A generalized finite element method for three-dimensional hydraulic fracture propagation: Comparison with experiments

摘要

In this article, 3-D simulations of hydraulic fracture propagation with the Generalized Finite Element Method (GFEM) are compared with several experiments. The GFEM in this work uses mesh adaptivity and a quadratic basis to control discretization error while avoiding the mapping of 3-D solutions between propagation steps. Linear Elastic Fracture Mechanics is adopted and geometrical singular enrichments are used around the fracture front for robust and accurate stress intensity factors extraction. The time step that leads to satisfaction of the propagation criterion is computed automatically using a simple and yet computationally efficient algorithm. The laboratory experiments used in this article include planar and nonplanar fracture geometries as well as propagation in toughness- and viscosity-dominated regimes. The time evolution of fracture radius and opening, and wellbore fluid pressure are compared with experimental data. They show that the GFEM captures well the relevant physics of the hydraulic fracturing process. A modification is proposed to one of the experimental setups to explore and demonstrate the 3-D capabilities and robustness of the method.