Sandstone rocks deep beneath the Moray Firth are being examined for the storage of CO2 emissions. This is the first time a consortium of the Scottish Government and industry has funded (£290,000) a study to test the suitability of a specific site for carbon storage.
The Captain Sandstone will be evaluated for its capacity, technical feasibility and commercial viability as a CO2 store by scientists at the Scottish Centre for Carbon Storage (SCCS). This is essential to plan for long-term storage of CO2 and to meet national targets for carbon emissions reduction.
The target rock in the Moray Firth is buried more than half a mile below the seabed and lies at least 30 miles into the North Sea. It is one of many sandstones filled with saltwater that provide more than 95% of potential CO2 storage capacity in the northern North Sea.
Dr Maxine Akhurst from the SCCS at the British Geological Survey said, “The Captain Sandstone has the potential to store decades of CO2 output from a coal-fired power station, like the existing plant at Longannet or a future CCS project such as Hunterston or Peterhead. In contrast, the depleted oil and gas fields within the sandstone have capacity for only a few years of power station output.”
The Scottish Energy Minister, Jim Mather said, “Scotland has significant advantages for the development of carbon capture and storage including knowledge and expertise in areas such as geology and engineering and in the North Sea oil and gas industry. We also have a tremendous offshore storage capacity and the outcome of this research will further increase our understanding of the potential for Scotland to take the lead in the development of carbon capture and storage.”
New geological mapping and modelling of the Captain Sandstone is appraising the thickness, extent and fluid flow properties of the rock. The study will also address the challenges of CO2 injection and monitoring to assess suitability of this and other North Sea sandstones.
The UK is investing hugely in carbon storage as it has a natural advantage being an island with close proximity to the sea; the abundance of exhausted gas and oil reserves providing many potential storage sites for CO2.
A study in 1996 revealed that UK has room in depleted oil reserves for 5.3 Gt of CO2 (5.3,000,000,000 t), and as much as 11- 15 Gt of CO2 in depleted gas reserves; this could amount to storage for 40 years of carbon emissions at current levels. The same study indicated that saline aquifers (such as Captain Sandstone) could have the potential to hold between 19 – 716 Gt of CO2, which would amount to 500 years of CO2 emissions. With this in mind it is easy to see why the UK is investigating these formations closer.
Computer modelling of CO2 injection into the rocks will test the storage site and its long-term performance to ensure CO2 remains permanently locked in. To transport CO2 from industrial plant to the offshore region it is envisaged that natural gas pipelines may be re-used, or new pipelines could be constructed, leading to a CO2 network (similar to the existing oil and gas networks).
The Scottish Government and commercial organisations with operational interests in Scotland are funding the project: Ayrshire Power Ltd (a Peel Energy company); BG Group, Doosan Babcock; National Grid; RWE npower; Schlumberger; Scottish and Southern Energy; ScottishPower; Senergy; Scottish Enterprise; Shell U.K; The Crown Estate; and Wood Mackenzie.
Read the article online at: https://www.oilfieldtechnology.com/drilling-and-production/03062010/moray_firth_to_become_carbon_sequestration_location/