A Technical Survey of Immiscible Gas Injection Projects

Reservoir, fluid, and oil recovery data were gathered for ongoing and completed projects which implemented immiscible gas injection as an enhanced oil recovery process. A data base consisting of information from 24 immiscible gas injection projects was compiled. Selected fluid, reservoir, and oil recovery parameters were analyzed using frequency plots and statistical analysis techniques in an effort to determine if correlation could be found between oil recovery and reservoir and fluid parameters. Because of the small amount of oil recovery information available, it was not possible to explore whether or not there was correlation between oil recovery and reservoir and fluid parameters. In spite of this, the study did generate some significant results. Several of these results are: the reservoir oil targeted for immiscible gas flooding tended to be a high gravity (≥ 35° API), low viscosity (≤ 0.5 cp) crude, most of the producing formations were deep (>7000 feet), high temperature (>150°F), high pressure (>3000 psi) reservoirs, and permeabilities of the producing formations tended to be low (<40 md).