Modeling Damage Induced by Deviatoric Stress in Rock: Theoretical Framework

Abstract

This work focuses on the development of a new anisotropic damage model for porous rocks. This damage model is formulated within the framework of thermodynamic irreversible processes. Flow rules are expressed with the energy release rate conjugate to damage, as opposed to stress in most rock damage models. The damage criterion is chosen so as to distinguish between tension and compression strength. Non-elastic deformation due to damage is computed by an associate flow rule to capture the development of crack-induced strains in the main directions of damage. Preliminary numerical results illustrate the potential for a crack to propagate under hydraulic pressure. This research work is expected to link damage mechanics with fracture propagation, for possible applications of hydraulic fracturing at reservoir scale.