Coupled Reactive Two-Phase Model Involving Dissolution and Dynamic Porosity for Deformable Porous Media Based on Mixture Coupling Theory

Abstract

Carbon capture and storage (CCS) has attracted significant attention owing to its impact on mitigating climate change. Many countries with large oil reserves are adopting CCS technologies to reduce the impact of fossil fuels on the environment. However, because of the complex interactions between multi-phase fluids, planning for CCS is challenging. One of the challenges is the integration of chemical reactions with multi-phase hydro-mechanical relationships in deformable porous media. In this study, a multi-phase hydro-mechanical reactive model for deformable porous media is established by using mixture coupling theory approach. The non-equilibrium thermodynamic approach is extended to establish the basic framework and Maxwell’s relations to build multi-scale coupling. Chemical reaction coupling is achieved through the extent of the reaction and chemical affinity. The developed model can simulate CCS by considering the effect of calcite dissolution on porosity and permeability. It has been found from the simulation that the chemical reaction has a major influence on porosity and permeability change compared to both pressure and mechanical strain effect. Also, as the dissolution reaction takes place, the stress/strain decrease on the solid matrix. The results of this study successfully bridge the knowledge gap between chemical reactions and mechanical deformation. Furthermore, insights from this model hold substantial implications for refining CCS processes. By providing a more accurate prediction of pressure changes and porosity/permeability evolution over time, this research paves the way for improved CCS operation planning, potentially fostering safer, more efficient, and economically feasible climate change mitigation strategies.