Time Lapse Seismic as a Complementary Tool for Infill Drilling

Time lapse seismic data have improved the drainage understanding of the Gullfaks oil field, and have resulted in several potential new infill drilling targets. The baseline survey was acquired in 1985, one year before production start-up. Since then, two more surveys have been acquired, one in 1995, and another one in 1996. Key elements in the proces of reducing the uncertainties are cross-disciplinary verifications and detailed geophysical analysis and modelling, where different saturation profiles are input to the model. In order to include the interpretational uncertainties in the proces of quantifying the amount of remaining oil for each of the observations, the volume estimates are presented as probability curves.