Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Document and Entity Information[Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 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	Q2
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