Suitability analysis and revised strategies for marine environmental carbon capture and storage (CCS) monitoring
Anna Lichtschlag, Christopher R. Pearce, Mikael Suominen, Jerry Blackford, Sergey M. Borisov, Jonathan M. Bull, Dirk de Beer, Marcella Dean, Mario Espósito, Anita Flohr, Jonas Gros, Matthias Haeckel, Veerle A.I. Huvenne, Rachael H. James, Dirk Koopmans, Петер Линке, Matthew C. Mowlem, Abdirahman M Omar, Allison Schaap, Mark Schmidt, Stefan Sommer, James Strong, Douglas P. Connelly
Abstract
Environmental monitoring of offshore Carbon Capture and Storage (CCS) complexes requires robust methodologies and cost-effective tools to detect, attribute and quantify CO 2 leakage in the unlikely event it occurs from a sub-seafloor reservoir. Various approaches can be utilised for environmental CCS monitoring, but their capabilities are often undemonstrated and more detailed monitoring strategies need to be developed. We tested and compared different approaches in an offshore setting using a CO 2 release experiment conducted at 120 m water depth in the Central North Sea. Tests were carried out over a range of CO 2 injection rates (6 - 143 kg d −1 ) comparable to emission rates observed from abandoned wells. Here, we discuss the benefits and challenges of the tested approaches and compare their relative cost, temporal and spatial resolution, technology readiness level and sensitivity to leakage. The individual approaches demonstrate a high level of sensitivity and certainty and cover a wide range of operational requirements. Additionally, we refer to a set of generic requirements for site-specific baseline surveys that will aid in the interpretation of the results. Critically, we show that the capability of most techniques to detect and quantify leakage exceeds the currently existing legal requirements.