Leonardo Guimarães

Federal University of Pernambuco

Chemo-mechanical-elastoplastic models applied to CCS projects

An appropriate understanding of the interaction and effects of thermal, hydraulic, mechanical and chemical (THMC) phenomena occurring in CCS projects can be greatly assisted by the development and use of coupled theoretical formulations. In this contribution one example of such a formulation is presented, where changes of mineral assemblage are expected when the rock is subjected to CO2 injection. This will affect porosity, permeability and also mechanical properties of the material. An important component of this formulation is an elastoplastic model developed within the framework of the critical states theory to consider deformations induced by the injection of reactive fluids in rocks under compressive stress states (potential pore collapse). Numerical simulations showed that the progressing CO2 injection results in mineral dissolution near the well, with changes of rock porosity and permeability. Chemically induced stresses and strains are evaluated considering different levels of coupling between chemical, hydraulic and mechanical problems.