ETI seeks partners to study impact of removing brine from under-sea CO2 stores

The Energy Technologies Institute is seeking partners for a project to study the impact of removing brine from under-sea stores that could be used to store captured carbon.

A previous ETI project in its Carbon Capture and Storage (CSS) technology programme led to the development of the UK's principal storage screening database, CO2Stored, which made a number of assumptions to estimate capacity and injectivity for each of the 550 stores off the UK's coast.

If a reservoir is pressurising as a result of CO2 injection, brine can potentially be removed through a purpose built well or wells from the store to depressurise it, and can still retain the operation and integrity of the store.

The brine could potentially be sent to another aquifer or disposed of in the sea. Brine production is a recognised way of controlling the reservoir pressure and potentially its flow, and its use is a contingency in several store designs.

Recent work published by Heriot Watt University showed that producing brine in the United Kingdom Continental Shelf may be beneficial to injection rates and storage.

This project will produce a cost-benefit analysis of brine production, using the CO2Stored database and models developed in the ETI's UK Storage Appraisal Project as a starting point. Analysis will cover both saline aquifers and oil gas reservoirs.

The first stage of the project will examine any changes in injectivity and storage capacity as a result of producing brine, the additional cost of the brine wells and the savings.

Paul Winstanley, ETI CCS Project Manager said: "The ETI's analysis of the UK energy system highlights the importance of CCS to an affordable, secure and sustainable low carbon energy system.

"This project will build on our earlier work and help to build the evidence base, increase knowledge and understanding about the stores we have identified and build confidence among potential operators and investors."

The request for proposals will close on 24 September 2015. The deadline for notification of intention to submit a proposal is 10 September 2015.