Introduction

Concern for greenhouse gases will undoubtedly increase carbon dioxide (CO₂) injection into geological formations for EOR and sequestration. The development of CO₂ plumes and subsequent dissolution into formation brine are essential mechanisms in most scenarios for sequestration. This paper describes laboratory tests on Frio sandstone core samples. Several types of displacement tests were performed; gas injection to a pseudo-residual brine saturation with respect to gas, followed by brine injection to a pseudo-residual saturation gas with respect to brine. The level of CO₂ saturation in the injected brine at reservoir pressure and temperature was varied from zero to over 90 %. This variation in CO₂ saturation in the injected brine was to determine the effect on the CO₂ saturation or plume size in the core.