Fit-For-Purpose Development Plan for FLO Reservoir Sand with Focus on Resolving Reservoir Connectivity and Fluid Contact Uncertainties

Abstract

FLO reservoir in the depth range of 8225-8780 ftss has an unknown nature of compartmentalization, unknown fluid property and also five well penetrations with none encountering OOWC (original oil water contact). Resolution of these uncertainties in this study created platform for the reservoir development in terms of growing production and increasing the reservoir ultimate recovery. This paper therefore focuses on an integrated approach of resolving uncertainties associated with key reservoir evaluation parameters to deliver a fit-for-purpose development plan of the reservoir. A multidisciplinary approach, involving integration of: PVT (Pressure Volume Temperature) Property estimation, Fault Seal Analysis (FSA), Petrophysical analysis and Dynamic simulation were employed to pin down these uncertainties in fluid contact and connectivity across blocks K, L and M within FLO reservoir. PVT property estimation was used to capture the phase behaviour of FLO reservoir fluids. While FSA, which relied on the degree of throw thickness and lithologic juxtaposition, was used to validate connectivity across fault blocks in FLO reservoir. Possible base case contact for the two producing blocks in the reservoir was established through dynamic reservoir model calibration by history matching for 41 years of production history. Results obtained from FSA, pressure profiles, sand-to-sand juxtaposition and dynamic history matching all combined showed an established hydraulic communication between reservoirs block K & M and also blocks K & L. The dynamic history matching with adjustments within physical meaning of basic history matching parameters realized 8525 ftss and 8810 ftss for POWC (present oil water contact) of the reservoir blocks K and M respectively. With these uncertainties resolved, different tests of development concepts were conducted and checked for economic viability and this showed that a "Do Nothing" approach with recovery of 3.6 MMstb should be adopted for FLO K and a "New Well" with recovery of 1.92 MMstb be drilled to develop FLO M.