Optimized design method for fracture network fracturing in ultra-low permeability fractured reservoirs based on fracture flow simulation

To enhance flow efficiency and production response in fracturing operations for ultra-low permeability fractured reservoirs, an optimized design method for fracture network fracturing based on fracture flow simulation is developed. Building upon DFN geometric modeling and fluid-solid coupling mechanisms, a multi-scale dynamic response model for fracture flow capacity is established. Integrating NSGA-II and surrogate modeling, a multi-objective optimization framework is constructed to achieve coordinated control over multiple factors including injection parameters, proppant configuration, and wellhead pressure. Using a typical low-permeability fractured sandstone block in the Ordos Basin as a case study, high-fidelity numerical simulations and parameter optimization were conducted. Results demonstrate that the optimized scheme effectively increases primary fracture opening and natural fracture connectivity rate, boosting recoverable reserves per well by 23.5% and reducing inter-well pressure disturbance index to 0.38, validating the method's applicability and robustness in complex fractured reservoirs.