Saline-aquifer CO2 sequestration in Japan-methodology of storage capacity assessment

A nationwide saline-aquifer CO2 storage capacity assessment has been carried out in Japan in two missions: In Mission 1, candidate saline aquifers were classified in terms of the type of geological structure and the amount of data available. Storage capacity for the entire country was then estimated based upon oil and gas exploration data (146 billion tons of CO2). The areas considered in the Mission were located mostly offshore and far from large CO2 emission sources. Mission 2 involved storage capacity estimation in 27 areas in the vicinity of large CO2 emission sources. These areas had been excluded in the Mission 1 capacity assessments. With national-scale geological survey results, a preliminary assessment was performed, and promising sedimentary basins were selected for more detailed examination. To date the overall storage capacity is still under discussion in Mission 2, whereas a systematic way of evaluating data quality and quantity is proposed, and comparative studies on the storage capacity estimation is in progress.