Mapping of paleo residual oil zones on the NCS and the potential for production by CO2-EOR

The study has identified 20 Statoil-operated fields with indications of a PROZ below the oil-water contact (OWC). Estimates of in-place volumes are presented for each of the fields, adding up to a total amount of PROZ oil in the identified fields in the order of 1 GSm3. Simulation of tertiary CO2-EOR on naturally water-flooded oil reservoirs with an underlying PROZ has been performed on generic North Sea oil reservoir models to investigate the potential for oil recovery from PROZs. CO2 storage capacity for the identified fields has been estimated based on results from the simulations.