Energen Corporation was a company engaged in hydrocarbon exploration. In 2018, the company was acquired by Diamondback Energy. As of 31 December 2017, the company had 444 million barrels of oil equivalent (2.72×109 GJ) 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.