Tailored Hydraulic Fracture Optimization for Deep Shale Gas Reservoirs with Complex Natural Fracture Networks

Deep shale reservoirs in the Sichuan Basin, China, present significant challenges due to their complex natural fracture networks, which require a customized hydraulic fracturing strategy to optimize fracture connectivity and production efficiency. This study investigates the effects of cluster number, pumping rate, and liquid intensity on fracture propagation across five natural fracture types: large-angle, small-angle, parallel near, parallel far, and perpendicular fractures. A boundary element method (BEM)-based numerical model was employed to simulate fracture behavior, stress interactions, and fracture interference effects. The results indicate that 12 clusters per stage, a pumping rate of 14 m3/min, and a liquid intensity of 20 m3/m optimize large-angle fracture containment, while 10 clusters per stage, a pumping rate of 16 m3/min, and a liquid intensity of 25 m3/m improve small-angle fracture connectivity. For parallel fractures, 6 clusters per stage, a pumping rate of 18 m3/min, and a liquid intensity of 30-35 m3/m maximize connectivity, whereas for perpendicular fractures, 6 clusters per stage, a pumping rate of 14 m3/min, and a liquid intensity of 20 m3/m ensure optimal containment. These findings establish a systematic framework for hydraulic fracturing optimization, enhancing reservoir stimulation, reducing operational risks, and improving hydrocarbon recovery in deep shale formations.