Influence of pore space heterogeneity on mineral dissolution and permeability evolution investigated using lattice Boltzmann method

Abstract

The influence of pore space heterogeneity on mineral dissolution and permeability evolution in porous media was investigated using a numerical approach. Artificial porous media were generated by the linear Boolean model, and pore heterogeneity was evaluated using the Euler–Poincaré characteristic (i.e., Euler number). We applied the lattice Boltzmann method with dual particle distribution functions to simulate mineral dissolution under the combined effect of fluid flow and a diffusion process. Simulations were conducted to investigate dissolution patterns for a wide range of Péclet (Pe) and Damköhler (Da) numbers and various pore geometries. Six dissolution regimes were observed, and two types of transition phenomena between these dissolution regimes could be characterized. At high Pe and Da, the dissolution patterns strongly depended on the pore heterogeneity. In addition, four types of porosity–permeability relationship were observed. These relationships were influenced by the pore heterogeneity at high Da numbers.