Effects of gas addition to steam and hot water on recovery of West Sak crude oil

A high pressure one-dimensional laboratory displacement study was undertaken to evaluate the effects of the addition of different gases to steam and hot water on the recovery of West Sak crude. The results of the steam/gas flood experiments indicate that the addition of gases to steam reduce the dew point of steam, reduce heat input requirements, increase the rate of recovery and ultimate recovery. Furthermore, there exists an optimum gas/steam ratio for which highest recovery is achievable. Distillation and swelling experiments show that the addition of CO₂ to steam enhances the distillation and thermal swelling of oil. The addition of a small amount of natural gas liquids (NGL) to methane increased the recovery the most when compared with CO₂, N₂, and CH₄ as additives to steam. The hot water alternate gas (WAG) displacement experiments show that the addition of CO₂ and CH₄ to hot water increases the ultimate recovery and the initial rate of recovery.