Pore-scale simulations of flow, transport, and reaction in porous media

Abstract

Physical observations and theoretical treatments of flow and transport in porous media are usually associated with three different length scales: pore (microscopic), local (lab) or macroscopic), and field. Dominant processes and governing equations may vary with scales. Extending from one scale to another requires upscaling (or downscaling), which allows the essence of physical processes at one level to be summarized at the coarser (or finer) level. In this work, we employ the method of lattice Boltzmann (LB) to simulate pore-scale multiphase flow, transport, and reaction in rock geometries. The LB method possesses a number of advantages for simulating flow and transport at the pore scale, including the ability to handle complex geometries (compared to conventional methods), no need to simplify the physics (compared to pore network models), and inherent parallel structure (amenable for massive parallel computation). LB simulations provide critical data for systematically investigating fundamental issues associated with flow and transport in porous media and for developing upscaling methods for predicting macroscopic quantities and characteristic relationships based on some statistical parameters of microscopic quantities. In this paper, the state of the art of this method will be discussed, and so are the following results: the dynamic evolution of rock pore geometries and the corresponding changes in permeability and porosity owing to convection, diffusion, and reaction; finger penetration in a channel; and, displacement of a three-dimensional immiscible droplet in a duct.