 , the company had of proved reserves, of which 58% was petroleum, 22% was natural gas, and 20% was and natural gas liquids and all of which were in the Permian Basin.The company, originally called Alabama Gas Corporation, was spun off from Southern Natural Gas (later, Sonat Inc.) in 1953 as part of an antitrust agreement.In 1985, the company was renamed Energen Corporation.