Connelly et al. (2022): Assuring the integrity of offshore carbon dioxide storage

D.P. Connelly, J.M. Bull, A. Flohr, A. Schaap, D. Koopmans, J.C. Blackford, P.R. White, R.H. James, C. Pearce, A. Lichtschlag, E.P. Achterberg, D. de Beer, B. Roche, J. Li, K. Saw, G. Alendal, H. Avlesen, R. Brown, S.M. Borisov, C. Böttner, P.W. Cazenave, B. Chen, A.W. Dale, M. Dean, M. Dewar, M. Esposito, J. Gros, R. Hanz, M. Haeckel, B. Hosking, V. Huvenne, J. Karstens, T. Le Bas, T.G. Leighton, P. Linke, S. Loucaides, J.M. Matter, S. Monk, M.C. Mowlem, A. Oleynik, A.M. Omar, K. Peel, G. Provenzano, U. Saleem, M. Schmidt, B. Schramm, S. Sommer, J. Strong, I. Falcon Suarez, B. Ungerboeck, S. Widdicombe, H. Wright, E. Yakushev IN: Renewable and Sustainable Energy Reviews 166:112670; DOI:10.1016/j.rser.2022.112670

The public must be assured that potential leakages from storage reservoirs can be detected and that therefore the CO2 is safely contained. The authors conducted a controlled release of 675 kg CO2 within sediments at 120 m water depth, to simulate a leak and test novel detection, quantification and attribution approaches. The authors show that even at a very low release rate (6 kg day⁻¹), CO2 can be detected within sediments and in the water column. Alongside detection the authors show the fluxes of both dissolved and gaseous CO2 can be quantified. The CO2 source was verified using natural and added tracers. The experiment demonstrates that existing technologies and techniques can detect, attribute and quantify any escape of CO2 from sub-seabed reservoirs as required for public assurance, regulatory oversight and emissions trading schemes.