Cosmic Ray Muon Imaging for the Monitoring and Characterization of Injected CO2 in Subsurface Reservoirs

Summary Cosmic ray muon radiography is the exploitation of the attenuation of naturally-occurring muons in order to image the subsurface. The approach is analogous to medical x-ray imaging, enabling 3D density reconstrutions through the application of density inversion algorithms. In this project, the authors have undertaken the first muon image of stored CO2 at a very shallow site, in order to demonstrate the sensitivity of the muon imaging technique to CO2 induced local density changes. The observed plume was in good agreement with an independent set of seismic measurements.