Study the effective factors on gravity drainage process by gas injection (GAGD) for improving oil recovery

Abstract

Gradual and stable relocation of oil by gas, especially when it’s with gravity drainage, can have very high coefficient. It is showing, considerable increase of oil recovery measured in compulsory state more than free fall. The most important advantage in gas injection procedure by gravity drainage is using gravity separation between injected gas and oil reservoir that counting as weak side in gas injection processes such as connected gas injection, and recurring injection gas and water .in this study, effects of gas injection, oil production, band number, type and pattern of production and injection wells, heterogeneous porous media, type of injection gas and active aquifer in tank from GAGD process, were considered. If rate of infiltration is under rate of critical injection, dominant forces will be gravity forces that lead to stable floods front and fingered phenomenon will disappear. More numerical of band’s number in system leads more recovery of oil. Horizontally injection wells don’t help improvement gravity drainage and revenue of vertically injection well helps GAGD. Type of injection gas doesn’t affect on rate oil recovery, although rate of co2 recovery was more than it.