Pore-scale simulation of dissolution-induced variations in rock mechanical properties

Reactive transport is simulated on rock geometries to explore the variation of mechanical properties of porous media. A numerical framework is developed to model reactive transport in sandstones and carbonates. Fluid flow, solute transport and chemical reactions are simulated directly on micro-CT images. Porosity profiles along the flow direction are computed during the dissolution to describe the change in the pore structures. Stress load cases on porous media are simulated and maps of deformation in the rocks are compared. Uniform deformation is observed in high Péclet regimes. Young's modulus and Poisson's ratio are calculated separately for a range of Péclet and Damköhler regimes. The findings show that mechanical properties in low Péclet regimes are more sensitive to porosity variations. For the same reaction regime, carbonates present a lower decrease in Young's modulus after reactions but a higher decline in Poisson's ratio in comparison with sandstones. This work reveals the strong dependency of mechanical properties on Péclet and Damköhler regimes in reactive transport.