Subseismic faults are small faults or fractures that may be difficult to determine but can have large consequences for fluid flow and pressure communication in the subsurface. Thus, knowing their distributions may be important in several subsurface applications, such as hydrocarbon exploration and exploitation, geothermal energy production, and subsurface CO₂ injection. The aim of this work is to use a stochastic model to populate a three-dimensional structural model of the subsurface with subseismic faults. The novelty of the proposed method is the conditioning of the stochastic model to input maps describing displacement and stress orientation along subsurface horizons. Hence, the resulting structural model will be consistent with these maps. The maps can originate from a variety of sources, for example, predictions of a geomechanical model or (indirect) measurements of subsurface displacements and stresses. The model uses simulated annealing as the optimization algorithm, where the residual between the displacement of the modeled subseismic faults and the input displacement map is minimized through an iterative process. Each subseismic fault is modeled with a three-dimensional displacement field around the fault slip plane, enabling comparisons with the input displacement map along a horizon. An example of how the model distributes the subseismic faults around larger known faults, using a synthetically created displacement map, is provided. The result shows that the model quickly converges towards a set of subseismic faults, giving total displacement and strike orientation close to the input maps.

亚地震断层是小断层或裂缝，可能难以确定，但会对地下的流体流动和压力交流产生重大影响。因此，了解它们的分布在一些地下应用中可能很重要，例如碳氢化合物勘探和开发、地热能生产和地下 CO ₂注射。这项工作的目的是使用随机模型来填充具有亚地震断层的地下三维结构模型。所提出方法的新颖之处在于将随机模型调节到描述沿地下层位的位移和应力方向的输入图。因此，由此产生的结构模型将与这些地图一致。地图可以源自各种来源，例如，地质力学模型的预测或地下位移和应力的（间接）测量。该模型使用模拟退火作为优化算法，其中通过迭代过程最小化模拟亚地震断层位移与输入位移图之间的残差。每个亚地震断层都使用断层滑动平面周围的三维位移场进行建模，从而能够与沿层位的输入位移图进行比较。提供了模型如何使用合成创建的位移图将亚地震断层分布在较大的已知断层周围的示例。结果表明，该模型快速收敛到一组亚地震断层，给出接近输入图的总位移和走向方向。