Multiple hydraulic fracturing treatment from horizontal wells has been widely used to enhance the productivity of unconventional hydrocarbons. Interaction among the fractures can cause the reorientation of fractures and lower the stimulation efficiency. We perform discrete element method (DEM) simulations to assess the influence of completion scheme on the trajectory and efficiency of fractures simultaneously-induced from two horizontal wells. Simulation of a single hydraulic fracture yields reasonable agreement with the theoretical solution regarding the fracture pattern and stress alteration and thus confirms the validity of the model. Stress shadowing effect caused by the opening of early fractures alters the state of local stress and thus leads to the appearance of dominant fractures and the reorientation of other fractures located in the altered stress field. Influences of the fracturing scheme including the distance between wells, the spacing between injection points, and arrangement of injection points are examined. The distribution uniformity index reveals that the effect of distance between wells on improving the efficiency of treatment is conditionally dependent on the spacing between injection points. Under the conditions considered in this study, the distance between wells enhance the efficiency only when the spacing reaches 40 m. Similarly, enlarging the spacing between injection points does not affect the distribution uniformity index when the distance between wells is 40 m, but effectively mitigate the stress shadowing effect and promotes the fracturing efficiency when the distance exceeds 60 m. Arrangement of injection point plays a negligible role on the fracturing efficiency compared with the spacing among them.

水平井的多次水力压裂处理已被广泛用于提高非常规烃的生产率。裂缝之间的相互作用会引起裂缝的重新定向并降低增产效率。我们执行离散元方法（DEM）模拟，以评估完井方案对两个水平井同时引起的裂缝轨迹和效率的影响。单个水力压裂的模拟与关于裂缝模式和应力变化的理论解产生了合理的一致性，从而证实了模型的有效性。由早期裂缝的张开引起的应力遮蔽效应改变了局部应力的状态，从而导致显性裂缝的出现和位于改变应力场中的其他裂缝的重新定向。研究了压裂方案的影响，包括井之间的距离，注入点之间的距离以及注入点的排列。分布均匀性指数表明，孔之间距离对提高处理效率的影响有条件地取决于注入点之间的间距。在本研究中考虑的条件下，仅当间距达到40 m时，井之间的距离才能提高效率。同样，当井距为40 m时，增大注水点之间的间距不会影响分布均匀性指数，但当井距超过60 m时，有效减轻了应力遮蔽效应并提高了压裂效率。相对于它们之间的间隔，注入点的排列对压裂效率的影响可忽略不计。