Oasis Midstream Partners (OMP) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 30, 2020
Document and Entity Information[Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-38212
Entity Registrant Name	Oasis Midstream Partners LP
Entity Incorporation State	DE
Entity Tax Identification Number	47-1208855
Entity Address, Address Line One	1001 Fannin Street
Entity Address, Address Line Two	Suite 1500
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	281
Local Phone Number	404-9500
Title of 12(b) Security	Common units representing limited partner interests
Trading Symbol	OMP
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001652133
Current Fiscal Year End Date	--12-31
Common Units
Document and Entity Information[Line Items]
Entity Common Stock, Shares Outstanding		20,061,366
Subordinated Units
Document and Entity Information[Line Items]
Entity Common Stock, Shares Outstanding		13,750,000

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 34,699,000	$ 4,168,000
Accounts receivable	4,470,000	5,969,000
Accounts receivable – Oasis Petroleum	62,800,000	77,571,000
Inventory	8,094,000	0
Prepaid expenses	2,937,000	1,923,000
Other current assets	1,679,000	138,000
Total current assets	114,679,000	89,769,000
Property, plant and equipment	1,177,654,000	1,155,503,000
Less: accumulated depreciation, amortization and impairment	(231,826,000)	(98,982,000)
Total property, plant and equipment, net	945,828,000	1,056,521,000
Operating lease right-of-use assets	1,880,000	5,207,000
Other assets	2,334,000	3,172,000
Total assets	1,064,721,000	1,154,669,000
Current liabilities
Accounts payable	2,510,000	2,478,000
Accounts payable – Oasis Petroleum	33,915,000	27,139,000
Accrued liabilities	12,854,000	50,210,000
Accrued interest payable	28,384,000	508,000
Current operating lease liabilities	2,006,000	3,005,000
Other current liabilities	634,000	594,000
Total current liabilities	80,303,000	83,934,000
Long-term debt	487,500,000	458,500,000
Asset retirement obligations	1,808,000	1,747,000
Operating lease liabilities	973,000	2,216,000
Other liabilities	4,961,000	3,644,000
Total liabilities	575,545,000	550,041,000
Commitments and contingencies
Equity
General Partner	1,027,000	1,026,000
Total partners’ equity	202,472,000	292,370,000
Non-controlling interests	286,704,000	312,258,000
Total equity	489,176,000	604,628,000
Total liabilities and equity	1,064,721,000	1,154,669,000
Common Units
Equity
Limited partners	172,087,000	225,339,000
Subordinated Units
Equity
Limited partners	$ 29,358,000	$ 66,005,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) - Parenthetical - shares	Sep. 30, 2020	Dec. 31, 2019
Common Units
Units issued (shares)	20,061,366	20,045,196
Units outstanding (shares)	20,061,366	20,045,196
Subordinated Units
Units issued (shares)	13,750,000	13,750,000
Units outstanding (shares)	13,750,000	13,750,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019		Sep. 30, 2020	Sep. 30, 2019
Revenues
Total revenues	$ 84,555	$ 103,550	[1]	$ 257,245	$ 297,805	[1]
Operating expenses
Costs of product sales	5,958	7,001	[1]	16,605	27,088	[1]
Operating and maintenance	12,682	18,009	[1]	44,030	54,975	[1]
Depreciation and amortization	9,083	9,143	[1]	31,161	26,825	[1]
Impairment	1,458	0	[1]	103,441	0	[1]
General and administrative	8,870	7,665	[1]	26,607	24,222	[1]
Total operating expenses	38,051	41,818	[1]	221,844	133,110	[1]
Operating income	46,504	61,732	[1]	35,401	164,695	[1]
Other expenses
Interest expense, net of capitalized interest	(2,753)	(4,612)	[1]	(38,196)	(12,911)	[1]
Other expenses	(7)	0	[1]	(150)	(4)	[1]
Total other expenses	(2,760)	(4,612)	[1]	(38,346)	(12,915)	[1]
Net income (loss)	43,744	57,120	[2]	(2,945)	151,780	[1]
Less: Net income attributable to Delaware Predecessor	0	1,818	[1]	0	4,104	[1]
Less: Net income attributable to non-controlling interests	16,483	23,866	[1]	29,319	68,499	[1]
Net income (loss) attributable to Oasis Midstream Partners LP	$ 27,261	$ 31,436	[1]	$ (32,264)	$ 79,177	[1]
Earnings per limited partner unit
Common units - Basic (in usd per share)	$ 0.78	$ 0.91	[1]	$ (1.05)	$ 2.30	[1]
Common units - Diluted (in usd per share)	$ 0.78	$ 0.91	[1]	$ (1.05)	$ 2.30	[1]
Common Units
Weighted average number of limited partner units outstanding
Weighted average number of limited partner units outstanding (Basic) (shares)	20,045	20,027	[1]	20,044	20,022	[1]
Weighted average number of limited partner units outstanding (Diluted) (shares)	20,048	20,038	[1]	20,044	20,039	[1]
General Partner
Other expenses
Net income (loss)	$ 1,027	$ 745	[2]
Net income (loss) attributable to Oasis Midstream Partners LP	1,027	745	[1]	$ 3,062	$ 1,474	[1]
Limited Partner
Other expenses
Net income (loss) attributable to Oasis Midstream Partners LP	26,234	30,691	[1]	$ (35,326)	$ 77,703	[1]
Limited Partner | Common Units
Other expenses
Net income (loss)	$ 15,560	$ 18,198	[2]
Weighted average number of limited partner units outstanding
Weighted average number of limited partner units outstanding (Basic) (shares)	20,045	20,027		20,044	20,022
Weighted average number of limited partner units outstanding (Diluted) (shares)	20,048	20,038		20,044	20,039
Midstream service revenues
Revenues
Total revenues	$ 69,354	$ 83,024		$ 217,381	$ 237,250
Midstream service revenues | Oasis Petroleum
Revenues
Total revenues	67,401	81,184	[1]	206,340	232,458	[1]
Midstream service revenues | Third Parties
Revenues
Total revenues	1,953	1,840	[1]	11,041	4,792	[1]
Product revenues
Revenues
Total revenues	15,201	20,526		39,864	60,555
Product revenues | Oasis Petroleum
Revenues
Total revenues	15,184	20,517	[1]	39,841	60,517	[1]
Product revenues | Third Parties
Revenues
Total revenues	$ 17	$ 9	[1]	$ 23	$ 38	[1]
[1]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.
[2]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands		Total	Non-controlling Interests	UnitholdersCommon Units	UnitholdersSubordinated Units	General Partner
Predecessor Equity Beginning Balance at Dec. 31, 2018		$ 6,227
Beginning balance at Dec. 31, 2018		557,672	$ 312,815	$ 192,581	$ 45,937	$ 112
Increase (Decrease) in Partners' Capital [Roll Forward]
Delaware predecessor capital contributions, net	[1]	4,902
Contributions from non-controlling interests		2,532	2,532
Distributions to non-controlling interests		(21,922)	(21,922)
Distributions to unitholders		(15,320)		(9,020)	(6,188)	(112)
Equity-based compensation		119		119
Other		(175)	(2,977)	2,881	(79)
Net income attributable to Delaware Predecessor	[1]	1,075
Net income (loss)	[1]	44,414	21,796	12,630	8,675	238
Predecessor Equity Ending Balance at Mar. 31, 2019		12,204
Ending balance at Mar. 31, 2019		572,222	312,244	199,191	48,345	238
Predecessor Equity Beginning Balance at Dec. 31, 2018		6,227
Beginning balance at Dec. 31, 2018		557,672	312,815	192,581	45,937	112
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income attributable to Delaware Predecessor	[2]	4,104
Net income (loss)	[2]	151,780
Predecessor Equity Ending Balance at Sep. 30, 2019		20,791
Ending balance at Sep. 30, 2019		606,774	313,781	213,468	57,989	745
Predecessor Equity Beginning Balance at Mar. 31, 2019		12,204
Beginning balance at Mar. 31, 2019		572,222	312,244	199,191	48,345	238
Increase (Decrease) in Partners' Capital [Roll Forward]
Delaware predecessor capital contributions, net	[1]	2,529
Contributions from non-controlling interests		1,709	1,709
Distributions to non-controlling interests		(21,659)	(21,659)
Distributions to unitholders		(16,122)		(9,421)	(6,463)	(238)
Equity-based compensation		100		100
Other		(217)		(102)	(115)
Net income attributable to Delaware Predecessor	[1]	1,211
Net income (loss)	[1]	50,246	22,837	15,241	10,466	491
Predecessor Equity Ending Balance at Jun. 30, 2019		15,944
Ending balance at Jun. 30, 2019		588,808	315,131	205,009	52,233	491
Increase (Decrease) in Partners' Capital [Roll Forward]
Delaware predecessor capital contributions, net	[1]	3,029
Contributions from non-controlling interests		870	870
Distributions to non-controlling interests		(26,086)	(26,086)
Distributions to unitholders		(17,051)		(9,823)	(6,737)	(491)
Equity-based compensation		84		84
Net income attributable to Delaware Predecessor	[2]	1,818
Net income (loss)	[1]	57,120	23,866	18,198	12,493	745
Predecessor Equity Ending Balance at Sep. 30, 2019		20,791
Ending balance at Sep. 30, 2019		606,774	313,781	213,468	57,989	745
Predecessor Equity Beginning Balance at Dec. 31, 2019		0
Beginning balance at Dec. 31, 2019		604,628	312,258	225,339	66,005	1,026
Increase (Decrease) in Partners' Capital [Roll Forward]
Contributions from non-controlling interests		6,167	6,167
Distributions to non-controlling interests		(25,964)	(25,964)
Distributions to unitholders		(19,265)		(10,833)	(7,425)	(1,007)
Equity-based compensation		66		66
Net income (loss)		(69,359)	2,040	(42,947)	(29,460)	1,008
Predecessor Equity Ending Balance at Mar. 31, 2020		0
Ending balance at Mar. 31, 2020		496,273	294,501	171,625	29,120	1,027
Predecessor Equity Beginning Balance at Dec. 31, 2019		0
Beginning balance at Dec. 31, 2019		604,628	312,258	225,339	66,005	1,026
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income attributable to Delaware Predecessor		0
Net income (loss)		(2,945)
Predecessor Equity Ending Balance at Sep. 30, 2020		0
Ending balance at Sep. 30, 2020		489,176	286,704	172,087	29,358	1,027
Predecessor Equity Beginning Balance at Mar. 31, 2020		0
Beginning balance at Mar. 31, 2020		496,273	294,501	171,625	29,120	1,027
Increase (Decrease) in Partners' Capital [Roll Forward]
Contributions from non-controlling interests		309	309
Distributions to non-controlling interests		(14,335)	(14,335)
Distributions to unitholders		(19,285)		(10,833)	(7,425)	(1,027)
Equity-based compensation		67		67
Net income (loss)		22,670	10,796	6,433	4,414	1,027
Predecessor Equity Ending Balance at Jun. 30, 2020		0
Ending balance at Jun. 30, 2020		485,699	291,271	167,292	26,109	1,027
Increase (Decrease) in Partners' Capital [Roll Forward]
Contributions from non-controlling interests		(1,077)	(1,077)
Distributions to non-controlling interests		(19,973)	(19,973)
Distributions to unitholders		(19,285)		(10,833)	(7,425)	(1,027)
Equity-based compensation		68		68
Net income attributable to Delaware Predecessor		0
Net income (loss)		43,744	16,483	15,560	10,674	1,027
Predecessor Equity Ending Balance at Sep. 30, 2020		0
Ending balance at Sep. 30, 2020		$ 489,176	$ 286,704	$ 172,087	$ 29,358	$ 1,027
[1]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.
[2]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income (loss)	$ (2,945)	$ 151,780	[1]
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	31,161	26,825	[1]
Impairment	103,441	0	[1]
Equity-based compensation expenses	201	303	[2]
Deferred financing costs amortization and other	815	660	[2]
Working capital and other changes:
Change in accounts receivable	16,270	(1,806)	[2]
Change in inventory	(8,440)	0	[2]
Change in prepaid expenses	(1,014)	454	[2]
Change in accounts payable and accrued liabilities	27,080	(685)	[2]
Change in other assets and liabilities, net	(164)	(1,953)	[2]
Net cash provided by operating activities	166,405	175,578	[2]
Cash flows from investing activities:
Capital expenditures	(52,163)	(186,702)	[2]
Net cash used in investing activities	(52,163)	(186,702)	[2]
Cash flows from financing activities:
Capital contributions from Delaware Predecessor, net	0	10,460	[2]
Capital contributions from non-controlling interests	5,399	5,111	[2]
Distributions to non-controlling interests	(60,272)	(69,667)	[2]
Distributions to unitholders	(57,835)	(48,493)	[2]
Deferred financing costs	0	(811)	[2]
Proceeds from revolving credit facility	29,000	118,000	[2]
Principal payments on revolving credit facility	0	(5,000)	[2]
Other	(3)	(453)	[2]
Net cash provided by (used in) financing activities	(83,711)	9,147	[2]
Increase (decrease) in cash and cash equivalents	30,531	(1,977)	[2]
Cash:
Beginning of period	4,168	6,649	[2]
End of period	34,699	4,672	[2]
Supplemental non-cash transactions:
Change in accrued capital expenditures	(29,751)	(9,147)	[2]
Change in asset retirement obligations	$ 61	$ 97	[2]
[1]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.
[2]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.

Organization and Nature of Oper

Organization and Nature of Operations	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Operations	Organization and Nature of Operations Organization. Oasis Midstream Partners LP (the “Partnership”) is a fee-based master limited partnership formed by its sponsor, Oasis Petroleum Inc. (together with its wholly-owned subsidiaries, “Oasis Petroleum”) to own, develop, operate and acquire a diversified portfolio of midstream assets in North America that are integral to the crude oil and natural gas operations of Oasis Petroleum and are strategically positioned to capture volumes from other producers. The Partnership conducts its business through its ownership of development companies: Bighorn DevCo LLC (“Bighorn DevCo”), Bobcat DevCo LLC (“Bobcat DevCo”), Beartooth DevCo LLC (“Beartooth DevCo”) and Panther DevCo LLC (“Panther DevCo” and collectively with Bighorn DevCo, Bobcat DevCo and Beartooth DevCo, the “DevCos”). Bobcat DevCo and Beartooth DevCo are jointly-owned with Oasis Petroleum through its wholly-owned subsidiary Oasis Midstream Services LLC (“OMS”). As of September 30, 2020, the Partnership’s assets and ownership interests in the DevCos were as follows: DevCo Areas Served Service Lines Partnership Ownership Bighorn DevCo Wild Basin – Natural gas processing – Crude oil stabilization – Crude oil blending – Crude oil and natural gas liquids storage – Crude oil transportation 100.0% Bobcat DevCo Wild Basin – Natural gas gathering – Natural gas compression – Gas lift – Crude oil gathering – Produced and flowback water gathering – Produced and flowback water disposal 35.3% Beartooth DevCo Alger – Produced and flowback water gathering – Produced and flowback water disposal – Freshwater supply and distribution 70.0% Panther DevCo Delaware Basin – Crude oil gathering – Produced and flowback water gathering – Produced and flowback water disposal 100% Nature of business. The Partnership generates the majority of its revenues through 15 -year, fee-based contractual arrangements with Oasis Petroleum for midstream services. These services include (i) gas gathering, compression, processing, gas lift and natural gas liquids (“NGLs”) storage services; (ii) crude oil gathering, stabilization, blending, storage and transportation services; (iii) produced and flowback water gathering and disposal services; and (iv) freshwater supply and distribution services. The revenue earned from these services is generally directly related to the volume of natural gas, crude oil, produced and flowback water and freshwater that flows through the Partnership’s systems. The Partnership’s operations are supported by significant acreage dedications from Oasis Petroleum. In addition, the Partnership is party to a number of third-party agreements across all of its DevCos in which the Partnership has the right to provide its full suite of midstream services to support existing and future third-party volumes.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements of the Partnership have not been audited by the Partnership’s independent registered public accounting firm, except that the Condensed Consolidated Balance Sheet at December 31, 2019 is derived from audited financial statements. In the opinion of management, all adjustments, consisting of normal recurring adjustments necessary for fair statement of the Partnership’s financial position have been included. Management has made certain estimates and assumptions that affect reported amounts in the condensed consolidated financial statements and disclosures of contingencies. Actual results may differ from those estimates. The results for interim periods are not necessarily indicative of annual results. These interim financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain disclosures have been condensed or omitted from these financial statements. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete consolidated financial statements and should be read in conjunction with the Partnership’s audited consolidated financial statements and notes thereto included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2019 (“2019 Annual Report”). 2019 Delaware Acquisition. On November 1, 2019, the Partnership entered into an agreement with Oasis Petroleum, pursuant to which Oasis Petroleum, through OMS (the “Delaware Predecessor”), agreed to assign to Panther DevCo, certain crude oil gathering and produced and flowback water gathering and disposal assets in the Delaware Basin (the “2019 Delaware Acquisition”). The 2019 Delaware Acquisition was accounted for as a transfer of net assets between entities under common control. As a result, the unaudited condensed consolidated financial statements for the period prior to the effective date of November 1, 2019 have been recast. These unaudited condensed consolidated financial statements include the results of the Delaware Predecessor for the three and nine months ended September 30, 2019, which were prepared from Oasis Petroleum’s historical cost-basis accounts and may not necessarily be indicative of the actual results had the Partnership owned the assets during the reported periods. Consolidation The Partnership’s condensed consolidated financial statements include its accounts and the accounts of the DevCos, each of which is controlled by the Partnership through its general partner, OMP GP LLC (the “General Partner”). All intercompany balances and transactions have been eliminated upon consolidation. Variable interest entity. The Partnership determined that Bobcat DevCo is a variable interest entity (“VIE”), since OMS’s equity at risk was established with non-substantive voting rights. The Partnership consolidates Bobcat DevCo in its financial statements under the VIE consolidation model, since the Partnership is the primary beneficiary and has the authority to direct the activities that most significantly affect Bobcat DevCo’s economic performance. Bighorn DevCo, Beartooth DevCo and Panther DevCo are not VIEs. The Partnership consolidates these entities in its financial statements under the voting interest consolidation model. Non-controlling interests. Non-controlling interests represent OMS’s retained ownership interests in Bobcat DevCo and Beartooth DevCo of 64.7% and 30%, respectively, as of September 30, 2020. Risks and Uncertainties Concentrations of market and credit risk. The Partnership has limited direct exposure to risks associated with fluctuating commodity prices due to the nature of its business and its long-term, fixed-fee contractual arrangements with its existing customers, including Oasis Petroleum. However, to the extent that the Partnership’s future contractual arrangements with customers, including Oasis Petroleum or third parties, do not provide for fixed-fee structures, the Partnership may become subject to more substantial direct commodity price risk. In addition, in response to a prolonged low commodity price environment, the Partnership’s customers could seek to amend existing contractual arrangements to reduce the volumetric fees the Partnership charges. As a substantial majority of the Partnership’s revenues are derived from Oasis Petroleum, the Partnership is indirectly subject to risks associated with fluctuating commodity prices to the extent that lower commodity prices adversely affect Oasis Petroleum’s production, drilling schedule or financial condition. Oasis Petroleum Restructuring. The markets for crude oil, natural gas and NGLs have been volatile, especially over the last several months and years. Commodity prices have weakened to historical lows as a result of the demand impacts from the global novel coronavirus 2019 (“COVID-19”) pandemic, coupled with the supply impacts from actions of Saudi Arabia and Russia. In light of a volatile market environment that drove a severe downturn in crude oil and natural gas prices, as well as the unprecedented impact of the COVID-19 pandemic, Oasis Petroleum engaged with its lenders and an ad hoc committee of noteholders regarding restructuring alternatives. On September 29, 2020, Oasis Petroleum entered into a restructuring support agreement (“RSA”) which contemplates a restructuring pursuant to a joint “pre-packaged” plan of reorganization (the “Oasis Petroleum Restructuring Plan”) to increase financial flexibility and reduce its debt. On September 30, 2020, in connection with the Oasis Petroleum Restructuring Plan, Oasis Petroleum filed voluntary petitions for relief under chapter 11 of title 11 of the United States Bankruptcy Code (“Chapter 11”) in the United States Bankruptcy Court for the Southern District of Texas. The Partnership and its subsidiaries, OMP Operating LLC (“OMP Operating”), Bighorn DevCo, Bobcat DevCo, Beartooth DevCo and Panther DevCo, were not included in Oasis Petroleum’s Chapter 11 filing. Oasis Petroleum continues to operate its business as “debtors-in-possession,” and the United States Bankruptcy Court for the Southern District of Texas has entered orders approving certain relief to enable Oasis Petroleum to operate in the ordinary course of business. Since Oasis Petroleum commenced its Chapter 11 bankruptcy proceedings, the Partnership has continued to interact with Oasis Petroleum under normal course pursuant to the terms of its existing commercial agreements. There are no cross-acceleration or cross-default provisions between the Oasis Petroleum credit agreement and the Partnership’s credit agreement; as a result, there was not an automatic acceleration of the Partnership’s outstanding indebtedness under the Revolving Credit Facility due to Oasis Petroleum’s Chapter 11 filing. COVID-19. The Partnership considered the impact of the ongoing COVID-19 pandemic on the assumptions and estimates used by management in the unaudited condensed consolidated financial statements for the reporting periods presented. As a result of lower forecasted throughput volumes driven by the significant decline in commodity prices, the Partnership recognized material asset impairment charges at March 31, 2020 (see Note 6 — Property, Plant and Equipment). Management’s estimates and assumptions were based on historical data and consideration of future market conditions. Given the uncertainty inherent in any projection, heightened by the possibility of unforeseen additional impacts from COVID-19, actual results may differ from the estimates and assumptions used, or conditions may change, which could materially affect amounts reported in the consolidated financial statements in the near term. Significant Accounting Policies There have been no material changes to the Partnership’s critical accounting policies and estimates from those disclosed in the 2019 Annual Report, other than as noted below. Financial instruments — credit losses. On January 1, 2020, the Partnership adopted Accounting Standards Update No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which replaces the incurred loss impairment methodology with a methodology that reflects estimated credit losses expected over the life of an exposure and requires consideration of historical data, current market conditions and reasonable and supportable forecasts to develop credit loss estimates. In accordance with ASU 2016-13, the Partnership uses the expected credit loss methodology to measure impairment of financial instruments, including accounts receivable, which may result in earlier recognition of credit losses than under previous GAAP. ASU 2016-13 does not apply to receivables between entities under common control. The adoption of ASU 2016-13 did not have a material impact on the Partnership’s financial position, cash flows or results of operations. Recent Accounting Pronouncements Reference rate reform. In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”). The amendments provide optional guidance for a limited time to ease the potential burden in accounting for reference rate reform. The new guidance provides optional expedients and exceptions for applying GAAP guidance to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments apply only to contracts and hedging relationships that reference the London Interbank Offered Rate or another reference rate expected to be discontinued due to reference rate reform. These amendments are effective immediately and may be applied prospectively to contract modifications made and hedging relationships entered into or evaluated on or before December 31, 2022. The Partnership is currently evaluating its contracts and the optional expedients provided by ASU 2020-04 and the impact the new standard will have on its consolidated financial statements and related disclosures.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Disaggregation of Revenues The following table presents revenues associated with contracts with customers for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 (1) 2020 2019 (1) (In thousands) Service revenues Crude oil, natural gas and NGL revenues $ 43,137 $ 49,624 $ 138,226 $ 143,556 Produced and flowback water revenues 26,217 33,400 79,155 93,694 Total service revenues 69,354 83,024 217,381 237,250 Product revenues Crude oil, natural gas and NGL revenues 13,863 15,388 31,165 42,246 Freshwater revenues 1,338 5,138 8,699 18,309 Total product revenues 15,201 20,526 39,864 60,555 Total revenues $ 84,555 $ 103,550 $ 257,245 $ 297,805 ___________________ (1) Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements. Prior Period Performance Obligations The Partnership records revenue when the performance obligations under the terms of its customer contracts are satisfied. The Partnership measures the satisfaction of its performance obligations using the output method based upon the volumes of crude oil, natural gas or water that flow through its systems. In certain cases, the Partnership is required to estimate these volumes during a reporting period and record any differences between the estimated volumes and actual volumes in the following reporting period. Such differences have historically not been significant. For the three and nine months ended September 30, 2020 and 2019, revenue recognized related to performance obligations satisfied in prior reporting periods was not material. Contract Balances Contract balances are the result of timing differences between revenue recognition, billings and cash collections. Contract assets relate to revenue recognized for accrued deficiency fees associated with minimum volume commitments where the Partnership believes it is probable there will be a shortfall payment and that a significant reversal of revenue recognized will not occur once the related performance period is completed and the customer is billed. Revenue recognized for accrued deficiency fees associated with minimum volume commitments is recorded under midstream services – third parties on the Partnership’s Condensed Consolidated Statement of Operations. Contract liabilities relate to aid in construction payments received from customers, which are recognized as revenue over the expected period of future benefit. The Partnership does not recognize contract assets or contract liabilities under its customer contracts for which invoicing occurs once the Partnership’s performance obligations have been satisfied and payment is unconditional. Contract balances are classified as current or long-term based on the timing of when the Partnership expects to receive cash for contract assets or recognize revenue for contract liabilities. Contract assets are recorded under other current assets on the Partnership’s Condensed Consolidated Balance Sheet. Contract liabilities are recorded under other current liabilities and other liabilities on the Partnership’s Condensed Consolidated Balance Sheet. The following table summarizes the changes in contract assets for the nine months ended September 30, 2020: (In thousands) Balance as of December 31, 2019 $ — Revenue recognized 1,538 Balance as of September 30, 2020 $ 1,538 The following table summarizes the changes in contract liabilities for the nine months ended September 30, 2020: (In thousands) Balance as of December 31, 2019 $ 3,681 Cash received 1,793 Revenue recognized (449) Balance as of September 30, 2020 $ 5,025 Remaining Performance Obligations The following table presents estimated revenue allocated to remaining performance obligations for contracted revenues that are unsatisfied (or partially satisfied) as of September 30, 2020 : (In thousands) 2020 (excluding nine months ended September 30, 2020) $ 6,067 2021 16,921 2022 17,175 2023 10,896 2024 11,089 Thereafter 2,768 Total $ 64,916 The partially and wholly unsatisfied performance obligations presented in the table above are generally limited to customer contracts which have fixed pricing and fixed volume terms and conditions, which generally include customer contracts with minimum volume commitment payment obligations. The Partnership has elected practical expedients, pursuant to Accounting Standards Codification 606, Revenue from Contracts with Customers , to exclude from the presentation of remaining performance obligations: (i) contracts with index-based pricing or variable volume attributes in which such variable consideration is allocated entirely to a wholly unsatisfied performance obligation or to a wholly unsatisfied promise to transfer a distinct service that forms part of a series of distinct services and (ii) contracts with an original expected duration of one year or less.

Transactions with Affiliates

Transactions with Affiliates	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Transactions with Affiliates	Transactions with Affiliates Revenues. The Partnership generates the majority of its revenues through 15-year, fee-based contractual arrangements with wholly-owned subsidiaries of Oasis Petroleum for midstream services as described in Note 1 — Organization and Nature of Operations. In addition, the Partnership sells the residue gas and NGLs recovered from its gas processing plants attributable to its third-party natural gas purchase agreements to Oasis Petroleum to market and sell to non-affiliated purchasers. On September 30, 2020, in connection with the Oasis Petroleum Restructuring Plan, Oasis Petroleum filed voluntary petitions for relief under Chapter 11 in the United States Bankruptcy Court for the Southern District of Texas (see Note 2 — Summary of Significant Accounting Policies — Risks and Uncertainties). Expenses. Oasis Petroleum provides substantial labor and overhead support to the Partnership pursuant to a 15-year services and secondment agreement. Oasis Petroleum performs centralized corporate, general and administrative services for the Partnership, such as legal, corporate recordkeeping, planning, budgeting, regulatory, accounting, billing, business development, treasury, insurance administration and claims processing, risk management, health, safety and environmental, information technology, human resources, investor relations, cash management and banking, payroll, internal audit, tax and engineering. Oasis Petroleum has also seconded to the Partnership certain of its employees to operate, construct, manage and maintain the Partnership’s assets. The expenses of executive officers and non-executive employees of Oasis Petroleum are allocated to the Partnership based on the amount of time spent managing its business and operations. The Partnership reimburses Oasis Petroleum for direct and allocated general and administrative expenses incurred by Oasis Petroleum for the provision of these services. The Partnership’s general and administrative expenses includes $7.9 million and $6.8 million from affiliate transactions with Oasis Petroleum for the three months ended September 30, 2020 and 2019, respectively, and $23.6 million and $21.6 million from affiliate transactions with Oasis Petroleum for the nine months ended September 30, 2020 and 2019, respectively.

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consist of the following: September 30, 2020 December 31, 2019 (In thousands) Accrued capital costs $ 3,353 $ 33,105 Accrued operating expenses 7,329 12,149 Other accrued liabilities 2,172 4,956 Total accrued liabilities $ 12,854 $ 50,210

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment consists of the following: September 30, 2020 December 31, 2019 (In thousands) Pipelines $ 529,470 $ 523,576 Natural gas processing plants 301,728 296,609 Produced and flowback water facilities 123,978 121,797 Compressor stations 184,735 143,276 Other property and equipment 34,363 34,231 Construction in progress 3,380 36,014 Total property, plant and equipment 1,177,654 1,155,503 Less: accumulated depreciation, amortization and impairment (231,826) (98,982) Total property, plant and equipment, net $ 945,828 $ 1,056,521 Long-lived asset impairment . Property, plant and equipment is stated at the lower of historical cost less accumulated depreciation or fair value if impaired. The Partnership routinely evaluates the existence of triggering events which could indicate the carrying amount of its property, plant and equipment may not be recoverable. Impairment indicators include, but are not limited to, sustained decreases in commodity prices, a decline in customer well results and lower throughput forecasts, changes in customer development plans and/or increases in construction or operating costs. The Partnership reviewed the carrying amounts of its asset groups for recoverability as of March 31, 2020, as a result of lower forecasted throughput volumes due to changes in customers’ development plans associated with lower commodity prices. The Partnership completed a Step 1 impairment analysis by comparing the undiscounted future cash flows to the carrying amounts for each of its crude oil, natural gas, freshwater and produced and flowback water asset groups in the Williston Basin and the Delaware Basin. During the nine months ended September 30, 2020, the Partnership recorded an impairment charge of $101.8 million to reduce the carrying value of its property, plant and equipment to the estimated fair value. In the Williston Basin, the Partnership recorded impairment charges of $35.8 million related to its crude oil asset group and $33.1 million related to its freshwater asset group. In the Delaware Basin, the Partnership recorded impairment charges of $17.9 million related to its crude oil asset group and $15.0 million related to its produced and flowback water asset group. The Partnership determined no impairment indicators existed as of September 30, 2020 and did not record an impairment charge for the three months ended September 30, 2020. If commodity prices continue to decline or remain at depressed levels for a prolonged period of time, if there are shut-ins of production from customers’ existing producing wells or if there are significant changes in customers’ future development plans, including Oasis Petroleum, to the extent they affect the Partnership’s operations, such circumstances may necessitate assessment of the carrying amount of the Partnership’s affected assets for recoverability and may result in additional impairment charges in the future. In addition, if the United States oil and gas industry continues to experience an imbalance of supply and demand as it endured during the nine months ended September 30, 2020, the Partnership’s operations could be adversely affected and future impairment charges could be incurred. Fair value measurements. Impairment expense was measured as the excess of the asset group’s carrying amount over its estimated fair value. Fair value was measured using a discounted cash flow model using Level 3 inputs. The inputs used are subject to management’s judgment and expertise and include, but are not limited to, estimated throughput volumes, estimated fixed and variable operating costs, estimated capital costs, estimated useful life of the asset group and discount rate. The estimated future cash flows were discounted at a market-based weighted average cost of capital of 10.4%. Fair value determinations require considerable judgment and are sensitive to changes in underlying assumptions and factors. As a result, there can be no assurance that the estimates and assumptions made for purposes of the impairment analysis will prove to be an accurate prediction of the future.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt The Partnership has a revolving credit facility among OMP Operating, as borrower, Wells Fargo Bank, N.A., as Administrative Agent (the “Administrative Agent”) and the lenders party thereto (as amended, the “Revolving Credit Facility”), which matures on September 25, 2022. The Revolving Credit Facility is available to fund working capital and to finance acquisitions and other capital expenditures of the Partnership. As of September 30, 2020, the aggregate commitments under the Revolving Credit Facility were $575.0 million. At September 30, 2020, the Partnership had $487.5 million of borrowings outstanding under the Revolving Credit Facility and a de minimis outstanding letter of credit, resulting in an unused borrowing capacity of $87.5 million. For the three and nine months ended September 30, 2020, the weighted average interest rate incurred on borrowings under the Revolving Credit Facility was 1.9% and 2.6%, respectively. The weighted average interest rate incurred on borrowings under the Revolving Credit Facility for the nine months ended September 30, 2020 excludes the Specified Default Interest (defined below). At December 31, 2019, the Partnership had $458.5 million of borrowings outstanding under the Revolving Credit Facility and a $1.7 million outstanding letter of credit. The unused portion of the Revolving Credit Facility is subject to a commitment fee ranging from 0.375% to 0.500%. The fair value of the Revolving Credit Facility approximates book value since borrowings under the Revolving Credit Facility bear interest at rates which are tied to current market rates. In the second quarter of 2020, the Partnership identified that a Control Agreement (as defined in the Revolving Credit Facility) had not been executed for a certain bank account before the account was initially funded with cash, which represented an event of default. In May 2020, the Partnership executed a Control Agreement with respect to the bank account, thereby completing the documentation required under the Revolving Credit Facility, and entered into a limited waiver of this past event of default with the Majority Lenders (as defined in the Revolving Credit Facility), which provided forbearance of additional interest owed (“Specified Default Interest”) of $28.0 million until the earlier of (i) November 10, 2020 and (ii) an additional event of default. The Specified Default Interest is included in interest expense, net of capitalized interest on the Partnership’s Condensed Consolidated Statement of Operations for the nine months ended September 30, 2020. No Specified Default Interest was recorded during the three months ended September 30, 2020. The Partnership and the Administrative Agent agreed to exclude the Specified Default Interest from the interest coverage ratio financial covenant calculation. On September 29, 2020, the Partnership and OMP Operating executed a Waiver, Discharge and Forgiveness Agreement and Forbearance Extension (the “Waiver and Forbearance Agreement”) to permanently waive payment of the Specified Default Interest, subject to certain conditions. Under the terms of the Waiver and Forbearance Agreement, the Administrative Agent and the lenders agreed to forbear from demanding payment of the Specified Default Interest until the earlier to occur of (i) an additional event of default and (ii) the occurrence of the maturity date provided for in the Senior Secured Superpriority Debtor-In-Possession Revolving Credit Agreement entered into on October 2, 2020, among Oasis Petroleum, the other parties party thereto, each of the lenders thereto and Wells Fargo Bank, N.A., as administrative agent and issuing bank. The effectiveness of the waiver, discharge and forgiveness of the Specified Default Interest is subject to certain conditions, namely, effectiveness of the Oasis Petroleum Restructuring Plan, as well as the maintenance of the material contracts between Oasis Petroleum and the Partnership or the Partnership’s subsidiaries. The Partnership was in compliance with the covenants under the Revolving Credit Facility at September 30, 2020.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory consists primarily of spare parts and equipment related to the Partnership’s midstream infrastructure. Inventory is stated at the lower of cost and net realizable value with cost determined on an average cost method. The Partnership assesses the carrying value of inventory and uses estimates and judgments when making any adjustments necessary to reduce the carrying value to net realizable value. Due to lower market prices, the Partnership recorded an inventory write-down of $0.4 million for the three months ended September 30, 2020 and $0.6 million for the nine months ended September 30, 2020. The carrying value of the Partnership’s inventory was $8.1 million at September 30, 2020. The Partnership had no inventory at December 31, 2019.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Partnership has various contractual obligations in the normal course of its operations. Included below is a description of the Partnership’s various future commitments as of September 30, 2020. Volume commitment agreements. As of September 30, 2020, the Partnership had certain agreements with an aggregate requirement to either deliver or purchase a minimum quantity of approximately 9.8 million barrels of water and approximately 24.8 million barrels of crude oil, prior to any applicable volume credits, within specified timeframes, all of which are 10 years or less. The estimable future commitments under these agreements were approximately $19.7 million as of September 30, 2020. The commitments under these arrangements are not recorded in the accompanying Condensed Consolidated Balance Sheet as of September 30, 2020. Litigation. The Partnership is party to various legal and/or regulatory proceedings from time to time arising in the ordinary course of business. When the Partnership determines that a loss is probable of occurring and is reasonably estimable, the Partnership accrues an undiscounted liability for such contingencies based on its best estimate using information available at the time. The Partnership discloses contingencies where an adverse outcome may be material, or where in the judgment of management, the matter should otherwise be disclosed. Mirada litigation. On March 23, 2017, Mirada Energy, LLC, Mirada Wild Basin Holding Company, LLC and Mirada Energy Fund I, LLC (collectively, “Mirada”) filed a lawsuit against Oasis Petroleum, Oasis Petroleum North America LLC (“OPNA”), and OMS, seeking monetary damages in excess of $100 million, declaratory relief, attorneys’ fees and costs ( Mirada Energy, LLC, et al. v. Oasis Petroleum North America LLC, et al. ; in the 334th Judicial District Court of Harris County, Texas; Case Number 2017-19911). Mirada asserts that it is a working interest owner in certain acreage owned and operated by Oasis Petroleum in Wild Basin. Specifically, Mirada asserts that Oasis Petroleum has breached certain agreements by: (1) failing to allow Mirada to participate in Oasis Petroleum’s midstream operations in Wild Basin; (2) refusing to provide Mirada with information that Mirada contends is required under certain agreements and failing to provide information in a timely fashion; (3) failing to consult with Mirada and failing to obtain Mirada’s consent prior to drilling more than one well at a time in Wild Basin; and (4) overstating the estimated costs of proposed well operations in Wild Basin. Mirada seeks a declaratory judgment that Oasis Petroleum be removed as operator in Wild Basin at Mirada’s election and that Mirada be allowed to elect a new operator; certain agreements apply to Oasis Petroleum and Mirada and Wild Basin with respect to this dispute; Oasis Petroleum be required to provide all information within its possession regarding proposed or ongoing operations in Wild Basin; and Oasis Petroleum not be permitted to drill, or propose to drill, more than one well at a time in Wild Basin without obtaining Mirada’s consent. Mirada also seeks a declaratory judgment with respect to Oasis Petroleum’s current midstream operations in Wild Basin. Specifically, Mirada seeks a declaratory judgment that Mirada has a right to participate in Oasis Petroleum’s Wild Basin midstream operations, consisting of produced and flowback water disposal, crude oil gathering and natural gas gathering and processing; that, upon Mirada’s election to participate, Mirada is obligated to pay its proportionate costs of Oasis Petroleum’s midstream operations in Wild Basin; and that Mirada would then be entitled to receive a share of revenues from the midstream operations and would not be charged any amount for its use of these facilities for production from the “Contract Area.” On June 30, 2017, Mirada amended its original petition to add a claim that Oasis Petroleum has breached certain agreements by charging Mirada for midstream services provided by its affiliates and to seek a declaratory judgment that Mirada is entitled to be paid its share of total proceeds from the sale of hydrocarbons received by OPNA or any affiliate of OPNA without deductions for midstream services provided by OPNA or its affiliates. On February 2, 2018 and February 16, 2018, Mirada filed a second and third amended petition, respectively. In these filings, Mirada alleged new legal theories for being entitled to enforce the underlying contracts, and added Bighorn DevCo, Bobcat DevCo and Beartooth DevCo as defendants, asserting that these entities were created in bad faith in an effort to avoid contractual obligations owed to Mirada. On March 2, 2018, Mirada filed a fourth amended petition that described Mirada’s alleged ownership and assignment of interests in assets purportedly governed by agreements at issue in the lawsuit. On August 31, 2018, Mirada filed a fifth amended petition that added the Partnership as a defendant, asserting that it was created in bad faith in an effort to avoid contractual obligations owed to Mirada. On July 2, 2019, Oasis Petroleum, OPNA, OMS, the Partnership, Bighorn DevCo, Bobcat DevCo and Beartooth DevCo (collectively “Oasis Entities”) counterclaimed against Mirada for a judgment declaring that Oasis Entities are not obligated to purchase, manage, gather, transport, compress, process, market, sell or otherwise handle Mirada’s proportionate share of oil and gas produced from OPNA-operated wells. The counterclaim also seeks attorney’s fees, costs and expenses. On November 1, 2019, Mirada filed a sixth amended petition that stated that Mirada seeks in excess of $200 million in damages and asserted that OMS is an agent of OPNA and OPNA, OMS, the Partnership, Bighorn DevCo, Bobcat DevCo and Beartooth DevCo are agents of Oasis Petroleum. Mirada also changed its allegation that it may elect a new operator for the subject wells to instead allege that Mirada may remove Oasis Petroleum as operator. On November 1, 2019, the Oasis Entities amended their counterclaim against Mirada for a judgment declaring that a provision in one of the agreements does not incorporate by reference any provisions in a certain participation agreement and joint operating agreement. The additional counterclaim also seeks attorney’s fees, costs and expenses. On the same day, the Oasis Entities filed an amended answer asserting additional defenses against Mirada’s claims. On March 13, 2020, Mirada filed a seventh amended petition that did not assert any new causes of action and did not add any new parties. Mirada did add an allegation that Oasis Petroleum breached its implied duty of good faith and fair dealing with respect to certain contracts. On April 30, 2020, Mirada abandoned its prior claims related to overstating the estimated costs of proposed well operations in Wild Basin. On September 28, 2020, the Oasis Entities entered into a Settlement and Mutual Release Agreement (the “Mirada Settlement Agreement”) with Mirada. The Mirada Settlement Agreement provides for, among other things, payment by OPNA to certain Mirada related parties of $42.8 million (with $20 million due on the effective date of the Oasis Petroleum Restructuring Plan, and the balance due on or before 180 days after the effective date of the Oasis Petroleum Restructuring Plan) and mutual releases, including, without limitation, release of all claims asserted in the Mirada litigation against the Oasis Entities. None of the Partnership, Bighorn DevCo, Bobcat DevCo, or Beartooth DevCo will contribute to the settlement payment. Solomon litigation. On or about August 28, 2019, Oasis Petroleum LLC, a wholly-owned subsidiary of Oasis Petroleum (“OP LLC”), was named as a defendant in the lawsuit styled Andrew Solomon, on behalf of himself and those similarly situated v. Oasis Petroleum, LLC , pending in the United States District Court for the District of North Dakota. The lawsuit alleged violations of the federal Fair Labor Standards Act (the “FLSA”) and Title 29 of the North Dakota Century Code (“Title 29”) as the result of OP LLC’s alleged practice of paying the plaintiff and similarly situated current and former employees overtime at rates less than required by applicable law, or failing to pay for certain overtime hours worked. The lawsuit requested that: (i) its federal claims be advanced as a collective action, with a class of all operators, technicians and all other employees in substantially similar positions employed by OP LLC who were paid hourly for at least one week during the three year period prior to the commencement of the lawsuit, who worked 40 or more hours in at least one workweek and/or eight or more hours on at least one workday; and (ii) its state claims be advanced as a class action, with a class of all operators, technicians, and all other employees in substantially similar positions employed by OP LLC in North Dakota during the two year period prior to the commencement of the lawsuit, who worked 40 or more hours in at least one workweek and/or worked eight or more hours in a day on at least one workday. On September 14, 2020, OP LLC entered into a Settlement Agreement and Release of All Claims with Mr. Solomon which provides for, among other things, payment by OP LLC of $15,000 and a release by Mr. Solomon of claims against OP LLC and its affiliates, which includes, but is not limited to, all claims asserted, or which could have been asserted, against OP LLC and its affiliates arising out of or relating in any way to the Solomon litigation. On September 25, 2020, the Solomon litigation was dismissed with prejudice. None of the Partnership, Bighorn DevCo, Bobcat DevCo, Beartooth DevCo or Panther DevCo will contribute to the settlement payment.

Equity-Based Compensation

Equity-Based Compensation	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Equity-Based Compensation	Equity-Based Compensation The Oasis Midstream Partners LP 2017 Long Term Incentive Plan (“LTIP”) provides for the grant, at the discretion of the Board of Directors of the General Partner, of options, unit appreciation rights, restricted units, phantom units, and other unit or cash-based awards. The purpose of awards under the LTIP is to provide additional incentive compensation to individuals providing services to the Partnership and to align the economic interests of such individuals with the interests of the Partnership’s unitholders. As of September 30, 2020, the aggregate number of common units that may be issued pursuant to any and all awards under the LTIP was equal to 2,793,360 common units. Restricted unit awards. The Partnership has granted to independent directors of the General Partner restricted unit awards under the LTIP, which vest over a one year period. These awards are accounted for as equity-classified awards since the awards will settle in common units upon vesting. Equity-based compensation expense is accounted for under the fair value method in accordance with GAAP. Under the fair value method for equity-classified awards, equity-based compensation expense is measured at the grant date based on the fair value of the award and is recognized over the vesting period. During the nine months ended September 30, 2020, the Partnership granted 16,170 restricted unit awards to certain independent directors at a weighted-average grant date fair value of $16.69 per common unit, which vest over a one year period. The Partnership recorded equity-based compensation expense of $0.1 million and $0.2 million for the three and nine months ended September 30, 2020, respectively, and $0.1 million and $0.3 million for the three and nine months ended September 30, 2019, respectively. Equity-based compensation expense is recorded under general and administrative expenses on the Partnership’s Condensed Consolidated Statements of Operations.

Partnership Equity and Distribu

Partnership Equity and Distributions	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Partnership Equity and Distributions	Partnership Equity and Distributions The following table details the distributions paid in respect of each period in which the distributions were earned for the periods presented: Distributions Limited Partners General Partner Period Record Date Distribution Date Distribution per limited partner unit Common units Subordinated units IDRs (In thousands) Q2 2019 August 16, 2019 August 28, 2019 $0.490 $ 9,822 $ 6,738 $ 463 Q3 2019 November 15, 2019 November 27, 2019 0.515 10,323 7,081 745 Q4 2019 February 13, 2020 February 27, 2020 0.540 10,833 7,425 1,027 Q1 2020 May 28, 2020 June 8, 2020 0.540 10,833 7,425 1,027 Q2 2020 August 14, 2020 August 27, 2020 0.540 10,833 7,425 1,027 Cash distributions. On November 3, 2020, the Board of Directors of the General Partner declared the quarterly cash distribution for the third quarter of 2020 of $0.54 per unit. In addition, the General Partner will receive a cash distribution of $1.0 million attributable to the incentive distribution rights related to earnings for the third quarter of 2020. These distributions will be payable on November 27, 2020 to unitholders of record as of November 13, 2020. Incentive distribution rights. The General Partner owns all of the Partnership’s incentive distribution rights (“IDRs”), which entitle it to increasing percentages, up to a maximum of 50.0%, of the cash the Partnership distributes in excess of $0.4313 per unit per quarter. The maximum distribution of 50.0% does not include any distributions that Oasis Petroleum may receive on common units or subordinated units that it owns.

Earnings (Loss) Per Limited Par

Earnings (Loss) Per Limited Partner Unit	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings (Loss) Per Limited Partner Unit	Earnings (Loss) Per Limited Partner Unit Earnings (loss) per limited partner unit is computed by dividing the respective limited partners’ interest in earnings (loss) attributable to the Partnership by the weighted average number of common and subordinated units outstanding. Because there is more than one class of participating securities, the Partnership uses the two-class method when calculating earnings (loss) per limited partner unit. The classes of participating securities include common units, subordinated units and IDRs. Diluted earnings (loss) per limited partner unit reflects the potential dilution that could occur if securities or agreements to issue common units, such as awards under the LTIP, were exercised, settled or converted into common units. When it is determined that potential common units should be included in diluted net income (loss) per limited partner unit calculation, the impact is reflected by applying the treasury stock method. There are no adjustments made to net income (loss) attributable to Oasis Midstream Partners LP in the calculation of diluted earnings (loss) per unit. Diluted weighted average limited partner units outstanding includes the dilutive effect of unvested restricted unit awards (see Note 10 — Equity-Based Compensation). For the nine months ended September 30, 2020, the diluted loss per share calculation excludes the anti-dilutive effect of unvested restricted unit awards. The following is a calculation of the basic and diluted weighted average units outstanding for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In thousands) Basic weighted average common units outstanding 20,045 20,027 20,044 20,022 Dilutive effect of restricted awards 3 11 — 17 Diluted weighted average common units outstanding 20,048 20,038 20,044 20,039 The following tables present the calculation of earnings (loss) per limited partner unit under the two-class method for each period presented: Nine Months Ended September 30, 2020 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income (loss) attributable to Oasis Midstream Partners LP Distribution declared $ 3,081 $ 32,499 $ 22,275 $ 57,855 Undistributed loss attributable to Oasis Midstream Partners LP — (53,452) (36,667) (90,119) Net income (loss) attributable to Oasis Midstream Partners LP $ 3,081 $ (20,953) $ (14,392) $ (32,264) Weighted average limited partners units outstanding Basic 20,044 Diluted 20,044 Net loss attributable to Oasis Midstream Partners LP per limited partner unit Basic $ (1.05) Diluted (1.05) Anti-dilutive restricted units 16 Nine Months Ended September 30, 2019 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income attributable to Oasis Midstream Partners LP Distribution declared $ 1,474 $ 29,567 $ 20,281 $ 51,322 Undistributed earnings attributable to Oasis Midstream Partners LP — 16,514 11,341 27,855 Net income attributable to Oasis Midstream Partners LP $ 1,474 $ 46,081 $ 31,622 $ 79,177 Weighted average limited partners units outstanding Basic 20,022 Diluted 20,039 Net income attributable to Oasis Midstream Partners LP per limited partner unit Basic $ 2.30 Diluted 2.30 Anti-dilutive restricted units 5 Three Months Ended September 30, 2020 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income attributable to Oasis Midstream Partners LP Distribution declared $ 1,027 $ 10,833 $ 7,425 $ 19,285 Undistributed earnings attributable to Oasis Midstream Partners LP — 4,730 3,246 7,976 Net income attributable to Oasis Midstream Partners LP $ 1,027 $ 15,563 $ 10,671 $ 27,261 Weighted average limited partners units outstanding Basic 20,045 Diluted 20,048 Net income attributable to Oasis Midstream Partners LP per limited partner unit Basic $ 0.78 Diluted 0.78 Anti-dilutive restricted units 13 Three Months Ended September 30, 2019 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income attributable to Oasis Midstream Partners LP Distribution declared $ 745 $ 10,323 $ 7,081 $ 18,149 Undistributed earnings attributable to Oasis Midstream Partners LP — 7,878 5,409 13,287 Net income attributable to Oasis Midstream Partners LP $ 745 $ 18,201 $ 12,490 $ 31,436 Weighted average limited partners units outstanding Basic 20,027 Diluted 20,038 Net income attributable to Oasis Midstream Partners LP per limited partner unit Basic $ 0.91 Diluted 0.91 Anti-dilutive restricted units 7

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements of the Partnership have not been audited by the Partnership’s independent registered public accounting firm, except that the Condensed Consolidated Balance Sheet at December 31, 2019 is derived from audited financial statements. In the opinion of management, all adjustments, consisting of normal recurring adjustments necessary for fair statement of the Partnership’s financial position have been included. Management has made certain estimates and assumptions that affect reported amounts in the condensed consolidated financial statements and disclosures of contingencies. Actual results may differ from those estimates. The results for interim periods are not necessarily indicative of annual results. These interim financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain disclosures have been condensed or omitted from these financial statements. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete consolidated financial statements and should be read in conjunction with the Partnership’s audited consolidated financial statements and notes thereto included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2019 (“2019 Annual Report”). 2019 Delaware Acquisition. On November 1, 2019, the Partnership entered into an agreement with Oasis Petroleum, pursuant to which Oasis Petroleum, through OMS (the “Delaware Predecessor”), agreed to assign to Panther DevCo, certain crude oil gathering and produced and flowback water gathering and disposal assets in the Delaware Basin (the “2019 Delaware Acquisition”). The 2019 Delaware Acquisition was accounted for as a transfer of net assets between entities under common control. As a result, the unaudited condensed consolidated financial statements for the period prior to the effective date of November 1, 2019 have been recast. These unaudited condensed consolidated financial statements include the results of the Delaware Predecessor for the three and nine months ended September 30, 2019, which were prepared from Oasis Petroleum’s historical cost-basis accounts and may not necessarily be indicative of the actual results had the Partnership owned the assets during the reported periods.
Consolidation	Consolidation The Partnership’s condensed consolidated financial statements include its accounts and the accounts of the DevCos, each of which is controlled by the Partnership through its general partner, OMP GP LLC (the “General Partner”). All intercompany balances and transactions have been eliminated upon consolidation. Variable interest entity. The Partnership determined that Bobcat DevCo is a variable interest entity (“VIE”), since OMS’s equity at risk was established with non-substantive voting rights. The Partnership consolidates Bobcat DevCo in its financial statements under the VIE consolidation model, since the Partnership is the primary beneficiary and has the authority to direct the activities that most significantly affect Bobcat DevCo’s economic performance. Bighorn DevCo, Beartooth DevCo and Panther DevCo are not VIEs. The Partnership consolidates these entities in its financial statements under the voting interest consolidation model.
Non-controlling interests	Non-controlling interests. Non-controlling interests represent OMS’s retained ownership interests in Bobcat DevCo and Beartooth DevCo of 64.7% and 30%, respectively, as of September 30, 2020.
Concentrations of market and credit risk	Concentrations of market and credit risk. The Partnership has limited direct exposure to risks associated with fluctuating commodity prices due to the nature of its business and its long-term, fixed-fee contractual arrangements with its existing customers, including Oasis Petroleum. However, to the extent that the Partnership’s future contractual arrangements with customers, including Oasis Petroleum or third parties, do not provide for fixed-fee structures, the Partnership may become subject to more substantial direct commodity price risk. In addition, in response to a prolonged low commodity price environment, the Partnership’s customers could seek to amend existing contractual arrangements to reduce the volumetric fees the Partnership charges. As a substantial majority of the Partnership’s revenues are derived from Oasis Petroleum, the Partnership is indirectly subject to risks associated with fluctuating commodity prices to the extent that lower commodity prices adversely affect Oasis Petroleum’s production, drilling schedule or financial condition. Oasis Petroleum Restructuring. The markets for crude oil, natural gas and NGLs have been volatile, especially over the last several months and years. Commodity prices have weakened to historical lows as a result of the demand impacts from the global novel coronavirus 2019 (“COVID-19”) pandemic, coupled with the supply impacts from actions of Saudi Arabia and Russia. In light of a volatile market environment that drove a severe downturn in crude oil and natural gas prices, as well as the unprecedented impact of the COVID-19 pandemic, Oasis Petroleum engaged with its lenders and an ad hoc committee of
CORVID-19	COVID-19. The Partnership considered the impact of the ongoing COVID-19 pandemic on the assumptions and estimates used by management in the unaudited condensed consolidated financial statements for the reporting periods presented. As a result of lower forecasted throughput volumes driven by the significant decline in commodity prices, the Partnership recognized material asset impairment charges at March 31, 2020 (see Note 6 — Property, Plant and Equipment). Management’s estimates and assumptions were based on historical data and consideration of future market conditions. Given the uncertainty inherent in any projection, heightened by the possibility of unforeseen additional impacts from COVID-19, actual results may differ from the estimates and assumptions used, or conditions may change, which could materially affect amounts reported in the consolidated financial statements in the near term.
Significant Accounting Policies	Significant Accounting Policies There have been no material changes to the Partnership’s critical accounting policies and estimates from those disclosed in the 2019 Annual Report, other than as noted below. Financial instruments — credit losses. On January 1, 2020, the Partnership adopted Accounting Standards Update No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which replaces the incurred loss impairment methodology with a methodology that reflects estimated credit losses expected over the life of an exposure and requires consideration of historical data, current market conditions and reasonable and supportable forecasts to develop credit loss estimates. In accordance with ASU 2016-13, the Partnership uses the expected credit loss methodology to measure impairment of financial instruments, including accounts receivable, which may result in earlier recognition of credit losses than under previous GAAP. ASU 2016-13 does not apply to receivables between entities under common control. The adoption of ASU 2016-13 did not have a material impact on the Partnership’s financial position, cash flows or results of operations. Recent Accounting Pronouncements Reference rate reform. In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”). The amendments provide optional guidance for a limited time to ease the potential burden in accounting for reference rate reform. The new guidance provides optional expedients and exceptions for applying GAAP guidance to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments apply only to contracts and hedging relationships that reference the London Interbank Offered Rate or another reference rate expected to be discontinued due to reference rate reform. These amendments are effective immediately and may be applied prospectively to contract modifications made and hedging relationships entered into or evaluated on or before December 31, 2022. The Partnership is currently evaluating its contracts and the optional expedients provided by ASU 2020-04 and the impact the new standard will have on its consolidated financial statements and related disclosures.

Organization and Nature of Op_2

Organization and Nature of Operations (Tables)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Ownership Interests in DevCos	As of September 30, 2020, the Partnership’s assets and ownership interests in the DevCos were as follows: DevCo Areas Served Service Lines Partnership Ownership Bighorn DevCo Wild Basin – Natural gas processing – Crude oil stabilization – Crude oil blending – Crude oil and natural gas liquids storage – Crude oil transportation 100.0% Bobcat DevCo Wild Basin – Natural gas gathering – Natural gas compression – Gas lift – Crude oil gathering – Produced and flowback water gathering – Produced and flowback water disposal 35.3% Beartooth DevCo Alger – Produced and flowback water gathering – Produced and flowback water disposal – Freshwater supply and distribution 70.0% Panther DevCo Delaware Basin – Crude oil gathering – Produced and flowback water gathering – Produced and flowback water disposal 100%

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents revenues associated with contracts with customers for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 (1) 2020 2019 (1) (In thousands) Service revenues Crude oil, natural gas and NGL revenues $ 43,137 $ 49,624 $ 138,226 $ 143,556 Produced and flowback water revenues 26,217 33,400 79,155 93,694 Total service revenues 69,354 83,024 217,381 237,250 Product revenues Crude oil, natural gas and NGL revenues 13,863 15,388 31,165 42,246 Freshwater revenues 1,338 5,138 8,699 18,309 Total product revenues 15,201 20,526 39,864 60,555 Total revenues $ 84,555 $ 103,550 $ 257,245 $ 297,805 ___________________ (1) Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.
Changes in Contract Liabilities	The following table summarizes the changes in contract assets for the nine months ended September 30, 2020: (In thousands) Balance as of December 31, 2019 $ — Revenue recognized 1,538 Balance as of September 30, 2020 $ 1,538 The following table summarizes the changes in contract liabilities for the nine months ended September 30, 2020: (In thousands) Balance as of December 31, 2019 $ 3,681 Cash received 1,793 Revenue recognized (449) Balance as of September 30, 2020 $ 5,025
Estimated Timing of Remaining Performance Obligation	The following table presents estimated revenue allocated to remaining performance obligations for contracted revenues that are unsatisfied (or partially satisfied) as of September 30, 2020 : (In thousands) 2020 (excluding nine months ended September 30, 2020) $ 6,067 2021 16,921 2022 17,175 2023 10,896 2024 11,089 Thereafter 2,768 Total $ 64,916

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consist of the following: September 30, 2020 December 31, 2019 (In thousands) Accrued capital costs $ 3,353 $ 33,105 Accrued operating expenses 7,329 12,149 Other accrued liabilities 2,172 4,956 Total accrued liabilities $ 12,854 $ 50,210

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, plant and equipment consists of the following: September 30, 2020 December 31, 2019 (In thousands) Pipelines $ 529,470 $ 523,576 Natural gas processing plants 301,728 296,609 Produced and flowback water facilities 123,978 121,797 Compressor stations 184,735 143,276 Other property and equipment 34,363 34,231 Construction in progress 3,380 36,014 Total property, plant and equipment 1,177,654 1,155,503 Less: accumulated depreciation, amortization and impairment (231,826) (98,982) Total property, plant and equipment, net $ 945,828 $ 1,056,521

Partnership Equity and Distri_2

Partnership Equity and Distributions (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Percentage Allocations of Available Cash from Operating Surplus	The following table details the distributions paid in respect of each period in which the distributions were earned for the periods presented: Distributions Limited Partners General Partner Period Record Date Distribution Date Distribution per limited partner unit Common units Subordinated units IDRs (In thousands) Q2 2019 August 16, 2019 August 28, 2019 $0.490 $ 9,822 $ 6,738 $ 463 Q3 2019 November 15, 2019 November 27, 2019 0.515 10,323 7,081 745 Q4 2019 February 13, 2020 February 27, 2020 0.540 10,833 7,425 1,027 Q1 2020 May 28, 2020 June 8, 2020 0.540 10,833 7,425 1,027 Q2 2020 August 14, 2020 August 27, 2020 0.540 10,833 7,425 1,027

Earnings (Loss) Per Limited P_2

Earnings (Loss) Per Limited Partner Unit (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Calculation of Basic and Diluted Weighted Average Number of Units Outstanding	The following is a calculation of the basic and diluted weighted average units outstanding for the periods presented: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In thousands) Basic weighted average common units outstanding 20,045 20,027 20,044 20,022 Dilutive effect of restricted awards 3 11 — 17 Diluted weighted average common units outstanding 20,048 20,038 20,044 20,039
Schedule of Net Income per Limited Partner Unit	The following tables present the calculation of earnings (loss) per limited partner unit under the two-class method for each period presented: Nine Months Ended September 30, 2020 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income (loss) attributable to Oasis Midstream Partners LP Distribution declared $ 3,081 $ 32,499 $ 22,275 $ 57,855 Undistributed loss attributable to Oasis Midstream Partners LP — (53,452) (36,667) (90,119) Net income (loss) attributable to Oasis Midstream Partners LP $ 3,081 $ (20,953) $ (14,392) $ (32,264) Weighted average limited partners units outstanding Basic 20,044 Diluted 20,044 Net loss attributable to Oasis Midstream Partners LP per limited partner unit Basic $ (1.05) Diluted (1.05) Anti-dilutive restricted units 16 Nine Months Ended September 30, 2019 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income attributable to Oasis Midstream Partners LP Distribution declared $ 1,474 $ 29,567 $ 20,281 $ 51,322 Undistributed earnings attributable to Oasis Midstream Partners LP — 16,514 11,341 27,855 Net income attributable to Oasis Midstream Partners LP $ 1,474 $ 46,081 $ 31,622 $ 79,177 Weighted average limited partners units outstanding Basic 20,022 Diluted 20,039 Net income attributable to Oasis Midstream Partners LP per limited partner unit Basic $ 2.30 Diluted 2.30 Anti-dilutive restricted units 5 Three Months Ended September 30, 2020 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income attributable to Oasis Midstream Partners LP Distribution declared $ 1,027 $ 10,833 $ 7,425 $ 19,285 Undistributed earnings attributable to Oasis Midstream Partners LP — 4,730 3,246 7,976 Net income attributable to Oasis Midstream Partners LP $ 1,027 $ 15,563 $ 10,671 $ 27,261 Weighted average limited partners units outstanding Basic 20,045 Diluted 20,048 Net income attributable to Oasis Midstream Partners LP per limited partner unit Basic $ 0.78 Diluted 0.78 Anti-dilutive restricted units 13 Three Months Ended September 30, 2019 General Partner Limited Partners IDRs Common units Subordinated units Total (In thousands, except per unit data) Net income attributable to Oasis Midstream Partners LP Distribution declared $ 745 $ 10,323 $ 7,081 $ 18,149 Undistributed earnings attributable to Oasis Midstream Partners LP — 7,878 5,409 13,287 Net income attributable to Oasis Midstream Partners LP $ 745 $ 18,201 $ 12,490 $ 31,436 Weighted average limited partners units outstanding Basic 20,027 Diluted 20,038 Net income attributable to Oasis Midstream Partners LP per limited partner unit Basic $ 0.91 Diluted 0.91 Anti-dilutive restricted units 7

Organization and Nature of Op_3

Organization and Nature of Operations (Details)	9 Months Ended
	Sep. 30, 2020
Oasis | Commercial Agreements with OPNA, Oasis Petroleum Marketing LLC (“OPM”) and OMS
Limited Partners' Capital Account [Line Items]
Term of contractual arrangements	15 years
Centralized Corporate, General and Administrative Services | Oasis | Commercial Agreements with OPNA, Oasis Petroleum Marketing LLC (“OPM”) and OMS
Limited Partners' Capital Account [Line Items]
Term of contractual arrangements	15 years
Bighorn DevCo
Limited Partners' Capital Account [Line Items]
Ownership interest (percent)	100.00%
Bobcat DevCo | Oasis Midstream Partners, LP
Limited Partners' Capital Account [Line Items]
Ownership interest (percent)	35.30%
Beartooth DevCo | Oasis Midstream Partners, LP
Limited Partners' Capital Account [Line Items]
Ownership interest (percent)	70.00%
Panther DevCo
Limited Partners' Capital Account [Line Items]
Ownership interest (percent)	100.00%

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Basis of Presentation (Details) - OMS Holdings LLC (“OMS”)	Sep. 30, 2020
Bobcat DevCo
Variable Interest Entity [Line Items]
Non-controlling interest (percent)	64.70%
Beartooth DevCo
Variable Interest Entity [Line Items]
Non-controlling interest (percent)	30.00%

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019		Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 84,555	$ 103,550	[1]	$ 257,245	$ 297,805	[1]
Service revenues
Disaggregation of Revenue [Line Items]
Total revenues	69,354	83,024		217,381	237,250
Product revenues
Disaggregation of Revenue [Line Items]
Total revenues	15,201	20,526		39,864	60,555
Crude oil and natural gas revenues | Service revenues
Disaggregation of Revenue [Line Items]
Total revenues	43,137	49,624		138,226	143,556
Produced and flowback water revenues | Service revenues
Disaggregation of Revenue [Line Items]
Total revenues	26,217	33,400		79,155	93,694
Natural gas and NGL revenues | Product revenues
Disaggregation of Revenue [Line Items]
Total revenues	13,863	15,388		31,165	42,246
Freshwater revenues | Product revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,338	$ 5,138		$ 8,699	$ 18,309
[1]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.

Revenue Recognition - Summary o

Revenue Recognition - Summary of Contract Assets and Contract Liabilities Activity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Change in Contract with Customer, Asset [Abstract]
Balance as of December 31, 2019	$ 0
Revenue recognized	1,538
Balance as of September 30, 2020	1,538
Contract with Customer, Liability [Abstract]
Balance as of December 31, 2019	3,681
Cash received	1,793
Revenue recognized	(449)
Balance as of September 30, 2020	$ 5,025

Revenue Recognition - Estimated

Revenue Recognition - Estimated Timing of Remaining Performance Obligation (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Timing of satisfaction of performance obligation	The partially and wholly unsatisfied performance obligations presented in the table above are generally limited to customer contracts which have fixed pricing and fixed volume terms and conditions, which generally include customer contracts with minimum volume commitment payment obligations.
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 64,916
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period	3 months
Remaining performance obligation	$ 6,067
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period	1 year
Remaining performance obligation	$ 16,921
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period	1 year
Remaining performance obligation	$ 17,175
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period	1 year
Remaining performance obligation	$ 10,896
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period	1 year
Remaining performance obligation	$ 11,089
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation period
Remaining performance obligation	$ 2,768

Transactions with Affiliates (D

Transactions with Affiliates (Details) - Commercial Agreements with OPNA, Oasis Petroleum Marketing LLC (“OPM”) and OMS - Oasis - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Related Party Transaction [Line Items]
Term of contractual arrangements			15 years
Centralized Corporate, General and Administrative Services
Related Party Transaction [Line Items]
Term of contractual arrangements			15 years
General and administrative	$ 7.9	$ 6.8	$ 23.6	$ 21.6
Interest expense, net		$ 0.1		$ 0.4

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued capital costs	$ 3,353	$ 33,105
Accrued operating expenses	7,329	12,149
Other accrued liabilities	2,172	4,956
Total accrued liabilities	$ 12,854	$ 50,210

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,177,654	$ 1,155,503
Less: accumulated depreciation, amortization and impairment	(231,826)	(98,982)
Total property, plant and equipment, net	945,828	1,056,521
Pipelines
Property, Plant and Equipment [Line Items]
Property, plant and equipment	529,470	523,576
Natural gas processing plants
Property, Plant and Equipment [Line Items]
Property, plant and equipment	301,728	296,609
Produced and flowback water facilities
Property, Plant and Equipment [Line Items]
Property, plant and equipment	123,978	121,797
Compressor stations
Property, Plant and Equipment [Line Items]
Property, plant and equipment	184,735	143,276
Other property and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	34,363	34,231
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 3,380	$ 36,014

Property, Plant and Equipment -

Property, Plant and Equipment - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Property, Plant and Equipment [Line Items]
Impairment	$ 101.8
Market-based weighted average cost of capital | Discounted cash flow
Property, Plant and Equipment [Line Items]
Weighted average cost of capital (percent)	10.40%
Crude oil asset group | Williston Basin
Property, Plant and Equipment [Line Items]
Impairment	$ 35.8
Crude oil asset group | Delaware Basin
Property, Plant and Equipment [Line Items]
Impairment	17.9
Freshwater asset group | Williston Basin
Property, Plant and Equipment [Line Items]
Impairment	33.1
Produced water asset group | Delaware Basin
Property, Plant and Equipment [Line Items]
Impairment	$ 15

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Line of Credit Facility [Line Items]
Additional interest charge	$ 0	$ 28,000,000
The Credit Agreement | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum aggregate commitment amount	575,000,000	575,000,000
Borrowings outstanding	487,500,000	487,500,000		$ 458,500,000
Unused borrowing capacity	$ 87,500,000	$ 87,500,000
Weighted average interest rate (percent)	1.90%		2.60%
Letters of credit outstanding				$ 1,700,000
The Credit Agreement | Revolving Credit Facility | Minimum
Line of Credit Facility [Line Items]
Commitment fee rate (percent)		0.375%
The Credit Agreement | Revolving Credit Facility | Maximum
Line of Credit Facility [Line Items]
Commitment fee rate (percent)		0.50%

Inventory (Details)

Inventory (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventory write-down	$ 400,000	$ 600,000
Inventory	$ 8,094,000	$ 8,094,000	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands, bbl in Millions	Sep. 28, 2020USD ($)	Sep. 14, 2020USD ($)	Nov. 01, 2019USD ($)	Mar. 23, 2017USD ($)	Sep. 30, 2020USD ($)bbl
Loss Contingencies [Line Items]
Delivery commitment					$ 19,700
Mirada Litigation
Loss Contingencies [Line Items]
Monetary damages sought (in excess of)			$ 200,000	$ 100,000
Mirada Litigation | Settled
Loss Contingencies [Line Items]
Payment to be made under settlement agreement	$ 42,800
Payment due on the effective date of the restructuring plan	$ 20,000
Solomon Litigation | Settled
Loss Contingencies [Line Items]
Payment due on the effective date of the restructuring plan		$ 15
Water Volume Commitment Agreements
Loss Contingencies [Line Items]
Minimum quantity to be delivered (barrels) | bbl					9.8
Purchase and delivery commitment period					10 years
Crude Oil Commitments
Loss Contingencies [Line Items]
Minimum quantity to be delivered (barrels) | bbl					24.8
Purchase and delivery commitment period					10 years

Equity-Based Compensation (Deta

Equity-Based Compensation (Details) - Long Term Incentive Plan (LTIP) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional number of shares reserved for issuance (shares)			2,793,360
Restricted Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			1 year
Units granted (shares)			16,170
Weighted-average grant date fair value (in usd per share)			$ 16.69
Equity-based compensation expense	$ 0.1	$ 0.1	$ 0.2	$ 0.3
Unrecognized compensation cost	$ 0.1		$ 0.1
Weighted average recognition period			3 months 18 days

Partnership Equity and Distri_3

Partnership Equity and Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands	Nov. 25, 2020	Nov. 03, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020
Distribution Made to Limited Partner [Line Items]
Distribution per limited partner unit (in dollars per share)				$ 0.540	$ 0.540	$ 0.540	$ 0.515	$ 0.490
General Partner
Distribution Made to Limited Partner [Line Items]
Cash distribution declared				$ 1,027	$ 1,027	$ 1,027	$ 745	$ 463
General Partner | Cash Distribution
Distribution Made to Limited Partner [Line Items]
Termination threshold as percentage of sum of minimum distribution multiplied by total number of units outstanding (percent)									50.00%
Basis for General Partners' interest in distributions (in dollars per share)			$ 0.4313
Common Units | Limited Partner
Distribution Made to Limited Partner [Line Items]
Cash distribution declared				10,833	10,833	10,833	10,323	9,822
Subordinated Units | Limited Partner
Distribution Made to Limited Partner [Line Items]
Cash distribution declared				$ 7,425	$ 7,425	$ 7,425	$ 7,081	$ 6,738
Subsequent Event
Distribution Made to Limited Partner [Line Items]
Distribution per limited partner unit (in dollars per share)		$ 0.54
Expected distribution | General Partner
Distribution Made to Limited Partner [Line Items]
Cash distribution declared	$ 1,000

Earnings (Loss) Per Limited P_3

Earnings (Loss) Per Limited Partner Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019		Sep. 30, 2020	Sep. 30, 2019
Net income attributable to Oasis Midstream Partners LP
Distribution declared	$ 19,285	$ 18,149		$ 57,855	$ 51,322
Undistributed loss attributable to Oasis Midstream Partners LP	7,976	13,287		(90,119)	27,855
Net income (loss) attributable to Oasis Midstream Partners LP	27,261	31,436		(32,264)	79,177
General Partner
Net income attributable to Oasis Midstream Partners LP
Distribution declared	1,027	745		3,081	1,474
Undistributed loss attributable to Oasis Midstream Partners LP	0	0		0	0
Net income (loss) attributable to Oasis Midstream Partners LP	$ 1,027	$ 745		$ 3,081	$ 1,474
Common Units
Weighted average units outstanding:
Basic weighted average common units outstanding (shares)	20,045	20,027	[1]	20,044	20,022	[1]
Diluted weighted average common units outstanding (in shares)	20,048	20,038	[1]	20,044	20,039	[1]
Common Units | Limited Partner
Weighted average units outstanding:
Basic weighted average common units outstanding (shares)	20,045	20,027		20,044	20,022
Dilutive effect of restricted awards (shares)	3	11		0	17
Diluted weighted average common units outstanding (in shares)	20,048	20,038		20,044	20,039
Net income attributable to Oasis Midstream Partners LP
Distribution declared	$ 10,833	$ 10,323		$ 32,499	$ 29,567
Undistributed loss attributable to Oasis Midstream Partners LP	4,730	7,878		(53,452)	16,514
Net income (loss) attributable to Oasis Midstream Partners LP	$ 15,563	$ 18,201		$ (20,953)	$ 46,081
Net income attributable to Oasis Midstream Partners LP per limited partner unit
Common units - Basic (in usd per share)	$ 0.78	$ 0.91		$ (1.05)	$ 2.30
Common units - Diluted (in usd per share)	$ 0.78			$ (1.05)	$ 2.30
Anti-dilutive restricted units (shares)	13	7		16	5
Subordinated Units | Limited Partner
Net income attributable to Oasis Midstream Partners LP
Distribution declared	$ 7,425	$ 7,081		$ 22,275	$ 20,281
Undistributed loss attributable to Oasis Midstream Partners LP	3,246	5,409		(36,667)	11,341
Net income (loss) attributable to Oasis Midstream Partners LP	$ 10,671	$ 12,490		$ (14,392)	$ 31,622
[1]	Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.