Maximizing Value of a Mature Asset Through Integration and Utilization of New Technology, Nigerian National Petroleum Corporation / Mobil Producing Nigeria (NNPC/MPN) Joint Venture
Bill Devlin1, Sali Jimoh2, Nsidibe I. Akata2, Larry Sumpter3, and Raymond H. Young2
1ExxonMobil Production Company, Houston, TX
2Mobil Producing Nigeria, Lagos, Nigeria
3ExxonMobil Upstream Research Company, Houston, TX
The field is a mature asset in the NNPC/MPN Joint Venture (JV) acreage in offshore Nigeria with a current reserve estimate of approximately 100mbo. Discovered in 1968, the field streamed in 1974. Production is from the disturbed and bedded Upper Biafra Member of the early Pliocene to late Miocene Agbada Formation. A peak oil rate of 40 kBD was attained prior to a steady production decline to 16 kBD by June 2007. Thirty-two years of production has resulted in differential fluid contact movements across the field. The height of the remaining oil column was considered the key risk for further infill drilling.
The desire to optimize the recovery of the remaining reserves necessitated an integrated field study employing static and dynamic data. Reservoir Connectivity Analysis (RCA) was used to establish the static and dynamic reservoir connectivity framework to aid the qualitative estimate of transmissibility across faults and erosional surfaces. This technology is an iterative workflow that leverages integration of structural and stratigraphic reservoir elements with dynamic pressure, production, and fluid data analyses to develop an understanding of production scale compartments, fluid migration pathways and remaining oil column thicknesses within the reservoir.
The study outcome was an inventory of infill drilling opportunities. The initial drilling campaign of 5 wells has been very successful with oil column heights and initial production rates close to or exceeding those predicted by the study. The drilling results demonstrate that most inter-reservoir connections established by fault juxtaposition and erosion are effective conduits for fluid flow during production.
AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery