Geological CO 2 Storage: Reactive Fluid Transport: Pore-Scale Study

Carbon capture and geological sequestration (CCS) emerges as an important alternative to mitigate global warming. The injection of supercritical CO2 triggers CO2 dissolution, water acidification, mineral dissolution, and transport. We investigate reactive fluid transport at the pore- and rock-joint scales using published kinetic rate laws for dissolution reactions in calcite, CaCO3, and anorthite CaAl2Si2O8. Reactivity is coupled with Navier-Stokes law and advection-diffusion transport equations to numerically investigate the evolution of the pore geometry, flow patterns, and species concentrations in soil and rocks. Numerical results are analyzed in terms of two dimensionless numbers, the Damköhler and Peclet numbers. Observed trends provide insight into the interplay among flow parameters including advection, diffusion, chemical reactions, and the evolution of the porous network in different transport-reaction regimes relevant to CO2 injection and geological storage.