Migration of CO2 in Porous Media Filled with water.

This paper describes experimental research on two-phase flow of supercritical carbon dioxide (CO2) and water in porous media under sequestration conditions. We used a magnetic resonance imaging technique to directly visualize the distribution of supercritical CO2 injected into porous media containing water. In-situ water saturation distributions in a Berea sandstone core and a packed bed of glass beads were successfully visualized at conditions that simulate those at 700 - 1000-m depths in an aquifer. By applying a coreflood interpretation method to our saturation data, we could describe the local Darcy phase velocities and capillary dispersion rate as a function of saturation. Next, the effect of buoyancy on the displacement process and gravity-dominated pure counter-current flow is discussed by comparing the data obtained at two conditions that model the aquifers at depths of 700 m and 1000 m. We found that buoyancy largely controls the pure counter-current flow in permeable porous media for conditions at 700 and 1000-m depths.