David B. McClelland

Anadarko Petroleum Corp. is an independent exploration and production company. It operates through the following segments: Exploration and Production; WES Midstream; and Other Midstream. The Exploration and Production segment focuses on the exploration, development, production, and sale of oil and natural gas. The WES Midstream and Other Midstream segment consists of gathering, compressing, treating, processing, and transporting of natural gas; gathering, stabilizing, and transporting of oil and natural gas liquids. The company was founded in 1959 and is headquartered in The Woodlands, TX.

Part of Occidental Petroleum Corp., Union Pacific Resources, Inc. is a company that is involved in railroads, gas, and oil production. The company is based in Bethlehem, PA.

Organized in 1998, Encore is a growing independent energy company engaged in the acquisition, development and exploitation of North American oil and natural gas reserves

Athlon Energy, Inc. operates as an independent exploration and production company. The firm engages in the acquisition, development and exploitation of unconventional oil and liquids-rich natural gas reserves in the Permian Basin. The company was founded in 2010 and is headquartered in Fort Worth, TX.

Athlon Energy LP produces oil and natural gas. The company was founded by Nelson Kevin Treadway, Jennifer L. Palko, Rusty Plemons, Bud W. Holmes and David B. McClelland and is headquartered in Fort Worth, TX.