A method of continuous seismic reservoir monitoring includes receiving a plurality of seismic data sets associated with a reservoir during a period, where the plurality of seismic data sets corresponds to seismic data received at different times during the period. The reservoir includes a plurality of reflectors, where each reflector has a reflection coefficient. For each of the plurality of seismic data sets, the reflection coefficients of the plurality of reflectors are determined by iteratively updating common focus point (CFP) operators associated with the plurality of reflectors and a plurality of acquisition surface locations. The reflection coefficients corresponding to different seismic data sets are compared to determine changes of the reflection coefficients during the period. The changes of the reflection coefficients are displayed.