Clayton Williams Energy, Inc. is an independent oil and gas company engaged in the exploration for and production of oil and natural gas primarily in its core area in Southern Reeves County, Texas. The Company operates through two segments: oil and gas exploration and production, and contract drilling services. The Company focuses on developmental drilling in prolific oil shale provinces. The Company has holdings in the oil shale plays in the United States, the Wolfcamp Shale in the Southern Delaware Basin of West Texas. Its exploration program consists of generating exploratory prospects, leasing the acreage related to these prospects, drilling exploratory wells on these prospects to determine if recoverable oil and gas reserves exist, drilling developmental wells on these prospects and producing and selling any resulting oil and gas production. The Permian Basin is a sedimentary basin in West Texas and Southeastern New Mexico.