Historically, the Duvernay East Shale Basin had been regarded as a seismicity‐quiescent region. However, an M_L 4.18‐magnitude earthquake on 04/03/2019 was triggered due to hydraulic fracturing of two horizontal wells. The physical mechanism and controlling factors of this large‐magnitude earthquake are not well understood. In this work, the coupled modeling of the M_L 4.18 case is conducted to quantify the poroelastic effects during fluid injection and to reveal the triggering mechanism of this earthquake cluster. Additional simulations of tested cases with different hydraulic, geomechanical, and operational parameters are also conducted to quantify the effects of these factors on hydraulically induced seismicity. It is found that the hydraulic fractures of two wells propagated within the Duvernay formation and connected with the inferred fault. The increase in pore pressure reduced the shear stress of the fault and caused the fault slip. The hydraulically induced seismicity is susceptible to the low permeable injection layer and high‐permeable fault, less rigid fault with low‐Biot's coefficient, large fluid injection, and proximity of hydraulic fracturing‐fault distance. Enlarging the distance between the stimulated well and seismogenic fault is the first‐order choice to mitigate seismic risks. Under the proximity of well‐fault distance, reducing the fracturing size job would be an effective approach to reduce the expected magnitude of hydraulically induced seismicity.

中文翻译：

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Duvernay东页岩盆地水力诱发地震控制因素的见解

从历史上看，杜韦奈东页岩盆地一直被认为是地震活动区。但是，由于两个水平井的水力压裂，于2019年4月3日引发了4.18级M _L地震。这场大地震的物理机制和控制因素尚未得到很好的理解。在这项工作中，耦合在所述M的建模_大号进行了4.18个案例，以量化流体注入过程中的孔隙弹性效应，并揭示该地震群的触发机制。还对具有不同水力，岩土力学和操作参数的测试案例进行了附加模拟，以量化这些因素对水力诱发地震活动的影响。发现两口井的水力压裂在Duvernay地层内传播，并与推断的断层有关。孔隙压力的增加减小了断层的剪切应力并引起了断层滑动。水力引起的地震活动易受低渗透注入层和高渗透断层的影响，刚性较弱的断层具有较低的比奥特系数，较大的流体注入量以及水力压裂断裂距离的接近性。扩大受激井与地震断层之间的距离是减轻地震风险的第一选择。在井距附近的情况下，减少压裂尺寸作业将是减少水力诱发地震活动预期幅度的有效方法。