Time-dependent reservoir characterization of the LF sand in the South Eugene Island 330 Field, Gulf of Mexico

Abstract

As 4-D seismic technologies enter the reservoir management arena, time-dependent reservoir characterization becoming more and more important. Because changes in fluid saturation and pore fluid pressure of a given reservoir can often cause detectable seismic amplitude changes, using time-lapse 3-D seismic data to delineate reservoir property changes seems to be inevitable. We have found that the resolution of 4-D seismic data sets is often higher than that of any single 3-D data set. Because of the uncertainties of constructed reservoir model, additional constraints must be introduced in the time-dependent reservoir characterization. We developed a method to integrate seismic inversion, geostatistical reservoir description, and reservoir simulation to update our initial reservoir model in terms of porosity and permeability. The updating of the model is based on minimization of the error between the predicted impedance differences and the observed impedance differences and the error between predicted production history and observed production history. The results obtained from the LF sand of the South Eugene Island 330 Field indicate that reservoir simulation is a critical complementary tool to verify 4-D signatures obtained from legacy time-lapse 3-D seismic data sets, and the errors between the predicted and observed impedance data and production data can be used to further constrain the initial reservoir model.