<SEC-DOCUMENT>0001193125-17-304734.txt : 20171005
<SEC-HEADER>0001193125-17-304734.hdr.sgml : 20171005
<ACCEPTANCE-DATETIME>20171005171335
ACCESSION NUMBER:		0001193125-17-304734
CONFORMED SUBMISSION TYPE:	SC 13D
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20171005
DATE AS OF CHANGE:		20171005
GROUP MEMBERS:		OASIS PETROLEUM LLC
GROUP MEMBERS:		OMS HOLDINGS LLC

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Oasis Midstream Partners LP
		CENTRAL INDEX KEY:			0001652133
		STANDARD INDUSTRIAL CLASSIFICATION:	DRILLING OIL & GAS WELLS [1381]
		IRS NUMBER:				471208855
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90129
		FILM NUMBER:		171125238

	BUSINESS ADDRESS:	
		STREET 1:		1001 FANNIN ST, STE 1500
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77002
		BUSINESS PHONE:		281-404-9500

	MAIL ADDRESS:	
		STREET 1:		1001 FANNIN ST, STE 1500
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77002

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Waha Energy Partners LP
		DATE OF NAME CHANGE:	20150902

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Wahah Midstream Services LP
		DATE OF NAME CHANGE:	20150901

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Oasis Petroleum Inc.
		CENTRAL INDEX KEY:			0001486159
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D

	BUSINESS ADDRESS:	
		STREET 1:		1001 FANNIN STREET
		STREET 2:		SUITE 1500
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77002
		BUSINESS PHONE:		281-404-9500

	MAIL ADDRESS:	
		STREET 1:		1001 FANNIN STREET
		STREET 2:		SUITE 1500
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77002
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D
<SEQUENCE>1
<FILENAME>d454116dsc13d.htm
<DESCRIPTION>SC 13D
<TEXT>
<HTML><HEAD>
<TITLE>SC 13D</TITLE>
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 <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION
</B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>WASHINGTON, DC 20549 </B></P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SCHEDULE 13D
</B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>(Rule 13d-101) </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO &#167; 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO 240.13d-2(a)
</B></P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>UNDER THE SECURITIES EXCHANGE ACT OF 1934 </B></P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:22pt; font-family:Times New Roman" ALIGN="center"><B>Oasis
Midstream Partners LP </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Name of Issuer) </B></P>
<P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Common Units Representing Limited Partner Interests </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Title of Class of Securities) </B></P>
<P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>67420T 206 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(CUSIP
Number) </B></P> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Nickolas J. Lorentzatos </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>1001 Fannin Street, Suite 1500, Houston TX 77002 </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Tel: (281) 404-9500 </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) </B></P>
<P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>September 25, 2017 </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Date
of Event which Requires Filing of this Statement) </B></P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">If the filing person has
previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of &#167;&#167;240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box.&nbsp;&nbsp;&#9744; </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Note.</B> Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See &#167;240.13d-7 for
other parties to whom copies are to be sent. </P> <P STYLE="font-size:4pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left">*</TD>
<TD ALIGN="left" VALIGN="top">The remainder of this cover page shall be filled out for a reporting person&#146;s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information
which would alter disclosures provided in a prior cover page. </TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The information required on the remainder of this cover page shall not be
deemed to be &#147;filed&#148; for the purpose of Section 18 of the Securities Exchange Act of 1934 (&#147;Act&#148;) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act
(however, <I>see</I> the Notes). </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>

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<TD VALIGN="top">CUSIP No. 67420T 206<B></B></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top" ALIGN="center">13D</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top" ALIGN="right"><B></B>Page 2 of 16<B></B> Pages</TD></TR>
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<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;1&nbsp;</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-TOP:1px solid #000000; BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">NAMES OF
REPORTING PERSONS</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">OMS Holdings LLC</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;2</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK THE APPROPRIATE BOX IF A MEMBER
OF A GROUP (<I>See</I> Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">(a)&nbsp;&nbsp;&#9744;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;&nbsp;&#9746;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;3</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SEC USE ONLY</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:1pt">&nbsp;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;4</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOURCE OF FUNDS (<I>See</I>
Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">OO</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;5</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK IF DISCLOSURE OF LEGAL
PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) or 2(e)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;6</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CITIZENSHIP OR PLACE OF
ORGANIZATION</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Delaware</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="middle" COLSPAN="3" ROWSPAN="4" STYLE="BORDER-LEFT:1px solid #000000; padding-left:8pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">NUMBER&nbsp;OF</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">SHARES</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">BENEFICIALLY</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">OWNED&nbsp;BY</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">EACH</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">REPORTING</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">PERSON</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">WITH</P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:1pt" align="left">&nbsp;</P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;7&nbsp;</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOLE VOTING POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">-0-</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;8</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SHARED VOTING POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units*</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;9</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOLE DISPOSITIVE POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">-0-</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top">10</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SHARED DISPOSITIVE POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units*</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">11</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-TOP:1px solid #000000; BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt">
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units**</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">12</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK BOX IF THE AGGREGATE AMOUNT IN
ROW (11) EXCLUDES CERTAIN SHARES (<I>see</I> Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">13</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">PERCENT OF CLASS REPRESENTED BY AMOUNT
IN ROW (11)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">71.6%**</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">14</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">TYPE OF REPORTING PERSON (<I>See</I>
Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">OO (Limited Liability Company)</P></TD></TR>
</TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">*</TD>
<TD ALIGN="left" VALIGN="top">Consists of 5,125,000 common units and 13,750,000 subordinated units representing limited partner interests in Oasis Midstream Partners LP. OMS Holdings LLC may also be deemed to be the indirect beneficial owner of a
large portion of the incentive&nbsp;distribution rights (which represent the right to receive increasing percentages of quarterly distributions in excess of specified amounts) through its controlling interest in OMP GP LLC. The subordinated units
may be converted into common units on a one-for-one basis upon the termination of the subordination period under certain circumstances as set forth in the Amended and Restated Agreement of Limited Partnership of Oasis Midstream Partners LP, which is
incorporated herein by reference to Exhibit&nbsp;3.1 to Oasis Midstream Partners LP&#146;s Current Report on Form&nbsp;8-K filed with the Securities and Exchange Commission on September 29, 2017. </TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">**</TD>
<TD ALIGN="left" VALIGN="top">Based on a total of 12,625,000 common units and 13,750,000 subordinated units outstanding as of September 29, 2017. </TD></TR></TABLE>

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<TD VALIGN="top">CUSIP No. 67420T 206<B></B></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top" ALIGN="center">13D</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top" ALIGN="right"><B></B>Page 3 of 16<B></B> Pages</TD></TR>
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<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;1&nbsp;</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-TOP:1px solid #000000; BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">NAMES OF
REPORTING PERSONS</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Oasis Petroleum LLC</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;2</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK THE APPROPRIATE BOX IF A MEMBER
OF A GROUP (<I>See</I> Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">(a)&nbsp;&nbsp;&#9744;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;&nbsp;&#9746;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;3</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SEC USE ONLY</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:1pt">&nbsp;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;4</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOURCE OF FUNDS (<I>See</I>
Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">OO</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;5</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK IF DISCLOSURE OF LEGAL
PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) or 2(e)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;6</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CITIZENSHIP OR PLACE OF
ORGANIZATION</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Delaware</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="middle" COLSPAN="3" ROWSPAN="4" STYLE="BORDER-LEFT:1px solid #000000; padding-left:8pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">NUMBER&nbsp;OF</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">SHARES</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">BENEFICIALLY</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">OWNED&nbsp;BY</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">EACH</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">REPORTING</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">PERSON</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">WITH</P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:1pt" align="left">&nbsp;</P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;7&nbsp;</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOLE VOTING POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">-0-</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;8</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SHARED VOTING POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units*</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;9</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOLE DISPOSITIVE POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">-0-</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top">10</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SHARED DISPOSITIVE POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units*</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">11</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-TOP:1px solid #000000; BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt">
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units**</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">12</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK BOX IF THE AGGREGATE AMOUNT IN
ROW (11) EXCLUDES CERTAIN SHARES (<I>see</I> Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">13</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">PERCENT OF CLASS REPRESENTED BY AMOUNT
IN ROW (11)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">71.6%**</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">14</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">TYPE OF REPORTING PERSON (<I>See</I>
Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">OO (Limited Liability Company)</P></TD></TR>
</TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">*</TD>
<TD ALIGN="left" VALIGN="top">Consists of 5,125,000 common units and 13,750,000 subordinated units representing limited partner interests in Oasis Midstream Partners LP, held of record by OMS Holdings LLC, a wholly owned subsidiary of Oasis
Petroleum LLC. Oasis Petroleum LLC may also be deemed to be the indirect beneficial owner of a large portion of the incentive&nbsp;distribution rights (which represent the right to receive increasing percentages of quarterly distributions in excess
of specified amounts) through OMS Holdings LLC&#146;s controlling interest in OMP GP LLC. The subordinated units may be converted into common units on a one-for-one basis upon the termination of the subordination period under certain circumstances
as set forth in the Amended and Restated Agreement of Limited Partnership of Oasis Midstream Partners LP, which is incorporated herein by reference to Exhibit&nbsp;3.1 to Oasis Midstream Partners LP&#146;s Current Report on Form&nbsp;8-K filed with
the Securities and Exchange Commission on September 29, 2017. </TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">**</TD>
<TD ALIGN="left" VALIGN="top">Based on a total of 12,625,000 common units and 13,750,000 subordinated units outstanding as of September 29, 2017. </TD></TR></TABLE>

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<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">CUSIP No. 67420T 206<B></B></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top" ALIGN="center">13D</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top" ALIGN="right"><B></B>Page 4 of 16<B></B> Pages</TD></TR>
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<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;1&nbsp;</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-TOP:1px solid #000000; BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">NAMES OF
REPORTING PERSONS</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Oasis Petroleum Inc.</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;2</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK THE APPROPRIATE BOX IF A MEMBER
OF A GROUP (<I>See</I> Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">(a)&nbsp;&nbsp;&#9744;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;&nbsp;&#9746;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;3</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SEC USE ONLY</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:1pt">&nbsp;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;4</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOURCE OF FUNDS (<I>See</I>
Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">OO</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;5</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK IF DISCLOSURE OF LEGAL
PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) or 2(e)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">&nbsp;&nbsp;6</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CITIZENSHIP OR PLACE OF
ORGANIZATION</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Delaware</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="middle" COLSPAN="3" ROWSPAN="4" STYLE="BORDER-LEFT:1px solid #000000; padding-left:8pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">NUMBER&nbsp;OF</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">SHARES</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">BENEFICIALLY</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">OWNED&nbsp;BY</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">EACH</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">REPORTING</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">PERSON</P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">WITH</P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:1pt" align="left">&nbsp;</P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;7&nbsp;</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOLE VOTING POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">-0-</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;8</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SHARED VOTING POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units*</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;9</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SOLE DISPOSITIVE POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">-0-</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top">10</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000">&nbsp;&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-RIGHT:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">SHARED DISPOSITIVE POWER</P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units*</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">11</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-TOP:1px solid #000000; BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt">
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">18,875,000 units**</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">12</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CHECK BOX IF THE AGGREGATE AMOUNT IN
ROW (11) EXCLUDES CERTAIN SHARES (<I>see</I> Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">&#9744;</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">13</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">PERCENT OF CLASS REPRESENTED BY AMOUNT
IN ROW (11)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">71.6%**</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-left:8pt">14</TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="5" STYLE="BORDER-RIGHT:1px solid #000000; BORDER-BOTTOM:1px solid #000000; padding-right:2pt"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">TYPE OF REPORTING PERSON (<I>See</I>
Instructions)</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">CO</P></TD></TR>
</TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">*</TD>
<TD ALIGN="left" VALIGN="top">Consists of 5,125,000 common units and 13,750,000 subordinated units representing limited partner interests in Oasis Midstream Partners LP, held of record by OMS Holdings LLC, a wholly owned subsidiary of Oasis
Petroleum LLC, a wholly owned subsidiary of Oasis Petroleum Inc. Oasis Petroleum Inc. may also be deemed to be the indirect beneficial owner of a large portion of the incentive&nbsp;distribution rights (which represent the right to receive
increasing percentages of quarterly distributions in excess of specified amounts) through OMS Holdings LLC&#146;s controlling interest in OMP GP LLC . The subordinated units may be converted into common units on a one-for-one basis upon the
termination of the subordination period under certain circumstances as set forth in the Amended and Restated Agreement of Limited Partnership of Oasis Midstream Partners LP, which is incorporated herein by reference to Exhibit&nbsp;3.1 to Oasis
Midstream Partners LP&#146;s Current Report on Form&nbsp;8-K filed with the Securities and Exchange Commission on September 29, 2017. </TD></TR></TABLE>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">**</TD>
<TD ALIGN="left" VALIGN="top">Based on a total of 12,625,000 common units and 13,750,000 subordinated units outstanding as of September 29, 2017. </TD></TR></TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Schedule 13D </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The reporting persons named in Item 2 below are hereby jointly filing this Schedule 13D (this &#147;Schedule 13D&#148;) because, due to
certain affiliations and relationships among the reporting persons, such reporting persons may be deemed to beneficially own some or all of the same securities directly or indirectly acquired from the Issuer (defined below) by one or more of the
reporting persons. In accordance with <FONT STYLE="white-space:nowrap">Rule&nbsp;13d-1(k)(1)&nbsp;promulgated</FONT> pursuant to the Act, the reporting persons named in Item 2 below have executed a written agreement relating to the joint filing of
this Schedule 13D, a copy of which is annexed hereto as Exhibit&nbsp;A. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B><U>Item&nbsp;1.&nbsp;Security and Issuer</U> </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">This Schedule 13D relates to the common units representing limited partner interests (the &#147;common units&#148;) and subordinated units
representing limited partner interests (the &#147;subordinated units,&#148; and together with the common units, the &#147;units&#148;), of Oasis Midstream Partners LP, a Delaware limited partnership (the &#147;Issuer&#148;). The principal executive
offices of the Issuer are located at 1001 Fannin Street, Suite 1500, Houston, Texas 77002. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B><U>Item&nbsp;2.&nbsp;Identity and Background </U></B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(a) This Schedule 13D is being filed jointly by each of the following persons: </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; margin-left:4%; text-indent:4%; font-size:10pt; font-family:Times New Roman">(i) OMS Holdings LLC, a Delaware limited liability company (&#147;OMS Holdings&#148;); </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; margin-left:4%; text-indent:4%; font-size:10pt; font-family:Times New Roman">(ii) Oasis Petroleum LLC, a Delaware limited liability company (&#147;Oasis Petroleum&#148;); </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; margin-left:4%; text-indent:4%; font-size:10pt; font-family:Times New Roman">(iii) Oasis Petroleum Inc., a Delaware corporation (&#147;OAS&#148; and together with OMS Holdings and Oasis Petroleum, the
&#147;Reporting Persons&#148;); </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">OAS is a public company and owns 100% of the equity interests of Oasis Petroleum. Oasis Petroleum owns
100% of the equity interests of OMS Holdings. OMS Holdings also owns 100% of the Class&nbsp;A Units of OMP GP LLC, a Delaware limited liability company and the general partner of the Issuer (the &#147;General Partner&#148;), which possesses all of
the management rights and approximately 90% of the economic benefits associated with the General Partner. The General Partner owns all of the incentive distribution rights in the Issuer (the &#147;incentive distribution rights&#148;). </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">OMS Holdings is a limited partner of the Issuer and the record holder of 5,125,000 common units and 13,750,000 subordinated units,
representing a 71.6% limited partner interest. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(b) The address of the principal office of each of the Reporting Persons is 1001 Fannin
Street, Suite 1500, Houston, Texas 77002. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(c) The name, residence or business address and present principal occupation or employment of
each director and executive officer of each of the Reporting Persons are listed on <U>Schedule I</U> hereto. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; margin-left:4%; text-indent:4%; font-size:10pt; font-family:Times New Roman">(i) OMS
Holdings&#146; principal business is to hold equity interests in certain subsidiaries that own certain gas gathering, crude oil gathering, produced water gathering, freshwater distribution and crude oil transportation assets as a wholly owned
subsidiary of Oasis Petroleum, to hold common units and subordinated units, and to hold equity interests in the General Partner; </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; margin-left:4%; text-indent:4%; font-size:10pt; font-family:Times New Roman">(ii) Oasis Petroleum&#146;s principal business is to engage in certain crude oil and natural gas exploration and production
activities as a wholly owned subsidiary of OAS and to hold equity interests in OMS Holdings; </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; margin-left:4%; text-indent:4%; font-size:10pt; font-family:Times New Roman">(iii) OAS&#146;s principal
business is crude oil and natural gas exploration and production and to hold equity interests in its subsidiaries, including Oasis Petroleum; </P>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(d) During the last five years, none of the Reporting Persons nor any directors and executive
officers of the Reporting Persons has been convicted in a criminal proceeding (excluding traffic violations and similar misdemeanors). </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(e)
During the last five years, none of the Reporting Persons was a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding has been or is subject to a judgment, decree or final order
enjoining future violations of, or prohibiting or mandating activities subject to, U.S. federal or state securities laws or finding any violations with respect to such laws. </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(f)&nbsp;Not applicable. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">In
accordance with the provisions of General Instruction C to Schedule&nbsp;13D, information concerning the general partners, executive officers, board of directors and each person controlling the Reporting Persons, as applicable (collectively, the
&#147;Covered Persons&#148;), required by Item&nbsp;2 of Schedule&nbsp;13D is provided on <U>Schedule</U><U></U><U>&nbsp;I</U> and is incorporated by reference herein. To the Reporting Persons&#146; knowledge, none of the Covered Persons listed on
<U>Schedule</U><U></U><U>&nbsp;I</U> as a director or executive officer of OMS Holdings, Oasis Petroleum or OAS has been, during the last five years, (i)&nbsp;convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors),
or (ii)&nbsp;a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or
mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B><U>Item&nbsp;3.&nbsp;Source and
Amount of Funds or Other Consideration </U></B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">In connection with the consummation of the Issuer&#146;s initial public offering (the
&#147;Offering&#148;) on September&nbsp;25, 2017, the Issuer entered into a Contribution Agreement (the &#147;Contribution Agreement&#148;) by and among the Issuer, Oasis Petroleum, OMS Holdings, Oasis Midstream Services LLC, a Delaware limited
liability company (&#147;OMS&#148;), the General Partner and OMP Operating LLC, a Delaware limited liability company (&#147;OMP Operating&#148;), whereby, concurrently with the closing of the Offering, OAS caused OMS to contribute to OMP Operating a
100% limited liability company interest in Bighorn DevCo LLC, a Delaware limited liability company, a 10% controlling limited liability company interest in Bobcat DevCo LLC, a Delaware limited liability company, and a 40% controlling limited
liability company interest in Beartooth DevCo LLC, a Delaware limited liability company, which collectively own certain midstream infrastructure assets developed by OAS in the Williston Basin of North Dakota and Montana, in exchange for (i)&nbsp;the
issuance by the Issuer to OMS Holdings of 5,125,000 common units, 13,750,000 subordinated units, (ii)&nbsp;a distribution of approximately $113.9&nbsp;million, (iii)&nbsp;the right to receive the Deferred Issuance and Distribution (as defined in the
Contribution Agreement) and (iv)&nbsp;the issuance to the General Partner of all of the incentive distribution rights. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Upon the
termination of the subordination period as set forth in the Amended and Restated Agreement of Limited Partnership of the Issuer, dated September&nbsp;25, 2017 (the &#147;Partnership Agreement&#148;), the subordinated units are convertible into
common units on a <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">one-for-one</FONT></FONT> basis. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">On
September&nbsp;25, 2017, certain Covered Persons acquired with personal funds, beneficial ownership of common units through the Issuer&#146;s directed unit program at the initial public offering price of $17.00 per common unit, as noted on
<U>Schedule I</U> attached hereto. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B><U>Item&nbsp;4.&nbsp;Purpose of Transaction </U></B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Reporting Persons acquired the units reported herein solely for investment purposes as partial consideration for the assets and operations
contributed by the Reporting Persons or their affiliates to the Issuer in connection with the Offering. The Reporting Persons may make additional purchases of common units either in the open market or in private transactions depending on the
Reporting Person&#146;s business, prospects and financial condition, the market for the common units, general economic conditions, stock market conditions and other future developments. </P>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The following describes plans or proposals that the Reporting Persons may have with respect to
the matters set forth in<BR> Item 4(a)-(j) of Schedule 13D: </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(a) The subordinated units owned of record by OMS Holdings are convertible
into common units on a <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">one-for-one</FONT></FONT> basis upon the termination of the subordination period as set forth in the Partnership Agreement. The Issuer may grant unit options,
unit appreciation rights, restricted units, unit awards, phantom units, distribution equivalent rights, cash awards, performance awards, other unit-based awards and substitute awards to employees and directors of the General Partner and its
affiliates pursuant to the Issuer&#146;s 2017 Long Term Incentive Plan adopted by the General Partner. The General Partner may acquire common units to issue pursuant to the 2017 Long Term Incentive Plan on the open market, directly from the Issuer,
from other Reporting Persons, or otherwise. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(b) None. </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(c) None. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(d) The General
Partner has sole responsibility for conducting the Issuer&#146;s business and for managing its operations and is ultimately controlled by OAS. Some of the executive officers and directors of OAS, Oasis Petroleum and OMS Holdings also serve as
executive officers or directors of the General Partner. Neither the General Partner nor its board of directors will be elected by the Issuer&#146;s unitholders. Through its indirect ownership of the General Partner, OAS has the right to elect the
General Partner&#146;s entire board of directors. The Reporting Persons, however, have no current intention of changing the board of directors or management of the General Partner, other than to potentially appoint one or more additional independent
directors. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(e)&nbsp;The Reporting Persons, as direct and indirect owners of the General Partner of the Issuer, may cause the Issuer to
change its dividend policy or its capitalization, through the issuance of debt or equity securities, from time to time in the future. The Reporting Persons, however, have no current intention of changing the present capitalization or dividend policy
of the issuer. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(f) None. </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(g) None. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(h) None. </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(i) None. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(j) Except as
described in this Item 4, the Reporting Persons do not have, as of the date of this Schedule 13D, any other plans or proposals that relate to or would result in any of the actions or events specified in clauses (a)&nbsp;through (i) of Item 4 of
Schedule 13D. The Reporting Persons may change their plans or proposals in the future. In determining from time to time whether to sell the common units reported as beneficially owned in this Schedule 13D (and in what amounts) or to retain such
securities, the Reporting Persons will take into consideration such factors as they deem relevant, including the business and prospects of the Issuer, anticipated future developments concerning the Issuer, existing and anticipated market conditions
from time to time, general economic conditions, regulatory matters and other opportunities available to the Reporting Persons. The Reporting Persons reserve the right to acquire additional securities of the Issuer in the open market, in privately
negotiated transactions (which may be with the Issuer or with third parties) or otherwise, to dispose of all or a portion of their holdings of securities of the Issuer or to change their intention with respect to any or all of the matters referred
to in this Item 4. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B><U>Item&nbsp;5.&nbsp;Interest in Securities of the Issuer </U></B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The information contained in rows 7, 8, 9, 10, 11 and 13 on the cover page of this Schedule 13D and the information set forth or incorporated
by reference in Items 2, 3, 4 and 6 are hereby incorporated herein by reference. </P>

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<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(a)-(b) The following disclosure assumes that there are a total of 12,625,000 common units and
13,750,000 subordinated units of the Issuer, which are the number of common units and subordinated units of the Issuer outstanding following the Offering, based on the Issuer&#146;s filing pursuant to Rule 424(b)(4) on September&nbsp;22, 2017 with
the SEC. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Pursuant to Rule <FONT STYLE="white-space:nowrap">13d-3</FONT> of the Act, the Reporting Persons may be deemed to beneficially
own 5,125,000 common units and 13,750,000 subordinated units of the Issuer, which constitutes approximately 71.6% of the outstanding common units and subordinated units of the Issuer. The Reporting Person have shared power to vote or to direct the
vote, and shared power to dispose or to direct the disposition of 5,125,000 common units and 13,750,000 subordinated units of the Issuer. </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(c) Except as set forth in Item 3 above or elsewhere in this Schedule 13D, none of the Reporting Persons has effected any transaction in the
Issuer&#146;s common units during the past 60 days. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(d) The Reporting Persons have the right to receive distributions from, and the
proceeds from the sale of, the respective common units reported by such persons on the cover pages of this Schedule 13D and in this Item 5. See <U>Schedule I</U> for the information applicable to the Covered Persons. Except for the foregoing and the
cash distribution described in Item 6 below, no other person is known by the Reporting Persons to have the right to receive or the power to direct the receipt of distributions from, or the proceeds from the sale of, common units beneficially owned
by the Reporting Persons or, to the Reporting Persons&#146; knowledge, the Covered Persons. </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">(e) Not applicable. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B><U>Item 6.&nbsp;Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer </U></B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The information set forth or incorporated in Item 3 and Item 4 is hereby incorporated herein by reference. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><U>The Partnership Agreement </U></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The General
Partner, as the sole general partner of the Issuer, and OMS Holdings, as the organizational limited partner of the Issuer, are party to the Partnership Agreement. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"><I>Cash Distributions</I> </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The
Issuer&#146;s cash distribution policy will require it to pay cash distributions at an initial distribution rate of $0.3750 per common unit per quarter ($1.50 per common unit on an annualized basis) to the extent the Issuer has sufficient cash from
operations after establishment of cash reserves and payment of fees and expenses, including payments to its general partner and its affiliates. The Issuer calls this quarterly distribution amount the &#147;minimum quarterly distribution,&#148; and
the Issuer&#146;s ability to pay it is subject to various restrictions and other factors. The Issuer will adjust the minimum quarterly distribution for the period ending December&nbsp;31, 2017 by an amount that covers the period from the closing of
the Offering through September&nbsp;30, 2017 based on the actual number of days in that period. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Issuer&#146;s Partnership Agreement
generally provides that the Issuer distribute cash each quarter during the subordination period in the following manner: </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="5%">&nbsp;</TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left">&#149;</TD>
<TD WIDTH="1%" VALIGN="top">&nbsp;</TD>
<TD ALIGN="left" VALIGN="top"><I>first,</I>&nbsp;to the holders of common units, until each common unit has received the minimum quarterly distribution of $0.3750 plus any arrearages from prior quarters; <I></I> </TD></TR></TABLE>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="5%">&nbsp;</TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left">&#149;</TD>
<TD WIDTH="1%" VALIGN="top">&nbsp;</TD>
<TD ALIGN="left" VALIGN="top"><I>second,</I>&nbsp;to the holders of subordinated units, until each subordinated unit has received the minimum quarterly distribution of $0.3750; and </TD></TR></TABLE>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="5%">&nbsp;</TD>
<TD WIDTH="2%" VALIGN="top" ALIGN="left">&#149;</TD>
<TD WIDTH="1%" VALIGN="top">&nbsp;</TD>
<TD ALIGN="left" VALIGN="top"><I>third,</I>&nbsp;to the holders of common units and subordinated units pro rata until each has received a distribution of $0.43125. </TD></TR></TABLE>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">If cash distributions to the unitholders exceed $0.43125 per common unit and subordinated unit in
any quarter, the unitholders and the General Partner, as the holder of the incentive distribution rights, will receive increasing percentages, up to 50%, of the cash the Issuer distributes in excess of that amount. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"><I>Conversion of Subordinated Units</I> </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The principal difference between the common units and subordinated units is that in any quarter during the subordination period, holders of the
subordinated units are not entitled to receive any distribution until the common units have received the minimum quarterly distribution plus any arrearages in the payment of the minimum quarterly distribution from prior quarters. The subordinated
units will not accrue arrearages. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The subordination period will end on the first business day after the Issuer has earned and paid an
aggregate amount of at least $1.50 (the minimum quarterly distribution on an annualized basis) multiplied by the total number of outstanding common and subordinated units for each of three consecutive,
<FONT STYLE="white-space:nowrap">non-overlapping</FONT> four-quarter periods ending on or after December&nbsp;31, 2020 and there are no outstanding arrearages on the common units. Notwithstanding the foregoing, the subordination period will end on
the first business day after the Issuer has paid an aggregate amount of at least $2.25 (150.0% of the minimum quarterly distribution on an annualized basis) multiplied by the total number of outstanding common and subordinated units and the related
distribution on the incentive distribution rights, for any four-quarter period ending on or after December&nbsp;31, 2018 and there are no outstanding arrearages on the common units. When the subordination period ends, all subordinated units will
convert into common units on a <FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">one-for-one</FONT></FONT> basis, and all common units will thereafter no longer be entitled to arrearages. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"><I>Issuance of Additional Units</I> </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Partnership Agreement authorizes the Issuer to issue an unlimited number of units on terms determined by the General Partner without
unitholder approval. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"><I>Limited Voting Rights</I> </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The General Partner controls the Issuer and the unitholders have only limited voting rights. Unitholders have no right to appoint the General
Partner or its directors. The General Partner may not be removed, except by a vote of the holders of at least 66 2/3% of the Issuer&#146;s units, including units owned by the General Partner and its affiliates. Because OMS Holdings owns 71.6% of the
Issuer&#146;s units, it has the ability to prevent the General Partner&#146;s involuntary removal. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"><I>Limited Call Right</I> </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">If at any time the General Partner and its affiliates own more than 80% of the outstanding common units, the General Partner has the right, but
not the obligation, to purchase all of the remaining common units at a price equal to the greater of (1)&nbsp;the average of the daily closing price of the common units over the 20 trading days preceding the date three days before notice of exercise
of the call right is first mailed and (2)&nbsp;the highest <FONT STYLE="white-space:nowrap">per-unit</FONT> price paid by the General Partner or any of its affiliates for common units during the <FONT STYLE="white-space:nowrap">90-day</FONT> period
preceding the date such notice is first mailed. </P> <P STYLE="margin-top:18pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman"><I>Registration Rights</I> </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Issuer has agreed to register for resale under the Securities Act of 1933 and applicable state securities laws any common units,
subordinated units or other limited partner interests proposed to be sold by the General Partner or any of its affiliates or their assignees if an exemption from the registration requirements is not otherwise available. These registration rights
continue for two years following any withdrawal or removal of the General Partner. The Issuer is obligated to pay all expenses incidental to the registration, excluding underwriting discounts. </P>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">

 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><U>The General Partner&#146;s Limited Liability Company Agreement </U></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Under the Amended and Restated Limited Liability Company Agreement of the General Partner (the &#147;GP LLC Agreement&#148;), OMS Holdings has
the right to elect the members of the board of directors of the General Partner. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">To the Reporting Persons&#146; knowledge, there are no
other contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Issuer. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">References to, and descriptions of, the Partnership Agreement as set forth in this Item 6 are qualified in their entirety by reference to the
Partnership Agreement filed as Exhibit 3.1 to the Issuer&#146;s current report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on September&nbsp;29, 2017, which is incorporated in its entirety in this Item 6. References
to, and descriptions of, the GP LLC Agreement as set forth in this Item 6 are qualified in their entirety by reference to the GP LLC Agreement filed as Exhibit 3.6 to the Issuer&#146;s Registration Statement (Registration <FONT
STYLE="white-space:nowrap">No.&nbsp;333-217976),</FONT> initially filed with the Commission on May&nbsp;12, 2017, which is incorporated in its entirety in this Item 6. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><U>Registration Rights Agreement </U></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">In
connection with the registration rights agreement by and among the Issuer and OMS Holdings (the &#147;Registration Rights Agreement&#148;), dated September&nbsp;25, 2017, the Issuer may be required to register the sale of the (i)&nbsp;common units
issued (or issuable) to OMS Holdings pursuant to the Contribution Agreement, (ii)&nbsp;subordinated units and (iii)&nbsp;common units issuable upon conversion of subordinated units pursuant to the terms of the Partnership Agreement (collectively,
the &#147;Registrable Securities&#148;) it holds. Under the Registration Rights Agreement, OAS has the right to request that the Issuer register the sale of Registrable Securities held by OMS Holdings, and OMS Holdings will have the right to require
the Issuer to make available shelf registration statements permitting sales of Registrable Securities into the market from time to time over an extended period, subject to certain limitations. Pursuant to the Registration Rights Agreement and the
Partnership Agreement, the Issuer may be required to undertake a future public or private offering and use the proceeds (net of underwriting or placement agency discounts, fees and commissions, as applicable) to redeem an equal number of common
units from OMS Holdings. In addition, the Registration Rights Agreement gives OMS Holdings &#147;piggyback&#148; registration rights under certain circumstances. The Registration Rights Agreement also includes provisions dealing with indemnification
and contribution and allocation of expenses. All of the Registrable Securities held by OMS Holdings and any permitted transferee will be entitled to these registration rights. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><U>The Underwriting Agreement </U></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">In connection
with the Underwriting Agreement, by and among the Issuer, the General Partner and Morgan Stanley&nbsp;&amp; Co. LLC and the other underwriters named therein, dated September&nbsp;20, 2017, relating to the Offering (the &#147;Underwriting
Agreement&#148;), OMS Holdings, certain of its affiliates and the executive officers and directors of the General Partner have agreed not to sell any common units they beneficially own for a period of 180 days from the date of the Underwriting
Agreement. References to, and descriptions of, the Underwriting Agreement as set forth in this Item 6 are qualified in their entirety by reference to the Underwriting Agreement filed as Exhibit 1.1 to the Issuer&#146;s current report on Form <FONT
STYLE="white-space:nowrap">8-K</FONT> filed with the Commission on September&nbsp;22, 2017, which is incorporated in its entirety in this Item 6. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B><U>Item&nbsp;7.&nbsp;Material to Be Filed as Exhibits </U></B></P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">


<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD WIDTH="90%"></TD></TR>


<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;A</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Joint Filing Agreement (filed herewith).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;B</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Amended and Restated Agreement of Limited Partnership of Oasis Midstream Partners LP (incorporated by reference to Exhibit&nbsp;3.1 to the Issuer&#146;s current report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File <FONT
STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;29, 2017 and incorporated herein by reference).</TD></TR></TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" style="COLOR:#999999" WIDTH="100%" ALIGN="CENTER">


<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">


<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="3%"></TD>
<TD WIDTH="90%"></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>

<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;C</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Amended and Restated Limited Liability Company Agreement of OMP GP LLC (incorporated by reference to Exhibit&nbsp;3.6 to the Issuer&#146;s registration statement on Form <FONT STYLE="white-space:nowrap">S-1</FONT> (File <FONT
STYLE="white-space:nowrap">No.&nbsp;333-217976)</FONT> initially filed with the Commission on May&nbsp;12, 2017 and incorporated herein by reference).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;D</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Contribution Agreement, dated as of September&nbsp;25, 2017, by and among Oasis Midstream Partners LP, Oasis Petroleum LLC, OMS Holdings LLC, Oasis Midstream Services LLC, OMP GP LLC and OMP Operating LLC (incorporated by reference
to Exhibit 10.1 of the Issuer&#146;s Current Report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;29, 2017).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit E</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Registration Rights Agreement, dated as of September&nbsp;25, 2017, by and between Oasis Midstream Partners LP and OMS Holdings LLC (incorporated by reference to Exhibit 10.9 of the Issuer&#146;s Current Report on Form <FONT
STYLE="white-space:nowrap">8-K</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;29, 2017).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit F</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Underwriting Agreement, dated September as of 20, 2017, by and among Oasis Midstream Partners LP, OMP GP LLC and Morgan Stanley&nbsp;&amp; Co. LLC, as the sole representative of the several underwriters named in Schedule I thereto
(incorporated by reference to Exhibit&nbsp;1.1 to the Issuer&#146;s current report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;22,
2017 and incorporated herein by reference).</TD></TR>
</TABLE>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>SIGNATURE </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true,
complete and correct. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dated:&nbsp;October 5, 2017 </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt">


<TR>
<TD WIDTH="12%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="87%"></TD></TR>


<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"><B>OASIS PETROLEUM INC.</B></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Nickolas J. Lorentzatos</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">Name:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Nickolas J. Lorentzatos</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Title:</P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Executive Vice President, General Counsel and Corporate Secretary</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"><B>OASIS PETROLEUM LLC </B></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Nickolas J. Lorentzatos</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">Name:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Nickolas J. Lorentzatos</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Title:</P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Executive Vice President, General Counsel and Corporate Secretary</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"><B>OMS HOLDINGS LLC</B></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Nickolas J. Lorentzatos</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">Name:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Nickolas J. Lorentzatos</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Title:</P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Executive Vice President, General Counsel and Corporate Secretary</TD></TR>
</TABLE></DIV>

<p Style='page-break-before:always'>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>SCHEDULE I </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The name and business address of each of the executive officers and directors of OMS Holdings LLC, Oasis Petroleum LLC and Oasis Petroleum Inc. are also set
forth below (outside of similar positions held with respect to other entities directly or indirectly managed or advised by the Issuer, OMS Holdings LLC, Oasis Petroleum LLC or Oasis Petroleum Inc.). </P>
<P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><U>Officers of OMS Holdings LLC </U></B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Thomas B. Nusz </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500, Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal
Occupation: Director and Chief Executive Officer of Oasis Petroleum Inc. and Chairman of the Board of OMP GP LLC </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 5,000 common units (1) </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Taylor L.
Reid </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite
1500, Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal Occupation: Director, President and Chief Operating Officer of Oasis Petroleum Inc. and Chief Executive Officer and
Director of OMP GP LLC </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially
Owned: 20,000 common units (2) </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Michael H. Lou </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis
Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500, Houston, TX 77002 </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal Occupation: Chief Financial Officer and Executive Vice President of Oasis Petroleum Inc. and President and Director of OMP GP LLC </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 25,000 common units
(3) </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Nickolas J. Lorentzatos </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500, Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal
Occupation: Executive Vice President, General Counsel and Corporate Secretary of Oasis Petroleum Inc. and Executive Vice President, General Counsel and Corporate Secretary and Director of OMP GP LLC </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 5,900 common units
(4) </P> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><U>Officers of Oasis Petroleum LLC<SUP STYLE="font-size:85%; vertical-align:top"></SUP> </U></B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Thomas B. Nusz </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Taylor L. Reid </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Michael H. Lou </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Nickolas J. Lorentzatos </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P> <P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><U>Officers of Oasis Petroleum
Inc. </U></B></P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Thomas B. Nusz </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Taylor L. Reid </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Michael H. Lou </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Nickolas J. Lorentzatos </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>
<P STYLE="margin-top:24pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><U>Directors of Oasis Petroleum Inc. </U></B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Thomas B. Nusz </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Taylor L. Reid </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(see above) </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">William J. Cassidy </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500, Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal
Occupation: Director of Oasis Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 0 common units</P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Ted Collins, Jr. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500,
Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal Occupation: Director of Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 25,000 common units
(5) </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">John E. Hagale </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500, Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal
Occupation: Director of Oasis Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 10,000 common units (6) </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Michael
McShane </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite
1500, Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal Occupation: Director of Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 0 common units</P>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Bobby S. Shackouls </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500,
Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal Occupation: Director of Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 0 common units</P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Douglas E. Swanson, Jr. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">c/o Oasis Petroleum Inc. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">1001 Fannin Street, Suite 1500, Houston, TX 77002 </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Principal
Occupation: Director of Oasis Petroleum Inc. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Citizenship: USA </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Amount Beneficially Owned: 0 common units</P>
<P STYLE="line-height:8.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000;width:10%">&nbsp;</P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(1) On September&nbsp;25, 2017,
Mr.&nbsp;Nusz purchased 5,000 units pursuant to the Issuer&#146;s directed unit program. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(2) On September&nbsp;25, 2017, Mr.&nbsp;Reid purchased 20,000
units pursuant to the Issuer&#146;s directed unit program. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(3) On September&nbsp;25, 2017, Mr.&nbsp;Lou purchased 25,000 units pursuant to the
Issuer&#146;s directed unit program. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(4) On September&nbsp;25, 2017, Mr.&nbsp;Lorentzatos purchased 5,900 units pursuant to the Issuer&#146;s directed
unit program. </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(5) On September&nbsp;25, 2017, Mr.&nbsp;Collins purchased 25,000 units pursuant to the Issuer&#146;s directed unit program. </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(6) On September&nbsp;25, 2017, Mr.&nbsp;Hagale purchased 10,000 units pursuant to the Issuer&#146;s directed unit program. </P>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Index to Exhibits </B></P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">


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<TD VALIGN="top" NOWRAP>Exhibit&nbsp;A</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Joint Filing Agreement (filed herewith).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;B</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Amended and Restated Agreement of Limited Partnership of Oasis Midstream Partners LP (incorporated by reference to Exhibit&nbsp;3.1 to the Issuer&#146;s current report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File <FONT
STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;29, 2017 and incorporated herein by reference).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;C</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Amended and Restated Limited Liability Company Agreement of OMP GP LLC (incorporated by reference to Exhibit&nbsp;3.6 to the Issuer&#146;s registration statement on Form <FONT STYLE="white-space:nowrap">S-1</FONT> (File <FONT
STYLE="white-space:nowrap">No.&nbsp;333-217976)</FONT> initially filed with the Commission on May&nbsp;12, 2017 and incorporated herein by reference).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;D</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Contribution Agreement, dated as of September&nbsp;25, 2017, by and among Oasis Midstream Partners LP, Oasis Petroleum LLC, OMS Holdings LLC, Oasis Midstream Services LLC, OMP GP LLC and OMP Operating LLC (incorporated by reference
to Exhibit 10.1 of the Issuer&#146;s Current Report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;29, 2017).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;E</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Registration Rights Agreement, dated as of September&nbsp;25, 2017, by and between Oasis Midstream Partners LP and OMS Holdings LLC (incorporated by reference to Exhibit 10.9 of the Issuer&#146;s Current Report on Form <FONT
STYLE="white-space:nowrap">8-K</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;29, 2017).</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" NOWRAP>Exhibit&nbsp;F</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">Underwriting Agreement, dated as of September 20, 2017, by and among Oasis Midstream Partners LP, OMP GP LLC and Morgan Stanley&nbsp;&amp; Co. LLC, as the sole representative of the several underwriters named in Schedule I thereto
(incorporated by reference to Exhibit&nbsp;1.1 to the Issuer&#146;s current report on Form <FONT STYLE="white-space:nowrap">8-K</FONT> (File <FONT STYLE="white-space:nowrap">No.&nbsp;001-38212)</FONT> filed with the Commission on September&nbsp;22,
2017 and incorporated herein by reference).</TD></TR>
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<TYPE>EX-99.A
<SEQUENCE>2
<FILENAME>d454116dex99a.htm
<DESCRIPTION>EX-99.A
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<TITLE>EX-99.A</TITLE>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>EXHIBIT A </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Joint Filing Agreement </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">This will confirm the agreement by and among all the undersigned that the Statement on Schedule 13D filed on or about this date and any
further amendments thereto with respect to the beneficial ownership by the undersigned of the common units and subordinated units of Oasis Midstream Partners LP, a Delaware limited partnership (the &#147;Issuer&#148;), and such other securities of
the Issuer that the undersigned may acquire or dispose of from time to time. This agreement is being filed on behalf of each of the undersigned in accordance with Rule <FONT STYLE="white-space:nowrap">13d-1(k)(1)</FONT> under the Securities Exchange
Act of 1934. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The undersigned further agree that each party hereto is responsible for timely filing of such Statement on Schedule 13D and
any further amendments thereto, and for completeness and accuracy of the information concerning such party contained therein, provided that no party is responsible for the completeness and accuracy of the information concerning the other party,
unless such party knows or has reason to believe that such information is inaccurate. The undersigned further agree that this agreement shall be included as an Exhibit to such joint filing. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">This agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall
constitute one and the same instrument. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">[Signatures on following page] </P>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">IN WITNESS WHEREOF, the undersigned have executed this agreement as of October 5, 2017. </P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
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<TD VALIGN="top" COLSPAN="3"><B>OASIS PETROLEUM INC.</B></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Nickolas J. Lorentzatos</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">Name:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Nickolas J. Lorentzatos</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Title:</P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Executive Vice President, General Counsel and Corporate Secretary</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"><B>OASIS PETROLEUM LLC </B></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Nickolas J. Lorentzatos</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">Name:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Nickolas J. Lorentzatos</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Title:</P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Executive Vice President, General Counsel and Corporate Secretary</TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"><B>OMS HOLDINGS LLC</B></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16" COLSPAN="3"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top" COLSPAN="3"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Nickolas J. Lorentzatos</P></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">Name:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Nickolas J. Lorentzatos</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Title:</P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">Executive Vice President, General Counsel and Corporate Secretary</TD></TR>
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