Supercritical CO2-Water Flow in Two-dimensional Porous Micromodels: Micro-PIV Experiments

Abstract:

Multiphase flow in porous media is pervasive in geological systems. One of the applications which has recently been subject of great interest is geological sequestration of CO₂ in deep saline aquifers. A primary goal of the studies in this area is predicting the migration of the injected CO₂ in the reservoir both a priori and a posteriori. The results from continuum-scale models, however, often have significant uncertainties, which in part stems from ignoring the pore-scale transport and displacement processes. One of the powerful tools that can help improve our understanding of pore-scale flow and transport processes is the microscopic particle image velocimetry (micro-PIV) technique, which yields temporally- and spatially-resolved velocity vector fields. We have studied drainage and imbibition processes in a homogeneous, two-dimensional porous micromodel with water and liquid/supercritical CO₂ as the two fluid phases at reservoir-relevant conditions. Instantaneous velocity vector fields in the aqueous phase were recorded that provide new insight about the flow at the pore-scale.