Optimizing Waterflooding Schemes and Completion Decisions in Deepwater environments using Formation Pressure While Drilling (FPWD): A Bonga Field Application

Abstract

A key uncertainty associated with Deepwater Turbidites is the reservoir continuity or connectivity, which has been observed in Bonga field. The Bonga field is one of the premier deepwater fields in Nigeria, discovered in 1996 and operated by Shell Nigeria Exploration and Production Company (SNEPCo) since 2005. With several wells under production, water flooding is employed for reservoir pressure management, aiding optimized recovery. Reservoir connectivity uncertainty is a typical issue with these deepwater turbidites, with adequate planning required to ensure risks associated with reservoir connectivity are accounted for and addressed. Although several producer and injector well-pairs have been drilled, data collected and analyzed, connectivity uncertainties still remain high in the field. One key source of information for understanding connectivity issues are formation pressure tests taken periodically (before and during the productive life of these reservoirs). In Deepwater Nigeria, these formation pressures are typically taken while drilling (Formation Pressure tests while drilling - FPWD), and augmented with data from down hole pressure gauges installed in many of the wells. This pressure data is acquired and analyzed to understand the reservoir pressure depletion trend, waterflood patterns and efficiency, as well as identify sand compartments within the reservoir. This paper discusses the use of formation pressure while drilling data in a new Bonga injector. The data was used to confirm connectivity with a paired updip oil producer, which was critical in making real-time decisions on completing the well, reducing drilling and completion risk, as wells as reducing the rig cost associated with the entire well operations.