Investigation on the Water-Alternating Gas Oil Recovery Potential Based on Injection Well Location for the Albertine Oil Reservoir, Uganda

Abstract

Uganda is naturally endowed with vast resources ranging from oil to precious stones including diamond among others. Venturing into exploration and development of these resources has recently taken a center stage. Currently, the Ugandan oil reservoir located in the Albertine region, Western Uganda has only been appraised and production has not begun. This study uses standard correlation equations, field analogs, and compares with existing literature to predict the future oil recovery potential of the Albertine reservoir using water flooding and water-alternating gas (WAG) as the enhanced oil recovery methods using Carbon dioxide as the injection gas. Field analogue results indicate that the oil recovery factor during primary production is 8% to 15% while the oil recovery factor during secondary production ranges from 18.2% to 62%. Simulation results show an oil recovery factor of 9.81% and 36.85% during primary and secondary production respectively. The optimum well location is 800ft from the producer with an oil recovery factor of 36.85%. Well location has an effect on over all oil recovery factor and higher recovery factor is achieved when the injection well is 800 ft from the producer. Water flooding yields 31.67% of the original oil in place (OOIP) while Carbon dioxide yields 62.30% of OOIP. When WAG injection process is preceded by waterflooding, the oil recovery factor is 5.57% higher than when WAG process is preceded by Carbon dioxide injection.