Pioneer Natural Resources Company was established in 1997 with the merger of Parker & Parsley Petroleum Company and MESA. It is one of the largest independent oil and gas exploration and production companies in the world. Headquartered in Dallas, the company has multiple locations throughout the United States, South Africa and Tunisia. Pioneer Natural Resources Company operates oil fields in the west region of Texas. It controls more than 600 wells and owns a Fain gas processing plant. Additionally, the company is one of the largest operators in the Hugoton gas field in Kansas and the West Panhandle gas field in the Texas Panhandle. Pioneer Natural Resources Company has a skilled staff of more than 1,500 employees.