Focused modifications in drilling, reservoir, and completion engineering from 2007 to the present have improved Bakken production, Williston Basin, as much as 50% to 75%. To achieve these results, a multidisciplinary team was established in 2008 and over the subsequent years altered critical completion variables such that even non-industry experts on Wall Street have taken serious notice [Filloon 2013]. Early vintage completions followed conventional wisdom by targeting the Middle Bakken formation that lies between the Lodge Pole and the Three Forks formations. However, the team altered the primary target with a successful exploitation of the Three Forks member, which has significant basin-wide ramifications. In 2007–08, original wellbore constructions included "kick outs" (i.e., multi-lateral), open-hole completions, short laterals, single-stage ported subs, sliding sleeves, and long stage intervals. In addition, the 2007–08 stimulation procedures and execution were erratic and inconsistent, resulting in a high percentage of premature screenouts. The production responses on these early vintage Middle Bakken completions were ordinary, averaging 330 bopd with an estimated ultimate recovery (EUR) of 300 Mboe. Interestingly, however, the Three Forks completions produced on average 550 bopd. In 2009, the operator curtailed activity to evaluate the 2007–08 results with this multidisciplinary team that ultimately re-designed the overall completion approach, including targeting the Three Fork interval. Because of the success in the Three Forks completions and the marginal response of the Bakken completions, this team recommended and made changes to the
horizontal landing target (i.e., drill the Three Forks);
lateral length (~2x increase from "640s" to "1280s");
formation contact (completion method, stage lateral length, and perforation spacing and density);
pumpdown operations;
critical fracturing mechanisms diagnosis;
proppant selection (ceramic versus sand);
flush procedure (include monitoring and assure consistency);
on-site, real-time pressure management and proppant schedule (e.g., included proppant slugs, altered mesh types, and adjusted ramp schedule);
treatment fluid design (25 lb/Mgal gel loading instead of 40 lb/Mgal gel loading); and
flowback and flow rate control.
With these changes, the operator deviated from conventional Williston Basin philosophy and drilled thirty "1280s" in 2010–2012. This resulted in wells achieving in excess of 1,500 bopd with a maximum of 2,500 bopd and EUR of ߡ,200 Mboe which are among the best in the Williston Basin. In comparison, direct offsets wells average less than 750 Mboe. The success of these Williston Basin wells is not the result of one breakthrough but rather the compilation of many sound engineering techniques that were carried out systematically. Applying these engineering practices, maintaining strict adherence to procedures, and not making drastic, unfounded changes ultimately optimized production in this Bakken project.
