Pioneer Natural Resources Company (NYSE:PXD) (“Pioneer” or “the Company”) today announced that the Company has placed on production its fourth horizontal Wolfcamp D interval well on its northern Spraberry/Wolfcamp acreage in the Midland Basin in west Texas. The University 7-43 10H, which is Pioneer’s first horizontal Wolfcamp D interval well in Andrews County, had a 24-hour peak initial production rate of 3,605 barrels oil equivalent per day (BOEPD), with an oil content of 74%. It was completed utilizing a 31-stage hybrid fracture stimulation over the well’s perforated lateral length of 7,382 feet. The well represents the highest horizontal 24-hour peak initial production rate for any interval in the Midland Basin to date. The Company also announced that it has placed on production its third horizontal Wolfcamp B interval well in Midland County. The E.T. O’Daniel #1H had a 24-hour peak initial production rate of 2,801 BOEPD, with an oil content of 75%. The well was completed utilizing a 39-stage hybrid fracture stimulation over the well’s perforated lateral length of 9,229 feet. It represents the highest 24-hour peak initial production rate for a Wolfcamp B interval well on Pioneer’s northern Spraberry/Wolfcamp acreage. Pioneer has 16 horizontal wells on production across its northern acreage, of which 10 wells are Wolfcamp Shale interval wells and six wells are Spraberry Shale wells in Midland, Martin, Andrews and Upton counties. Of the six Spraberry Shale wells, four wells were placed on production in late October/early November. They are currently flowing back fracture stimulation water and have therefore not yet achieved 24-hour peak initial production rates. Since the Spraberry Shale interval wells are at shallower depths than the Wolfcamp Shale interval wells, these wells can flow back fracture stimulation water for 30 days to 60 days before achieving initial peak production rates due to lower subsurface pressures.