Monitoring subsurface CO2 emplacement and security of storage using muon tomography

Abstract

Storage of supercritical carbon dioxide in the deep subsurface is arguably the most viable industrial scale process available to stop increase of atmospheric CO2. Today, monitoring CO2 emplacement and possible leakage is a major challenge; methods are episodic and expensive. Cosmic-ray muon tomography has been used to investigate hidden archaeological and geological features. We developed a model to test if this approach would work for monitoring CO2 storage and show that muon detection is a viable method. Our results indicate that we could detect as little as 0.4% change in the mean reservoir density at about 1km depth (equivalent to 7% of pore volume). Hence, cosmic ray muon detection could monitor migration of injected CO2 continuously and inexpensively and help rapid introduction of this essential technology.