David R. Winchester

Chaparral Energy LLC produces oil and natural gas. It specializes in enhanced oil recovery and has an inventory of carbon dioxide tertiary recovery projects in the Mid-Continent and Permian Basin. The company was founded by Mark A. Fischer and Charles A. Fischer, Jr. in April 1988 and is headquartered in Oklahoma City, OK.

Canvas Energy, Inc. engages in the acquisition, exploitation, exploration and production of onshore oil and natural gas. It focuses on deposits of Stack, Meramec and Osage, Oswego, and Woodford located in Oklahoma and the Texas Panhandle. The company was founded by Mark A. Fischer and Charles A. Fischer in April 1988 and is headquartered in Oklahoma City, OK.

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.