The main storage-related challenges for accelerated deployment of CCS are capacity, confidence and cost. These challenges are to be addressed by focusing on improving strategies for monitoring and management of the pore pressure distribution in the CO2 storage reservoir. Pressure-driven decision support protocols are to be developed for safe and cost-effective reservoir monitoring. These protocols will enable the operator to maximize CO2 storage capacity and quickly turn monitoring data indicating non-conformance into plans for corrective actions. A new extended method is developed for inverting and de-noising reservoir pressure and water saturation changes from time-lapse AVO differences and time-shifts for the purpose of CCS monitoring and conformance. Detailed reservoir pressure and saturation fronts are obtained for seismic timelapse data in the Norwegian offshore, honouring reservoir compartments and fault boundaries found in comparative studies. Applications on CCS and non-CCS fields offshore Norway were researched in synthetic and field data cases for purposes of benchmarking, pre-storage analysis, monitoring plans and conformance studies. Back-estimations of pressure and saturation changes were successful for both synthetic and field data and have made this method substantially more credible for field cases and seismic history matching.