Pore-Scale Characterization of Two-Phase Flow Using Integral Geometry

Abstract

The pore-scale morphological description of two-phase flow is fundamental to the understanding of relative permeability. In this effort, we visualize multiphase flow during core flooding experiments using X-ray microcomputed tomography. Resulting phase morphologies are quantified using Minkowski Functionals and relative permeability is measured using an image-based method where lattice Boltzmann simulations are conducted on connected phases from pore-scale images. A capillary drainage transform is also employed on the imaged rock structure, which provides reasonable results for image-based relative permeability measurements even though it provides pore-scale morphologies for the wetting phase that are not comparable to the experimental data. For the experimental data, there is a strong correlation between non-wetting phase Euler characteristic and relative permeability, whereas there is a weak correlation for the wetting phase topology. The relative permeability of some rock types is found to be more sensitive to topological changes than others, demonstrating the influence that phase connectivity has on two-phase flow. We demonstrate the influence that phase morphology has on relative permeability and provide insight into phase topological changes that occur during multiphase flow.