Upper Burgan is a multi-layered reservoir in Sabiriyah Field of North Kuwait, currently undergoing initial phase of Water flood development. A highly complex reservoir with respect to reservoir heterogeneity; connectivity and structural compartmentalization based on detailed analogous study, the preliminary experience with the water flood performance was too dismal to achieve the target injection rates. A detailed channel mapping work has been completed which has enhanced the sub surface understanding to add value to the ongoing drilling/production and injection plans. Challenges posed by the heterogeneity and compartmentalization coupled with poor Injectivity initially slowed down the pace of the water flood development of the reservoir.
The Integrated Reservoir Management (IRM) approach with a distinctive strategy for depletion & pressure support for each of its segments has immensely helped the short term production build-up and sustaining the rates. The strategy is focused at producing the high reservoir pressure segments and managing the production from the depleted crestal part in tandem with ongoing water injection; aggressive pressure monitoring and cooperation from the operational teams. The current/short term drilling plan has been set to target the segments with higher reservoir pressures for well placement. The synergy with drilling activities in overlying Mauddud and underlying Lower Burgan reservoirs has helped in valuable data acquisition and swapping of wells for short term production requirements opportunistically.
The case history in the paper illustrates how the IRM approach in Upper Burgan is helping to manage & sustain the production rates at higher levels than predicted in the past, beating the impact of reservoir heterogeneity; Injectivity challenges and delayed water flood and at the same time, staying above the bubble point pressure.