the relative intrinsic values and financial performance of Archrock and Archrock Partners, and the inclusion in the merger agreement of other structural protections such as the AROC board's ability to change its recommendation in favor of the AROC share issuance or to terminate the merger agreement in certain circumstances.

        As part of the overall mix of information it considered, the AROC board also considered the following factors, none of which individually was determinative of the AROC board's decision to recommend the merger but all of which, taken together, were viewed as generally supporting the merger:

    the scope of the due diligence investigation conducted by Archrock and the results thereof;

    the expected earnings, cash flow and balance sheet impact of the merger;

    the relative financial performance, risks and prospects of Archrock and Archrock Partners;

    the historical and then-current stock price information of AROC and APLP; and

    the interests that certain Archrock executive officers and directors may have with respect to the merger in addition to their interests as AROC stockholders. See "The Merger—Interests of Certain Persons in the Merger" beginning on page 76 for further information.

        The AROC board concluded that, overall, the potential benefits of the merger to Archrock and Archrock's stockholders outweighed the risks.

        The AROC board realized that there can be no assurance about future results, including results considered or expected as described in the factors listed above. This explanation of the AROC board's reasoning and all other information presented in this section is forward-looking in nature and, therefore, should be read in light of the factors discussed under the heading "Cautionary Statement Regarding Forward-Looking Statements" beginning on page 32 and "Risk Factors" beginning on page 25.

Recommendations of the APLP Conflicts Committee and the APLP Board and Their Reasons for the Merger

        The APLP conflicts committee consists of three independent directors: James G. Crump, G. Stephen Finley and Edmund P. Segner, III. The APLP board authorized the APLP conflicts committee to (i) consider, review, evaluate and analyze the merger, the merger agreement and the related arrangements, including, without limitation, any potential conflicts arising in connection therewith, (ii) negotiate, or delegate to any person the authority to negotiate, any terms of the merger, the merger agreement and the related arrangements as it may deem necessary or appropriate, in its sole discretion, (iii) consult with management of the Managing GP in connection with discussions and/or negotiations concerning potential terms and conditions of the merger, the merger agreement and the related arrangements, (iv) determine whether the merger, the merger agreement and the related arrangements are in the best interests of Archrock Partners, (v) consider such other matters as may be requested by the APLP board from time to time or as otherwise deemed appropriate by the APLP conflicts committee, in its sole discretion and (vi) determine whether to approve, and, if so approved, whether to recommend that the APLP board approve, the merger, the merger agreement and the related arrangements, with any such approval of the APLP conflicts committee constituting "Special Approval" for all purposes under the Archrock Partners partnership agreement, including Section 7.9(a) thereof.

        On January 1, 2018, the APLP conflicts committee (i) determined that the merger agreement and the proposed merger are in the best interests of Archrock Partners, including the APLP unaffiliated unitholders, (ii) approved, and recommended that the APLP board approve, the proposed merger and the execution and delivery of the merger agreement and (iii) recommended that the APLP board submit the merger agreement to a vote of the APLP common unitholders and resolved to recommend

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approval of the merger agreement by the APLP common unitholders. The APLP conflicts committee's approval constitutes "Special Approval" for all purposes under the Archrock Partners partnership agreement, including Section 7.9(a) thereof.

        Later on January 1, 2018, the APLP board (acting based, in part, upon the recommendation of the APLP conflicts committee) unanimously determined that the merger and the merger agreement, including the transactions contemplated thereby, are in the best interests of Archrock Partners, including the APLP unaffiliated unitholders, approved the execution, delivery and performance of the merger agreement and the transactions contemplated thereby, including the merger, and resolved to submit the merger and the merger agreement to a vote of the APLP common unitholders and recommend approval of the merger agreement by the APLP common unitholders.

        The Managing GP, the APLP conflicts committee, and the APLP board have not, including, without limitation, in making the determinations set forth above, assumed any obligations to Archrock Partners or its limited partners (whether fiduciary, contractual, implied, or otherwise) other than those obligations that may exist in the Archrock Partners partnership agreement. Under the Archrock Partners partnership agreement, whenever Managing GP makes a determination or takes any other action, in its capacity as the general partner of Archrock Partners, Managing GP must make such determination or take such other action in good faith and is not subject to any other or different standard under applicable law (other than the implied contractual covenant of good faith and fair dealing). In order for a determination or other action to be in "good faith" for purposes of the Archrock Partners partnership agreement, Managing GP must believe that the determination or other action is in the best interests of Archrock Partners. Nothing in this joint proxy statement/prospectus or the actions or determinations of Managing GP, the APLP conflicts committee, or the APLP board described in this joint proxy statement/prospectus should be read to mean that Managing GP, the APLP conflicts committee, or the APLP board assumed any obligations to Archrock Partners or its limited partners (whether fiduciary, contractual, implied, or otherwise) other than those obligations that may exist in the Archrock Partners partnership agreement. You are urged to read the full text of the Archrock Partners partnership agreement, which is incorporated by reference into this joint proxy statement/prospectus. See "Where You Can Find More Information" beginning on page 200.

        The APLP conflicts committee consulted with its financial and legal advisors and considered many factors in making its determination and approvals with respect to the merger and the merger agreement and the related recommendation to the APLP board and the APLP common unitholders. The APLP conflicts committee viewed the following factors as generally positive or favorable in arriving at its determination, approvals and recommendations:

    The exchange ratio of 1.40 of a share of AROC common stock for each outstanding APLP common unit held by APLP unaffiliated unitholders represents an implied market value of $14.70 per APLP common unit based upon the closing price of AROC common stock on December 29, 2017 (the last trading day before the public announcement of the merger), and represents an implied premium of 23.4% to the closing price of APLP common units on December 29, 2017 and 23.9% to the 10 trading day volume-weighted average price of APLP common units for the period ended on December 29, 2017.

    Archrock's status as a corporation following the merger provide a number of benefits relative to Archrock Partners' MLP structure, including that corporations attract a broader set of investors as compared to MLPs because certain types of institutional investors face prohibitions or limitations on investing in entities other than corporations and that APLP common unitholders will benefit from enhanced voting and other rights as stockholders of a corporation as compared to unitholders of an MLP controlled by a general partner.

    The merger eliminates the potential burden on Archrock Partners' cost of capital resulting from the incentive distributions payable to Archrock, which could from time to time make it more

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      challenging for Archrock Partners to pursue accretive acquisitions and relatively more expensive to fund its capital program. The merger is expected to provide APLP common unitholders with equity ownership in an entity with a substantially lower cost of capital, which is expected to provide greater ability to pursue accretive capital projects and acquisitions.

    The merger will provide APLP common unitholders with equity ownership in an entity with anticipated stronger coverage with respect to dividends, which is expected to result in (i) greater market confidence in the combined company, (ii) an enhanced outlook for dividend growth and (iii) better positioning for varying and uncertain industry and commodity pricing environments.

    The APLP conflicts committee selected and retained its own legal and financial advisors with knowledge and experience with respect to public merger and acquisition transactions, MLPs, Archrock Partners' industry generally, and Archrock Partners particularly, as well as substantial experience advising MLPs and other companies with respect to transactions similar to the merger.

    The valuation analyses of Archrock and Archrock Partners prepared by Evercore and reviewed and discussed with the APLP conflicts committee, including a discounted cash flow analysis of Archrock Partners, a precedent transactions analysis, a peer group trading analysis of Archrock and Archrock Partners and a premiums paid analysis.

    The delivery of an opinion, dated January 1, 2018, by Evercore to the APLP conflicts committee to the effect that, as of the date of such opinion, and based upon and subject to the factors, procedures, assumptions, qualifications, limitations and other matters set forth in its written opinion (as more fully described below under "—Opinion of the Financial Advisor to the APLP Conflicts Committee"), the exchange ratio provided for pursuant to the merger agreement was fair, from a financial point of view, to the APLP unaffiliated unitholders.

    The APLP conflicts committee's belief that the merger consideration represented the greatest amount of consideration that Archrock would have been willing to agree to pay at the time of the APLP conflicts committee's determination and approval.

    The merger will simplify Archrock's corporate structure and eliminate potential conflicts of interest between Archrock and Archrock Partners.

    The merger is expected to create synergies in the form of cost savings and other efficiencies, including reduced SEC filing requirements and other cost savings as a result of maintaining one public company rather than two.

    The exchange ratio is fixed and therefore the implied value of the consideration payable to APLP unaffiliated unitholders will increase in the event that the market price of AROC common stock increases prior to the closing of the merger.

    The terms and conditions of the merger were determined through arm's-length negotiations between the APLP conflicts committee and the AROC board and their respective representatives and advisors.

    The terms of the merger agreement, principally:

    the provisions allowing the APLP conflicts committee to change its recommendation with respect to the Archrock Partners merger proposal if it has determined in good faith after consultation with its financial advisers and outside legal counsel that failure to take such action would be inconsistent with its duties under the Archrock Partners partnership agreement or applicable laws (as described under "The Merger Agreement—The Managing GP Recommendation and Archrock Partners Adverse Recommendation Change");

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      the provisions limiting Archrock's ability to consider unsolicited offers from third parties for Archrock (as described under "The Merger Agreement—No Solicitation by Archrock of Alternative Proposals");

      the provisions requiring Archrock to hold a special stockholders' meeting as soon as practicable to approve the Archrock stock issuance, even in the event the AROC board effects an AROC adverse recommendation change (as described under "The Merger Agreement—Archrock Recommendation and Archrock Adverse Recommendation Change");

      the provisions requiring Archrock to vote the APLP common units it beneficially owns in favor of the Archrock Partners merger proposal;

      the pre-closing covenants applicable to Archrock providing protection to APLP common unitholders by restricting Archrock's ability to take certain actions prior to the closing of the merger that could reduce the value of the merger consideration;

      the provisions requiring the consent of the APLP conflicts committee to any amendment of or granting of a waiver under the merger agreement;

      Archrock's obligation to pay a termination fee or an expense reimbursement amount to Archrock Partners in certain circumstances in connection with termination of the merger agreement (as described under "The Merger Agreement—Termination of the Merger Agreement" and "The Merger Agreement—Effect of Termination; Termination Fees"); and

      the consummation of the merger is not conditioned on financing.

    The APLP conflicts committee's belief that potential alternative transactions with third parties were not achievable due to Archrock's control of Archrock Partner's general partner.

        The APLP conflicts committee viewed the following factors as generally negative or unfavorable in arriving at its determination, approvals and recommendations:

    The APLP unaffiliated unitholders will receive shares of AROC common stock that are expected, throughout calendar years 2018, 2019 and 2020 to pay a lower dividend as compared to the expected distribution on APLP common units on a stand-alone basis.

    The merger will be a taxable transaction to some APLP unaffiliated unitholders for U.S. federal income tax purposes.

    Following the merger, the income of the resulting combined entity will be subject to double taxation (at the combined company and shareholder levels) for U.S. federal income tax purposes, while income of Archrock Partners is currently subject to only one level of tax (at the unitholder level).

    Although the merger is subject to approval by a majority of the outstanding APLP common units entitled to vote at the APLP special meeting, APLP common units held by Archrock and its affiliates (representing approximately 41% of the outstanding APLP common units as of the record date for the Archrock Partners special meeting) will count towards the determination of whether the merger agreement has been adopted by APLP common unitholders, and there is no requirement for separate approval by the APLP unaffiliated unitholders.

    The exchange ratio is fixed and therefore the implied value of the consideration payable to APLP unaffiliated unitholders will decrease in the event that the market price of AROC common stock decreases prior to the closing of the merger.

    The APLP conflicts committee was not authorized to and did not conduct an auction process or other solicitation of interest from third parties for the acquisition of Archrock Partners. Since

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      Archrock indirectly controls Archrock Partners, the APLP conflicts committee believed that it was unrealistic to expect an unsolicited third-party acquisition proposal to acquire assets or control of Archrock Partners, and it was unlikely that the APLP conflicts committee could conduct a meaningful process to solicit interest in the acquisition of assets or control of Archrock Partners.

    There is risk that the potential benefits expected to be realized in the merger might not be fully realized, or might not be realized within the expected time period.

    The merger may not be completed in a timely manner, or at all, which could result in significant costs and disruption to Archrock Partners' normal business.

    Certain terms of the merger agreement, principally:

    the provisions allowing the AROC board to make an Archrock adverse recommendation change in response to a superior proposal (as described under "The Merger Agreement—Archrock Recommendation and Archrock Adverse Recommendation Change");

    the provisions allowing for Archrock to participate in negotiations with a third party in response to an unsolicited alternative proposal, which may, in certain circumstances, result in a superior proposal for Archrock (as described under "The Merger Agreement—No Solicitation by Archrock of Alternative Proposals");

    the provisions requiring Archrock Partners to hold a special meeting as soon as practicable to approve the merger, even in the event that the APLP conflicts committee or APLP board effects an APLP adverse recommendation change (as described under "The Merger Agreement—Managing GP Recommendation and APLP Adverse Recommendation Change"); and

    Archrock Partners' obligation to pay an expense reimbursement amount to Archrock in connection with termination of the merger agreement as a result of a material uncured breach by Archrock Partners under the merger agreement (as described under "The Merger Agreement—Termination of the Merger Agreement" and "The Merger Agreement—Effect of Termination; Termination Fees").

    APLP common unitholders are not entitled to appraisal rights under the merger agreement, the Archrock Partners partnership agreement or Delaware law.

    APLP common unitholders will be foregoing the potential benefits that could be realized by remaining common unitholders of a stand-alone entity.

    AROC common stock may not trade at the expected valuations.

    The resulting combined company might not achieve its projected financial results.

    Litigation may be commenced in connection with the merger and such litigation may increase costs and result in a diversion of management focus.

    Some of Managing GP's directors and executive officers may have interests in the merger that are different from, or in addition to, those of the APLP unaffiliated unitholders.

        In view of the variety of factors and the quality and amount of information considered, the APLP conflicts committee as a whole did not find it practicable to and did not quantify or otherwise assign relative weights to the specific factors considered in reaching its determination but conducted an overall analysis of the merger. Individual members of the APLP conflicts committee may have given different relative considerations to different factors.

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        The explanation of the reasoning of the APLP conflicts committee and certain information presented in this section are forward-looking in nature and, therefore, the information should be read in light of the factors discussed in the sections entitled "Cautionary Statement Regarding Forward-Looking Statements" and "Risk Factors."

        In reaching its conclusions regarding the merger, the APLP board not only considered the process by which the APLP conflicts committee has made its recommendations but also considered the matters described above or considered by the APLP conflicts committee. As in the case of the APLP conflicts committee, in view of the variety of factors and the quality and amount of information considered, the APLP board as a whole did not find it practicable to and did not quantify or otherwise assign relative weights to the specific factors considered in reaching its determination but conducted an overall review of the merger. Individual members of the APLP board may have given different relative considerations to different factors.

Unaudited Projected Financial Information

        Neither Archrock nor Archrock Partners routinely publishes projections as to long-term future performance or earnings. However, in connection with the proposed merger, Archrock management and the General Partner's management ("Archrock Partners management") prepared and provided to the AROC board, the APLP board and the APLP conflicts committee certain internal projections (the "Projections") regarding the future financial performance of Archrock, Archrock Partners and Pro Forma Archrock with respect to 2018 through 2020. The Projections were used by the AROC board, the APLP board and the APLP conflicts committee for the purposes of evaluating the merger. The Projections also were provided to Citi and Evercore for their use and reliance in connection with their respective financial analyses and opinions described in the sections entitled "—Opinion of the Financial Advisor to Archrock" and "—Opinion of the Financial Advisor to APLP Conflicts Committee."

        A summary of the Projections is included below to give AROC stockholders and APLP common unitholders access to certain unaudited projections that were made available to the AROC board, the APLP board, the APLP conflicts committee and Archrock's and the APLP conflicts committee's respective advisors in connection with the merger.

        Archrock and Archrock Partners each caution you that uncertainties are inherent in projections of any kind. None of Archrock, Archrock Partners or any of their respective affiliates, officers, directors, advisors or other representatives has made or makes any representation or can give any assurance to any Archrock stockholder or APLP common unitholder regarding the ultimate performance of Archrock or Archrock Partners compared to the summarized information set forth below or that any projected results will be achieved.

        The inclusion of the following Projections in this joint proxy statement/prospectus should not be regarded as an indication that Archrock, Archrock Partners or their respective advisors or other representatives considered or consider the Projections to be necessarily indicative of actual future performance or events, and the Projections set forth below should not be relied upon as such. Accordingly, AROC stockholders and APLP common unitholders are cautioned not to place undue reliance on the Projections.

        The accompanying prospective financial information was not prepared with a view toward public disclosure or toward compliance with the published guidelines established by the American Institute of Certified Public Accountants for preparation or presentation of prospective financial information. In the view of Archrock management and Archrock Partners management, the Projections were prepared on a reasonable basis, reflected the best available estimates and judgments based on the facts and circumstances existing at the time such projections were prepared, and presented, to the best of Archrock management's and Archrock Partners management's knowledge and belief, the expected

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course of action and the expected future financial performance of Archrock and Archrock Partners, as applicable.

        The Projections included in this joint proxy statement/prospectus have been prepared by, and are the responsibility of, Archrock management and Archrock Partners management. Neither Deloitte & Touche LLP ("Deloitte"), nor any other independent accountants, have compiled, examined or performed any procedures with respect to the prospective financial information, nor have they expressed any opinion or any other form of assurance on such information or its achievability, and they assume no responsibility for, and disclaim any association with, the prospective financial information. The Deloitte reports incorporated by reference into this joint proxy statement/prospectus relate to historical financial information of Archrock and Archrock Partners, respectively.

        While presented with numerical specificity, the Projections and the estimates of the cost savings, synergies, and transaction expenses described below reflect numerous estimates and assumptions made by Archrock management and Archrock Partners management with respect to industry performance and competition, general business, economic, market and financial conditions and matters specific to each of Archrock's and Archrock Partners' businesses, all of which are difficult to predict and many of which are beyond Archrock's and Archrock Partners' control. In developing the Projections, Archrock management and Archrock Partners management made numerous material assumptions, with respect to Archrock, Archrock Partners and the pro forma company for the periods covered by such Projections, including:

    growth in global demand for natural gas;

    growth in the production of natural gas in the United States;

    growth in outsourced contract operations services in the United States;

    utilization and depreciation of Archrock and Archrock Partners compression assets;

    expected pricing in the market for contract operations services;

    expected cost of sales for contract operations services;

    revenue and cost of sales in the aftermarket services business;

    required selling, general and administrative ("SG&A") spending levels;

    organic growth opportunities and potential economic returns;

    the amount of maintenance, growth, and other capital expenditures;

    the level of distributions paid by Archrock Partners;

    the level of dividends paid by Archrock;

    outstanding debt during applicable periods, and the availability and cost of funding; and

    other general business, market and financial assumptions.

        The pro forma projections are based on the Archrock and Archrock Partners standalone projections and also reflect such estimates and assumptions.

        The summaries of the Projections provided to the AROC board, the APLP board and the APLP conflicts committee are not included in this joint proxy statement/prospectus in order to induce any Archrock stockholder or APLP common unitholder to vote in favor of the AROC stock issuance proposal or the Archrock Partners merger proposal, as applicable. By including in this joint proxy statement/prospectus a summary of certain of the Projections, none of Archrock, Archrock Partners or any of their respective advisors or other representatives have made or are making any representation to any person regarding the ultimate performance of Archrock, Archrock Partners or the combined company. The Projections cover multiple years and such information by its nature becomes less predictive with each succeeding year.

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        The following table sets forth a summary of the Projections with respect to Archrock, Archrock Partners and the combined company for 2018 through 2020:

(in millions, expect per share amounts)(1)
  2018E   2019E   2020E  

Archrock

                   

Standalone EBITDA(2)

  $ 55   $ 71   $ 74  

Cash available for dividend(3)(4)

  $ 40   $ 51   $ 52  

Cash available for dividend per share(3)(4)

  $ 0.57   $ 0.72   $ 0.73  

Dividend per share

  $ 0.48   $ 0.48   $ 0.48  

Archrock Partners

   
 
   
 
   
 
 

EBITDA, as adjusted(5)

  $ 281   $ 332   $ 372  

Distributable cash flow(6)

  $ 163   $ 200   $ 233  

Distributable cash flow per unit(6)

  $ 2.11   $ 2.38   $ 2.62  

Distribution per unit

  $ 1.14   $ 1.14   $ 1.14  

Pro Forma Archrock(7)

   
 
   
 
   
 
 

EBITDA, as adjusted(8)

  $ 304   $ 371   $ 413  

Cash available for dividend(9)

  $ 161   $ 220   $ 255  

Cash available for dividend per share(9)

  $ 1.25   $ 1.71   $ 1.98  

Dividend per share

  $ 0.53   $ 0.58   $ 0.64  

        In addition to the Projections, management of Archrock and Archrock Partners provided the AROC board, the APLP conflicts committee, Citi and Evercore with estimates of the cost savings and synergies expected to result from the merger. Specifically, management of Archrock and Archrock Partners estimated that the merger would result in approximately $2 to $3 million per year in cost savings, primarily as a result of reduced general and administrative expenses associated with having one public company instead of two public companies.

        Additionally, at the request of the APLP conflicts committee and Evercore, Archrock management and Archrock Partners management also prepared for the APLP conflicts committee and Evercore an upside and downside case for the year ending December 31, 2018, together the "Sensitivity Cases." No Sensitivity Cases were prepared by Archrock management and Archrock Partners management for the years ending December 31, 2019 and 2020. The Sensitivity Cases are set forth in the following table:

(in millions, expect per share amounts)(1)
  Downside Case
2018E
  Upside Case
2018E
 

Archrock

             

Standalone EBITDA(2)

  $ 49   $ 60  

Cash available for dividend(3)(10)

  $ 25   $ 35  

Cash available for dividend per share(3)(10)

  $ 0.35   $ 0.49  

Dividend per share

  $ 0.48   $ 0.48  

Archrock Partners

   
 
   
 
 

EBITDA, as adjusted(5)

  $ 259   $ 292  

Distributable cash flow(6)

  $ 141   $ 174  

Distributable cash flow per unit(6)

  $ 1.90   $ 2.19  

Distribution per unit

  $ 1.14   $ 1.14  

(1)
Archrock and Archrock Partners are unable, without unreasonable efforts, to provide a quantitative reconciliation of non-GAAP projections of EBITDA, cash available for dividend, cash available for dividend per share, EBITDA, as adjusted, distributable cash flow and distributable cash flow per unit, because net income or loss, maintenance and

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    other capital expenditures, expense or benefit from income taxes and cash tax expense or refund cannot be estimated as a result of the level of unpredictability and uncertainty associated with these items. For these same reasons, Archrock and Archrock Partners are unable to assess the probable significance of these excluded items.

(2)
Standalone EBITDA, a non-GAAP measure, is defined as distributions received by Archrock from Archrock Partners, plus Archrock's deconsolidated gross margin, less the following deconsolidated items: SG&A expense, and (gain) loss on sale of property, plant and equipment.

(3)
Cash available for dividend, a non-GAAP measure, is defined as distributions received by Archrock from Archrock Partners, plus Archrock's deconsolidated gross margin, less the following deconsolidated items: maintenance and other capital expenditures, cash SG&A expense, cash interest expense associated with Archrock's debt, cash taxes and (gain) loss on sale of property, plant and equipment. Cash available for dividend per share is defined as cash available for dividend divided by outstanding shares.

(4)
Projected financial information for 2018E excludes approximately $10 million in other capital expenditures primarily associated with increased truck fleet maintenance, which was deferred during recent periods of market volatility and depressed commodity prices. Taking into account such capital expenditures, cash available for dividend and cash available for dividend per share for 2018E would have been $30 million and $0.43, respectively.

(5)
EBITDA, as adjusted, a non-GAAP measure, is defined as net income (loss) excluding income taxes, interest expense, depreciation and amortization expense, long-lived asset impairment, restructuring charges, expensed acquisition costs, debt extinguishment costs, non-cash SG&A costs and other items.

(6)
Distributable cash flow, a non-GAAP measure, is defined as net income (loss) (a) plus depreciation and amortization expense, long-lived asset impairment, restructuring charges, expensed acquisition costs, non-cash SG&A costs, debt extinguishment costs and interest expense, less (b) cash interest expense (excluding amortization of deferred financing fees, amortization of debt discount and non-cash transactions related to interest rate swaps) and maintenance capital expenditures and (c) excluding gains or losses on asset sales and other items.

(7)
Pro forma calculations assume closing of the merger on January 1, 2018.

(8)
Archrock pro forma EBITDA, as adjusted, a non-GAAP measure, is defined as net income (loss) excluding income taxes, interest expense, depreciation and amortization expense, long-lived asset impairment, restructuring charges, expensed acquisition costs, debt extinguishment costs and other items.

(9)
Archrock pro forma cash available for dividend, a non-GAAP measure, is defined as net income (loss) (a) plus depreciation and amortization expense, long-lived asset impairment, restructuring charges, expensed acquisition costs, non-cash SG&A costs, debt extinguishment costs and interest expense, less (b) cash interest expense (excluding amortization of deferred financing fees, amortization of debt discount and non-cash transactions related to interest rate swaps) and maintenance and other capital expenditures and (c) excluding gains or losses on asset sales and other items. Projected financial information for 2018E does not exclude approximately $10 million in other capital expenditures primarily associated with increased truck fleet maintenance, which was deferred during recent periods of market volatility and depressed commodity prices.

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(10)
The Sensitivity Cases provided to the APLP conflicts committee and Evercore for 2018E do not exclude approximately $10 million in other capital expenditures primarily associated with increased truck fleet maintenance, which was deferred during recent periods of market volatility and depressed commodity prices.

        Archrock management and Archrock Partners management also advised the AROC board, the APLP conflicts committee, Citi and Evercore that the merger is expected to result in a partial tax basis step-up of Archrock Partners' subsidiaries' assets. The basis step-up is expected to create increased tax deductions for the combined company as a result of higher tax depreciation and amortization, such that the combined company is not expected to pay federal cash income taxes through 2023. This estimate is based upon assumptions Archrock has made regarding, among other things, income, capital expenditures and net working capital. Further, the IRS or other tax authorities could challenge one or more tax positions that Archrock takes, such as the classification of assets under the income tax depreciation rules, the characterization of expenses for income tax purposes and the tax classification of the merger. Further, any change in law may affect Archrock's tax position. While Archrock expects that its deductions and NOL carryforwards will be available to it as a future benefit, in the event that they are not generated as expected, are successfully challenged by the IRS (in a tax audit or otherwise) or are subject to future limitations as described under the heading "Risk Factors—Tax Risks Related to the Merger and the Ownership of AROC Common Stock Received in the Merger—Archrock's ability to use NOLs to offset future income may be limited", Archrock's ability to realize these benefits may be limited.

        NONE OF ARCHROCK OR ARCHROCK PARTNERS (OR ANY OF THEIR RESPECTIVE AFFILIATES, OFFICERS, DIRECTORS OR MANAGERS) INTENDS TO UPDATE OR OTHERWISE REVISE THE ABOVE PROJECTIONS TO REFLECT CIRCUMSTANCES EXISTING AFTER THE DATE WHEN MADE OR TO REFLECT THE OCCURRENCE OF FUTURE EVENTS, EVEN IF ANY OR ALL OF THE ASSUMPTIONS UNDERLYING SUCH PROJECTIONS ARE NO LONGER APPROPRIATE.

Opinion of the Financial Advisor to Archrock

        Archrock has engaged Citi to act as its financial advisor in connection with the proposed merger. In connection with Citi's engagement, the AROC board requested that Citi evaluate the fairness, from a financial point of view, to Archrock of the exchange ratio provided for pursuant to the merger agreement. On January 1, 2018, at a meeting of the AROC board held to evaluate the proposed merger, Citi rendered an oral opinion, confirmed by delivery of a written opinion dated January 1, 2018, to the AROC board to the effect that, as of such date and based on and subject to various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken, the exchange ratio provided for pursuant to the merger agreement was fair, from a financial point of view, to Archrock.

        The full text of Citi's written opinion, dated January 1, 2018, which describes the assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken, is attached as Annex B to this joint proxy statement/prospectus and is incorporated into this joint proxy statement/prospectus by reference. The description of Citi's opinion set forth below is qualified in its entirety by reference to the full text of Citi's opinion. Citi's opinion was provided for the information of the AROC board (in its capacity as such) in connection with its evaluation of the exchange ratio from a financial point of view to Archrock and did not address any other terms, aspects or implications of the merger. Citi expressed no view as to, and its opinion did not address, the underlying business decision of Archrock to effect or enter into the merger, the relative merits of the merger as compared to any alternative business strategies that might exist for Archrock or the effect of any other transaction which Archrock might engage in or consider. Citi's opinion is not intended to

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be and does not constitute a recommendation to any securityholder as to how such securityholder should vote or act on any matters relating to the proposed merger or otherwise.

        In arriving at its opinion, Citi:

    reviewed a draft, dated January 1, 2018, of the merger agreement;

    held discussions with certain senior officers, directors and other representatives of Archrock concerning the businesses, operations and prospects of Archrock and Archrock Partners;

    reviewed certain publicly available and other business and financial information relating to Archrock and Archrock Partners provided to or discussed with Citi by the management of Archrock, including certain financial forecasts and other information and data relating to Archrock and Archrock Partners provided to or discussed with Citi by the management of Archrock;

    reviewed certain information and data relating to the potential strategic implications and financial, operational and tax benefits (including the amount, timing and achievability thereof) anticipated by the management of Archrock to result from the merger;

    reviewed the financial terms of the merger as set forth in the merger agreement in relation to, among other things, current and historical market prices of AROC common stock and APLP common units, the financial condition and historical and projected cash flows and other operating data of Archrock and Archrock Partners, and the capitalization of Archrock and Archrock Partners;

    analyzed certain financial, stock market and other publicly available information relating to the businesses of other companies whose operations Citi considered relevant in evaluating those of Archrock and Archrock Partners;

    considered, to the extent publicly available, the financial terms of certain other transactions which Citi considered relevant in evaluating the merger;

    evaluated certain potential pro forma financial effects of the merger relative to Archrock and Archrock Partners each on a standalone basis utilizing the financial forecasts and other information and data relating to Archrock and Archrock Partners and the potential strategic implications and financial, operational and tax benefits referred to above; and

    conducted such other analyses and examinations and considered such other information and financial, economic and market criteria as Citi deemed appropriate in arriving at its opinion.

        In rendering its opinion, Citi assumed and relied, without independent verification, upon the accuracy and completeness of all financial and other information and data publicly available or provided to or otherwise reviewed by or discussed with Citi and upon the assurances of the management and other representatives of Archrock that they were not aware of any relevant information that was omitted or that remained undisclosed to Citi. With respect to the financial forecasts and other information and data (including, without limitation, as to net operating loss carryforwards and other tax attributes of Archrock and the potential strategic implications and financial, operational and tax benefits anticipated by the management of Archrock to result from the merger) that Citi was directed to utilize in its analyses, Citi was advised by the management of Archrock and Citi assumed, with Archrock's consent, that such forecasts and other information and data were reasonably prepared on bases reflecting the best currently available estimates and judgments of such management as to, and were a reasonable basis upon which to evaluate, the future financial performance of Archrock and Archrock Partners (in the case of Archrock Partners, under alternative cash distribution scenarios), the potential strategic implications and financial, operational and tax benefits (including the amount, timing and achievability thereof) anticipated by the management of

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Archrock to result from, and other potential pro forma financial effects of, the merger and the other matters covered thereby. Citi expressed no opinion as to any financial forecasts and other information or data (or underlying assumptions on which any such financial forecasts and other information or data are based) provided to or otherwise reviewed by or discussed with Citi and Citi assumed, with Archrock's consent, that the financial results, including with respect to the potential strategic implications and financial, operational and tax benefits anticipated to result from the merger, reflected in such financial forecasts and other information and data would be realized in the amounts and at the times projected.

        Citi relied, at Archrock's direction, upon the assessments of the management of Archrock as to, among other things, (i) matters relating to the separation of Archrock and Exterran Corporation consummated in November 2015 (the "spin-off"), including any continuing tax indemnities and other arrangements in connection therewith, (ii) the distribution policies of each of Archrock and Archrock Partners on a standalone basis and of the pro forma combined entity following consummation of the merger, (iii) the potential impact on Archrock and Archrock Partners of market, competitive, cyclical and other trends and developments in and prospects for, and governmental, regulatory and legislative matters relating to or otherwise affecting, the oil and natural gas, energy infrastructure and natural gas compression industries, including commodity pricing, supply and demand for natural gas, oil and natural gas liquids, and supply and demand for contract natural gas compression services, which are subject to significant volatility and which, if different than as assumed, could have a material impact on Citi's analyses or opinion, (iv) existing and future contracts and relationships, agreements and arrangements with, and the ability to attract, retain and/or replace, key customers, suppliers, service providers and other commercial relationships of Archrock and Archrock Partners, and (v) the ability to integrate the operations of Archrock and Archrock Partners. Citi assumed, with Archrock's consent, that there would be no developments with respect to any such matters that would have an adverse effect on Archrock, Archrock Partners or the merger (including the contemplated benefits thereof) or that otherwise would be meaningful in any respect to Citi's analyses or opinion.

        Citi did not make, and it was not provided with, an independent evaluation or appraisal of the assets or liabilities (contingent, accrued, derivative, off-balance sheet or otherwise) of Archrock, Archrock Partners or any other entity and Citi did not make any physical inspection of the properties or assets of Archrock, Archrock Partners or any other entity. Citi expressed no view or opinion as to the potential impact on Archrock, Archrock Partners or any other entity of any pending or potential litigation, claims or governmental, regulatory or other proceedings, enforcement actions or investigations. Citi assumed, with Archrock's consent, that the merger would be consummated in accordance with its terms and in compliance with all applicable laws, documents and other requirements, without waiver, modification or amendment of any material term, condition or agreement, and that, in the course of obtaining the necessary governmental, regulatory or third party approvals, consents, releases, waivers and agreements for the merger, no delay, limitation, restriction or condition, including any divestiture requirements, amendments or modifications, would be imposed or occur that would have an adverse effect on Archrock, Archrock Partners or the merger (including the contemplated benefits thereof) or that otherwise would be meaningful in any respect to Citi's analyses or opinion. Citi also assumed, with Archrock's consent, that the merger would qualify for the intended tax treatment contemplated by the merger agreement. Citi's opinion, as expressed therein, relates to the relative values of Archrock and Archrock Partners. Citi did not express any view or opinion as to the actual value of AROC common stock or any other securities when issued in connection with the merger or the prices at which AROC common stock, APLP common units or any other securities will trade or otherwise be transferable at any time, including following the announcement or consummation of the merger. Representatives of Archrock advised Citi, and Citi further assumed, that the final terms of the merger agreement would not vary materially from those set forth in the draft reviewed by Citi. Citi did not express any view or opinion with respect to accounting, tax, regulatory, legal or similar matters, including, without limitation, tax consequences resulting from the spin-off, the merger or

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otherwise or changes in, and the impact of, U.S. tax laws, regulations and governmental and legislative policies on Archrock, Archrock Partners or the merger (including the contemplated benefits thereof), and Citi relied, with Archrock's consent, upon the assessments of representatives of Archrock as to such matters.

        Citi's opinion did not address any terms (other than the exchange ratio to the extent expressly specified therein), aspects or implications of the merger, including, without limitation, the form or structure of the merger or any other agreement, arrangement or understanding to be entered into in connection with or contemplated by the merger or otherwise. Citi expressed no view as to, and its opinion did not address, the fairness (financial or otherwise) of the amount or nature or any other aspect of any compensation or other consideration to any officers, directors or employees of any parties to the merger, or any class of such persons, relative to the exchange ratio or otherwise. Citi's opinion was necessarily based upon information available, and financial, stock market and other conditions and circumstances existing and disclosed, to Citi as of the date of its opinion. Although subsequent developments may affect its opinion, Citi has no obligation to update, revise or reaffirm its opinion. As the AROC board was aware, the credit, financial and stock markets, and the industries in which Archrock and Archrock Partners operate, have experienced and continue to experience volatility and Citi expressed no view or opinion as to any potential effects of such volatility on Archrock, Archrock Partners or the merger (including the contemplated benefits thereof). The issuance of Citi's opinion was authorized by Citi's fairness opinion committee.

        In preparing its opinion, Citi performed a variety of financial and comparative analyses, including those described below. The summary of the analyses below is not a complete description of Citi's opinion or the analyses underlying, and factors considered in connection with, Citi's opinion. The preparation of a financial opinion is a complex analytical process involving various determinations as to the most appropriate and relevant methods of financial analysis and the application of those methods to the particular circumstances and, therefore, a financial opinion is not readily susceptible to summary description. Citi arrived at its ultimate opinion based on the results of all analyses and factors assessed as a whole, and it did not draw, in isolation, conclusions from or with regard to any one factor or method of analysis. Accordingly, Citi believes that the analyses must be considered as a whole and that selecting portions of its analyses and factors or focusing on information presented in tabular format, without considering all analyses and factors or the narrative description of the analyses, could create a misleading or incomplete view of the processes underlying such analyses and its opinion.

        In its analyses, Citi considered industry performance, general business, economic, market and financial conditions and other matters existing as of the date of its opinion, many of which are beyond the control of Archrock and Archrock Partners. No company, business or transaction reviewed is identical or directly comparable to Archrock, Archrock Partners or the merger and an evaluation of these analyses is not entirely mathematical; rather, the analyses involve complex considerations and judgments concerning financial and operating characteristics and other factors that could affect the public trading, acquisition or other values of the companies, businesses or transactions reviewed or the results from any particular analysis.

        The estimates contained in Citi's analyses and the ranges resulting from any particular analysis are not necessarily indicative of actual values or predictive of future results or values, which may be significantly more or less favorable than those suggested by such analyses. In addition, analyses relating to the value of businesses or securities do not purport to be appraisals or to reflect the prices at which businesses or securities actually may be sold or acquired. Accordingly, the estimates used in, and the results derived from, Citi's analyses are inherently subject to substantial uncertainty.

        Citi was not requested to, and it did not, recommend or determine the specific consideration payable in the merger. The type and amount of consideration payable in the merger were determined through negotiations between Archrock and Archrock Partners and the decision to enter into the

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merger agreement was solely that of the AROC board. Citi's opinion was only one of many factors considered by the AROC board in its evaluation of the merger and should not be viewed as determinative of the views of the AROC board or Archrock management with respect to the merger or the exchange ratio.

Financial Analyses

        The summary of the financial analyses described below under this heading "—Financial Analyses" is a summary of the material financial analyses prepared and reviewed with the AROC board in connection with Citi's opinion, dated January 1, 2018. The summary set forth below does not purport to be a complete description of the financial analyses performed by, and underlying the opinion of, Citi, nor does the order of the financial analyses described represent the relative importance or weight given to those financial analyses by Citi. Certain financial analyses summarized below include information presented in tabular format. In order to fully understand the financial analyses, the tables must be read together with the text of each summary as the tables alone do not constitute a complete description of the financial analyses. Considering the data in the tables below without considering the full narrative description of the financial analyses, including the methodologies and assumptions underlying the financial analyses, could create a misleading or incomplete view of such financial analyses. Citi assumes no responsibility if future results are different from those described, whether or not any such difference is material. Approximate implied per share and implied per APLP common unit equity value reference ranges (other than such ranges derived from historical stock trading histories and Wall Street research analysts' stock price targets) were rounded to the nearest $0.05 and selected approximate implied value reference ranges for Archrock's retained midstream business (as defined below) and Archrock's GP/IDR interests (as defined below) reflect rounding to the nearest $5 million. For purposes of the financial analyses described below, the term EBITDA is used generally to refer to earnings before interest, taxes, depreciation and amortization and, in the case of Archrock Partners, the term EBITDA, as adjusted, is used to refer to net income (loss) excluding income taxes, interest expense, depreciation and amortization expense, long-lived asset impairment, restructuring charges, expensed acquisition costs, debt extinguishment costs, non-cash SG&A costs and other items. Financial data utilized for Archrock and Archrock Partners in the financial analyses described below, to the extent based on financial forecasts and estimates of management, were based on financial forecasts and other information and data relating to Archrock and Archrock Partners provided to or discussed with Citi by the management of Archrock, referred to as the Archrock forecasts and the Archrock Partners forecasts, respectively.

        In calculating implied exchange ratio reference ranges as reflected in the financial analyses described below, other than the selected precedent transactions analysis, Citi divided the low-ends (or high-ends, as the case may be) of the approximate implied per APLP common unit equity value reference ranges derived for Archrock Partners from such analyses by the high-ends (or low-ends, as the case may be) of the approximate implied per share equity value reference ranges derived for Archrock from such analyses in order to calculate the low-ends (or high-ends) of the implied exchange ratio reference ranges. In calculating an implied exchange ratio reference range as reflected in the selected precedent transactions analysis described below, Citi divided the low-end (or high-end, as the case may be) of the approximate implied per APLP common unit equity value reference range derived for Archrock Partners from such analysis by the high-end (or low-end, as the case may be) of the approximate implied per share equity value reference range derived for Archrock from the selected public companies analysis of Archrock (on a consolidated basis) described below in order to calculate the low-end (or high-end) of the implied exchange ratio reference range.

        Selected Public Companies Analyses.    Citi performed separate selected public companies analyses of Archrock (both on a consolidated and sum-of-the-parts basis) and Archrock Partners in which Citi

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reviewed certain financial and stock market information relating to Archrock, Archrock Partners and the selected publicly traded entities listed below.

        Archrock (consolidated).    In its selected public companies analysis of Archrock on a consolidated basis, Citi reviewed certain financial and stock market information relating to Archrock and the following seven selected entities that Citi considered generally relevant as publicly traded master limited partnerships ("MLPs"), limited partnerships ("LPs") and limited liability companies that serve as general partners ("GPs") for entities with operations in the midstream energy industry, which are collectively referred to as the Archrock selected companies:

    Antero Midstream GP LP

    Energy Transfer Equity, L.P.

    EnLink Midstream, LLC

    EQT GP Holdings, LP

    NuStar GP Holdings, LLC

    Tallgrass Energy GP, LP

    Western Gas Equity Partners, LP

        Citi reviewed, among other information, closing unit or stock prices, as applicable (as of December 29, 2017), as a multiple of calendar year 2018 and calendar year 2019 estimated cash available for distribution or dividend, as applicable, referred to as CAFD, per unit or share. Citi also reviewed indicative yields, calculated as the most recently announced quarterly distribution or dividend per unit or share, as annualized, divided by the closing unit or stock price on December 29, 2017, and calendar year 2018 and calendar year 2019 estimated yields. Financial data of the Archrock selected companies were based on publicly available Wall Street research analysts' estimates, public filings and other publicly available information. Financial data of Archrock was based on the Archrock forecasts and public filings.

        The overall low to high calendar year 2018 and calendar year 2019 estimated CAFD per unit multiples and overall low to high indicative yields as of December 29, 2017 and calendar year 2018 and calendar year 2019 estimated yields observed for the Archrock selected companies were as follows:

    calendar year 2018 estimated CAFD per unit multiples: 7.5x to 45.3x (with a mean of 18.9x and a median of 14.3x);

    calendar year 2019 estimated CAFD per unit multiples: 7.2x to 27.5x (with a mean of 15.6x and a median of 14.5x);

    indicative yields as of December 29, 2017: 1.2% to 13.9% (with a mean of 6.1% and a median of 5.8%);

    calendar year 2018 estimated yields: 2.2% to 13.9% (with a mean of 6.7% and a median of 6.4%); and

    calendar year 2019 estimated yields: 3.6% to 13.9% (with a mean of 7.4% and a median of 7.1%).

        Citi observed that the calendar year 2018 and calendar year 2019 estimated CAFD per share multiples for Archrock were 18.4x and 14.5x, respectively, based on the Archrock forecasts, the indicative yield as of December 29, 2017 for Archrock was 4.6% based on public filings and the calendar year 2018 and calendar year 2019 estimated yields for Archrock were each 4.6% based on the Archrock forecasts. Citi then applied the following selected ranges of calendar year 2018 and calendar year 2019 estimated CAFD per unit multiples derived from the Archrock selected companies to

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corresponding data of Archrock based on the Archrock forecasts, the following selected range of indicative yields as of December 29, 2017 derived from the Archrock selected companies to Archrock's most recently announced quarterly dividend per share, as annualized, based on public filings, and the following selected ranges of calendar year 2018 and calendar year 2019 estimated yields derived from the Archrock selected companies to Archrock's estimated dividends per share for calendar years 2018 and 2019 based on the Archrock forecasts, respectively:

    calendar year 2018 estimated CAFD per unit multiples: 11.4x to 18.4x;

    calendar year 2019 estimated CAFD per unit multiples: 11.6x to 14.5x;

    indicative yields as of December 29, 2017: 6.9% to 4.6%;

    calendar year 2018 estimated yields: 7.6% to 4.6%; and

    calendar year 2019 estimated yields: 8.5% to 4.6%.

        This analysis indicated a selected approximate implied per share equity value reference range for Archrock on a consolidated basis of $6.75 to $10.50.

        Archrock (sum-of-the-parts).    Citi also performed a selected public companies analysis of Archrock on a sum-of-the-parts basis to derive an approximate implied per share equity value reference range for Archrock based on approximate implied values for (i) Archrock's retained midstream assets, which are referred to as Archrock's retained midstream business, (ii) Archrock's limited partner interests in Archrock Partners, which are referred to as Archrock's LP interests, and (iii) Archrock's general partner interest and IDRs in Archrock Partners (collectively, "Archrock's GP/IDR interests").

        In evaluating Archrock's retained midstream business, Citi performed a discounted cash flow analysis of such business by calculating the estimated present value (as of December 31, 2017) of the unlevered free cash flows that such business was expected to generate during the fiscal years ending December 31, 2018 through December 31, 2020 based on the Archrock forecasts. Citi calculated terminal values for Archrock's retained midstream business by applying to such business' fiscal year 2020 estimated EBITDA, after taking into account Archrock's SG&A expenses, a selected range of EBITDA multiples of 7.8x to 11.0x. The present values (as of December 31, 2017) of the cash flows and terminal values were then calculated using a selected range of discount rates of 9.2% to 10.6%. This analysis indicated a selected approximate implied value reference range for Archrock's retained midstream business of $190 million to $295 million.

        In evaluating Archrock's LP interests, Citi utilized the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners of $10.60 to $17.65 from the selected public companies analysis of Archrock Partners described below under "—Selected Public Companies Analyses—Archrock Partners," which selected approximate implied per APLP common unit equity value reference range indicated a selected approximate implied value reference range for Archrock's LP interests of $308 million to $513 million.

        In evaluating Archrock's GP/IDR interests, Citi reviewed certain financial and stock market information relating to Archrock and the Archrock selected companies. Citi reviewed, among other information, implied GP values, calculated as implied equity values based on closing stock or unit prices on December 29, 2017 plus total debt, preferred equity and minority interests (as applicable), less cash and cash equivalents and less the value of LP units held by the relevant GP and other non-GP related assets, as a multiple of calendar year 2018 and calendar year 2019 estimated post-tax GP cash flows. Financial data of the Archrock selected companies were based on publicly available Wall Street research analysts' estimates, public filings and other publicly available information. Financial data of GP/IDR interests in Archrock Partners was based on the Archrock Partners forecasts. The overall low to high calendar year 2018 and calendar year 2019 estimated post-tax GP cash flow multiples observed for the Archrock selected companies were 8.3x to 41.0x (with a mean of 22.2x and a

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median of 16.0x) and 7.7x to 32.3x (with a mean of 18.3x and a median of 15.6x), respectively. Citi observed that the calendar year 2018 and calendar year 2019 estimated post-tax GP cash flow multiples for Archrock were 25.9x and 25.9x, respectively, based on the Archrock forecasts. Citi then applied selected ranges of calendar year 2018 and calendar year 2019 estimated post-tax GP cash flow multiples derived from the Archrock selected companies of 12.8x to 25.9x and 12.5x to 25.9x, respectively, to the calendar year 2018 and 2019 estimated post-tax GP/IDR cash flows of GP/IDR interests in Archrock Partners. This analysis indicated a selected approximate implied value reference range for Archrock's GP/IDR interests of $15 million to $35 million.

        The analyses described above of Archrock's retained midstream business, Archrock's LP interests and Archrock's GP/IDR interests indicated an overall selected approximate implied per share equity value reference range for Archrock of $6.20 to $10.85.

        Archrock Partners.    In its selected public companies analysis of Archrock Partners, Citi reviewed certain financial and stock market information relating to Archrock Partners and the following five selected entities that Citi considered generally relevant as publicly traded companies and MLPs with operations in the midstream energy industry, which are collectively referred to as the Archrock Partners selected companies:

    Crestwood Equity Partners LP

    CSI Compressco LP

    SemGroup Corporation

    Summit Midstream Partners, LP

    USA Compression Partners, LP

        Citi reviewed, among other information, enterprise values, calculated as implied equity values based on closing unit or stock prices, as applicable, on December 29, 2017 plus the implied market value of the GP (as applicable), total debt, preferred equity and minority interests (as applicable) and less cash and cash equivalents, as a multiple of calendar year 2018 and calendar year 2019 estimated EBITDA (or EBITDA, as adjusted, in the case of Archrock Partners), and stock or unit prices (as applicable and as of December 29, 2017) as a multiple of calendar year 2018 and calendar year 2019 estimated distributable cash flow per share or LP unit. Citi also reviewed indicative yields, calculated as the most recently announced quarterly distribution or dividend per unit or share, as annualized, divided by the closing unit or stock price on December 29, 2017, and calendar year 2018 and calendar year 2019 estimated yields. Financial data of the Archrock Partners selected companies were based on publicly available Wall Street research analysts' estimates and public filings. Financial data of Archrock Partners was based on the Archrock Partners forecasts and public filings.

        The overall low to high calendar year 2018 and calendar year 2019 estimated EBITDA multiples, calendar year 2018 and calendar year 2019 estimated distributable cash flow per share or LP unit multiples, indicative yields as of December 29, 2017 and calendar year 2018 and calendar year 2019 estimated yields observed for the Archrock Partners selected companies were as follows:

    calendar year 2018 estimated EBITDA multiples: 7.8x to 11.2x (with a mean of 9.6x and a median of 10.0x);

    calendar year 2019 estimated EBITDA multiples: 7.3x to 9.6x (with a mean of 8.6x and a median of 9.0x);

    calendar year 2018 estimated distributable cash flow per share or LP unit multiples: 4.7x to 12.0x (with a mean of 8.2x and a median of 8.0x);

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    calendar year 2019 estimated distributable cash flow per share or LP unit multiples: 4.8x to 8.3x (with a mean of 7.2x and a median of 7.8x);

    indicative yields as of December 29, 2017: 6.0% to 13.7% (with a mean of 10.6% and a median of 11.2%);

    calendar year 2018 estimated yields: 6.1% to 13.7% (with a mean of 10.7% and a median of 11.6%); and

    calendar year 2019 estimated yields: 6.8% to 13.7% (with a mean of 11.0% and a median of 12.0%).

        Citi observed that the calendar year 2018 and calendar year 2019 estimated EBITDA, as adjusted, multiples and calendar year 2018 and calendar year 2019 estimated distributable cash flow per APLP common unit multiples for Archrock Partners were 7.8x, 6.6x, 5.7x and 5.0x, respectively, based on the Archrock Partners forecasts, the indicative yield as of December 29, 2017 for Archrock Partners was 9.6% based on public filings and the calendar year 2018 and calendar year 2019 estimated yields for Archrock Partners were each 9.6% based on the Archrock Partners forecasts. Citi then applied the following selected ranges of calendar year 2018 and calendar year 2019 estimated EBITDA multiples and calendar year 2018 and calendar year 2019 estimated distributable cash flow per share or LP unit multiples derived from the Archrock Partners selected companies to the calendar year 2018 and calendar year 2019 estimated EBITDA, as adjusted, and calendar year 2018 and calendar year 2019 estimated distributable cash flow per APLP common unit of Archrock Partners based on the Archrock Partners forecasts, the following selected range of indicative yields as of December 29, 2017 derived from the Archrock Partners selected companies to Archrock Partners' most recently announced quarterly distribution per APLP common unit, as annualized, based on public filings, and the following selected ranges of calendar year 2018 and calendar year 2019 estimated yields derived from the Archrock Partners selected companies to Archrock Partners' estimated distributions per APLP common unit for calendar years 2018 and 2019 based on the Archrock Partners forecasts, respectively:

    calendar year 2018 estimated EBITDA multiples: 7.8x to 11.0x;

    calendar year 2019 estimated EBITDA multiples: 6.6x to 9.6x;

    calendar year 2018 estimated distributable cash flow per share or LP unit multiples: 5.7x to 8.8x;

    calendar year 2019 estimated distributable cash flow per share or LP unit multiples: 5.0x to 8.3x;

    indicative yields as of December 29, 2017: 12.7% to 9.6%;

    calendar year 2018 estimated yields: 12.7% to 9.6%; and

    calendar year 2019 estimated yields: 13.1% to 9.6%.

        This analysis indicated a selected approximate implied per APLP common unit equity value reference range for Archrock Partners of $10.60 to $17.65.

        Utilizing the selected approximate implied per share equity value reference range derived for Archrock on a consolidated basis and the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners, in each case as described above, Citi calculated the following implied exchange ratio reference range, as compared to the exchange ratio:

Implied Exchange Ratio Reference Range

1.010x - 2.615x
  Exchange Ratio

1.40x

        Utilizing the selected approximate implied per share equity value reference range derived for Archrock on a sum-of-the-parts basis and the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners, in each case as described above, Citi calculated the following implied exchange ratio reference range, as compared to the exchange ratio:

Implied Exchange Ratio Reference Range

0.977x - 2.847x
  Exchange Ratio

1.40x

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        Selected Precedent Transactions Analysis.    Using publicly available information, Citi reviewed financial data relating to the following 11 selected transactions that Citi considered generally relevant as transactions involving acquisitions of natural gas compression assets, referred to as the Archrock Partners selected precedent transactions:

Announced
  Acquiror   Seller/Target
January 2017  

Kodiak Gas Services,  LLC

 

Lucid Energy Group,  LLC

October 2016  

Archrock Partners,  L.P.

 

Archrock,  Inc.

April 2015  

Exterran Partners,  L.P.

 

Exterran Holdings,  Inc.

July 2014  

Compressco Partners,  L.P.

 

Compressor Systems,  Inc.

July 2014  

Exterran Partners,  L.P.

 

MidCon Compression,  L.L.C.

February 2014  

Access Midstream Partners,  L.P.

 

MidCon Compression,  L.L.C.

February 2014  

Exterran Partners,  L.P.

 

MidCon Compression,  L.L.C.

January 2014  

Compressco Partners,  L.P.

 

Undisclosed

August 2013  

USA Compression Partners,  LP

 

S&R Compression,  LLC

March 2013  

Exterran Partners,  L.P.

 

Exterran Holdings,  Inc.

November 2012  

Crestwood Midstream Partners LP

 

Enerven Compression,  LLC

        Citi reviewed, among other information and to the extent publicly available, transaction values (based on the consideration payable in the Archrock Partners selected precedent transactions) as a multiple of the target entity's next 12 months estimated EBITDA as of the date of announcement of the transactions. Financial data of the Archrock Partners selected precedent transactions were based on publicly available Wall Street research analysts' estimates, public filings and other publicly available information. Financial data of Archrock Partners was based on the Archrock Partners forecasts.

        The overall low to high next 12 months estimated EBITDA multiples observed for the Archrock Partners selected precedent transactions were 7.5x to 9.6x (with a mean of 8.5x and a median of 8.4x). Citi then applied a selected range of next 12 months estimated EBITDA multiples of 8.4x to 9.6x derived from the Archrock Partners selected precedent transactions to the calendar year 2018 estimated EBITDA, as adjusted, of Archrock Partners. This analysis indicated a selected approximate implied per APLP common unit equity value reference range for Archrock Partners of $14.00 to $18.60.

        Utilizing the selected approximate implied per share equity value reference range derived for Archrock on a consolidated basis described above under "—Selected Public Companies Analyses—Archrock (consolidated)," and the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners as described above under "—Selected Precedent Transactions Analysis," Citi calculated the following implied exchange ratio reference range, as compared to the exchange ratio:

Implied Exchange Ratio Reference Range

1.333x - 2.756x
  Exchange Ratio

1.40x

        Discounted Cash Flow Analyses.    Citi performed separate discounted cash flow analyses of Archrock, both on a consolidated and sum-of-the-parts basis, and Archrock Partners.

        Archrock (consolidated).    Citi performed a discounted cash flow analysis of Archrock on a consolidated basis by calculating the estimated present value (as of December 31, 2017) of CAFD per share that Archrock was forecasted to generate during the fiscal years ending December 31, 2018 through December 31, 2020 after taking into account Archrock's projected cash taxes based on the Archrock forecasts. Citi calculated terminal values for Archrock by applying to Archrock's fiscal year 2020 estimated CAFD per share a selected range of CAFD per share multiples of 11.4x to 18.4x. The present values (as of December 31, 2017) of the CAFD per share and terminal values were then calculated using a selected range of discount rates of 9.4% to 11.2%. In calculating the estimated

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present value (as of December 31, 2020 and then as of December 31, 2017) of Archrock's projected cash taxes, Citi utilized the same ranges of multiples and discount rates. This analysis indicated a selected approximate implied per share equity value reference range for Archrock of $5.90 to $9.40.

        Archrock (sum-of-the-parts).    Citi also performed a discounted cash flow analysis of Archrock on a sum-of-the-parts basis to derive an approximate implied per share equity value reference range for Archrock based on approximate implied values for Archrock's retained midstream business, Archrock's LP interests and Archrock's GP/IDR interests after taking into account Archrock's projected cash taxes.

        In evaluating Archrock's retained midstream business, Citi utilized the selected approximate implied value reference range derived for such business from the discounted cash flow analysis of such business described above under "—Selected Public Companies Analyses—Archrock (sum-of-the-parts)." In evaluating Archrock's LP interests, Citi utilized the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners from the discounted cash flow analysis of Archrock Partners described below under "—Discounted Cash Flow Analyses—Archrock Partners." In evaluating Archrock's GP/IDR interests, Citi performed a discounted cash flow analysis of GP/IDR interests in Archrock Partners by calculating the estimated present value of the pre-tax GP/IDR cash flows that Archrock Partners was expected to generate during the fiscal years ending December 31, 2018 through December 31, 2020 based on the Archrock Partners forecasts. Citi calculated implied terminal values for GP/IDR interests in Archrock Partners by applying to Archrock Partners' fiscal year 2020 estimated pre-tax GP/IDR cash flows a selected range of pre-tax GP/IDR cash flow multiples of 12.8x to 25.9x. The present values (as of December 31, 2017) of pre-tax GP/IDR cash flows and terminal values were then calculated using a selected range of discount rates of 9.4% to 11.2%. For purposes of this analysis, Citi took into account Archrock's projected cash taxes based on the Archrock forecasts. In calculating the estimated present value (as of December 31, 2017) of Archrock's projected cash taxes, Citi utilized a selected range of CAFD per share multiples of 11.4x to 18.4x and a selected range of discount rates of 9.4% to 11.2%.

        The analyses described above of Archrock's retained midstream business, Archrock's LP interests, Archrock's GP/IDR interests and Archrock's projected cash taxes indicated an overall selected approximate implied per share equity value reference range for Archrock of $7.00 to $10.85.

        Archrock Partners.    Citi performed a discounted cash flow analysis of Archrock Partners by calculating the estimated present value (as of December 31, 2017) of distributable cash flow per APLP common unit as adjusted to reflect a coverage ratio of 1.0x, referred to as adjusted distributable cash flow per APLP common unit, that Archrock Partners was forecasted to generate during the fiscal years ending December 31, 2018 through December 31, 2020 based on the Archrock Partners forecasts. Citi calculated terminal values for Archrock Partners by applying to Archrock Partners' fiscal year 2020 estimated adjusted distributable cash flow per APLP common unit a selected range of distributable cash flow per LP unit multiples of 5.7x to 8.8x. The present values (as of December 31, 2017) of the adjusted distributable cash flows per APLP common unit and terminal values were then calculated using a selected range of discount rates of 8.6% to 10.8%. This analysis indicated a selected approximate implied per APLP common unit equity value reference range for Archrock Partners of $16.20 to $23.20.

        Utilizing the selected approximate implied per share equity value reference range derived for Archrock on a consolidated basis and the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners, in each case as described above, Citi calculated the following implied exchange ratio reference range, as compared to the exchange ratio:

Implied Exchange Ratio Reference Range

1.723x - 3.932x
  Exchange Ratio

1.40x

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        Utilizing the selected approximate implied per share equity value reference range derived for Archrock on a sum-of-the-parts basis and the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners, in each case as described above, Citi calculated the following implied exchange ratio reference range, as compared to the exchange ratio:

Implied Exchange Ratio Reference Range

1.493x - 3.314x
  Exchange Ratio

1.40x

Certain Additional Information

        Citi also observed certain additional information that was not considered part of its financial analyses with respect to its opinion but was noted for informational purposes, including the following:

    historical closing prices of AROC common stock and APLP common units during the 52-week period ended December 29, 2017, which indicated during such period (a) low and high closing prices for AROC common stock of approximately $8.30 and $16.40 per share and low and high closing prices for APLP common units of approximately $10.58 and $18.55, and (b) an implied exchange ratio reference range of 1.099x to 1.509x;

    publicly available Wall Street research analysts' price targets for AROC common stock and APLP common units, which indicated an overall low to high target stock price range for AROC common stock of $12.00 to $16.00 per share and overall low to high target unit price range for APLP common units of $15.50 to $20.00 per unit, and an implied exchange ratio reference range of 0.969x to 1.667x; and

    Citi performed, for informational reference, discounted cash flow analyses of Archrock, both on a consolidated and sum-of-the-parts basis, utilizing generally the same methodologies described above under "—Discounted Cash Flow Analyses—Archrock (consolidated)" and "—Discounted Cash Flow Analyses—Archrock (sum-of-the-parts)" but assuming, for purposes of the terminal period, a normalized coverage ratio and related distributions per APLP common unit as provided by Archrock management. On a consolidated basis, this indicated a selected approximate implied per share equity value reference range for Archrock of $10.40 to $16.95 and, based on this range and the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners as described above under "—Discounted Cash Flow Analyses—Archrock Partners," an implied exchange ratio reference range of 0.956x to 2.231x. On a sum-of-the-parts basis, this indicated an overall selected approximate implied per share equity value reference range for Archrock of $8.35 to $13.95 and, based on this range and the selected approximate implied per APLP common unit equity value reference range derived for Archrock Partners as described above under "—Discounted Cash Flow Analyses—Archrock Partners," an implied exchange ratio reference range of 1.161x to 2.778x.

        Other.    Citi also observed certain illustrative pro forma financial effects of the merger on, among other things, Archrock's estimated CAFD per share and Archrock Partners' estimated distributable cash flow per APLP common unit for calendar years 2018 (both before and after adjusting for certain one-time capital expenditures in such year), 2019 and 2020 and Archrock's estimated dividends per share and Archrock Partners' estimated distributions per APLP common unit in such years, based on the Archrock forecasts, the Archrock Partners forecasts and publicly available information and after taking into account potential strategic implications and financial, operational and tax benefits anticipated by the management of Archrock to result from the merger, which indicated that the merger could be:

    relative to Archrock on a standalone basis, (a) accretive to Archrock's estimated CAFD per share (i) in calendar year 2018, by approximately 191.6% before adjusting for certain one-time

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      capital expenditures in such year and approximately 133.1% after adjusting for such expenditures, (ii) in calendar year 2019, by approximately 136.5%, and (iii) in calendar year 2020, by approximately 170.6%, and (b) accretive to Archrock's estimated dividends per share by approximately 10.0%, 21.0% and 33.1% in calendar years 2018, 2019 and 2020, respectively, assuming a dividend growth rate of approximately 10% to 15% through calendar year 2020; and

    relative to Archrock Partners on a standalone basis, (a) dilutive to Archrock Partners' estimated distributable cash flow per APLP common unit for calendar year 2018 by approximately 16.9% before adjusting for certain one-time capital expenditures in such year and approximately 11.8% after adjusting for such expenditures, (b) accretive to Archrock Partners' estimated distributable cash flow per APLP common unit for calendar years 2019 and 2020 by approximately 0.5% and 5.7%, respectively, and (c) dilutive to Archrock Partners' estimated distributions per APLP common unit by approximately 35.2%, 28.7% and 21.5% in calendar years 2018, 2019 and 2020, respectively.

        Actual results achieved by Archrock, Archrock Partners and the pro forma combined company may vary from forecasted results and variations may be material.

Miscellaneous

        Archrock has agreed to pay Citi for its services in connection with the proposed merger an aggregate fee of $5 million, of which a portion was payable upon delivery of Citi's opinion and $4 million is payable contingent upon consummation of the merger. In addition, Archrock agreed to reimburse Citi for Citi's expenses, including fees and expenses of counsel, and to indemnify Citi and related parties against certain liabilities, including liabilities under federal securities laws, arising out of Citi's engagement.

        As the AROC board was aware, Citi and its affiliates in the past have provided, currently are providing and in the future may provide investment banking, commercial banking and other similar financial services to Archrock and certain of its affiliates unrelated to the proposed merger, for which services Citi and its affiliates received and expect to receive compensation, including, during the two-year period prior to the date of Citi's opinion, having acted or acting as (i) financial advisor to Archrock in connection with certain merger and acquisition transactions and (ii) a lender under a credit facility of an affiliate of Archrock, for which services described in clauses (i) and (ii) above Citi and its affiliates received during such two-year period aggregate fees of less than $500,000 from Archrock. As the AROC board also was aware, Citi and its affiliates in the past have provided, currently are providing and in the future may provide investment banking, commercial banking and other similar financial services to Archrock Partners and certain of its affiliates, for which services Citi and its affiliates received and expect to receive compensation, including, during the two-year period prior to the date of Citi's opinion, having acted or acting as (i) joint lead manager for an equity offering of Archrock Partners, (ii) sales agent for at-the-market equity offerings of Archrock Partners and (iii) a lender under certain credit facilities of an affiliate of Archrock Partners, for which services described in clauses (i) through (iii) above Citi and its affiliates received during such two-year period aggregate fees of approximately $2.5 million from Archrock Partners. In the ordinary course of business, Citi and its affiliates may actively trade or hold the securities of Archrock, Archrock Partners and their respective affiliates for their own account or for the account of customers and, accordingly, may at any time hold a long or short position in such securities. In addition, Citi and its affiliates (including Citigroup Inc. and its affiliates) may maintain relationships with Archrock, Archrock Partners and their respective affiliates.

        Archrock selected Citi to act as financial advisor in connection with the proposed merger based on Citi's reputation, experience and familiarity with Archrock, Archrock Partners and their respective

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businesses. Citi is an internationally recognized investment banking firm that regularly engages in the valuation of businesses and their securities in connection with mergers and acquisitions, negotiated underwritings, competitive bids, secondary distributions of listed and unlisted securities, private placements and valuations for estate, corporate and other purposes.

Opinion of the Financial Advisor to the APLP Conflicts Committee

        The APLP conflicts committee retained Evercore Group L.L.C. ("Evercore") as its financial advisor with respect to the provision of (i) financial advisory services to the APLP conflicts committee and (ii) an opinion to the APLP conflicts committee as to the fairness, from a financial point of view, to the APLP unaffiliated unitholders of the exchange ratio provided for pursuant to the merger agreement. At the request of the APLP conflicts committee at a meeting of the APLP conflicts committee held on January 1, 2018, Evercore rendered its oral opinion to the APLP conflicts committee that, as of January 1, 2018, based upon and subject to the assumptions, procedures, qualifications, limitations and other matters considered by Evercore in connection with the preparation of its opinion, the exchange ratio provided for pursuant to the merger agreement is fair, from a financial point of view, to the APLP unaffiliated unitholders. Evercore subsequently confirmed its oral opinion in a written opinion on the same date.

        The opinion speaks only as of the date it was delivered and not as of the time the merger will be completed or any other date. The opinion does not reflect changes that may occur or may have occurred after January 1, 2018, which could alter the facts and circumstances on which Evercore's opinion was based. It is understood that subsequent events may affect Evercore's opinion, but Evercore does not have any obligation to update, revise or reaffirm its opinion.

        Evercore's opinion was directed to the APLP conflicts committee (in its capacity as such), and only addressed the fairness from a financial point of view, as of January 1, 2018, to the APLP unaffiliated unitholders of the exchange ratio provided for pursuant to the merger agreement. Evercore's opinion did not address any other term or aspect of the merger. The full text of the written opinion that describes the assumptions made, procedures followed, qualifications and limitations of the review undertaken, and other matters considered by Evercore in rendering its opinion, is attached hereto as Annex C. The summary of Evercore's opinion set forth in this joint proxy statement/prospectus is qualified in its entirety by reference to the full text of the written opinion. However, neither the written opinion nor the summary of such opinion and the related analyses set forth in this joint proxy statement/prospectus are intended to be, and they do not constitute, a recommendation as to how APLP common unitholders or any other person should act or vote with respect to the merger or any other matter.

        Evercore's opinion to the APLP conflicts committee was among several factors taken into consideration by the APLP conflicts committee in making its recommendation to the board of directors of the Managing GP regarding the merger.

        In connection with rendering its opinion and performing its related financial analysis, Evercore, among other things:

    i.
    reviewed certain publicly-available historical business and financial information relating to Archrock Partners and Archrock that Evercore deemed to be relevant, including their Annual Reports on Form 10-K for the year ended December 31, 2016, Quarterly Reports on Form 10-Q for the quarters ended March 31, 2017, June 30, 2017 and September 30, 2017 and certain Current Reports on Form 8-K, in each case as filed with or furnished to the U.S. Securities and Exchange Commission by Archrock and Archrock Partners since January 1, 2017;

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    ii.
    reviewed certain non-public historical financial statements and other non-public historical financial and operating data relating to Archrock Partners and Archrock prepared and furnished to Evercore by management of Archrock Partners and Archrock;

    iii.
    reviewed certain non-public projected financial and operating data and assumptions relating to Archrock Partners and Archrock prepared and furnished to Evercore by management of Archrock Partners and Archrock, which include certain sensitivity cases prepared by management of Archrock Partners and Archrock;

    iv.
    discussed the past and current operations, financial projections and current financial condition of Archrock Partners and Archrock with management of Archrock Partners and Archrock (including their views on the risks and uncertainties of achieving such projections);

    v.
    reviewed the reported prices and the historical trading activity of APLP common units and AROC common stock;

    vi.
    reviewed publicly available research analysts estimates for Archrock's and Archrock Partners' future financial performance, in each case, on a standalone basis;

    vii.
    compared the financial performance of Archrock Partners and Archrock and their stock market trading multiples with those of certain other publicly traded companies that Evercore deemed relevant;

    viii.
    compared the financial performance of Archrock Partners and Archrock and the valuation multiples relating to the merger with those of certain other transactions that Evercore deemed relevant;

    ix.
    reviewed the premiums paid in certain historical transactions that Evercore deemed relevant and compared such premiums to those implied by the merger;

    x.
    performed discounted cash flow analyses on Archrock Partners based on the APLP Financial Projections—Management Case (as defined below);

    xi.
    performed discounted distribution analyses on Archrock Partners based on the APLP Financial Projections—Management Case;

    xii.
    performed discounted dividends analyses on Archrock based on the AROC Financial Projections—Management Case (as defined below);

    xiii.
    reviewed a draft of the merger agreement; and

    xiv.
    performed such other analyses and examinations and considered such other factors that Evercore deemed appropriate for the purposes of providing its opinion.

        For purposes of its analysis and opinion, Evercore assumed and relied upon, without undertaking any independent verification of, the accuracy and completeness of all of the information publicly available, and all of the information supplied or otherwise made available to, discussed with, or reviewed by Evercore, and Evercore assumes no liability therefor. With respect to the projected financial and operating data relating to Archrock Partners and Archrock referred to above, Evercore assumed that such data were reasonably prepared on bases reflecting the best currently available estimates and good faith judgments of the management of Archrock Partners and Archrock as to the future financial performance of Archrock Partners and Archrock under the alternative business assumptions stated therein. Evercore did not express a view as to any projected financial and operating data or any judgments, estimates or assumptions on which they are based. Evercore relied, at the APLP conflicts committee's direction, without independent verification, upon the assessments of the management of Archrock Partners and Archrock as to the future financial and operating performance

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of Archrock Partners and Archrock and Evercore has assumed that Archrock Partners and Archrock will realize the benefits that each expects to realize from the merger.

        For purposes of rendering its opinion, Evercore assumed, in all respects material to its analysis, that the merger agreement would be executed and delivered (in the draft form reviewed by Evercore), that the representations and warranties of each party contained in the merger agreement (in the draft form reviewed by Evercore) would be true and correct, that each party will perform all of the covenants and agreements required to be performed by it under the merger agreement and that all conditions to the consummation of the merger will be satisfied without material waiver or modification thereof. Evercore further assumed that all governmental, regulatory or other consents, approvals or releases necessary for the consummation of the merger will be obtained without any material delay, limitation, restriction or condition that would have an adverse effect on Archrock Partners, or the consummation of the merger or materially reduce the benefits to the APLP unaffiliated unitholders.

        Evercore did not make nor assume any responsibility for making any independent valuation or appraisal of the assets or liabilities of Archrock Partners or Archrock, nor was Evercore furnished with any such appraisals, nor did Evercore evaluate the solvency or fair value of Archrock Partners under any state or federal laws relating to bankruptcy, insolvency or similar matters. Evercore's opinion was necessarily based upon information made available to Evercore as of the date of its opinion and financial, economic, monetary, market, regulatory and other conditions and circumstances as they existed and as could be evaluated by Evercore on the date of its opinion. It is understood that subsequent developments may affect Evercore's opinion and that Evercore does not have any obligation to update, revise or reaffirm its opinion.

        The estimates contained in Evercore's analyses and the results from any particular analysis are not necessarily indicative of future results, which may be significantly more or less favorable than suggested by such analyses. In addition, analyses relating to the value of businesses or assets neither purport to be appraisals nor do they necessarily reflect the prices at which businesses or assets may actually be sold. Accordingly, Evercore's analyses and estimates are inherently subject to substantial uncertainty.

        In arriving at its opinion, Evercore did not attribute any particular weight to any particular analysis or factor considered by it, but rather made qualitative judgments as to the significance and relevance of each analysis and factor. Several analytical methodologies were employed by Evercore in its analyses, and no one single method of analysis should be regarded as determinative of the overall conclusion reached by Evercore. Each analytical technique has inherent strengths and weaknesses, and the nature of the available information may further affect the significance of particular techniques. Accordingly, Evercore believes that its analyses must be considered as a whole and that selecting portions of its analyses and of the factors considered by it, without considering all analyses and factors in their entirety, could create a misleading or incomplete view of the evaluation process underlying its opinion. The conclusion reached by Evercore, therefore, is based on the application of Evercore's experience and judgment to all analyses and factors considered by Evercore, taken as a whole.

        Evercore was not asked to pass upon, and expressed no opinion with respect to, any matter other than whether the exchange ratio provided for pursuant to the merger agreement is fair, from a financial point of view, as of the date of the opinion, to the APLP unaffiliated unitholders. Evercore's opinion did not express any opinion as to the structure, terms (other than the exchange ratio) or effect or any other aspect of the merger, including, without limitation, the tax consequences of the merger. Evercore did not express any view on, and its opinion does not address, the fairness of the proposed transaction to, or any consideration received in connection therewith by, the holders of any other securities, creditors or other constituencies of Archrock Partners, nor as to the fairness of the amount or nature of any compensation to be paid or payable to any of the officers, directors or employees of Archrock Partners, the General Partner or Managing GP, or any classes of such persons, whether relative to the exchange ratio or otherwise.

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        Evercore assumed that any modification to the structure of the merger will not vary in any respect material to its analysis. Evercore's opinion did not address the relative merits of the merger as compared to other business or financial strategies that might have been available to Archrock Partners, nor did it address the underlying business decision of Archrock Partners to engage in the merger. In arriving at its opinion, Evercore was not authorized to solicit, and did not solicit, interest from any third party with respect to the acquisition of any or all of APLP common units or any business combination or other extraordinary transaction involving Archrock Partners. Evercore's opinion did not constitute a recommendation to the APLP conflicts committee or to any other persons in respect of the merger, including as to how any holders of APLP common units should vote or act in respect of the merger. Evercore expressed no opinion as to the price at which APLP common units or AROC common stock will trade at any time. Evercore is not a legal, regulatory, accounting or tax expert and has assumed the accuracy and completeness of assessments by Archrock Partners and Archrock and their advisors with respect to legal, regulatory, accounting and tax matters.

        The following is a summary of the material financial analyses performed by Evercore in connection with the preparation of its opinion and reviewed with the APLP conflicts committee on January 1, 2018. Unless the context indicates otherwise, enterprise values and equity values used in the selected MLPs and corporations analysis described below were calculated using the closing price of the selected MLPs and corporations listed below as of December 29, 2017, and transaction values for the selected transactions analysis described below were calculated on an enterprise value basis based on the value of the equity consideration and other public information available at the time of the relevant transaction's announcement. The analyses summarized below include information presented in tabular format. In order to fully understand the financial analyses performed, the tables must be considered together with the textual summary of the analyses.

        No entity or transaction used in the analyses of entities or transactions summarized below is identical or directly comparable to Archrock Partners, Archrock or the merger. As a consequence, mathematical derivations (such as the high, low, mean and median) of financial data are not by themselves meaningful, and these analyses must take into account differences in the financial and operating characteristics of the selected entities and differences in the structure and timing of the selected transactions and other factors that would affect the public trading value and acquisition value of the entities considered.

    Projections

        See "The Merger—Unaudited Projected Financial Information" for a description of certain non-public historical and projected financial and operating data and assumptions, relating to Archrock Partners and Archrock, prepared and furnished to Evercore by management of Archrock Partners and Archrock.

    Analysis of Archrock Partners

        Evercore performed a series of analyses to derive indicative valuation ranges for APLP common units and applied each of the resulting implied valuation ranges to derive a range of implied exchange ratios of the APLP common units to AROC common stock, and compared these ratios to the exchange ratio provided for pursuant to the merger agreement.

        Evercore performed its analyses utilizing three years of financial projections for Archrock Partners provided by Archrock Partners' and Archrock's management which are referred to in this section as "APLP Financial Projections—Management Case," and one year of financial projections for two sensitivity cases provided by Archrock Partners' and Archrock's management, which are referred to in this section as "APLP Financial Projections—Upside Case" and "APLP Financial Projections—Downside Case." The APLP Financial Projections—Management Case, APLP Financial

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Projections—Upside Case and the APLP Financial Projections—Downside Case are collectively referred to in this section as the "APLP Financial Projections." The APLP Financial Projections were not adjusted by Evercore.

    Discounted Cash Flow Analysis

        Evercore performed a discounted cash flow analysis of Archrock Partners by valuing the cash flows to be received by Archrock Partners based solely on the APLP Financial Projections—Management Case. Evercore calculated the per unit value range for APLP common units by utilizing a range of discount rates with a mid-point equal to Archrock Partners' weighted average cost of capital ("WACC"), as estimated by Evercore based on the Capital Asset Pricing Model ("CAPM"), and terminal values based on a range of estimated EBITDA exit multiples as well as perpetuity growth rates. Evercore assumed a range of discount rates of 9.0% to 10.5%, a range of estimated EBITDA exit multiples of 7.0x to 8.0x and a range of perpetuity growth rates of 1.5% to 2.5%. Tax depreciation was assumed to be allocated 100% to a seven-year modified accelerated cost recovery system schedule and the applicable tax rate was assumed to be 21%, per management of Archrock Partners and Archrock.

        Evercore's discounted cash flow analysis for Archrock Partners resulted in an implied equity value per unit range of $11.84 per unit to $17.39 per unit based on the range of estimated EBITDA exit multiples and an implied equity value per unit range of $14.75 per unit to $28.81 per unit based on the range of perpetuity growth rates.

    Discounted Distribution Analysis

        Evercore performed a discounted distribution analysis of the APLP common units based on the present value of the future cash distributions to the APLP common unitholders. The projected distributions utilized by Evercore were based on the APLP Financial Projections—Management Case. Evercore assumed (i) a terminal yield range of 9.0% to 10.5% based on trading of the APLP common units over the last 52 weeks prior to the public announcement of the merger, (ii) a cost of equity of 13.5% to 14.5% based on CAPM and (iii) a cost of equity of 13.0% to 14.0% based on expected market total return for MLPs and corporations that Evercore deemed to have certain characteristics that are similar to Archrock Partners. Evercore determined an implied equity value per unit range of $10.04 per unit to $11.51 per unit based on CAPM and an implied equity value per unit range of $10.15 per unit to $11.64 per unit based on expected market total return.

    Precedent M&A Transaction Analysis

        Evercore reviewed selected publicly available information for historical transactions involving compression assets announced since January 2012 and selected 12 transactions that involved assets that

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Evercore deemed to have certain characteristics similar to those of Archrock Partners, although Evercore noted that none of the selected transactions were directly comparable to the merger:

Date Announced
  Acquiror / Target (Seller)

10/31/2016

  Archrock Partners LP / Archrock, Inc. Assets

4/20/2015

  Exterran Partners, L.P. / Exterran Holdings, Inc. Assets

10/23/2014

  EnLink Midstream Partners, LP / E2 Appalachian Compression, LLC and E2 Energy Services, LLC

7/20/2014

  Compressco Partners, L.P. / Compressor Systems, Inc.

7/14/2014

  Exterran Partners, L.P. / MidCon Compression, LLC Assets

6/2/2014

  Enerflex Ltd / Axip Energy Services

2/28/2014

  Access Midstream Partners, L.P. / MidCon Compression, LLC Assets

2/28/2014

  Exterran Partners, L.P. / MidCon Compression, LLC Assets

8/13/2013

  USA Compression Partners, LP / S&R Compression, LLC

3/8/2013

  Exterran Partners, L.P. / Exterran Holdings, Inc. Assets

11/26/2012

  Crestwood Marcellus Midstream, LLC / Enerven Compression, LLC

2/23/2012

  Exterran Partners, L.P. / Exterran Holdings, Inc. Assets

        Evercore reviewed the EBITDA multiples paid in the selected historical transactions and derived a range of relevant implied multiples of transaction value to EBITDA of 7.5x to 9.0x for 2018 EBITDA for its precedent transactions analysis. Evercore then applied this range of selected multiples to estimated 2018 EBITDA from the APLP Financial Projections. The mean and median implied multiples of transaction value to EBITDA are set forth below:

Benchmark (All Reviewed Transactions)
  Mean   Median  
Transaction Value / EBITDA     8.1x     8.0x  

 

Benchmark (Only Corporate Transactions)
  Mean   Median  
Transaction Value / EBITDA     8.6x     8.5x  

        Evercore determined an implied equity value per unit range by utilizing (i) the APLP Financial Projections—Management Case of $10.57 per unit to $16.43 per unit, (ii) the APLP Financial Projections—Upside Case implied equity value per unit range of $11.76 per unit to $17.86 per unit and (iii) the APLP Financial Projections—Downside Case of $8.31 per unit to $13.73 per unit.

    Peer Group Trading Analysis

        Evercore performed a peer group trading analysis of Archrock Partners by reviewing and comparing the market values and trading multiples of the following compression MLPs and corporations that Evercore deemed to have certain characteristics that are similar to those of Archrock Partners:

    Compression MLPs:

      CSI Compressco LP

      USA Compression Partners, LP

    Compression Corporations:

      Exterran Corporation

      Natural Gas Services Group, Inc.

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        Although the peer group was compared to Archrock Partners for purposes of this analysis, no MLP or corporation used in the peer group analysis is identical or directly comparable to Archrock Partners. In order to calculate peer group trading multiples, Evercore relied on publicly available filings with the SEC and other regulatory agencies and equity research analyst estimates.

        For each of the peer group MLPs and corporations, Evercore calculated the following trading multiples:

    Enterprise Value / 2018 EBITDA, which is defined as Enterprise Value divided by estimated EBITDA for the calendar year 2018; and

    Enterprise Value / 2019 EBITDA, which is defined as Enterprise Value divided by estimated EBITDA for the calendar year 2019.

        The mean and median trading multiples are set forth below. The table also includes relevant multiple ranges selected by Evercore based on the resulting range of multiples and certain other considerations related to the specific characteristics of Archrock Partners noted by Evercore.

Benchmark (Contract Compression MLPs)
  Mean   Median  

Enterprise Value / 2018 EBITDA

    9.2x     9.2x  

Enterprise Value / 2019 EBITDA

    8.6x     8.6x  

 

Benchmark (Contract Compression Corporations)
  Mean   Median  

Enterprise Value / 2018 EBITDA

    7.7x     7.7x  

Enterprise Value / 2019 EBITDA

    6.6x     6.6x  

 

Benchmark
  Reference Range  

Enterprise Value / 2018 EBITDA

    7.5x - 9.0x  

Enterprise Value / 2019 EBITDA

    7.0x - 9.0x  

        Evercore applied the Enterprise Value to EBITDA multiple reference ranges illustrated above to estimated 2018 and 2019 EBITDA from the APLP Financial Projections—Management Case. Evercore determined an implied equity value per unit range by utilizing the APLP Financial Projections—Management Case of $10.57 per unit to $22.88 per unit.

        Evercore also applied the Enterprise Value to EBITDA multiple reference ranges illustrated above to estimated 2018 EBITDA from the APLP Financial Projections—Upside Case and APLP Financial Projections—Downside Case. Evercore determined an implied equity value per unit range by utilizing (i) the APLP Financial Projections—Upside Case of $11.76 per unit to $19.90 per unit and (ii) the APLP Financial Projections—Downside Case of $8.31 per unit to $15.53 per unit.

    Premiums Paid Analysis

        Evercore also reviewed selected publicly available information for historical premiums paid in (i) MLP merger transactions generally and (ii) MLP buy-in transactions specifically. Evercore considered that, historically, MLP merger and buy-in premiums have varied widely based on specific considerations with respect to each transaction, with a range for MLP buy-in transactions of (i) (8.6%) to 27.9% premium to the one-day trailing price, (ii) (1.8%) to 27.7% to the five-day trailing price and (iii) 1.0% to 52.4% to the 30-day trailing price and a median premium for MLP buy-in transactions of (i) 15.0% to the one-day trailing price, (ii) 13.8% to the five-day trailing price and (iii) 12.7% to the 30-day trailing price, and a range for all MLP merger transactions of (i) (8.6%) to 31.6% premium to the one-day trailing price, (1.8%) to 35.8% to the five-day trailing price and (iii) 1.0% to 52.4% to the 30-day trailing price and a median premium for all MLP merger transactions of (i) 14.8% to the one-day trailing price, (ii) 13.7% to the five-day trailing price and (iii) 11.7% to the 30-day trailing

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price. Evercore noted that none of the selected transactions or the selected MLPs or companies that participated in the selected transactions were directly comparable to the merger or Archrock Partners.

        The selected transactions, implied premiums paid considering the per unit offer price relative to the targets' prior one-day, five-day and 30-day closing unit prices, and resulting minimum, maximum, mean and median data were as follows:

Date Announced
  Acquiror   Target
6/2/17   World Point Terminals, Inc.   World Point Terminals, LP*
3/18/17   Energy Transfer Partners, L.P.   PennTex Midstream Partners, LP*
3/3/17   VTTI B.V.   VTTI Energy Partners LP*
2/1/17   ONEOK, Inc.   ONEOK Partners, L.P.*
1/26/17   Enbridge Energy Co, Inc.   Midcoast Energy Partners, L.P.*
10/24/16   American Midstream Partners, LP   JP Energy Partners LP
9/26/16   TransCanada Corporation   Columbia Pipeline Partners LP*
8/1/16   Transocean Ltd.   Transocean Partners LLC*
5/31/16   SemGroup Corporation   Rose Rock Midstream, L.P.*
11/3/15   Targa Resources Corp.   Targa Resources Partners LP*
10/26/15   Western Refining, Inc.   Northern Tier Energy LP*
7/13/15   MPLX LP   MarkWest Energy Partners, L.P.
5/13/15   The Williams Companies, Inc.   Williams Partners L.P. *
5/6/15   Crestwood Equity Partners LP   Crestwood Midstream Partners LP*
1/26/15   Energy Transfer Partners, L.P.   Regency Energy Partners LP
10/27/14   Access Midstream Partners LP   Williams Partners L.P.
10/13/14   Targa Resource Partners LP   Atlas Pipeline Partners, L.P.
10/1/14   Enterprise Products Partners L.P.   Oiltanking Partners L.P.
8/10/14   Kinder Morgan, Inc.   Kinder Morgan Energy Partners, L.P.*
8/10/14   Kinder Morgan, Inc.   El Paso Pipeline Partners, L.P.*
10/10/13   Regency Energy Partners LP   PVR Partners, L.P.
8/27/13   Plains All American Pipeline, L.P.   PAA Natural Gas Storage LP*
5/7/13   Pioneer Natural Resources Company   Pioneer Southwest Energy Partners L.P.*
5/6/13   Inergy Midstream, L.P.   Crestwood Midstream Partners LP
1/29/13   Kinder Morgan Energy Partners, L.P.   Copano Energy, L.L.C.
2/23/11   Enterprise Products Partners L.P.   Duncan Energy Partners L.P.*

*
MLP Buy-in Transactions


MLP Buy-Ins Premiums

 
  1-Day   5-Day   30-Day  

Median

    15.0 %   13.8 %   12.7 %

Mean

    13.4 %   14.1 %   16.2 %

Max

    27.9 %   27.7 %   52.4 %

Min

    (8.6 )%   (1.8 )%   1.0 %

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All Transactions Premiums

 
  1-Day   5-Day   30-Day  

Median

    14.8 %   13.7 %   11.7 %

Mean

    14.1 %   14.3 %   15.9 %

Max

    31.6 %   35.8 %   52.4 %

Min

    (8.6 )%   (1.8 )%   1.0 %

        For MLP buy-in transactions, Evercore applied a "1-Day" median premium reference of 15.0%, a "5-Day" median premium reference of 13.8% and a "30-Day" median premium reference of 12.7% to Archrock Partners' prior one trading day closing price of $11.79 as of December 28, 2017, prior five trading day closing unit price of $11.79 as of December 22, 2017 and prior 30 day closing unit price of $10.61 as of November 29, 2017, respectively, resulting in an implied equity value per unit range of $11.96 to $13.56.

        For all MLP merger transactions, Evercore applied a "1-Day" median premium reference of 14.8%, a "5-Day" median premium reference of 13.7% and a "30-Day" median premium reference of 11.7% to Archrock Partners' prior one trading day closing price of $11.79 as of December 28, 2017, prior five trading day closing unit price of $11.79 as of December 22, 2017 and prior 30 day closing unit price of $10.61 as of November 29, 2017, respectively, resulting in an implied equity value per unit range of $11.85 to $13.53.

    Analysis of Archrock

        Evercore performed a series of analyses to derive indicative valuation ranges for AROC common stock. Evercore performed its analyses utilizing three years of financial projections for Archrock provided by Archrock's management which are referred to in this section as "AROC Financial Projections—Management Case," and one year of financial projections for two sensitivity cases provided by Archrock Partners' and Archrock's management, which are referred to in this section as "AROC Financial Projections—Upside Case" and "AROC Financial Projections—Downside Case." The AROC Financial Projections—Management Case, AROC Financial Projections—Upside Case and the AROC Financial Projections—Downside Case are collectively referred to in this section as the "AROC Financial Projections." The AROC Financial Projections were not adjusted by Evercore.

    Discounted Dividend Analysis

        Evercore performed a discounted dividend analysis of AROC common stock based on the present value of the future cash dividends to the AROC stockholders. The projected dividends utilized by Evercore were based on the AROC Financial Projections—Management Case. Evercore assumed (i) a terminal yield range of 4.0% to 5.0% based on trading of AROC common stock over the last 52 weeks prior to the public announcement of the merger, (ii) a cost of equity of 13.5% to 14.5% based on CAPM and (iii) a cost of equity of 13.0% to 14.0% based on expected market total return for MLPs and corporations that Evercore deemed to have certain characteristics that are similar to those of Archrock. Evercore determined an implied equity value per unit range of $7.58 per share to $9.40 per share based on CAPM and an implied equity value per unit range of $7.67 per share to $9.52 per share based on expected market total return.

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    Peer Group Trading Analysis

        Evercore performed a peer group trading analysis of Archrock by reviewing and comparing the market values and trading multiples of the following compression corporations that Evercore deemed to have certain characteristics that are similar to those of Archrock:

    Compression Corporations:

      Exterran Corporation

      Natural Gas Services Group, Inc.

        Although the peer group was compared to Archrock for purposes of this analysis, no corporation used in the peer group analysis is identical or directly comparable to Archrock. In order to calculate peer group trading multiples, Evercore relied on publicly available filings with the SEC and other regulatory agencies and equity research analyst estimates.

        For each of the peer group companies, Evercore calculated the following trading multiples:

    Enterprise Value / 2018 EBITDA, which is defined as Enterprise Value divided by estimated consolidated EBITDA for the calendar year 2018; and

    Enterprise Value / 2019 EBITDA, which is defined as Enterprise Value divided by estimated consolidated EBITDA for the calendar year 2019.

        The mean and median trading multiples are set forth below. The table also includes relevant multiple ranges selected by Evercore based on the resulting range of multiples and certain other considerations related to the specific characteristics of Archrock noted by Evercore.

Benchmark (Contract Compression Corporations)
  Mean   Median  

Enterprise Value / 2018 EBITDA

    7.7x     7.7x  

Enterprise Value / 2019 EBITDA

    6.6x     6.6x  

 

Benchmark
  Reference Range  

Enterprise Value / 2018 EBITDA

    7.0x - 8.0x  

Enterprise Value / 2019 EBITDA

    6.0x - 7.0x  

        Evercore applied the Enterprise Value to EBITDA multiple reference ranges illustrated above to estimated 2018 and 2019 consolidated EBITDA from the AROC Financial Projections—Management Case. Evercore determined an implied equity value per share range by utilizing the AROC Financial Projections—Management Case of $9.65 per share to $16.32 per share.

        Evercore also applied the Enterprise Value to EBITDA multiple reference ranges illustrated above to estimated 2018 consolidated EBITDA from the AROC Financial Projections—Upside Case and AROC Financial Projections—Downside Case. Evercore determined an implied equity value per unit range by utilizing (i) the AROC Financial Projections—Upside Case of $11.26 per unit to $15.73 per unit and (ii) the AROC Financial Projections—Downside Case of $6.92 per share to $10.77 per share.

    Exchange Ratio Summary

        Evercore analyzed the implied exchange ratios from the valuation techniques utilized for the valuation of Archrock Partners and Archrock. These valuation techniques included the Discounted Distribution Analysis, Discounted Dividend Analysis, Precedent M&A Transaction Analysis and Peer Group Trading Analysis. For the implied exchange ratios based on Discounted Distribution Analysis, Discounted Dividend Analysis and Peer Group Trading Analysis, Evercore compared the high value to the high value, and the low value to the low value for each technique. For the implied exchange ratios

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based on the Precedent M&A Transaction Analysis, Evercore compared the high value of Archrock Partners to the closing share price of Archrock as of December 29, 2017 and the low value of Archrock Partners to the share price of Archrock as of December 29, 2017.

        The resulting exchange ratio ranges were (i) 1.224x to 1.325x for Discounted Distribution and Discounted Dividend Analysis based on CAPM, (ii) 1.223x to 1.324x for Discounted Distribution and Discounted Dividend Analysis based on expected market total return, (iii) 1.202x to 1.442x for Peer Group Trading Analysis utilizing the APLP Financial Projections—Downside Case and the AROC Financial Projections—Downside Case, (iv) 1.095x to 1.403x for the Peer Group Trading Analysis utilizing the APLP Financial Projections—Management Case and the AROC Financial Projections—Management Case, (v) 1.045x to 1.265x for the Peer Group Trading Analysis utilizing the APLP Financial Projections—Upside Case and the AROC Financial Projections—Upside Case, (vi) 0.792x to 1.307x for the Precedent M&A Transaction Analysis utilizing the APLP Financial Projections—Downside Case, (vii) 1.006x to 1.565x for the Precedent M&A Transaction Analysis utilizing the APLP Financial Projections—Management Case and (vii) 1.120x to 1.701x for the Precedent M&A Transaction Analysis utilizing the APLP Financial Projections—Upside Case.

    General

        Evercore and its affiliates engage in a wide range of activities for their own accounts and the accounts of customers. In connection with these businesses or otherwise, Evercore and its affiliates and/or their respective employees, as well as investment funds in which any of them may have a financial interest, may at any time, directly or indirectly, hold long or short positions and may trade or otherwise effect transactions for their own accounts or the accounts of customers, in debt or equity securities, senior loans and/or derivative products relating to Archrock Partners, Archrock and their respective affiliates, for its own account and for the accounts of its customers and, accordingly, may at any time hold a long or short position in such securities or instruments.

        The APLP conflicts committee selected Evercore to provide financial advice in connection with its evaluation of the merger because of, among other reasons, Evercore's experience, reputation and familiarity with the midstream sector of the energy industry and because its investment banking professionals have substantial experience in transactions similar to the merger.

        The description set forth above constitutes a summary of the analyses employed and factors considered by Evercore in rendering its opinion to the APLP conflicts committee. The preparation of a fairness opinion is a complex, analytical process involving various determinations as to the most appropriate and relevant methods of financial analysis and the application of those methods to the particular circumstances and is not necessarily susceptible to partial analysis or summary description.

        Pursuant to the terms of the engagement of Evercore, Evercore will receive a fee of $2,000,000 for its services, of which $200,000 became payable upon the execution of its engagement letter, $800,000 became payable upon delivery of the opinion and $1,000,000 will become payable upon closing of the merger. In addition, Archrock Partners has agreed to reimburse certain of Evercore's expenses and to indemnify Evercore against certain liabilities arising out of its engagement.

        During the two year period prior to the date hereof, no material relationship existed between Evercore or any of its affiliates, on the one hand, and Archrock Partners or Archrock or any of their respective affiliates, on the other hand, pursuant to which compensation was or is intended to be received by Evercore or its affiliates as a result of such a relationship. Evercore may provide financial or other services to Archrock Partners or Archrock in the future and in connection with any such services Evercore may receive compensation.

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No Appraisal Rights

        Neither AROC stockholders nor APLP common unitholders are entitled to appraisal rights in connection with the merger under applicable law or contractual appraisal rights under Archrock's organizational documents, the Archrock Partners partnership agreement or the merger agreement.

Listing of AROC Common Stock to be Issued in the Merger; Delisting and Deregistration of APLP Common Units

        Archrock expects to obtain approval to list, on the NYSE, the AROC common stock to be issued pursuant to the merger agreement, which approval is a condition to the merger. Upon completion of the merger, APLP common units currently listed on NASDAQ will cease to be listed on NASDAQ and will be subsequently deregistered under the Exchange Act.

Accounting Treatment

        The merger will be accounted for in accordance with ASC 810. Because Archrock controls Archrock Partners both before and after the merger, the changes in Archrock's ownership interest in Archrock Partners resulting from the merger will be accounted for as an equity transaction, and no gain or loss will be recognized in Archrock's consolidated statement of operations. In addition, the tax effects of the merger are reported as adjustments to long-term assets associated with discontinued operations, deferred income taxes, additional paid-in capital and accumulated other comprehensive income consistent with ASC 740.

Interests of Certain Persons in the Merger

        In considering the recommendations of the APLP conflicts committee and the APLP board, APLP common unitholders should be aware that some of the executive officers and directors of the Managing GP have interests in the transaction that may differ from, or may be in addition to, the interests of APLP common unitholders generally. These interests may present such directors and executive officers with actual or potential conflicts of interests, and these interests, to the extent material, are described below. The APLP conflicts committee and the APLP board were aware of these interests and considered them, among other matters, prior to providing their respective approvals and recommendations with respect to the merger agreement.

        In considering the recommendations of the AROC board, AROC stockholders should be aware that some of the executive officers and directors of Archrock have interests in the transaction that may differ from, or may be in addition to, the interests of AROC stockholders generally. These interests may present such directors and executive officers with actual or potential conflicts of interests, and these interests, to the extent material, are described below. The AROC board was aware of these interests and considered them, among other matters, prior to providing its approval and recommendation with respect to the merger agreement.

    Common Directors and Current Named Executive Officers

        For 2017, the currently serving Named Executive Officers of Archrock also currently serve as the Named Executive Officers of Archrock Partners. These "Named Executive Officers," who are also identified below under "Executive Compensation—Compensation Discussion and Analysis," are:

    D. Bradley Childers is President and Chief Executive Officer of Archrock and Managing GP;

    Raymond K. Guba is Interim Chief Financial Officer of Archrock and Managing GP;

    Stephanie C. Hildebrandt is Senior Vice President, General Counsel and Secretary of Archrock and Senior Vice President and General Counsel of Managing GP;

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    Jason G. Ingersoll is Vice President, Sales of Archrock and Managing GP; and

    Robert E. Rice is Senior Vice President and Chief Operating Officer of Archrock and Senior Vice President of Managing GP.

        Each of these individuals will retain his or her position with Archrock following the merger. In addition, Mr. Childers, Chairman of the APLP board, is also a director of Archrock and Mr. Rice and Ms. Hildebrandt serve as directors of Managing GP.

        For purposes of the Named Executive Officers' compensation arrangements with Archrock and APLP, the merger will not constitute a "change in control" of either Archrock or APLP. Accordingly, the Named Executive Officers will not become entitled to any compensation or benefits, including any accelerated vesting of their equity awards, upon or in connection with the consummation of the merger.

    Indemnification and Insurance

        The merger agreement provides that from and after the effective time of the merger, Archrock and Archrock Partners (as the surviving entity of the merger) jointly and severally agree to indemnify and hold harmless against any reasonable cost or expenses (including attorneys' fees), judgments, fines, losses, claims, damages or liabilities, penalties and amounts paid in settlement in connection with any actual or threatened legal proceeding, and provide advancement of expenses with respect to each of the foregoing to, any person who is now, or has been or becomes at any time prior to the effective time of the merger, an officer, director or employee of Archrock Partners or any of its subsidiaries or the Managing GP, to the fullest extent permitted under applicable law.

        In addition, Archrock and Archrock Partners (continuing as a wholly owned indirect subsidiary of Archrock) will honor the provisions regarding elimination of liability of officers and directors, indemnification of officers, directors and employees and advancement of expenses contained in the organizational documents of Archrock Partners and the Managing GP immediately prior to the effective time of the merger and ensure that the organizational documents of Archrock Partners and the Managing GP or any of their respective successors or assigns, if applicable, will contain provisions no less favorable with respect to indemnification, advancement of expenses and exculpation of present and former directors, officers, employees and agents of Archrock Partners and the Managing GP than are presently set forth in such organizational documents. In addition, Archrock will maintain in effect for six years from the effective time of the merger Archrock's current directors' and officers' liability insurance policies covering acts or omissions occurring at or prior to the effective time of the merger with respect to such indemnified persons, provided that in no event will Archrock be required to expend more than an amount per year equal to 300% of current annual premiums paid by Archrock for such insurance.

    Directors and Executive Officers of Archrock After the Merger

        The directors and executive officers of Archrock prior to the merger are expected to continue as directors and executive officers of Archrock after the merger.

    Security Ownership of Directors and Executive Officers

        The following table sets forth the beneficial ownership of the directors and executive officers of Archrock and Archrock Partners in (i) APLP common units prior to the merger, (ii) AROC common

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stock prior to the merger and (iii) AROC common stock after giving effect to the merger, in each case as of March 14, 2018.

Name of Beneficial Owner
  APLP
Common
Units(1)
  Percentage of
APLP
Common Units
Outstanding(2)
  AROC
Common Stock
Prior to the
Merger(3)
  Percentage of
Shares of
AROC
Common Stock
Outstanding(4)
  AROC
Common Stock
after the
Merger(5)
  Percentage of
AROC
Common Stock
Outstanding
after the
Merger
 

Anne-Marie N. Ainsworth

            43,803     *     43,803     *  

Wendell R. Brooks

            49,169     *     49,169     *  

D. Bradley Childers

    104,726     *     736,642     *     883,259     *  

James G. Crump

    35,040     *             49,056     *  

G. Stephen Finley

    37,647     *             52,706     *  

Raymond K. Guba

                         

Gordon T. Hall

            134,631     *     134,631     *  

Frances Powell Hawes

            43,803     *     43,805     *  

Donna A. Henderson

            39,856     *     39,856     *  

Stephanie C. Hildebrandt

            98,398     *     98,398     *  

J.W.G. Honeybourne

            86,109     *     86,109     *  

Jason G. Ingersoll

    5,258     *     78,938     *     86,300     *  

James H. Lytal

            43,803     *     43,803     *  

Mark A. McCollum

    2,000     *     79,951     *     82,751     *  

Robert E. Rice

    23,615     *     192,535     *     225,596     *  

Edmund P. Segner

    29,637     *             41,492     *  

*
Less than 1 percent.

(1)
Includes APLP common units held by members of the family of the director or executive officer for which the director or executive officer has sole or shared voting or investment power. Does not include unvested phantom units held by Messrs. Childers (72,428), Ingersoll (7,488) and Rice (14,670), awarded under APLP's long-term incentive plans; such phantom units will be converted to AROC restricted stock units and will be subject to substantially the same terms, including vesting. Does not include approximately 29,065,000 APLP common units held by Archrock and its subsidiaries, which, when combined with the 2 percent general partner interest held by a subsidiary of Archrock, represent an approximate 42.6% interest in Archrock Partners at March 9, 2018, with respect to which each officer and director disclaims beneficial ownership.

(2)
The percent of Archrock Partners voting securities owned is based on the outstanding common units on March 9, 2018.

(3)
Includes shares of AROC common stock held by members of the family of the director or executive officer for which the director or executive officer has sole or shared voting or investment power and shares of AROC common stock held in Archrock's 401(k) Plan. Includes unvested restricted stock held by Ms. Henderson (30,633), Ms. Hildebrandt (98,398) and Messrs. Childers (393,189), Ingersoll (52,299), Rice (103,687) and by each of Mmes. Ainsworth and Hawes and Messrs. Brooks, Hall, Honeybourne, Lytal and McCollum (9,868). Does not include vested options to purchase AROC common stock held by Messrs. Childers (373,553) and Rice (62,424).

(4)
The percent of Archrock voting securities owned is based on outstanding shares of AROC common stock on March 9, 2018.

(5)
Rounded up to the nearest whole share where applicable.

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THE MERGER AGREEMENT

        This section of this joint proxy statement/prospectus describes the material provisions of the merger agreement, but does not describe all of the terms of the merger agreement and may not contain all of the information about the merger agreement that is important to you. The following summary is qualified by reference to the complete text of the merger agreement, which is attached as Annex A to this joint proxy statement/prospectus and incorporated by reference herein. You are urged to read the full text of the merger agreement because it is the legal document that governs the merger.

        The merger agreement and this summary of its terms have been included to provide you with information regarding the terms of the merger agreement. Factual disclosures about Archrock, Archrock Partners or any of their respective subsidiaries or affiliates contained in this joint proxy statement/prospectus or their respective public reports filed with the SEC may supplement, update or modify the factual disclosures contained in the merger agreement and described in this summary. The representations, warranties, and covenants contained in the merger agreement were made only for purposes of the merger agreement, as of a specific date. These representations were made solely for the benefit of the parties to the merger agreement and may be subject to important qualifications and limitations agreed upon by the contracting parties, including being qualified by confidential disclosures made for the purpose of allocating risk between parties to the merger agreement rather than the purpose of establishing these matters as facts, and may apply standards of materiality in ways that are different from those generally applicable to reports filed with the SEC or from what may be viewed as material by investors. These representations do not survive completion of the merger. For the foregoing reasons, one should not read these representations or any description thereof as characterizations of the actual state of facts or condition of Archrock or Archrock Partners at any time, which are disclosed in the other information provided elsewhere in this joint proxy statement/prospectus or incorporated by reference herein.

The Merger; Effective Time; Closing

        Subject to the terms and conditions of the merger agreement and in accordance with Delaware law, at the effective time of the merger, Merger Sub, an indirect wholly owned subsidiary of Archrock, will merge with and into Archrock Partners, with Archrock Partners continuing as the surviving entity and a wholly owned indirect subsidiary of Archrock.

        At the effective time of the merger, each APLP common unit issued and outstanding will be converted into the right to receive 1.40 shares of AROC common stock, other than (i) APLP common units that are owned immediately prior to the effective time of the merger by Archrock Partners, which will be automatically cancelled and will cease to exist, and (ii) APLP common units owned immediately prior to the effective time of the merger by the Managing GP, Archrock or any subsidiaries of Archrock (other than Archrock Partners), which will remain outstanding, unaffected by the merger. The General Partner Interest (as defined in the Archrock Partners partnership agreement) will also remain outstanding, unaffected by the merger.

        Archrock will not issue any fractional shares of AROC common stock in the merger. Instead of receiving any fractions of AROC common stock, all fractions of AROC common stock to which a holder of APLP common units would otherwise have been entitled shall be aggregated and the resulting fraction will be rounded up to the nearest whole share of AROC common stock.

        In addition, at the effective time of the merger, each award of APLP phantom units (whether vested or unvested) that is outstanding as of immediately prior to the effective time will be assumed by Archrock and converted into an award of AROC RSUs granted under AROC's 2013 Stock Incentive Plan representing a number of shares of AROC common stock equal to (i) the number of APLP phantom units subject to such award as of immediately prior to the effective time, multiplied by (ii) 1.40, rounded down to the nearest whole AROC RSU. Each such award of AROC RSUs shall be subject to the same vesting, forfeiture and other terms and conditions (including form(s) of payment

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and distribution equivalent rights, if any) applicable to the converted award of APLP phantom units as of immediately prior to the effective time.

        The effective time of the merger will occur at such time as Archrock and Archrock Partners cause a certificate of merger to be duly filed with the Secretary of State of the State of Delaware or at such later date or time as may be agreed by Archrock and Archrock Partners in writing and specified in the certificate of merger.

        The closing of the merger will take place on the second business day after the satisfaction or waiver of the conditions set forth in the merger agreement (other than conditions that by their nature are to be satisfied at the closing but subject to the satisfaction or waiver of those conditions), or at such other place, date and time as Archrock and Archrock Partners may agree.

Conditions to Completion of the Merger

        Archrock and Archrock Partners may not complete the merger unless each of the following conditions is satisfied or waived:

    Archrock Partners has obtained APLP common unitholder approval;

    Archrock has obtained AROC stockholder approval;

    any waiting period applicable to the transactions contemplated by the merger agreement under the HSR Act shall have been terminated or must have expired (early termination of the waiting period under the HSR Act was granted on February 9, 2018);

    no restraint is in effect enjoining, restraining, preventing or prohibiting the completion of the transactions contemplated by the merger agreement or making the completion of the transactions contemplated by the merger agreement illegal;

    the registration statement of which this joint proxy statement/prospectus forms a part must have been declared effective under the Securities Act and no stop order suspending the effectiveness of the registration statement will have been issued and no proceedings for that purpose will have been initiated or threatened by the SEC; and

    the AROC common stock deliverable to the APLP common unitholders as contemplated by the merger agreement must have been approved for listing on the NYSE, subject to official notice of issuance.

        The obligations of Archrock and Merger Sub to effect the merger are subject to the satisfaction or waiver of the following additional conditions:

    the representations and warranties in the merger agreement of Archrock Partners, the General Partner and the Managing GP:

    with respect to Archrock Partners', the General Partner's and the Managing GP's authority to execute the merger agreement and complete the transactions contemplated by the merger agreement, the applicable unitholder voting requirements for approval of the merger agreement and transactions contemplated thereby, and the absence of certain changes or events, being true and correct in all respects, in each case, both when made and at and as of the date of the closing, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date);

    with respect to Archrock Partners' capitalization, being true and correct in all respects, other than immaterial misstatements or omissions, both when made and at and as of the date of the closing, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date);

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      with respect to all other representations and warranties, being true and correct at and as of the closing, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date), except where the failure of such representations and warranties to be so true and correct (without giving effect to any limitation as to "materiality" or "material adverse effect" set forth in any individual representation or warranty, other than with respect to the filing of documents with the SEC, undisclosed liabilities, internal controls, absence of certain changes or events, information supplied for inclusion in this joint proxy statement/prospectus, and for purposes of the definition of an Archrock Partners material contract) does not have, and would not reasonably be expected to have, individually or in the aggregate a "material adverse effect" on Archrock Partners;

    Archrock Partners, the General Partner and the Managing GP having performed in all material respects all obligations required to be performed by each of them under the merger agreement; and

    the receipt by Archrock of an officer's certificate signed on behalf of Archrock Partners, the General Partner and the Managing GP by an executive officer of the Managing GP certifying that the preceding conditions have been satisfied.

        The obligation of Archrock Partners to effect the merger is subject to the satisfaction or waiver of the following additional conditions:

    the representations and warranties in the merger agreement of Archrock:

    with respect to its authority to execute the merger agreement and complete the transactions contemplated by the merger agreement, and the applicable stockholder voting requirements for approval of the issuance of AROC common stock in connection with the merger, and the absence of certain changes or events, being true and correct in all respects, in each case, both when made and at and as of the date of the closing, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date);

    with respect to its capitalization, being true and correct in all respects, other than immaterial misstatements or omissions, both when made and at and as of the date of the closing, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date);

    with respect to all other representations and warranties, being true and correct at and as of the closing, as if made at and as of such time (except to the extent expressly made as of an earlier date, in which case as of such date), except where the failure of such representations and warranties to be so true and correct (without giving effect to any limitation as to "materiality" or "material adverse effect" set forth in any individual representation or warranty, other than with respect to the filing of documents with the SEC, undisclosed liabilities, internal controls, absence of certain changes or events, information supplied for inclusion in this joint proxy statement/prospectus, and for purposes of the definition of an Archrock material contract) does not have, and would not reasonably be expected to have, individually or in the aggregate a "material adverse effect" on Archrock;

    Archrock and Merger Sub having performed in all material respects all obligations required to be performed by each of them under the merger agreement; and

    the receipt by Archrock Partners of an officer's certificate signed on behalf of Archrock by an executive officer of Archrock certifying that the preceding conditions have been satisfied.

        For purposes of the merger agreement, the term "material adverse effect" means, when used with respect to a person, any change, condition, effect, event or occurrence that, individually or in the aggregate, has had or would reasonably be expected to have a material adverse effect on the business,

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financial condition or results of operations of such person and its subsidiaries, taken as a whole, or prevents or materially impedes, interferes with or hinders a party's ability to consummate the transactions contemplated by the merger agreement, including the merger, on or before September 30, 2018; provided, however, that any adverse changes, conditions, effects, events or occurrences resulting from or due to any of the following shall be disregarded in determining whether there has been a material adverse effect: (i) changes, conditions, effects, events or occurrences generally affecting the United States or global economy, the financial, credit, debt, securities or other capital markets or political, legislative or regulatory conditions or changes in the industries in which such person operates; (ii) the announcement or pendency of the merger agreement or the transactions contemplated by the merger agreement or, except specifically for purposes of determining whether there is a breach of the representations and warranties made by Archrock, Archrock Partners and the Managing GP that the execution, delivery and performance of the merger agreement and the completion of the merger and the other transactions contemplated by the merger agreement do not violate or conflict with such party's organizational documents, applicable laws or certain contracts, and the satisfaction of the closing conditions set forth in the merger agreement (and described above under "—Conditions to Completion of the Merger") with respect to such representations and warranties, the performance of the merger agreement; (iii) any change in the market price or trading volume of the limited partnership interests, shares of common stock or other equity securities of such person (it being understood and agreed that the foregoing does not preclude any other party to the merger agreement from asserting that any facts or occurrences giving rise to or contributing to such change that are not otherwise excluded from the definition of material adverse effect should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a material adverse effect); (iv) acts of war, terrorism or other hostilities (or the escalation of the foregoing) or natural disasters or other force majeure events; (v) changes in any applicable laws or regulations applicable to such person or applicable accounting regulations or principles or the interpretation thereof; (vi) any legal proceedings commenced by or involving any current or former member, partner or stockholder of such person or any of its subsidiaries arising out of or related to the merger agreement or the transactions contemplated by the merger agreement; (vii) changes, effects, events or occurrences generally affecting the prices of oil, natural gas, natural gas liquids or other commodities; (viii) any failure of a person to meet any internal or external projections, forecasts or estimates of revenues, earnings or other financial or operating metrics for any period (it being understood and agreed that the foregoing does not preclude any other party to the merger agreement from asserting that any facts or occurrences giving rise to or contributing to such failure that are not otherwise excluded from the definition of material adverse effect should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a material adverse effect); and (ix) with respect to Archrock only, any effect to the extent resulting from a change, condition, effect, event or occurrence that has a material adverse effect on Archrock Partners and its subsidiaries; provided, however, that changes, effects, events or occurrences referred to in clauses (i), (iv), (v) and (vii) above shall be considered for purposes of determining whether there has been or would reasonably be expected to be a material adverse effect if and to the extent such changes, effects, events or occurrences has had or would reasonably be expected to have a disproportionate adverse effect on such person and its subsidiaries, taken as a whole, as compared to other companies of similar size operating in the industries in which such person and its subsidiaries operate.

        For purposes of the merger agreement, except where expressly provided otherwise, Archrock Partners, the General Partner, the Managing GP and their respective subsidiaries are not considered subsidiaries of Archrock or affiliates of Archrock or any of its subsidiaries.

Representations and Warranties

        The merger agreement contains representations and warranties by Archrock and Merger Sub, on the one hand, and Archrock Partners, the General Partner and the Managing GP, on the other hand.

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These representations and warranties have been made solely for the benefit of the other party to the merger agreement and:

    may be intended not as statements of fact, but rather as a way of allocating the risk to one of the parties if those statements prove to be inaccurate;

    have been qualified by disclosures that were made to the other party in connection with the negotiation of the merger agreement, which disclosures may not be reflected in the merger agreement; and

    may apply standards of materiality in a way that is different from what may be viewed as material to you or other investors.

        Accordingly, these representations and warranties should not be read alone, but instead should be read only in conjunction with the information provided elsewhere in this joint proxy statement/prospectus and in the documents incorporated by reference into this joint proxy statement/prospectus, which may include information that updates, modifies or qualifies the information set forth in the representations and warranties.

        The representations and warranties made by both Archrock and Merger Sub, on the one hand, and Archrock Partners, the General Partner and the Managing GP, on the other hand relate to, among other things:

    organization, standing and similar organizational matters;

    capital structure;

    due authorization of the merger agreement and the transactions contemplated by the merger agreement, absence of any conflicts with third parties created by such transactions and the voting requirements for such transactions;

    required consents and approvals of governmental entities in connection with the transactions contemplated by the merger agreement;

    documents filed with the SEC, financial statements included in those documents since December 31, 2014;

    no undisclosed liabilities or obligations;

    maintenance of a system of internal controls;

    absence of changes or events since December 31, 2016;

    legal proceedings;

    compliance with applicable laws and permits;

    information supplied in connection with this joint proxy statement/prospectus and the registration statement of which it is a part;

    taxes and other tax matters;

    material contracts;

    benefit plans and other labor matters;

    environmental matters;

    property;

    intellectual property;

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    opinions of financial advisors;

    brokers and other advisors;

    insurance;

    the Investment Company Act of 1940, as amended; and

    no other representations and warranties.

        Additional representations and warranties made only by Archrock to Archrock Partners relate to, among other things, ownership of APLP common units.

Conduct of Business Prior to Closing

        Under the merger agreement, each of Archrock and Merger Sub, on the one hand, and Archrock Partners, the General Partner and the Managing GP, on the other hand, has undertaken certain covenants that place restrictions on it and its respective subsidiaries from the date of the merger agreement until the earlier of the termination of the merger agreement in accordance with its terms and the effective time of the merger, unless the other party gives its prior written consent (which consent cannot be unreasonably withheld, conditioned or delayed).

        Subject to certain exceptions, unless Archrock consents in writing (which consent cannot be unreasonably withheld, conditioned or delayed), the General Partner, the Managing GP and Archrock Partners have agreed, and will cause their respective subsidiaries, to (i) conduct its business in the ordinary course of business consistent with past practice, (ii) use commercially reasonable efforts to maintain and preserve intact its business organization and the goodwill of those having business relationship with it and retain the services of its present officers and key employees, (iii) use commercially reasonable efforts to keep in full force and effect all material permits and all material insurance policies maintained by Archrock Partners and its subsidiaries, other than changes to such policies made in the ordinary course of business, and (iv) use commercially reasonable efforts to comply in all material respects with all applicable laws and the requirements of certain material contracts of Archrock Partners.

        Subject to certain exceptions, unless Archrock consents in writing (which consent cannot be unreasonably withheld, conditioned or delayed), the General Partner, the Managing GP and Archrock Partners, will not, and will not permit their respective subsidiaries to:

    amend the organizational documents (whether by merger, consolidation, conversion or otherwise) of any such entity in any manner that would reasonably be expected to prevent or in any material respect hinder, impede or delay the ability of the parties to satisfy any of the conditions to or the consummation of the merger or the other transactions contemplated by the merger agreement;

    declare, authorize, set aside or pay any dividend or distribution payable in cash, equity or property in respect of any APLP common units, other than regular quarterly cash distributions on the APLP common units not to exceed $0.285 per APLP common unit per quarter;

    make any acquisition or disposition, directly or indirectly (including by merger, consolidation, acquisition of assets, tender or exchange offer or otherwise), of any business or any corporation, partnership, limited liability company, joint venture or other business organization or division thereof or any property or assets of any other person, other than acquisitions or dispositions (x) in the ordinary course of business or (y) outside the ordinary course of business the consideration for which does not exceed $25 million in value in the aggregate;

    split, combine, divide, subdivide, reverse split, reclassify, recapitalize or effect any other similar transaction with respect to any such entity's capital stock or other equity interests;

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    solely with respect to Archrock Partners, adopt a plan or agreement of complete or partial liquidation, dissolution or restructuring or a plan or agreement of reorganization under any bankruptcy or similar law;

    waive, release, assign, settle or compromise any claim, action or proceeding, including any state or federal regulatory proceeding seeking damages or injunction or other equitable relief, which waiver, release, assignment, settlement or compromise would reasonably be expected to result in an Archrock Partners material adverse effect; or

    agree, in writing or otherwise, to take any of the foregoing actions, or take any action or agree, in writing or otherwise, to take any action, including proposing or undertaking any merger, consolidation or acquisition, in each case, that would reasonably be expected to prohibit, prevent or in any material respect hinder, impede or delay the ability of the parties to satisfy any of the conditions to or the completion of the merger or the other transactions contemplated by the merger agreement.

        Subject to certain exceptions, unless Archrock Partners consents in writing (which consent cannot be unreasonably withheld, conditioned or delayed), Archrock has agreed, and will cause each of its subsidiaries, to (i) conduct its business in the ordinary course of business consistent with past practice, (ii) use commercially reasonable efforts to maintain and preserve intact its business organization and the goodwill of those having business relationship with it and retain the services of its present officers and key employees, (iii) use commercially reasonable efforts to keep in full force and effect all material permits and all material insurance policies maintained by Archrock and its subsidiaries, other than changes to such policies made in the ordinary course of business, and (iv) use commercially reasonable efforts to comply in all material respects with all applicable laws and the requirements of certain material contracts of Archrock.

        Subject to certain exceptions, unless Archrock Partners consents in writing (which consent cannot be unreasonably withheld, conditioned or delayed), Archrock will not, and will not permit its subsidiaries to:

    amend Archrock's or any of its subsidiaries' organizational documents (whether by merger, consolidation, conversion or otherwise) in any manner that would reasonably be expected to (a) prevent or in any material respect hinder, impede or delay the ability of the parties to satisfy any of the conditions to or the completion of the merger or the other transactions contemplated by the merger agreement, or (b) adversely affect (1) the economic benefits to be obtained by the holders of public common units upon the consummation of the merger or (2) the terms of Archrock's shares in any material respect;

    declare, authorize, set aside or pay any dividend or distribution payable in cash, stock or property in respect of any of Archrock's capital stock, other than regular quarterly cash dividends on the AROC common stock in the ordinary course of business consistent with past practice and other than dividends or distributions with a record date after the effective time of the merger; provided, however, that nothing contained in the merger agreement prohibits Archrock from increasing the quarterly cash dividend on the AROC common stock;

    make any acquisition or disposition, directly or indirectly (including by merger, consolidation, acquisition of assets, tender or exchange offer or otherwise), of any business or any corporation, partnership, limited liability company, joint venture or other business organization or division thereof or any property or assets of any other person, other than acquisitions or dispositions (x) in the ordinary course of business or (y) outside the ordinary course of business the consideration for which does not exceed $25 million in value in the aggregate;

    merge, consolidate or enter into any other business combination transaction or agreement with any person;

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    split, combine, divide, subdivide, reverse split, reclassify, recapitalize or effect any other similar transaction with respect to any of Archrock's capital stock or other equity interests;

    issue or sell any shares of AROC common stock, issue or sell any preferred stock, or grant or issue any warrant, option, right, contract, call, or other security or instrument granting the holder thereof the right to acquire shares of AROC common stock or any other capital stock of Archrock or its subsidiaries, in each case, other than pursuant to an equity incentive plan of Archrock existing on January 1, 2018;

    solely with respect to Archrock, adopt a plan or agreement of complete or partial liquidation, dissolution or restructuring or a plan or agreement of reorganization under any bankruptcy or similar law;

    directly or indirectly purchase, acquire or otherwise become beneficial owner of (or direct Archrock Partners to repurchase, redeem or otherwise acquire) any APLP common units (other than APLP common units held by Archrock or its subsidiaries on January 1, 2018);

    waive, release, assign, settle or compromise any claim, action or proceeding, including any state or federal regulatory proceeding seeking damages or injunction or other equitable relief, which waiver, release, assignment, settlement or compromise would reasonably be expected to result in an Archrock material adverse effect; or

    agree, in writing or otherwise, to take any of the foregoing actions, or take any action or agree, in writing or otherwise, to take any action, including proposing or undertaking any acquisition or disposition, in each case, that would reasonably be expected to prohibit, prevent or in any material respect hinder, impede or delay the ability of the parties to satisfy any of the conditions to or the completion of the merger or the other transactions contemplated by the merger agreement.

No Solicitation by Archrock of Alternative Proposals

        The merger agreement contains detailed provisions prohibiting Archrock from seeking any proposal for an acquisition of 25% or more of Archrock's assets or equity that would reasonably be expected to prevent or materially impede, interfere with, hinder or delay the completion of the transactions contemplated by the merger agreement (an "alternative proposal"). Under these "no solicitation" covenants, Archrock has agreed that it will not, and will cause its subsidiaries and use reasonable best efforts to cause its and its subsidiaries' respective representatives not to, directly or indirectly, except as permitted by the merger agreement:

    solicit, initiate, knowingly facilitate or knowingly encourage the submission of an alternative proposal (including any acquisition structured as a merger, consolidation or share exchange);

    participate in any discussions or negotiations regarding, or furnish any information with respect to, any proposal or offer from any person relating to, or that could reasonably be expected to lead to, an alternative proposal;

    knowingly assist, participate in or facilitate in any other manner any effort or attempt by any person to do or seek any of the foregoing;

    enter into any acquisition agreement with respect to any alternative proposal (other than a confidentiality agreement containing customary provisions); or

    make an Archrock adverse recommendation change.

        Archrock has agreed that it will, and will cause its subsidiaries and use reasonable best efforts to cause its and its subsidiaries' respective representatives to, cease and cause to be terminated any discussions or negotiations with any persons conducted prior to the execution of the merger agreement

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with respect to an alternative proposal and immediately prohibit any access by any person to confidential information relating to a possible alternative proposal.

        After the date of the merger agreement and before Archrock obtains its stockholders' approval, if (i) Archrock has received a written alternative proposal that the AROC board believes is bona fide (ii) the AROC board, after consultation with Archrock's financial advisors and outside legal counsel, determines in good faith that such alternative proposal constitutes or could reasonably be expected to lead to or result in a superior proposal and, after consultation with Archrock's outside legal counsel, failure to take such action would be inconsistent with its duties under applicable laws, and (iii) such alternative proposal did not result from a material breach of the "no solicitation" covenants in the merger agreement, then Archrock may (x) furnish information, including confidential information, with respect to Archrock and its subsidiaries to the person making such alternative proposal and (y) participate in discussions or negotiations regarding such alternative proposal; provided, however, that (A) Archrock and its respective subsidiaries will not, and will use their reasonable best efforts to cause their respective representatives not to, disclose any non-public information to such person unless Archrock has, or first enters into, a confidentiality agreement with such person and (B) Archrock will provide to Archrock Partners, the General Partner and the Managing GP non-public information with respect to Archrock Partners and its subsidiaries that was not previously provided or made available to Archrock Partners, the General Partner and the Managing GP prior to or substantially concurrently with providing or making available such non-public information to such other person.

Archrock Recommendation and Archrock Adverse Recommendation Change

        Under the merger agreement, Archrock, through the AROC board, has agreed to recommend that AROC stockholders vote in favor of the AROC stock issuance proposal (the "AROC board recommendation"). Subject to the provisions described below, the merger agreement provides that Archrock, directly or indirectly, will not:

    solicit, initiate, knowingly facilitate or knowingly encourage the submission of an alternative proposal (including any acquisition structured as a merger, consolidation or share exchange);

    participate in any discussions or negotiations regarding, or furnish any information with respect to, any proposal or offer from any person relating to, or that could reasonably be expected to lead to, an alternative proposal;

    knowingly assist, participate in or facilitate in any other manner any effort or attempt by any person to do or seek any of the foregoing;

    enter into any acquisition agreement with respect to any alternative proposal (other than a confidentiality agreement containing customary provisions); or

    (a) withdraw, modify or qualify, or propose publicly to withdraw, modify or qualify, in a manner adverse to Archrock Partners, the AROC board recommendation, (b) fail to include the AROC board recommendation in this joint proxy statement/prospectus, (c) authorize, approve, declare advisable, adopt or recommend or propose to publicly authorize, approve, declare advisable, adopt or recommend, any alternative proposal, (d) authorize Archrock or any of its subsidiaries to enter into an alternative acquisition agreement or enter into an agreement, arrangement or understanding with respect to any alternative proposal (other than a confidentiality agreement containing customary provisions), or (e) if an alternative proposal has been publicly known (including by way of media rumors or speculations with respect thereto) or been delivered to Archrock, fail to publicly recommend against such alternative proposal within ten business days of a request by Archrock Partners and to reaffirm the AROC board recommendation within such ten business day period upon such request.

        Each of the foregoing actions is referred to as an "Archrock adverse recommendation change."

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        Notwithstanding these restrictions, after the date of the merger agreement and before Archrock obtains its stockholders' approval, if (i) Archrock has received a written alternative proposal that the AROC board believes is bona fide, (ii) the AROC board, after consultation with Archrock's financial advisors and outside legal counsel, determines in good faith that such alternative proposal constitutes or could reasonably be expected to lead to or result in a superior proposal and, after consultation with Archrock's outside legal counsel, failure to take such action would be inconsistent with its duties under applicable laws and (iii) such alternative proposal did not result from a material breach of the "no solicitation" covenants in the merger agreement, then Archrock may (x) furnish information, including confidential information, with respect to Archrock and its subsidiaries to the person making such alternative proposal and (y) participate in discussions or negotiations regarding such alternative proposal; provided, however, that (A) Archrock and its respective subsidiaries will not, and will use their reasonable best efforts to cause their respective representatives not to, disclose any non-public information to such person unless Archrock has, or first enters into, a confidentiality agreement with such person and (B) Archrock will provide to Archrock Partners, the General Partner and the Managing GP non-public information with respect to Archrock Partners and its subsidiaries that was not previously provided or made available to Archrock Partners, the General Partner and the Managing GP prior to or substantially concurrently with providing or making available such non-public information to such other person.

        Notwithstanding these restrictions, before Archrock obtains its stockholder approval, the AROC board may make a change in recommendation or terminate the merger agreement if in response to a superior proposal and following consultation with outside legal counsel, the AROC board determines that the failure to make a change in recommendation or terminate the merger agreement would be inconsistent with its fiduciary duties under applicable laws.

        The merger agreement further provides that the AROC board may not make a change in recommendation or terminate the merger agreement unless: (i) Archrock has provided prior written notice to Archrock Partners stating that the AROC board, after consultation with Archrock's financial advisors and outside legal counsel, has determined in good faith that the alternative proposal it received constitutes a superior proposal and describing the material terms of such proposal at least three calendar days in advance of its intention to take such action with respect to a change in recommendation (provided that any material amendment to the terms of an alternative proposal will require a new notice and a new notice period, except that such notice period shall be for two days from the time Archrock Partners received such new notice, as opposed to three days); (ii) Archrock has negotiated, and has used its reasonable best efforts to cause Archrock's financial advisors and outside legal counsel to negotiate, with Archrock Partners, the General Partner and the Managing GP in good faith (to the extent Archrock Partners, the General Partner and the Managing GP desire to negotiate) to make such adjustments in the terms and conditions of the merger agreement; and (iii) the AROC board again concludes in good faith and taking into account any adjustment or modification to the terms and conditions of the merger agreement proposed by Archrock Partners, that the alternative proposal continues to constitute a superior proposal or the failure