This paper presents a time-explicit, fully coupled, hydro-mechanical model to simulate the two-phase flow process in fractured porous media, considering the geomechanical effect. Two solvers are developed, and mutual hydro/mechanical interactions are considered: (i) a novel finite volume discrete fracture–matrix model (FV-DFM) for two-phase flow, through both pores and fractures; and (ii) a combined finite-discrete element method (FDEM) for mechanical responses (e.g., deformation and fracturing). Particularly, a novel two-phase exchange flow model is applied at the matrix–fracture interface, which overcomes the difficulty in realistically capturing the discontinuity (e.g., pressure, saturation, and normal flux) across fractures. Meanwhile, non-uniform time steps of fracture and matrix flow are adopted to improve computational efficiency while maintaining accuracy. The performance of the proposed model is validated against existing results and applied to a practical waterflooding process considering fracture propagation. Results show that the model can well predict the two-phase flow process (e.g., pressure/saturation field, reservoir recovery) in fractured reservoirs, and reveal the important HM coupled effect on the flow process (e.g., the stress-dependent permeability and fracture propagation), with important implication for hydrocarbon reservoirs and CO₂ geological storage.

本文提出了一种时间显式、完全耦合的流体力学模型，用于模拟裂缝性多孔介质中的两相流过程，并考虑地质力学效应。开发了两个求解器，并考虑了相互的水力/机械相互作用：（i）一种新颖的有限体积离散裂缝矩阵模型（FV-DFM），用于穿过孔隙和裂缝的两相流；(ii) 用于机械响应（例如变形和断裂）的组合有限离散元方法（FDEM）。特别是，一种新颖的两相交换流模型应用于基质-裂缝界面，克服了实际捕获裂缝间不连续性（例如压力、饱和度和法向通量）的困难。同时，采用裂缝和基质流的非均匀时间步长，在保持精度的同时提高计算效率。所提出模型的性能根据现有结果进行了验证，并应用于考虑裂缝扩展的实际注水过程。结果表明，该模型能够很好地预测裂缝性油藏中的两相流过程（如压力/饱和度场、储层采收率等），并揭示了重要的重模耦合对流动过程的影响（如应力相关的渗透率和裂缝）。传播），对于碳氢化合物储层和CO ₂地质封存具有重要意义。