We study the impact of reservoir heterogeneity on fault slip in shale reservoirs subject to hydraulic stimulation. We construct a two-dimensional numerical model representing the horizontal cross-section of a faulted heterogeneous shale formation and simulate coupled hydro-mechanical processes in the system during and after high-pressure fluid injection. We conceptualize the natural fault as a geological composite consisting of a fault core and a damage zone that involves a set of subsidiary fractures parallel to the fault strike. We couple the solid deformation and fault displacement with the Darcy flow based on poro-elasticity principles and hydro-mechanical constitutive relations. The heterogeneous nature of the permeability field of the shale reservoir is mimicked as a random field governed by a log-normal probability density function and prescribed correlation lengths. We elucidate the linkage between fault slip and fluid flow field, permitting the capture of the spatio-temporal evolution of preferential flow channels and their consequences on fault slip and induced seismicity. We report a significant role of reservoir heterogeneity in fault reactivation when the hydraulic fracture is away from the fault but at a distance smaller than the correlation length. The results of our research have important implications for many fluid injection-related geoengineering activities.

我们研究了油藏非均质性对页岩储层受水力增产作用的断层滑动的影响。我们构建了一个二维数值模型，该模型代表了一个断层非均质页岩地层的水平横截面，并在高压流体注入过程中和注入之后模拟了系统中的耦合水力作用过程。我们将自然断层概念化为由断层核心和破坏区组成的地质复合体，破坏区包括与断层走向平行的一组辅助裂缝。我们基于孔隙弹性原理和流体力学本构关系将固体变形和断层位移与达西流耦合。页岩储层渗透率场的非均质性被模拟为由对数正态概率密度函数和规定的相关长度控制的随机场。我们阐明了断层滑动和流体流场之间的联系，允许捕获优先流动通道的时空演化及其对断层滑动和诱发地震活动的影响。当水力压裂远离断层但距离小于相关长度时，我们报告了储层非均质性在断层活化中的重要作用。我们的研究结果对许多与流体注入有关的地球工程活动具有重要意义。可以捕获优先流动通道的时空演化及其对断层滑动和地震活动性的影响。当水力压裂远离断层但距离小于相关长度时，我们报告了储层非均质性在断层活化中的重要作用。我们的研究结果对许多与流体注入有关的地球工程活动具有重要意义。可以捕获优先流动通道的时空演化及其对断层滑动和地震活动性的影响。当水力压裂远离断层但距离小于相关长度时，我们报告了储层非均质性在断层活化中的重要作用。我们的研究结果对许多与流体注入有关的地球工程活动具有重要意义。