A coupled lattice Boltzmann model for simulating reactive transport in CO2 injection

Abstract

A lattice Boltzmann method (LBM) based computational REV model of geochemical reaction is proposed to describe the geochemical reactions of both solute ions transport and solid phase CaCO3 dissolution in CO 2-saturated water as well as their effects on the velocity fields of fluid flows during a CO2 injection process. This includes the porosity change with the calcium carbonate dissolution and its feedback impacts on fluid flows. The proposed model is implemented in our in-house LBM code and verified through a hypothetic numerical experiment. The interaction between chemical reactions and fluid advection-diffusion processes is investigated through comparing simulation results of different species distribution at different stages. It has been well known that even a small porosity change induced by the chemical reaction would cause an obvious permeability change. Our present results validate that rule, and furthermore yield a numerical relationship between porosity change and fluid velocity increase at different time steps. This demonstrates that the proposed LBM geochemical reaction model may serve as a reliable approach to investigate the reactive transport in reservoirs of CO2 injection. © 2014 Elsevier B.V. All rights reserved.