Pioneer Natural Resources is an independent oil and natural gas exploration and production company headquartered in Irving, Texas. The company operates in the Permian Basin, specifically in the Cline Shale, which is part of the Spraberry Trend. Pioneer is the largest acreage holder in the Permian Basin. The company was created in 1997 by the merger of Parker & Parsley Petroleum Company and MESA Inc., owned by T. Boone Pickens. Pioneer is known for making smart decisions, conservative hedges, and shrewd deals as it assembles acreage and drilling plays. The company is committed to its employees and believes that it is in a people business first and an oil business second. Pioneer offers internships and apprenticeships starting as early as the second year of college. In October 2023, ExxonMobil agreed to acquire Pioneer in the largest merger in the energy industry in 20 years, with closing expected in the first half of 2024.