3. Storing the CO2 in the North Sea
From the Northern Lights onshore storage facilities in Øygarden, Norway, the CO2 will be pumped through a subsea pipeline to the Aurora storage complex around 100 km offshore. The CO2 will be injected into the storage complex, which is a 2.6 km deep saline aquifer.
The aquifer has two primary storage units (sand reservoirs) and an overlaying sealing layer (cap rock) that ensures the CO2 containment. The sand reservoirs have pore space between a rock framework, and this porous space is currently filled with brine (saline water).
The CO2 will displace the brine and stay trapped in the porous space, where a small portion will mineralise, some of it will dissolve in the brine, and most of it will be permanently structurally trapped.