How

Carbon Capture and Storage (CCS) involves capturing the CO₂ where it is produced, for example in a coal-fired power station, or at a cement or steel manufacturing plant, transporting it to a geological repository and pumping it deep into the ground where it is permanently stored and thus locked away from the atmosphere.

Illustration © of UNIS

Capture and transport

Over the past 20 years a lot of research has been done on various methods for capturing and transporting CO₂ safely and successfully in Norway. The Technology Centre of Mongstad (TCM), the world’s largest test centre for CO₂ capture was opened  in 2012, and Norway’s new flagship “Longship CCS” will take this technology to the next level.

Storage

Once captured the CO₂ is transported by pipeline or ship to a permanent storage site and pumped into a deep underground geological repository, commonly 2-3 km below the surface or seafloor. A good geological repository consists of a large underground structure or ‘container’, with a porous storage rock and an impermeable cap rock on top of the storage rock to seal it off. This type of repository has held Norway’s oil and natural gas reserves safely underground for millions of years, and therefore lends confidence that CO₂ also can be stored safely for a long time.

Any new CO₂ storage site needs rigorous verification, and CO₂ storage sites in use sites that have  reached their storage capacity, are monitored to guarantee that the CO₂ remains in the repository. The verification and monitoring processes ensure that the storage rock has sufficient pore space, that CO₂ can be injected at optimal injection rates, that migration of the CO₂ in the storage rock can be predicted, and that the cap rock remains an efficient seal.

Verification and monitoring processes require deep knowledge of the geological, geophysical, and geomechanical properties of the repository. This is where the UiO Geoscience department can best deploy their experts. To research and advise on potential CO₂ repositories and develop and improve monitoring techniques.