Understanding fluid flow in fractured porous media under coupled thermal–hydrological–mechanical (THM) conditions is a fundamental aspect of geothermal energy extraction. In this study, we developed a fully coupled THM model, incorporating porosity and permeability variations, to scrutinize the process of geothermal energy extraction within fractured porous reservoirs. Moreover, we accentuated the significance of natural fracture orientation and hydraulic fracture permeability on fluid trajectories and heat extraction efficiency. Simulation results revealed that hydraulic fractures predominantly govern fluid channels and thermal exchange between injected water and the reservoir. Interconnected natural fractures bolster water migration into the reservoir, while detached fractures exert minimal influence on fluid dynamics, underscoring the crucial role of fracture connectivity in optimizing heat extraction efficiency. The sensitivity analysis indicated that larger fracture angles marginally hinder pressure and cool-water dispersion into the fractured reservoir, resulting in subtle enhancements in heat extraction rates and average production temperatures. An upsurge in hydraulic fracture permeability augments fluid velocity and thermal exchange, thereby fostering heat extraction efficiency. The THM model developed in this study offers a comprehensive insight into fluid flow within fractured porous media and its implications on geothermal energy extraction.

了解热-水文-机械（THM）耦合条件下裂隙多孔介质中的流体流动是地热能提取的一个基本方面。在这项研究中，我们开发了一个完全耦合的 THM 模型，结合了孔隙度和渗透率的变化，以仔细检查裂缝性多孔储层内地热能提取的过程。此外，我们强调了天然裂缝方向和水力裂缝渗透率对流体轨迹和排热效率的重要性。模拟结果表明，水力裂缝主要控制流体通道以及注入水与储层之间的热交换。相互连接的天然裂缝促进水运移到储层中，而分离的裂缝对流体动力学的影响最小，强调裂缝连通性在优化排热效率方面的关键作用。敏感性分析表明，较大的裂缝角度会略微阻碍压力和冷水扩散到裂缝性储层中，从而导致排热率和平均生产温度略有提高。水力压裂渗透率的升高增加了流体速度和热交换，从而提高了排热效率。本研究中开发的 THM 模型提供了对裂缝多孔介质内流体流动及其对地热能提取的影响的全面了解。导致排热率和平均生产温度的微妙提高。水力压裂渗透率的升高增加了流体速度和热交换，从而提高了排热效率。本研究中开发的 THM 模型提供了对裂缝多孔介质内流体流动及其对地热能提取的影响的全面了解。导致排热率和平均生产温度的微妙提高。水力压裂渗透率的升高增加了流体速度和热交换，从而提高了排热效率。本研究中开发的 THM 模型提供了对裂缝多孔介质内流体流动及其对地热能提取的影响的全面了解。