At the 4th International Workshop on Offshore Geologic CO2 Storage, the STEMM-CCS sessions provided a lot of reassurance on offshore environmental monitoring. Held jointly with the STEMM-CCS Open Science Meeting, the workshop attracted 150 CCS specialists from across the globe to the western Norwegian city of Bergen, with the University of Bergen playing excellent and welcoming hosts.

The STEMM-CCS sessions conveyed many results from this remarkable project funded by the EU Horizon 2020 programme. The overall conclusion was that it demonstrated that in the unlikely event of a CO2 leak occurring, it can be successfully detected, attributed and quantified using the range of sensors, instruments, tools and techniques developed and used by the project.

Central to the project was the controlled release experiment; the first sub-seafloor release of CO2 to be carried out under real life conditions and water depths, implemented at a site near the Goldeneye platform in the North Sea. In considering the 'finding a needle in a haystack' scenario, the project included some monitoring cost estimates, which were reasonable against overall CCS project costs.

Results also enabled the understanding of the complex environmental baselines, and modelling and assessment of the local, regional and wider impacts of hypothetical leak scenarios. This included placing in context against the much more extensive impacts from other marine activities. The project also investigated fluid flow pathways in the overburden.

There is too much information to be covered in a single blog; there are more than twenty papers going to a Special Issue of the IJGGC!And so the project has drawn together a high-level summary of the results and tools in a Research Highlights publication, which also captures great images of the work at the field site in the North Sea in May 2019. View the Research Highlights and more information here.

IEAGHG facilitated the results to be presented at the London Convention annual meeting in October 2019, as evidence-base in support of the CO2 export proposal. The former chair of the London Convention's Scientific Group, Craig Vogt (ex US EPA), responded:

We wrote the words in the guidance document in 2006 with good intentions, and now we have just seen the STEMM-CCS project prove we can do what we wrote.

Craig Vogt

IEAGHG was honoured to serve on the STEMM-CCS Stakeholder Advisory Board. Well done to all involved for a very successful project. We look forward to the tools being used on offshore CCS projects around the world.

Tim Dixon


The RSS James Cook, RV Poseidon, and the Goldeneye platform. Courtesy NOC.