Brian R. Stewart

U.S. Well Services LLC provides oil field services. It engages in pressure pumping and related services, including high-pressure hydraulic fracturing in unconventional oil and natural gas basins. The firm operates in the Marcellus and Utica shale regions that cover West Virginia, Pennsylvania and Ohio. The company was founded by Edward S. Self III and Jeffrey McPherson on February 21, 2012 and is headquartered in Houston, TX.

Society of Petroleum Engineers, Inc. provides petroleum engineering services. The non-profit company is based in Allen, TX and has subsidiaries in United States, India and Canada.

American Petroleum Institute (API) is the only national trade association that represents all aspects of America's oil and natural gas industry. Its more than 400 corporate members, from the largest major oil company to the smallest of independents, come from all segments of the industry. They are producers, refiners, suppliers, pipeline operators and marine transporters, as well as service and supply companies that support all segments of the industry.

Eco-Stim Energy Solutions, Inc. is an oilfield services company, which engages in the provision of well stimulation, coiled tubing, and field management services to the upstream oil and gas industry. The company was founded in 2003 and is headquartered in Katy, TX.