A coupled phase-field and reactive-transport framework for fracture propagation in poroelastic media

Abstract

We present a novel approach to model hydro-chemo-mechanical responses in rock formations subject to fracture propagation within chemically active rock formations. The framework developed integrates the mechanisms of reactive transport, fluid flow and transport in porous media, and phase-field modelling of fracture propagation in poroelastic media. The solution approach integrates the geochemical package PHREEQC with a finite-element open-source platform, FEniCs. The PHREEQC solver is used to calculate the localized chemical reaction, including solid dissolution/precipitation. The resulting solid weakening by chemical damage is estimated from the reaction-induced porosity change. The proposed coupled model was verified with previous numerical results and applied to a synthetic case exhibiting hydraulic fracturing enhanced with chemical damage. Simulation results suggest that mechanical failure could be accelerated in the presence of ongoing chemical processes due to rock weakening and porosity changes, allowing the nucleation, growth, and development of fractures.