3D modelling techniques. © BRGM - Patrick Desbordes

Explained: ULTimateCO2 in simple terms

3D geometrical model of Paris Basin showing the depositional environment of the Dogger. © BRGM - Sunseare Gabalda


The research carried out within ULTimateCO2 is highly complex – but this is not a reason for not explaining what we’re doing to people and leaving them in the dark



CO2 Capture and Storage, known as CCS, encompasses a range of technologies to capture CO2 at power stations and industrial plants, transport it by pipeline or ship to a storage location, and inject it via a well into a suitable deep geological formation for permanent storage. CCS is a smart solution that can contribute to reducing our CO2 emissions and therefore to tackling climate change and associated impacts (sea level rise, ocean acidification,…). But how can we be sure that the CO2 will not leak to the surface or harm the subsurface environment? … and this not only in the years immediately after injection, but also in the “long term”, i.e. 1000s of years after site closure? Is CO2 storage safe for future generations, …for our grandchildren’s children’s children… and beyond?


  • a four-year project coordinated by BRGM, uniting 12 partners (research institutes, universities, industrialists) and a varied panel of experts (NGOs, national authority representatives, IEAGHG, …) in the aim of shedding light on the long-term processes associated with the geological storage of CO2.
  • research is based on a multidisciplinary approach bringing together: laboratory experiments, numerical modelling and field data. The combination of these three methods of study leads to more robust findings. The results will increase our understanding of the long-term effects of CO2 storage in terms of the main physical and chemical processes involved and their impacts.

© BRGM - Didier Depoorter


In order to be in a position to guarantee safe and efficient CO2 storage in the long term, we need to zoom in on any potential failure scenarios. Our research focuses on three crucial elements (or potential ‘weak spots’) of a storage site:


But studying small-scale, localized features does not give the full picture of the whole storage site and any impact on its regional surroundings. This is why ULTimateCO2 also focuses on the regional scale, namely that of a sedimentary basin (10s to 100s km extension) in order to cover the whole CO2 storage site permit area, including the CO2 plume and its extension from the injection point (< 10 km).

But are the research results reliable? What level of confidence can we have? Because ULTimateCO2 studies highly complex processes on time scales stretching to several thousands of years, we apply an uncertainty assessment to the numerical modeling results to increase insight into the spectrum of the possible outcomes from the modelling. Different uncertainty quantification approaches will be adopted to accurately estimate the errors associated with the simulations carried out, which will increase confidence in our predictions and guidelines on the long-term behaviour of a CO2 storage reservoir.

So what will be achieved through 4 years of collaborative research?© BRGM - François Michel

Increased confidence in the long-term efficiency and safety of CO2 storage will be gained through:

  • Improved scientific knowledge of the physical and chemical processes that could influence the long-term fate of geologically stored CO2 (CO2 trapping mechanisms in the reservoir; sealing capacity of the caprock; leakage associated with mechanical and chemical damage in the well vicinity)
  • Improved and validated tools for predicting long-term storage site performance
  • More robust long-term predictions of CO2 evolution during geological storage

And what will the results be used for?

The project outcomes will be disseminated to four target groups for their use: EU policy makers & regulators, CO2 storage developers & industry, the scientific community and NGOs (who in turn reach the general public) in the aim of increasing each group’s understanding of the long-term efficiency and safety of CO2 geological storage. Some concrete examples are:

  • Guidelines on the long-term performance of storage sites in terms of efficiency and security aimed at operators and regulators
  • A better understanding by the scientific community of what to monitor, resulting in better designed monitoring programmes
  • Reassurance, based on scientific facts, of citizens concerned by a planned CO2 geological storage site
  • Sound criteria on which a site can be defined as secure: vital before transferring responsibility of a site after closure from CO2 storage operators to authorities

Dernière mise à jour le 27.01.2016