I. Brumley

XTO Energy Inc. operates as a domestic energy producer engaged in the acquisition, development, and discovery of oil and natural gas properties in the United States. It specializes in the development of tight gas, shale gas, coal bed methane, and unconventional oil resources. The company was founded by Steve Palko, Bob Simpson and Jon Brumley in 1986 and is headquartered in Spring, TX.

Pioneer Natural Resources Co. operates as an independent oil and gas exploration and production company. The firm engages in hydrocarbon exploration in the Cline Shale. It focuses on the operation of the Permian Basin, Eagle Ford Shale, Rockies, and West Panhandle projects. The company was founded by Scott Douglas Sheffield on April 2, 1997, and is headquartered in Irving, TX.

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

Encore Operating LP provides oil and gas exploration services. The company was founded in 1998 and is headquartered in Plano, TX.

Encore Energy Partners LP acquires and develops existing oil and natural gas properties. The firm operates through one business segment, the oil and natural gas exploration and production industry in the United States. The company was founded on February 13, 2007 and is headquartered in Houston, TX.

Texas Heart Institute provides an avenue for exchange of ideas relating to the clinical and research activities. It provide an avenue for exchange of ideas relating to the clinical and research activities among the present and former Cardiology fellows, trainees, and teaching staff of the Texas Heart Institute. The company was founded by Denton A. Cooley in 1989 and is headquartered in Houston, TX.