Oasis Petroleum Inc. is an independent exploration and production company. The Company is focused on the acquisition and development of unconventional oil and natural gas resources in the North Dakota and Montana regions of the Williston Basin. Its segments include Exploration and Production, Well Services, and Midstream Services. The exploration and production segment is engaged in the acquisition and development of oil and natural gas properties. The well services business segment (OWS) performs completion services for the Company's oil and natural gas wells operated by Oasis Petroleum North America LLC (OPNA). The midstream services business segment (OMS) performs salt water gathering and disposal services, fresh water services, natural gas gathering and processing and crude oil gathering and transportation and other midstream services for the Company's oil and natural gas wells operated by OPNA. The Company also operates a well services business and a midstream services business.