Viability Assessment Of Polymer Flooding In A Heavy Oil Reservoir In Uganda

Polymer flooding is one of the most applicable enhanced recovery oil recovery methods in petroleum production industry.Polymer flooding consists of mixing long chain polymer molecules with the injected water in order to raise the water viscosity.This method advances the vertical and areal sweep efficiency as a consequence of improving the water/oil mobility ratio.Studies have proved that with the application of EOR,30 to 60 percent,or more,of the reservoir's original oil can be extracted,matched with 20 to 40 percent using primary and secondary recovery.H20 is a sandstone oil reservoir located in the Albertine Graben in southwestern Uganda.This reservoir is a new pool case with waxy and viscous medium-heavy oil with pressure close to the bubble point pressures.As a result,international oil companies have suggested different EOR methods including steam flooding,carbon dioxide flooding and polymer flooding as tertiary recovery options to solve this kind of problem.The purpose of this research is therefore to assess the viability of polymer flooding on this reservoir.Numerical reservoir simulation and conventional reservoir engineering methods were employed in this study.In the study the following parameters have been successfully optimized: Well pattern,well spacing and well number,injection-production ratio,polymer injection timing,polymer number of slugs,polymer concentration and Economic evaluation.Inverted 9 spot pattern and of 450 m well spacing were found to be the most suitable.This research has discovered that H20 reservoir is a good candidate for polymer flooding.Polymer injection increased the recovery by 2% and offset the cost of the polymer injection.NPV with water flooding = 187,150,413.4$ while NPV with polymer = 199,839,642.3 $.A profit of 12,689,228.9 US dollars is obtained making the polymer project viable.