Quantification of Injected CO2 Volumes from 4D Seismic Anomalies & Associated Uncertainties

To facilitate large scale deployment of Carbon Capture and Storage (CCS) a reliable monitoring strategy must be in place to verify that the injected CO2 remains well contained and is not leaking from the storage reservoir. Monitoring using time-lapse (4D) active seismic benefits from a large amount of know-how from the oil and gas industry and is one of the most accurate methods to determine the spatio-temporal evolution of the plume. Here we present a workflow developed to quantify the volume of CO2 directly from 4D seismic anomalies by forward simulating the expected seismic response using a petro-elastic model. The method has been applied to successfully model case study data from the Otway pilot project and has been able to quantify the mass of injected CO2 from the observed 4D anomalies.