Quantitative Seismic Monitoring of a Saline Aquifer: A Feasibility Study for the CO2 Injection (The Pilot Site Ketzin, Germany)

Carbon dioxide (CO2) storage requires a proven monitoring methodology. In this study we investigate whether seismic methods are able to quantitatively detect relatively small amounts of CO2 (20-60 kilotons) injected into a saline aquifer. The 3D time-lapse (4D) seismic data were acquired at Ketzin. 85-95% injected CO2 could be imaged quantitatively. Nevertheless this estimate contains considerable uncertainties. Results of 4D seismic forward modeling at four wells penetrating the reservoir prove this quantitative interpretation supporting the conclusion that the 4D seismic method is a suitable technique to monitor even relatively small amounts of injected CO2 quantitatively.