Seventy Seven Energy Inc., a diversified oilfield services company, provides a range of wellsite services and equipment to land-based exploration and production customers in the United States. It operates through three segments: Drilling, Hydraulic Fracturing, and Oilfield Rentals. The Drilling segment offers land-based drilling services. The Hydraulic Fracturing segment provides hydraulic fracturing and other well stimulation services. The Oilfield Rentals segment offers rental tools for land-based oil and natural gas drilling, completion, and workover activities. It provides a line of rental tools, such as drill pipes, drill collars, tubing, blowout preventers, frac and mud tanks, and environmental containment tools. This segment also offers air drilling, flowback services, and services associated with the transfer of water to the wellsite for well completions. As of December 31, 2016, Seventy Seven Energy Inc. owned a fleet of 91 drilling rigs and 13 hydraulic fracturing fleets. The company was formerly known as Chesapeake Oilfield Operating, L.L.C. and changed its name to Seventy Seven Energy Inc. in June 2014. Seventy Seven Energy Inc. was founded in 2011 and is headquartered in Oklahoma City, Oklahoma. The company operates independently of Chesapeake Energy Corporation, as of June 30, 2014. As of April 20, 2017, Seventy Seven Energy Inc. operates as a subsidiary of Patterson-UTI Energy, Inc.