Reservoir Connectivity Analysis and Its Application in Development of a Highly Compartmentalised and Stacked Reservoir in Malaysia

Abstract

Reservoir connectivity analysis plays an important role in understanding and successful development of compartmentalized and stacked reservoirs. The field compartments are initially defined based on the geological boundaries such as faults, shale layers, and other geological barriers. Well penetrations, fluid contact measurements, and initial pressure distribution surveys will complete the static connectivity of the compartments prior to production data. Reservoir behavior in the production time scale may change the initial understanding of the compartments system. Dynamic connectivity can bring surprises which affect the development plan and may require more investment to manage them. For a brown field development with such a complex structure, it is vital to have a systematic analytical approach in place to integrate the available data which had highlighted the missing gaps for the future development plan and helped to locate the remaining oil in place. This paper demonstrates the above concept in Baram field; a highly compartmentalized and stacked reservoir located offshore Miri in Sarawak, Malaysia. Based on the available production data and by using reservoir engineering techniques like material balance, reservoir uncertainty analysis and history matching; dynamic reservoir connectivity was defined. Fault seal analysis was evaluated to understand the behavior of the faults during the depletion phase of the field. The estimation of fault’s transmissibility compliments the material balance outcome and was refined in dynamic modeling/ history matching. Geomechanics study of the field proved useful to evaluate the impact of stress change during the future pressure maintenance study as a part of the brown field development plan.