Simulation of Time-lapse for the Ketzin CO2 Storage Site Assuming a Single Seismic ACROSS and Multi-seismic Receivers

Time-lapse-studies of the physical state of the injection zones or fractured zones is a key component in the CCS, CO2-EOR and shale-gas development. Monitoring systems using the seismic-ACROSS can be one of the most suitable methods for these purposes. We have made simulations assuming a single ACROSS source and a multi-seismometer- array installed at the Ketzin pilot site for CO2 storage in Germany. At Ketzin, CO2 has been injected since July, 2008. About 62 ktons of super-critical CO2 have been injected to date at about 630-650 m depth, and injection will continue into 2013. To monitor how the injected CO2 behaves after injection is extremely important for studying the long term behavior of a storage site. The objectives of this study are to find the most suitable locations for an ACROSS-source and receivers at the Ketzin site given infrastructure constraints. Results using the velocity-density structure site model show that a rectangular injection zone 200 m wide and 10 m thick at 665 m depth is well imaged. This result encourages us to plan for using an ACROSS-source for time-lapse-studies to monitor the migration of injected CO2 at Ketzin, even after injection has finished.