Pioneer had originally planned to reduce the vertical drilling program in the Spraberry field from 40 rigs to 27 to 30 rigs during the second half of 2012 as the Company increased its horizontal rig count in the Wolfcamp Shale play. However, the Company has reduced its vertical rig count to 25 rigs in response to the earlier-than-anticipated increase to five horizontal Wolfcamp Shale rigs.
The Company continues to drill vertically to deeper intervals in the Spraberry field below the Wolfcamp interval (vertical Wolfcamp 40-acre type curve EUR of 140 MBOE with typical 24-hour initial production (“IP”) rate of 90 BOEPD). Production from this deeper drilling has exceeded expectations and is the primary contributor to the production outperformance by this asset over the first nine months of 2012. The deeper drilling includes the Strawn, Atoka and Mississippian intervals. The original 2012 drilling program called for the Wolfcamp to be the deepest interval completed in approximately 50% of the wells, with the remaining 50% of the wells to be drilled deeper to intervals below the Wolfcamp interval. The latest drilling program now calls for 65% of the wells to be deepened below the Wolfcamp interval.
Pioneer placed 43 vertical comingled Strawn wells on production in the third quarter, with an average 24-hour IP rate of 175 BOEPD. Production data continues to support an incremental gross EUR per well from the Strawn interval of 30 MBOE. Pioneer continues to estimate that 70% of its Spraberry acreage position is prospective for the Strawn interval.
The Company placed 27 comingled vertical Atoka wells on production during the third quarter, with an average 24-hour IP rate of 167 BOEPD. Results from well tests continue to support an incremental gross EUR of 50 MBOE to 70 MBOE for wells completed in the Atoka interval. Pioneer continues to believe the Atoka interval is prospective in 40% to 50% of its Spraberry acreage position.