Time-lapse analysis of sparse 3D seismic data from the CO2 storage pilot site at Ketzin, Germany

The Ketzin pilot site is the first European on-shore CO2 storage project site. Injection started in June 2008 and until the latest repeat survey in February 2011 around 45,000 t of CO2 had been injected into a saline aquifer at approximately 630 m depth. Seismic monitoring methods that have been applied at the Ketzin site comprise baseline and repeat observations at various scales. We present here time-lapse results from sparse 3D seismic data measurements at Ketzin, which were acquired to link downhole surveys with conventional 3D surface seismic surveys. The results are consistent with the 3D seismic time-lapse studies over the injection site and show that the sparse 3D geometry can be used to map the CO2 in the reservoir at a significantly lower effort than the conventional 3D surveying. The last repeat survey indicates preferential migration of the CO2 to the west. There are no indications of migration into the caprock on either of the repeat surveys.

► Presented are time-lapse results from sparse 3D seismic data at the Ketzin site.
► A comparison with the full 3D results is conducted.
► The sparse 3D geometry can qualitatively map the CO2 in the reservoir.
► The last repeat survey indicates preferential migration of the CO2 to the west.
► Time-lapse analysis indicate that there is no leakage into the caprock.