Characterization of Mineral Dissolution in Fracture-Pore Type Rocks Using the Lattice Boltzmann Method.

Mineral dissolution in fractured-pore rocks is a critical process in subsurface applications, including petroleum extraction, geothermal energy development, and carbon dioxide sequestration. Understanding the evolution of geometric topology and permeability is essential for scaling up research and guiding engineering design. In this study, we integrated a linear Boolean model with a self-affine rough surface approach to generate synthetic fracture-pore rock structures with varying degrees of matrix geometrical heterogeneity. The dual-distribution function lattice Boltzmann method was employed to simulate the mineral dissolution and quantify permeability evolution across a broad spectrum of Péclet (Pe) and Damköhler (Da) numbers. Our results indicate that changes in mechanical aperture and reactive surface area are primarily governed by the Da number. Furthermore, under high Pe and Da conditions, increased matrix heterogeneity leads to nonlinear alterations in permeability. Finally, we proposed a predictive diagram for permeability evolution during mineral dissolution under diverse matrix heterogeneity scenarios.