Hydraulic fracturing may induce or trigger an earthquake while injecting fluid into strata to initiate a new fracture so as to promote oil and gas production. Previous studies have confirmed that the injection of fluids into the formation, especially hydraulic fracturing, is closely related to seismic activity. However, the mechanism through which fluid injection changes the stress field of rock mass and interacts with the in situ stress state is still poorly understood. This study focused on the short‐term mechanism coupling shear stress and hydraulic fracturing in an experimental simulation. Preexisting tension fractures were initiated and propagated by loading shear force. The fracture propagation path of hydraulic fracturing was closely related to the preexisting fractures formed by the preshear stress. Short‐term hydraulic fracturing promoted fracture propagation and acoustic emission events (or microearthquake signals), but it was less likely to cause rock mass instability or a large earthquake. The long‐term fluid injection could saturate preexisting fractures and infiltrate rock mass to increase the pore pressure and change the in situ stress field in a large area to induce an earthquake.

中文翻译：

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水力压裂引发的短期破坏机制

水力压裂可能在将流体注入地层中引发新的裂缝时引发或引发地震，从而促进油气的生产。先前的研究已经证实，将流体注入地层，尤其是水力压裂，与地震活动密切相关。但是，对于流体注入改变岩体应力场并与原地应力状态相互作用的机理仍然知之甚少。这项研究的重点是在模拟实验中将剪应力与水力压裂耦合的短期机理。先前存在的拉伸断裂是通过加载剪切力而开始并扩展的。水力压裂的裂缝传播路径与由预剪应力形成的既有裂缝密切相关。短期水力压裂促进了裂缝的传播和声发射事件（或微地震信号），但不太可能引起岩体失稳或大地震。长期注水可能会使先前存在的裂缝饱和并渗透到岩体中，从而增加孔隙压力并改变大面积的原地应力场，从而引发地震。