Carbon Dioxide Site Storage Monitoring Using Cosmic Ray Muons

Climate change drives a global need to decarbonise and reduce emissions of CO2 into the atmosphere. Carbon Capture and Storage (CCS) is a critical technology that enables countries to undergo a fast transition to net zero emissions. The development of efficient and effective carbon dioxide storage involves the act of liquifying and storing carbon dioxide in natural geological reservoirs. As the dense phase CO2 is injected, deep underground, into a suitable storage site it will naturally pool underneath a capping layer, and develop a plume. However, there are many regulatory and other factors which means that simply injecting CO2 into the sub-surface isn't sufficient. Of utmost importance is the need to assure public and operator confidence in the entire CCS process. Notably this also means that the CO2 is, indeed, effectively captured and is not passing through the subsurface and re-entering the atmosphere. Conventionally such monitoring takes place episodically via technologies based on seismic sensing, this paper introduces the first results from a novel monitoring approach which uses muons - naturally-occurring radiation - to provide continuous density information of a CCS plume post-injection. Results from the world's first use of this muon imaging technology in field trials in Norway in summer 2023 will be presented and compared with data from traditional seismic measurements that were executed concomitantly.