Application of Compositional Simulation in Seismic Modeling and Numerical Well Testing for Gas Condensate Reservoirs

Abstract

Recognition of condensate blockage is important in reservoir monitoring and management since the secondary operations such as gas cycling might need to be triggered to re-pressurize the reservoir. This study addresses the monitoring of a realistic gas condensate reservoir by time-lapse seismic data and transient well test analysis. A compositional reservoir modelling is employed to perform the numerical well test simulation. However, implementing a compositional fluid flow simulation highlights the limitations of the current petro-elastic model (PEM). Therefore we have developed an approach to consider the compositional changes of the fluid in the petro-elastic modelling. The equivalent black-oil model results are cross-validated against the compositional PEM as well. Our results show that the original widely used Batzle & Wang approach should be modified for a gas/condensate system. We show that the response strength of the well testing and the 4D seismic are complementary in each particular flow period (drawdown and build-up) which can be coupled to give useful information for reservoir monitoring purposes.