Hydraulic Fracture Completion Optimization in Fayetteville Shale: Case Study

Abstract

In November 2014, a hydraulic fracture completion optimization study was designed and executed in the Fayetteville Shale. The well with the optimized completion is the #3 well, which is an unconventional dry gas well located in Conway County, Arkansas. This well is a 13-stage horizontal well landed in Lower Fayetteville (FL2) completed with slickwater carrying 100 mesh and 30/70 proppant, using a plug-and-perf approach. The objective of the hydraulic fracture completion optimization was to minimize the differences in rock breakdown stress between clusters within each stage. The intent of minimizing the differences in stress is to ensure that each perforation cluster has an equal fracture initiation pressure, resulting in an equal fracture propagation from each cluster. Successful fracture propagation in every cluster of each stage then hopefully results in improved hydrocarbon production. The results of this hydraulic fracture completion optimization are intriguing because the optimized well, #3, is the westernmost well on a 6-well pad and had by far the highest production per foot of completed lateral, and per pound of proppant, of all wells on that pad. The production from the #3 well in the first month was approximately 56 cubic meters per day-meter (m3/d-m) [604 cubic feet per day per completed foot of lateral (cfd/ft)], compared with 45 m3/d-m (486 cfd/ft) for the adjacent well to the east, compared with approximately 27 m3/d-m (286 cfd/ft) for the easternmost four wells. Additionally, the #3 well had a substantially lower average treating pressure than the other five wells on the pad, which may suggest that more fractures were propagated in it than in the other wells. Extensive postfracture testing has not been conducted on this well pad to clarify exactly how much hydraulic fracture completion optimization contributed to the success of the #3 well. However, existing research and data can help inform theories about hydraulic fracture completion optimization. A “no impact” theory suggests that a regional geologic trend is responsible for the production uplift of the westernmost two wells. An “extreme impact” theory suggests that hydraulic fracture completion optimization is primarily responsible for the production uplift of both wells (and the wells are in hydraulic communication through their fracture stimulations).