Numerical Simulation of Hydraulic Fracturing Based on the Extended Finite Element Method

Abstract

Abstract-This paper proposed a numerical model to simulate the hydraulic fracture propagation based on the extended finite element method(XFEM), in which a fracture representation is explicit and independent of the mesh grid. The fully coupled formulation described various physical phenomena, including the solid skeleton deformation as well as the fluid flow in porous medium, along the fracture and through the fracture sides toward the surrounding porous medium. The interactive integral method is applied to calculate the stress intensity factor in consideration of fluid pressure on fracture faces. The maximum circumferential stress criterion is used for identifying the fracture growth condition and orientation. In comparison with the current existing XFEM models for hydraulic fracturing, this approach neither needs to introduce leak-off coefficient to describe the fluid leak-off phenomenon, nor requires to assume fracture propagation orientation. Data indicates that the model is valid through a comparison of the model numerical solutions with the semi-analytical(KGD) solution . In the end, fractures simultaneously propagate from three perforating clusters in the horizontal well is simulated at the end of this paper.Keywords-extended finite element method; hydraulic fracture propagation; the interactive integral; horizontal well