Defining Reservoir-Rock Properties, Deep-water Depositional Facies of the Qua Iboe member, Pliocene, Offshore Nigeria

Abstract

Abstract Reservoir facies provide the critical interrelationships among (1) basic reservoir lithologies, (2) reservoir properties, and (3) wire-line log measurements. In addition, each reservoir facies is linked to its depositional environment, thus providing the basis for understanding its three-dimensional geometry and interconnection. A reservoir-facies classification has been designed for the deep-water deposits of the Pliocene Qua Iboe Member of the Agbada Formation as they occur in Mobil Producing Nigeria's (MPN) Joint Venture Acreage. The facies are based on lithology and registered to laboratory-measured reservoir properties. Grain-size characteristics such as size, sorting, and terrigenous mud content are the principal factors that control reservoir properties. All reservoir facies have been precisely quantified in terms of routine and special core analysis and their compatibility with completions fluids has been tested. Furthermore, quantitative wire-line log criteria have been developed, allowing recognition of the reservoir facies in uncored wells with considerable accuracy. Log and reservoir properties associated with the facies are tailored to burial depth for each field, and even different reservoirs within a single field. Using these standardized classification schemes for all MPN reservoirs allows for better communication among reservoir technologists and the transfer of insights gained from one field to other fields.