Barry L. McMahan

Parker Wellbore is a drilling and production company. The private company is based in Houston, TX and has subsidiaries in Norway. The company was founded in 1934. The CEO is Alexander Esslemont.

Western States Petroleum Association engages in petroleum exploration, production, refining, transportation, and marketing. The private company is based in Sacramento, CA.

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.

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.

Seneca Resources Co. LLC explores, develops, and purchases natural gas and oil reserves. The company was founded on June 9, 1913 and is headquartered in Houston, TX.