Numerical simulation of proppant embedment in rough surfaces based on full reverse reconstruction

Abstract

AbstractIn the hydraulic fracturing process of shale reservoir, proppant will embed and deform under the action of high closure stress. Thus, it is necessary to analyze the mechanical process and influencing factors of proppant embedding in shale. This study reproduced rough fracture surface of real rock slabs based on the reverse reconstruction method and obtained the mechanical parameters of the rock slab and proppant. In this study, a numerical model for the elastoplastic deformation of the proppant embedding in the rough fracture surface, along with mechanical test experiments, is proposed. The reliability of the numerical model is verified by the proppant embedding simulation experiment. Based on this model, the process of proppant embedding in a rough fracture under the action of closing stress and the factors influencing the width of supporting fracture were analyzed. The results show that the embedment degree of the proppant is different in different areas of the rough fracture surface. Furthermore, a stress concentration effect is apparent. The proppant embedment becomes significant after the slab enters the plastic deformation stage under high closure stress. The slabs with high roughness and low Young's modulus or proppants with small particle sizes and high Young's moduli result in a smaller width of the propped fracture.