Optimising CO2 storage in geological formations: A case study ofshore Scotland - CO2 MultiStore project

Carbon capture, transport and storage (CCS) is considered a key technology to provide a secure, low-carbon energy supply and reduce the greenhouse gas emissions (DECC, 2014) that contribute to the adverse effects of climatic change (IPCC, 2014). Commercialisation projects for the permanent storage of carbon dioxide (CO2) captured at power plants are currently in the design stage for the Peterhead, White Rose, Caledonia Clean Energy (DECC, 2013, 2015) and Don Valley projects. Storage of the CO2 captured by these projects is planned in strata deep beneath the North Sea in depleted hydrocarbon fields or regionally extensive sandstones containing brine (saline aquifer sandstones).
The vast majority of the UK and Scotland’s potential storage resource, which is of European significance (SCCS, 2009), is within brine-saturated sandstone formations. The sandstone formations are each hundreds to thousands of square kilometres in extent and underlie all sectors of the North Sea. The immense potential to store CO2 in these rocks can only be fully achieved by the operation of more than one injection site within each formation.
Government, university and research institutes, industry, and stakeholder organisations have anticipated the need
to inform a second phase of CCS developments following on from a commercialisation project in Scotland. The CO2MultiStore study, led by Scottish Carbon Capture and Storage (SCCS), investigates the operation of more than one injection site within a storage formation using a North Sea case study. The Captain Sandstone, within the mature oil and gas province offshore Scotland, contains the Goldeneye Field, which is the planned storage site for the Peterhead CCS project. Previous research (SCCS, 2011) was augmented by data from offshore hydrocarbon exploration and detailed investigation of the Goldeneye Field for CO2 storage (Shell, 2011a-i).