Abstract Hydraulic fracturing induces the shear failure of natural fracture which contributes to complex fracture network. The magnitude of fracture slip potentially causes some undesirable consequences including wellbore instability, casing deformation and fault reactivation. Therefore, it is important to predict the fracture slip induced by hydraulic fracturing for a safe and efficient stimulation. In this paper, we used a 2D hydro-mechanical coupled model to predict the injection-induced slip. The hydraulic and natural fractures are embedded in formations with cohesive zone model. The fracture propagation, rock deformation and wellbore slip displacement are captured in the 2D model. The wellbore slip displacement is input into a small-scale 3D mechanical model of casing in slip rock to simulate casing behavior. Casing curvature is also introduced to assess casing integrity. Results indicate that the rock deforms asymmetrically with respect to the wellbore after the shear failure of natural fracture. Particularly, there is a shear slip along the natural fracture. The simulation result shows that the casing failure mechanism is shear deformation induced by the fracture slip during hydraulic fracturing. The curvature of deformed casing is larger than that of directional well trajectory. The predicted results are validated by the logging and operation data from the field. This work provides a novel quantitative method for predicting fracture slip and evaluating well integrity during hydraulic fracturing.

中文翻译：

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水力压裂页岩气井诱导裂缝滑移和套管变形的量化

摘要 水力压裂引起天然裂缝剪切破坏，导致裂缝网络复杂。裂缝滑动的幅度可能会导致一些不良后果，包括井眼不稳定、套管变形和断层再激活。因此，预测水力压裂引起的裂缝滑动对于安全有效的增产非常重要。在本文中，我们使用二维流体机械耦合模型来预测注入引起的滑移。水力和天然裂缝嵌入在具有粘性带模型的地层中。裂缝扩展、岩石变形和井眼滑动位移都被记录在二维模型中。井眼滑动位移被输入到滑动岩​​石中套管的小型 3D 力学模型中，以模拟套管行为。还引入了套管曲率来评估套管完整性。结果表明，天然裂缝发生剪切破坏后，岩石相对于井眼发生不对称变形。特别是，沿天然裂缝存在剪切滑移。模拟结果表明，套管破坏机制是水力压裂过程中裂缝滑移引起的剪切变形。变形套管的曲率大于定向井轨迹的曲率。预测结果由现场的测井和操作数据验证。这项工作为在水力压裂过程中预测裂缝滑动和评估井的完整性提供了一种新的定量方法。特别是，沿天然裂缝存在剪切滑移。模拟结果表明，套管破坏机制是水力压裂过程中裂缝滑移引起的剪切变形。变形套管的曲率大于定向井轨迹的曲率。预测结果由现场的测井和操作数据验证。这项工作为在水力压裂过程中预测裂缝滑动和评估井的完整性提供了一种新的定量方法。特别是，沿天然裂缝存在剪切滑移。模拟结果表明，套管破坏机制是水力压裂过程中裂缝滑移引起的剪切变形。变形套管的曲率大于定向井轨迹的曲率。预测结果由现场的测井和操作数据验证。这项工作为在水力压裂过程中预测裂缝滑动和评估井的完整性提供了一种新的定量方法。预测结果由现场的测井和操作数据验证。这项工作为在水力压裂过程中预测裂缝滑动和评估井的完整性提供了一种新的定量方法。预测结果由现场的测井和操作数据验证。这项工作为在水力压裂过程中预测裂缝滑动和评估井的完整性提供了一种新的定量方法。