The combination of horizontal well drilling and staged fracturing technology is one of the most effective ways to increase unconventional oil and gas production. The orientation of the horizontal wellbore is mostly considered to be consistent with the minimum horizontal principal stress in the numerical simulation. However, horizontal wellbores are usually at an angle to the minimum principal stress in field operations. In this case, the dynamic growth of the fractures will be limited during subsequent perforation and fracturing operations. Therefore, the objective of this paper is to build an effective numerical model to investigate the propagation of hydraulic fractures in the case of a horizontal wellbore that is not co-linear with the minimum horizontal principal stress. The extended finite element method is applied for multi-stage fracturing flow-solid coupling in horizontal wells. In addition, the effect of sequential and alternate fracturing on the propagation of fractures in horizontal wells was compared. The simulation results show that fracture growth on one side of the horizontal wellbore is severely restricted as the pinch angle increases. It is most evident in sequential fracturing mode while increasing the fracture spacing is one of the effective ways to reduce inter-fracture interference. Meanwhile, compared to sequential fracturing, alternate fracturing is more effective in reducing inter-fracture interference, allowing for effective fracturing at closer fracture spacing. Finally, the density of the fracturing section has been increased, and a higher reservoir reconstruction area can be obtained. This work, for the first time, evaluates the dynamic propagation of fractures when the horizontal wellbore is not collinear with the minimum horizontal principal stress orientation and helps operators to optimize the fracturing process.

水平井钻井与分段压裂技术相结合是提高非常规油气产量的最有效途径之一。在数值模拟中，水平井筒的方位大多被认为与最小水平主应力一致。然而，水平井眼通常与现场作业中的最小主应力成一定角度。在这种情况下，裂缝的动态增长将在随后的射孔和压裂作业中受到限制。因此，本文的目的是建立一个有效的数值模型来研究在水平井眼与最小水平主应力不共线的情况下水力裂缝的扩展。将扩展有限元法应用于水平井多级压裂流固耦合。此外，还比较了序贯压裂和交替压裂对水平井裂缝扩展的影响。模拟结果表明，随着夹角的增大，水平井筒一侧的裂缝扩展受到严重限制。以序贯压裂方式最为明显，而增大缝间距是减少缝间干扰的有效途径之一。同时，与序贯压裂相比，交替压裂在减少缝间干扰方面更有效，可以在更近的缝距下进行有效压裂。最后，提高了压裂段的密度，可以获得更高的储层改造面积。