Discrete Fracturing of a Deep, Unconventional Shale Play Using Multilateral Technology

Abstract

Drilling, completing, and fracturing unconventional formation wells in North America are now commonplace and will play a major role in the future of natural-gas production on which the nation will depend. What is not as common, however, is to drill, complete, and fracture multiple lateral branches from a single main wellbore. Multilateral wells have been routinely drilled for a number of applications, and shale plays are a natural progression for its use. Augmenting a multilateral well with selective fracturing of each leg is as straightforward as fracturing a single horizontal well. Using conventional equipment and techniques, a multilateral well (with any number of laterals) can accommodate any type of fracturing system and program with pressures up to 12,500 psi and complete isolation of the lateral junction(s). In this project, a plug-and-perf system was used to address 10+ intervals in each leg, with average stimulation pressures up to 9,000 psi. By employing multilateral completion systems in unconventional wells, operators can lower drilling and completion costs, lower risk, help avoid non-productive time, reduce well count and surface footprint by combining two or more targets into one well, and maximize the net-pay-per-foot drilled ratio. This paper will discuss the implementation and execution of this project as the first dual lateral well by any operator in the Granite Wash at vertical depths over 12,000 ft and measured depths reaching beyond 17,000 ft. This well targeted two different sections of the Granite Wash (a complex series of sands, shales, and siltstones that run from the Northern Texas Panhandle into Oklahoma) from a single main wellbore with commingled production rates doubling typical single horizontal well performance. Additionally, significant cost savings were achieved in contrast to drilling two separate single horizontal wells.