Novel fracture network modeling method for tight reservoirs integrating mechanical and geometric characteristics

Discrete fracture network (DFN) modeling is widely applied to characterize fracture systems in tight reservoirs, yet its accuracy is often limited by the lack of integration between geological, geometric, and mechanical controls. To address these challenges, a fracture network modeling approach based on mechanical-geometric criteria (FNMmg) is introduced. The method incorporates five analytical strategies: (1) simulation of stratabound fracture dips using gap angles relative to bedding normals; (2) scale-weighted orientation statistics to emphasize the contribution of dominant fractures; (3) orientation generation via a cumulative probability curve to avoid errors from group partitioning; (4) fracture element representation to enable hierarchical coalescence; and (5) fusion rules combining geometric similarity with mechanical and diagenetic principles. Application to the Triassic Chang 6 tight sandstones in the Ordos Basin, China, demonstrates that FNMmg can reproduce multiscale fracture systems with improved geological consistency. Validation against tracer monitoring in 34 well pairs achieved an overall connectivity consistency of about 91%, including 86% accuracy for fracture-type and 93% for pore-type or unconnected cases, demonstrating FNMmg’s utility in identifying effective fracture flow paths, thereby supporting reservoir connectivity analysis. These results indicate that FNMmg provides a practical framework that explicitly integrates fracture mechanics, geometry, and data-driven constraints, offering a basis for reservoir characterization, connectivity analysis, and development optimization in tight sandstone settings.