The STEMM-CCS project has successfully achieved all of its goals. Using data collected on a large number of research cruises, the most extensive characterization of the marine environment in the Central North Sea has been produced, compiling geological, hydrographical and chemical data for the area. This has enabled the identification of further data that are needed to fully understand the complex North Sea environment. Application of advanced computer models has allowed identification of the temporal behaviour of key biogeochemical features of the North Sea.
STEMM-CCS carried out one of the world’s most ambitious in situ experiments, successfully performing a controlled release of CO2 to simulate a low-level leak from a storage reservoir. This experiment was performed at a water depth of 120m in the North Sea above the Goldeneye hydrocarbon reservoir, a proposed site for CO2 storage.
The project advanced a suite of in situ sensors, including the most accurate and sensitive total alkalinity sensor ever produced. Techniques for automated analysis of images for baseline surveys were also advanced and published and a number of papers were published on the advancement of the models used and developed in the STEMM-CCS project.
Two geophysics cruises gathered seismic data over an existing chimney structure in the North Sea and the area over the Goldeneye storage complex. A third cruise performed the first drilling of a North Sea chimney structure, acquiring long sediment core samples from the Scanner pockmark in the North Sea. These data allow predictions about the role existing geological chimneys may have in the potential leakage of CO2 from storage reservoirs in the future.
Novel engineering approaches were used for the main release experiment equipment including: a bespoke drill rig from Cellula Robotics, to insert pipes below the seabed to release the CO2 at the right depth and location for the study; a system to place 3 tonnes of CO2 onto the seabed safely, linked to the release pipes and under the control of the ship above; and, upgrading a commercial AUV to increase its capability, allowing more measurements of the chemical and physical environment during its photo imaging surveys of the seabed.
The project has generated interest from scientific, policy and public communities and has presented at a large number of international CCS and technology fora. STEMM-CCS partners are on the advisory boards of projects in the USA and have growing links with Norwegian, Japanese and Australian funded projects.
