A document by Santiago PENA CLAVIJO. Click on the document to view its contents.

We use a coupled thermodynamically consistent framework to model reactive chemo-mechanical responses of solid solutions. Specifically, we focus on chemically active solid solutions that are subject to mechanical effects due to heterogeneous stress distributions. The stress generation process is driven solely by volume changes associated with the chemical processes. We use this model to describe the underlying physics during standard geological processes. Furthermore, simulation results of a three-species solid solution provide insights into the phenomena and verify the interleaving between mechanical and chemical responses in the solid. In particular, we show the evolution of the thermodynamic pressure as the system goes to a steady state.

We present a novel approach to model hydro-chemo-mechanical responses in rock formations subject to fracture propagation within chemically active rock formations. The developed framework integrates the mechanisms of reactive transport, fluid flow and transport in porous media, and fracture propagation in poroelastic media using the phase-field model. The solution approach integrates the geochemical package PHREEQC with a finite-element open-source platform, FEniCs. Thereby, 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.