Seismic Interferometry Applied to Walkaway VSP Data in the Seismic Monitoring of CO2 Storage Security - A Synthetic Study

The CO2SINK project is the first EU onshore CO2 storage project and officially started in April 2004 at the Ketzin anticline near Berlin, Germany. One of the seismic methods that has been applied there is vertical seismic profiling (VSP). VSP data may allow faults to be detected that cannot be imaged with surface seismic data. These faults may be a security risk for CO2 storage. However, the imaging range of traditional VSP methods is limited, therefore, we decided to test the potential of seismic interferometry to redatum walkaway VSP (or moving source profiling, MSP) data sets to SWP (single well profile) data sets. The redatumed data sets may provide better image resolution because the redatumed geometry is closer to the target fault. We generated both acoustic and elastic walkaway VSP synthetic data sets based on the geological structure at Ketzin, and then applied seismic interferometry to redatum the data sets to SWP data sets to enhance the imaging of a fault.