Abstract
This paper leverages a comprehensive dataset of drainage measurements from four observation lateral projects in the Bakken to rigorously characterize conductivity along the hydraulic fracture length and drainage as a function of distance away from the lateral. These drainage mapping projects also included fiber optic measurements of completion effectiveness (completion well distributed acoustic sensing or DAS), fracture morphology (offset well distributed strain sensing or DSS) and microseismic data, providing a complete dataset to evaluate fracture geometry. The first drainage mapping project was published by Cipolla et. al. (2022), with two more projects published by McKimmy et. al. (2025). Additional insights were published by Liang et. al. (2022).
A fully coupled hydraulic fracture and reservoir simulation model was calibrated to match this comprehensive fracture geometry, drainage, and well performance dataset. The model calibration is summarized in the paper. The calibrated model was used to evaluate the impact of proppant loading and treatment size on well productivity and ultimate oil recovery for well spacing of 500, 770, and 1080 ft. Average proppant loading was varied from an average of 0.6 lbs of proppant added per gallon of fluid (PPA) to 2 PPA. And jobs sizes representing standard, large, and very large treatment volumes were modeled. Slickwater fluids and typical proppant schedules were used for all simulations.
Typical slickwater treatments utilize an average proppant concentration of about 1 PPA (total lbs proppant/total gallons of fluid) and there has been little focus on the impact of higher proppant concentrations on well productivity and oil recovery. This paper provides new insights into the impact of proppant concentration on well productivity and oil recovery in the Bakken.
The drainage measurements showed that fracture conductivity in the Bakken is low, and drainage is limited to about 50% of the fracture half-length. Fracture conductivity and drainage may be adequate in the first 25% of the productive half-length, but drainage is materially impeded in the second 25% of the productive half-length due to very low fracture conductivity. The modeling indicated that increasing proppant loading improved well productivity and ultimate recovery for all treatments sizes and well spacing evaluated. However, there were diminishing incremental increases in well productivity and oil recovery as treatment size increased, especially for the 500 and 770 ft well spacing. A detailed economic analysis was performed and the normalized results presented in the paper.
