Study on the Effect of an Alternate Injection Pattern of Proppant on Hydraulic Fracture Closure Morphology

In previous studies of the transportation of proppants within fractures and the morphology of proppant-supported fractures, researchers have generally treated the fractures as static and have overlooked the interactions between fractures and the proppant during the dynamic closure caused by filtration. To address this limitation, we propose a semi-implicit method to calculate the complete fluid–structure interaction equations for the fracture, fluid, and proppant. The results show that there are three types of closed fracture patterns formed by alternate proppant injection at the end of filtration loss, and the third pattern of fracture formed by injecting small particles first and then large particles has the best support length and filling effect. More effects of the particle size and injection pattern of the injected proppant on the fracture closure pattern after the end of filtration loss are shown graphically and analyzed in detail.