Complex, non-planar fracture geometry is often observed in multi-stage hydraulic fracturing. The opening of hydraulic fractures results in a disturbance of local stress, which in turn affects the propagation of the adjacent fractures (stress shadow effect). The interaction between multiple fractures is of major importance in the design of fracturing treatments. In this study, a fully-coupled three-dimensional lattice-spring code is utilized to study the interference among multiple fractures. The results indicate that simultaneous propagating fractures can move towards or away from each other, resulting in complicated non-planar geometry and branching of hydraulic fractures. In an isotropic stress field, continued fracture propagation involves reorientation into a direction normal to the initial fracture plane, leading to an S-shaped fracture geometry. Higher Young's modulus values amplify the interaction of multiple fractures, resulting in more secondary fractures normal to the initial fracture plane and the greater dimension of fracture. Treatments assuming a higher magnitude of fluid viscosity /injection rate induce more branches at the tips of the primary fracture. An adjacent layer with a low modulus restricts the height growth of fractures, whereas the lateral growth and the stress interference will be in contrast relatively enhanced. This study provides further insight into the design and optimization of multiple-stage hydraulic fracturing in horizontal wells.

在多级水力压裂中经常观察到复杂的非平面裂缝几何形状。水力裂缝的开放导致局部应力的扰动，进而影响相邻裂缝的传播（应力阴影效应）。在压裂处理的设计中，多个裂缝之间的相互作用至关重要。在这项研究中，一个全耦合的三维晶格弹簧代码被用来研究多个裂缝之间的干涉。结果表明，同时传播的裂缝可以相互靠近或远离，从而导致复杂的非平面几何形状和水力裂缝的分支。在各向同性应力场中，连续的裂缝扩展包括重新定向到垂直于初始裂缝平面的方向，导致形成S形裂缝。较高的杨氏模量值会放大多个裂缝的相互作用，从而导致更多的垂直于初始裂缝平面的次生裂缝和更大的裂缝尺寸。假设流体粘度/注入速率更高的处理方法会在初级裂缝的尖端产生更多的分支。具有低模量的相邻层限制了裂缝的高度增长，相反，横向增长和应力干扰将相对增强。该研究为水平井多级水力压裂的设计和优化提供了进一步的见识。导致更多的垂直于初始裂缝平面的次生裂缝和更大的裂缝尺寸。假设流体粘度/注入速率更高的处理方法会在初级裂缝的尖端产生更多的分支。具有低模量的相邻层限制了裂缝的高度增长，相反，横向增长和应力干扰将相对增强。该研究为水平井多级水力压裂的设计和优化提供了进一步的见识。导致更多的垂直于初始裂缝平面的次生裂缝和更大的裂缝尺寸。假设流体黏度/注入速率更高的处理，会在初级裂缝的尖端产生更多的分支。具有低模量的相邻层限制了裂缝的高度增长，相反，横向增长和应力干扰将相对增强。该研究为水平井多级水力压裂的设计和优化提供了进一步的见识。相反，横向生长和应力干扰将相对增强。该研究为水平井多级水力压裂的设计和优化提供了进一步的见识。相反，横向生长和应力干扰将相对增强。该研究为水平井多级水力压裂的设计和优化提供了进一步的见识。