Optimize Oil & Gas Recovery from the Woodford Shale, Via Novel EOR and Stimulation Processes

Abstract As of September, 2024, there were 6,566 horizontal Woodford shale oil producing wells, that had an average cumulative oil and gas recovery of 120,000 barrels of oil and 1 Billion cubic feet of gas. Average lateral length is 6,750 feet and average TVD is 7,940 feet. Average GOR is 10,400 SCF/STB. Most of these wells are situated in the SCOOP and STACK play areas of Oklahoma. Woodford shale primary oil recovery is only about 5-8% of the oil in place, and the formation is generally slightly overpressured. As a result, there is a tremendous amount of oil remaining after primary production that may be recovered via novel wells stimulation and enhanced oil recovery (EOR) processes. This paper describes the application of a commercial compositional reservoir simulation model to assess two novel, proprietary shale oil EOR processes and a novel hydraulic fracture stimulation method in a production history matched horizontal well producing oil and gas from the Woodford shale. The paper illustrates how these proprietary shale oil EOR and hydraulic fracture stimulation treatment processes may be implemented to significantly enhance oil and gas recovery, while reducing the cost per barrel and GHG emissions impact of production. The novel shale oil EOR methods, named SuperEOR and UltraEOR, utilize a triplex pump to inject a tuned composition liquid solvent into the shale oil reservoir, and a method to recover the injectant at the surface, for storage and reinjection. The processes are fully integrated with compositional reservoir simulation to optimize the recovery of residual oil and gas during each injection and production cycle. These patented shale oil EOR processes have numerous advantages over cyclic gas injection – faster and greater oil recovery, lower cost than primary production, less risk of interwell communication, precludes the need for artificial lift, and lower environmental impact. If implemented early in the well life, their application will produce substantially more oil and gas sooner, resulting in a shallower decline rate and greater reserves and hence better overall economics. Since SuperEOR and UltraEOR are implemented in a closed loop system in existing wells without need for artificial lift, the carbon foot print and overall environmental impact of SuperEOR and UltraEOR oil production is much lower than that of primary recovery. The novel hydraulic fracture stimulation method, named CycleStim, may be applied in virtually any well to improve near-wellbore fracturing and inflow performance. The SuperEOR process has been proven successful in the Eagle Ford shale since late 2022, where it recovered 44% more oil than its prior cumulative in the first 10 months of EOR operation. Additional SuperEOR projects are currently in development. Compositional reservoir simulation modeling of these novel processes in the modeled Woodford shale EOR project well, indicates the SuperEOR and UltraEOR processes may increase oil recovery by more than 3X and 5X of forecasted primary production in 20 years of operation, respectively.