Sec Form 4 Filing - Oasis Petroleum Inc. @ Oasis Midstream Partners LP - 2021-03-30

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Oasis Petroleum Inc. 2. Issuer Name and Ticker or Trading Symbol Oasis Midstream Partners LP [ OMP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 1001 FANNIN ST., SUITE 1500 3. Date of Earliest Transaction (MM/DD/YY) 03/30/2021 (Street) HOUSTON, TX77002 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common units representing limited partner interests 03/30/2021 J( 1 )( 2 ) 14,644,220 ( 1 ) ( 2 ) A 37,469,220 I See Footnote ( 3 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Oasis Petroleum Inc. 1001 FANNIN ST., SUITE 1500 HOUSTON, TX77002 X Oasis Petroleum LLC 1001 FANNIN ST., SUITE 1500 HOUSTON, TX77002 X OMS Holdings LLC 1001 FANNIN ST., SUITE 1500 HOUSTON, TX77002 X Signatures /s/ Nickolas J. Lorentzatos, Executive Vice President, General Counsel and Corporate Secretary of Oasis Petroleum Inc. 04/01/2021 Signature of Reporting Person Date /s/ Nickolas J. Lorentzatos, Executive Vice President, General Counsel and Corporate Secretary of Oasis Petroleum LLC 04/01/2021 Signature of Reporting Person Date /s/ Nickolas J. Lorentzatos, Executive Vice President, General Counsel and Corporate Secretary of OMS Holdings LLC 04/01/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Pursuant to that certain Contribution and Simplification Agreement, dated as of March 22, 2021, by and among Oasis Midstream Partners LP (the "Issuer"), OMS Holdings LLC ("OMS Holdings"), Oasis Midstream Services LLC, OMP GP LLC (the "General Partner"), OMP Operating LLC, OMP DevCo Holdings Corp., Beartooth DevCo LLC, Bobcat DevCo LLC, OMS Holdings Merger Sub, LLC and, for certain limited purposes set forth therein, Oasis Petroleum Inc. ("OAS"), among other things, (a) OAS caused OMS to contribute certain assets to OMP Operating, as the Issuer's designee, in exchange for the distribution to OMS Holdings of consideration including 12,949,644 common units representing limited partner interests ("common units") and (b) the Issuer and the General Partner caused the Incentive Distribution Rights (as defined in the Contribution and Simplification Agreement) to be cancelled and converted into 1,850,356 common units, 1,694,576 of which were distributed to OMS Holdings, which is now is the ( 2 )(continued from footnote 1) sole member of the General Partner. ( 3 )This Form 4 is being jointly filed by OMS Holdings, Oasis Petroleum LLC ("Oasis Petroleum") and OAS. As of March 30, 2021, OMS Holdings directly owns 37,469,220 common units, Oasis Petroleum directly owns 100% of the outstanding membership interests in OMS Holdings and OAS directly owns 100% of the outstanding membership interests in Oasis Petroleum. Accordingly, OAS and Oasis Petroleum may be deemed to be an indirect beneficial owner of the securities of the Issuer held by OMS Holdings.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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