Successful Application of Capacitance Resistance Modeling to UnderstandReservoir Dynamics in Brown Field Waterflood - A Niger Delta Swamp FieldCase Study

摘要

Capacitance Resistance Model (CRM) is an analytical tool for estimating reservoir properties andconnectivity between producer-injector pairs in an established waterflooded oil reservoir system. Theanalysis incorporates historical production data, injection rates and available bottom hole pressures. InSwamp Field B (Niger Delta Nigeria), there were concerns of connectivity between producer and injectorpairs in the K2 reservoir. CRM analysis was applied to resolve the uncertainty in producer-injectorconnectivity and provide better understanding of the reservoir flow dynamics. Understanding the connectivity between existing injectors and producers, to ensure adequate waterinjection distribution for reservoir voidage balance and pressure maintenance necessitated a geologic andengineering review of existing data. The results of the study revealed strong inter-well connectivity between active producers and two idleinjectors in the reservoir for the period analyzed, corroborating a revised geologic interpretation of thereservoir. The idle injectors were previously left shut-in due to a geologic interpretation of the presence ofshale impacting connectivity and performance. Upon implementing recommendations from the study, an immediate pressure and production responsewas observed within three months of restoring the two idle injectors. The reactivation of the idle injectorsalso resulted in $20 MM savings by averting further work on a proposed new water injector. This paper discusses the application of CRM in understanding producer-injector connectivity andemphasizes the use of digital analytic tools to better understand waterflood performance and addresschallenges with balancing voidage and maintaining reservoir pressure. It demonstrates the value of CRMtechnique in brown fields and the multidisciplinary approach adopted. Further application of similartechniques in other waterflood reservoirs within Chevron Nigeria is currently ongoing.