Discrimination between Pressure-saturation Changes in Compacting Reservoirs Using Time-lapse Amplitudes and Travel Time

Expressions for estimation of changes in saturation and effective stress have been derived using time-lapse amplitudes and travel time information for compacting reservoir. Here we investigate three new combinations or methods in addition to the earlier method (based on PP-AVO data only) for compacting reservoir. These expressions are tested on synthetic models for 10 different reservoir scenarios for various degrees of pressure and fluid saturation changes. We find that the uncertainties in estimated pressure and saturation changes reduce significantly if we use time-lapse amplitude of PP and PS. Again inclusion of travel time information further reduces uncertainties in the final pressure estimates. The results show the importance of integrating different seismic attributes to stabilize the estimates of pressure and saturation changes for compacting reservoir.