During horizontal well staged fracturing, there is stress interference between multiple transverse fractures in the same perforation cluster. Theoretical analysis and numerical calculation methods are applied in this study. We analysed the mechanism of induced stress interference in a single fracture under different fracture spacings and principal stress ratios. We also investigated the hydraulic fracture morphology and synchronous expansion process under different fracture spacings and principal stress ratios. The results show that the essence of induced stress is the stress increment in the area around the hydraulic fracture. Induced stress had a dual role in the fracturing process. It created favourable ground stress conditions for the diversion of hydraulic fractures and the formation of complex fracture network systems, inhibited fracture expansion in local areas, stopped hydraulic fractures, and prevented the formation of effective fractures. The curves of the maximum principal stress, minimum principal stress, and induced principal stress difference with distance under different fracture lengths, different fracture spacings, and different principal stress ratios were consistent overall. With a small fracture spacing and a small principal stress ratio, intermediate hydraulic fractures were difficult to initiate or arrest soon after initiation, fractures did not expand easily, and the expansion speed of lateral hydraulic fractures was fast. Moreover, with a smaller fracture spacing and a smaller principal stress ratio, hydraulic fractures were more prone to steering, and even new fractures were produced in the minimum principal stress direction, which was beneficial to the fracture network communication in the reservoir. When the local stress and fracture spacing were appropriate, the intermediate fracture could expand normally, which could effectively increase the reservoir permeability.

在水平井分段压裂过程中，同一射孔簇中的多个横向裂缝之间存在应力干扰。本文采用理论分析和数值计算方法。我们分析了在不同的裂缝间距和主应力比下，单个裂缝中诱发应力干扰的机理。我们还研究了在不同裂缝间距和主应力比下的水力裂缝形态和同步膨胀过程。结果表明，诱导应力的实质是水力压裂周围区域应力的增加。诱导应力在压裂过程中具有双重作用。它为水力裂缝的转移和复杂的裂缝网络系统的形成创造了有利的地面应力条件，抑制了局部裂缝的扩展，停止了水力裂缝，并阻止了有效裂缝的形成。在不同的断裂长度，不同的断裂间距和不同的主应力比下，最大主应力，最小主应力和诱导主应力随距离的变化曲线总体上是一致的。裂缝间距小，主应力比小，中间水力裂缝难以起裂或起裂后立即停止，裂缝不易扩张，侧向水力裂缝的扩张速度快。此外，随着裂缝间距的减小和主应力比的减小，水力裂缝更易于转向，甚至在最小主应力方向上也产生了新的裂缝，有利于储层裂缝网络的通讯。当局部应力和裂缝间距合适时，中间裂缝可以正常扩张，有效地提高了储层的渗透率。