An innovative study of rocks beneath the UK North Sea has revealed that the secure and permanent storage of carbon dioxide (CO2) within a single geological storage formation can be optimised by injecting CO2 at more than one point simultaneously.

The findings could help to unlock an immense CO2 storage resource underlying all sectors of the North Sea for the storage of Europe’s carbon emissions, and will inform the work of those managing and operating this natural asset.

The process of storing CO2 captured from power plants and industrial facilities in deep geological formations is known as Carbon Capture and Storage (CCS) and is a key technological solution for meeting climate change targets over the coming decades.

The research by scientists and prospective site operators has used a UK North Sea case study – the Captain Sandstone – to predict the performance of a potential CO2 storage formation when the greenhouse gas is injected at two points at the same time over three decades.

The study’s conclusions will help to increase confidence among regulators and investors in the secure containment of CO2 within “multiple user” storage formations.

The findings also suggest that the Captain Sandstone, which lies more than a mile beneath the Moray Firth off north east Scotland, could securely store at least 360 Million tonnes (Mt) of CO2 in just one sixth of its area when CO2 is injected at a rate of between 6 and 12 Mt per year over three decades.

Researchers on the CO2MultiStore joint industry project used cutting-edge methods, which will, in future, reduce the effort and resources needed to characterise other extensive storage sandstones that could be suitable for CO2 storage. As a result, generic learning from the project will be of considerable value to prospective site operators worldwide.

Energy Minister Fergus Ewing said: “Carbon Capture and Storage (CCS) has the potential to be one of the most cost-effective technologies for decarbonisation of our power and industrial sectors, as well as those of economies worldwide. With £2.5 million of funding already committed this year to undertake substantial industrial research and feasibility studies in Grangemouth, the Scottish Government is already playing a pivotal role in the development and commercialisation of this innovative, exciting technology.

“This research confirms how the huge CO2 storage resource potential beneath the North Sea can be optimised, which, combined with the infrastructure already in place, again reinforces the huge opportunity for Scotland around CCS. CCS can contribute significantly to the diversity and security of electricity supply, and also has a unique role to play in providing a continuing supply of flexible clean fossil fuel capacity that is able to respond to demand in the way that other low-carbon technologies cannot.

“Many experts have set out the case that in order to achieve global climate change progress CCS technology must be developed and implemented to generating stations. We will continue to work with a range of partners to firmly establish this cutting-edge technology in Scotland, making full use of our huge potential.”

Dr Maxine Akhurst, British Geological Survey, who led the project for SCCS, said: “Our study is one of the keys that will unlock the potential CO2 storage capacity underlying the North Sea and release this immense storage resource. Our results show that by using more than one injection site in a single sandstone operators can store greater volumes of CO2 compared to using a single injection site, so increasing Europe’s capacity to reduce greenhouse gas emissions.”