Stress transfer caused by injection-induced fault reactivation plays a significant role in triggering induced seismicity. This work aims to investigate to which extent the shear slip stress transfer mechanism might have contributed to a 4-month period of heightened microseismicity around one of the horizontal injection wells (KB-502) at the In Salah CO₂ storage site. Building upon previous reservoir modelling and history matching work by the authors, coupled geomechanical and reservoir modelling of CO₂ injection at KB-502 was carried out, featuring the explicit simulation of injection-induced fault reactivation and stress transfer, and the implementation of a strain-dependent permeability model to represent the fault hydrological behaviour. This approach allows a much-improved overall match to the field bottomhole pressures at KB-502 over the previous results, where fault zone reactivation and associated dynamic permeability behaviour were not considered, especially over the 4-month period of interest. Based upon the coupled modelling results, Coulomb stress changes were used to evaluate the potential for enhanced microseismicity related to CO₂ injection-induced fault reactivation at KB-502. Analyses on the potential for microseismicity have shown that seismic events are likely to take place in both hydraulically connected regions and stress transfer influenced regions. The variation of computed Coulomb stress changes in near-fault areas compares favourably with the heightened field recorded seismicity during the period modelled. The integrated interpretation of microseismic monitoring and coupled geomechanics and reservoir modelling have suggested that the shear slip stress transfer mechanism was active and contributed to the occurrence of induced seismicity at In Salah.

由注入引起的断层再激活引起的应力传递在触发诱发地震活动中起着重要作用。这项工作旨在调查在In Salah CO ₂储存地点的一个水平注入井（KB-502）周围，剪切滑动应力传递机制可能在多大程度上导致了4个月的微地震活动。基于作者先前的油藏建模和历史匹配工作，将CO _2的地质力学和油藏建模耦合在一起在KB-502进行了注入，其特征在于对注入诱发的断层再激活和应力传递进行了显式模拟，并实现了依赖于应变的渗透率模型来表示断层的水文行为。与以前的结果相比，这种方法可以大大改善与KB-502井底井眼压力的总体匹配，在该结果中，没有考虑断层带再激活和相关的动态渗透性，特别是在感兴趣的4个月期间。根据耦合的建模结果，使用库仑应力变化来评估与CO ₂相关的增强微震的潜力KB-502注入引起的故障重新激活。对微震可能性的分析表明，地震事件很可能发生在水力连通区域和受应力传递影响的区域。在模拟期间，计算出的断层附近库仑应力变化的变化与现场记录的高地震活动性相比具有优势。对微地震监测以及地质力学和储层建模的综合解释表明，剪切滑移应力传递机制是活跃的，并有助于在萨拉赫地区诱发地震活动。