A total of 24 displacements were made in sand packs, the majority of which involved use of a synthetic crude formulated to be similar to a West Texas crude. Results suggest that miscibility can be produced at 1100 psig and 109/sup 0/F, from mass transfer through a multiple contact process. Chromatography suggest that the mechanism is one of condensation rather than vaporization. Methane in the injected carbon dioxide increased, while 5% propane decreased the minimum miscibility pressure. The presence of increased methane concentrations (methane banks) is not an indication that miscibility was not attained, but only that first contact miscibility was not attained at run pressure. Studies have been conducted in a Berea sandstone core with a reconstituted crude from the Brookhaven Field in South Mississippi. The core containing crude and a connate water saturation was waterflooded. Results indicate that a significant portion of the residual oil can be mobilized and produced at a reasonable water cut prior to abandonment at a GOR of 30,000 SCF/STB. It is concluded that studies of this process as a tertiary oil recovery technique should be done in consolidated systems longer than six feet.