Development of Numerical Simulation Code for Hydraulic Fracturing Using Embedded Crack Element

Abstract

Hydraulically driven fracture propagation in rock may occur in mixed mode (Mode I and II). The purpose of this study is the development of the numerical simulation code that can predict a mixed mode crack propagation with a fracture process zone during hydraulic fracturing in a deep rock mass. A finite element analysis with an embedded crack element is adopted to the simulation code. The embedded crack element represents a crack as a displacement discontinuity within a continuum element. A crack constitutive model for mixed mode fracture is incorporated into the embedded crack element. The results from single element calculation indicate that the softening behaviour is reproduced in tension and shear mode, and the dilational behaviour during shear slip is captured. The analysis of hydraulic fracturing demonstrates that the mixed mode cracking is reproduced.