At the end of the second quarter 2018, five of the eight wells on County Line put on production during the quarter had cleaned up and reached average peak 24-hour IP of 164 Boed per 1,000 lateral feet (84% oil) from an average lateral length of 7,247 feet.
At Mustang Springs, the 29 wells were in four one-half-mile wide drilling spacing units (DSUs), one with a 14 well density, two with an 11 well density and one with a ten well density. At the end of the second quarter 2018, six of the 29 wells on Mustang Springs put on production during the quarter had cleaned up and achieved average peak 24-hour IP of 152 Boed per 1,000 feet (84% oil) from an average lateral length of 7,405 feet.
The Company also provided an update on performance of its high-density pilot consisting of 22 wells in a one-half mile wide DSU that was in a very early stage of well cleanup at the end of the first quarter 2018. Of these 22 wells, five were drilled in the Middle Spraberry, seven in the Spraberry Shale, one in the Dean, two in the Wolfcamp A and seven in the Wolfcamp B formations. These wells achieved an average peak 24-hour IP of 88 Boed per 1,000 feet (84% oil) and had an average peak IP30 of 75 Boed per 1,000 feet (83% oil). The performance of these wells met Company expectations given the relatively high density (effectively 47 wellbores per mile-wide unit) compared to the surrounding DSU’s and the performance of these wells has been instrumental in informing the Company's understanding of tank-style development and future DSU and target reservoir well density optimization.
During the second quarter 2018 the Company, as part of its risk management strategy, continued to enter into financial derivatives and physical sales agreements for oil production from the Permian Basin. As of the end of quarter approximately 97% of the Company’s 50.0 Mbod of gross field-level Permian oil production was gathered and transported by pipeline. The Company estimates it has flow assurance, via sales agreements with refiners and marketers, on more than 95% of its current and projected gross oil volumes for the remainder of 2018 and 2019. The Company also has 6.0 MMbbls in 2018 and 7.5 MMbbls in 2019 of its projected Permian net oil volumes either covered by basis swaps or sold in markets outside of the Midland Basin. See tables provided at the end of this release for details regarding the Company’s derivatives.
At the end of the second quarter 2018, the Company had 25 gross-operated horizontal wells in process of being drilled (of which 13 had surface casing set, but had no drilling rig present), two horizontal wells at total depth under drilling rigs (average working interest 100%), 12 horizontal wells waiting to be completed (average working interest 98%), five horizontal wells undergoing completion (average working interest 96%), and eight fully completed horizontal wells awaiting first production, which were part of a tank "pressure wall" (average working interest 100%).
Current QEP-operated drilled and completed authorization for expenditure (AFE) well costs for the Permian Basin are detailed on slide 21 of the July 2018 Investor Presentation.
At the end of the second quarter 2018, the Company had five operated rigs in the Permian Basin. The Company released one of its operated rigs during mid-July 2018.
Slides 7-12 in the July 2018 Investor Presentation depict QEP's acreage and activity in the Permian Basin.
Williston Basin net oil equivalent production averaged approximately 49.0 Mboed (86% liquids) during the second quarter 2018, an 18% increase compared with the first quarter 2018 and a 3% decrease compared with the second quarter 2017.
In the second quarter 2018, the Company put on production 11 gross-operated horizontal wells (average working interest 92%). The wells were completed with an average lateral length of 10,030 feet and had an average peak 24-hour IP of 289 Boed per 1,000 feet (80% oil). Seven of the eleven wells had 30 or more days on production with an average peak IP 30 of 213 Boed per 1,000 feet (77% oil).