EDINBURGH, UK -- Controlled production of brine from rocks deep beneath the North Sea could increase the amount of carbon dioxide (CO2)that could be injected for subsurface storage in the area, according to Scottish Carbon Capture & Storage (SCCS).
This could help the UK reduce the cost per metric ton of tackling its carbon emissions, according to new research.
A multi-disciplinary project, funded by theEnergy Technologies Institute (ETI), has studied how brine production, normally associated with oil and gas operations, can enhance the storage potential of saline aquifers already identified as optimal CO2 stores.
Another benefit of using brine production alongside CO2 storage could be the opportunity to convert smaller aquifers into economically viable stores. In addition, the lifespan of certain storage sites could be lengthened, allowing operators to increase the injection rate at a later date as new CO2 sources come onstream.
TheUK is thought to hold some of the world’s best geological CO2 storage, up to 2.5 km (1.55 mi) below the North Sea, for use in carbon capture and storage (CCS) projects.
Suitable sites have already been identified by CO2Stored, the UK's offshore storage atlas, a product of the ETI’s UK Storage Appraisal Project.
SCCS partner Heriot-Watt University led the latest research, assisted by consultancy Element Energ and scientists and engineers from Durham University and T2 Petroleum.
Professor Eric Mackay, of Heriot-Watt University said: “We studied a set of potential CO2 stores, identified from the UK’s offshore storage atlas, to assess the value of brine production in terms of both increasing CO2 storage capacity and bringing down the unit cost of storage.
“Our findings suggest an eightfold increase in capacity is possible, plus a host of other benefits for a developing CCS industry in the UK.”
The researchers recommend further work including an assessment of how much economic value brine production would bring when CO2 stores are handed over to a “competent authority” for longer-term operations and/or monitoring.
ETU plans to issue a full report on the findings later this year.