Micro-PIV measurements of multiphase flow of water and supercritical CO2 in 2D heterogeneous porous micromodels

Abstract:

Multiphase flow of water and supercritical carbon dioxide (CO₂) in porous media is central to geological sequestration of CO₂ into saline aquifers. However, our fundamental understanding of the coupled flow dynamics of CO₂ and water in complex geologic media still remains limited, especially at the pore scale. Recently, studies have been carried out in 2D homogeneous models with the micro-PIV technique, yielding very interesting observations of pore-scale flow transport. The primary aim of this work is to leverage this experimental protocol to quantify the pore-scale flow of water and liquid/supercritical CO₂ in 2D heterogeneous porous micromodels under reservoir-relevant conditions. The goal is to capture the dynamics of this multi-phase flow in a porous matrix that mimics the heterogeneity of natural rock. Fluorescent microscopy and the micro-PIV technique are employed to simultaneously measure the spatially-resolved instantaneous velocity field in the water and quantify the instantaneous spatial configuration of both phases. The results for heterogeneous micromodels will be presented and compared with those for homogeneous micromodels, yielding valuable insight into flow processes at the pore scale in natural rock.