Abstract The inclusion of special interface elements between standard finite elements is becoming a common technique to model discontinuities in porous media using the finite element method (FEM). Recently, it was proved that high aspect ratio (HAR) elements can reproduce very satisfactorily the main features of behavior observed in a single hydraulically-induced fracture. In this paper, the mesh fragmentation technique (MFT) is proposed to extend the application of HAR elements to simulate more general problems involving the formation of hydraulic fractures in rocks by introducing this type of element in-between the standard FE of a typical mesh. The proposed framework makes use of standard FE techniques. Therefore, it is relatively easy to upgrade an existing FE program for continuous porous media to deal with evolving discontinuities. The proposed approach is verified and validated against available analytical and numerical solutions. The crack patterns predicted by the MFT are also compared with the ones observed in the laboratory. The formation of multiple fractures is also analyzed. In all cases, the proposed technique was able to properly capture the main features of rock behavior subjected to hydraulic fracturing.

中文翻译：

---

使用网格破碎技术的水力压裂水力-机械耦合建模

摘要 在标准有限元之间包含特殊的界面元素正成为使用有限元方法 (FEM) 对多孔介质中的不连续性进行建模的常用技术。最近，证明高纵横比 (HAR) 元素可以非常令人满意地再现在单个水力诱导裂缝中观察到的主要行为特征。在本文中，通过在典型网格的标准有限元之间引入这种类型的元素，提出了网格破碎技术 (MFT)，以扩展 HAR 元素的应用，以模拟涉及岩石中水力裂缝形成的更一般问题。提议的框架使用标准的有限元技术。因此，升级现有的连续多孔介质有限元程序以处理不断变化的不连续性相对容易。所提出的方法已针对可用的解析和数值解进行验证和验证。MFT 预测的裂纹模式也与实验室观察到的模式进行了比较。还分析了多条裂缝的形成。在所有情况下，所提出的技术都能够正确捕捉受到水力压裂的岩石行为的主要特征。