CO2 Storage Atlas of the Norwegian Continental Shelf: Methods Used to Evaluate Capacity and Maturity of the CO2 Storage Potential.

Abstract A CO 2 storage atlas of different sectors of the Norwegian Continental Shelf has been elaborated by the Norwegian Petroleum Directorate (NPD) in the period 2011 to 2013 and is now compiled into one volume. Main objectives were to facilitate selection of sites which are suited for future CO 2 sequestration projects and to document the total storage capacity of the Norwegian sectors of the North Sea, the Norwegian Sea and the southern Barents Sea. The most attractive aquifers and structures were investigated by geomodelling and reservoir simulation. 5 case studies of different types of aquifers, structures and abandoned fields illustrate how the typical storage options were evaluated. There is a tendency that calculated storage efficiency and storage capacity based on estimates of pore volumes will decrease when the storage assessment units are matured by more detailed studies. The study was based on the assumption of no water production, and it was observed that storage capacity was usually limited by pressure build- up in the investigated aquifers. The case of pressure maintenance by water production has not been studied, but could lead to significantly higher values for storage capacity. The study indicates that CO 2 could be used to recover oil from naturally occurring residual oil zones which commonly occur in areas with deep erosion.