Experimental study demonstrates complete piston-like oil displacement using miscible enriched-gas banks in porous media, indicating smaller gas volumes are needed for effective recovery.
Key Points
Determine the displacement efficiency of small enriched-gas banks driven by methane in porous media and evaluate the effects of bank size and gas composition on oil recovery.
Conducted displacement experiments in a sand-packed tube measuring 20 feet in length and 1/2 inch in diameter.
Tested a ternary hydrocarbon system composed of methane, butane, and decane at 2,500 psia and 160°F.
Oil-miscible enriched gas driven by methane displaced 100% of the oil in contacted zones in a piston-like manner.
Immiscible gas compositions yielded lower displacement efficiency, with the enriched-gas bank traveling through the sand pack at a lower velocity than the methane driving gas.
Miscible conditions between the enriched gas and crude oil allowed for smaller bank sizes and reduced the total required gas volume compared to immiscible drives.