Greensand carbon capture and storage

A partnership led by INEOS Energy, an oil and gas company with operations in the North Sea, in collaboration with Wintershall DEA, Maersk Drilling and the National Geological Survey of Denmark and Greenland (GEUS), is spearheading a new phase of large-scale carbon capture & storage.

Under the project name Greensand, the main partners together with a consortium of 20 companies including Ramboll are looking to validate the technical and commercial feasibility of reusing a depleted oil and gas field to store CO2 under the seabed. The pilot test will be carried out at the Nini West platform in the Danish North Sea, where half a million tonnes of CO2 are expected to be stored by 2025.

Greensand was awarded DKK 197 million (€26,5 million) in public funding from the Energy Technology Development Program (EUDP), which is led by the Danish Energy Agency to support private companies and universities advance the green transition. For the pilot phase, Ramboll was appointed to carry out environmental assessments, risk analyses and flow assurance studies.

The carbon is first captured onshore, likely from large emitters such as power plants or cement producers. It is then transported by ship to Nini West in the Siri oil and gas field. Here it will be injected into the Paleocene sandstone formation about 1800 metres below the seabed. By repurposing offshore oil platforms in the North Sea, it is possible to safely inject CO2 into the ground, as the area is geographically stable and has retained oil and gas for approximately 20 million years. This makes it a safe location to permanently store CO2.

Carbon capture & storage is high on the agenda as a critical decarbonisation solution. There is general agreement globally that it will be required to meet the carbon emission reduction targets and the aspirations of the Paris Agreement.

According to GEUS, the Danish underground can potentially store 12 to 22 billion tonnes of CO2. This is between 400 and 700 times greater than Denmark’s annual CO2 emissions at the current level.

If the Greensand carbon capture & storage project proves viable, it is set to become one of Europe’s first large-scale carbon capture & storage projects, with potential to store up to eight million tonnes of CO2 annually by 2030.