Measuring Reservoir Compaction Using Time-lapse Timeshifts

Time-lapse timeshifts refer to the differences in two-way seismic travel times that are frequently observed in the analysis of time-lapse seismic surveys. One source of timeshifts originates inside the reservoir interval as a result of changes in the pore-fluid properties that alter the seismic velocity. Another is from changes in seismic velocity and layer thickness that occur both inside and outside of the reservoir as a result of reservoir compaction and stress and strain redistribution in the surrounding formations.