Modelling the Effects of Condensate Banking on High CGR Reservoirs

This paper presents the results of a study undertaken to evaluate the effect(s) of condensate banking on retrograde gas reservoirs particularly, high condensate gas ratio (CGR) reservoirs. The effects of composition, fluid properties, liquid dropout rate, and the gas-oil relative permeability on gas productivity, were investigated using a scaling number, the Capillary Number, Nc. Results from the case study show that the impact of condensate banking would be severe for these reservoirs if the physical processes expected in these reservoirs are not correctly modelled. Also, the impact is not likely to be serious if the reservoir conditions are favourable as are prevalent in the Niger Delta basin of Nigeria.