Design of Dual-Porosity – Dual-Permeability Model of Ekofisk Field

Abstract

Naturally fractured reservoirs contain a substantial portion of the world’s hydrocarbon reserves. However, development of these fields poses a considerable challenge. The complex geological framework of fractured reservoirs requires proper fracture network characterization for a reliable simulation model. This work outlines a systematic methodology to construct a dual-porosity – dual-permeability model of Ekofisk field, with the aim to closely represent fluid flow behavior in an actual fractured reservoir. Reservoir rock and fluid properties, as well as fracture characterization of the field is represented in this paper. Three variants of the model were developed, namely single-porosity, dual-porosity and dual-porosity – dual-permeability models.Fluid flow performances of the models were compared and evaluated through macroscopic observation of oil production rate, cumulative oil production as well as field and bottom-hole pressures. Significant differences in fluid flow were observedbetween single-porosity model and the other two models due to the existence of the fracture network. Smaller differences were observed between dual-porosity and dual-porosity – dual-permeability models due to the matrix – to – matrix and matrix – to – well fluid flow interactions.