3D Processing of Seismic Data from the Ketzin CO2 Storage Site, Germany

Sammanfattning: The accumulation of CO2 in the atmosphere is considered to be the main reason for the global warming effect. The emissions can be reduced substantially by capturing and storing the CO2. The CO2SINK project was Europe’s first onshore project for the geological storage and monitoring of CO2. This project started operation near the town of Ketzin, Germany in the North East German basin in April 2004 and has continued as the CO2MAN project since April 2010. The main focus of the project was to develop the basis for Carbon Capture and Storage techniques by injecting CO2 and monitoring of CO2 in a saline aquifer in order to develop confidence for future geological storage of CO2 in Europe. In September 2004, a pilot seismic survey was performed in order to determine the necessary parameters for the conduction of a later 3D baseline seismic survey[i].  The pilot survey was performed along two perpendicular profiles near to the CO2 injection site. Pseudo 3D and 2D reflection seismic data were acquired. The results from 2D processing of the data contributed to planning of the 3D baseline survey. In this study the pseudo 3D data from the pilot seismic reflection survey is used to perform 3D processing for the first time. A significant part of the study is the correlation of results with the 3D baseline seismic survey and borehole data. All significant horizons, possible faults and traces of remnant gas were identified. Correlation with the 3D baseline, integration with the borehole data and time/depth contour maps showed good agreement with the 3D baseline survey and well log data. Low fold data, acquisition geometry, time shifts and source generated noise produces severe distortion in the data. Due to these limitations it was difficult to obtain good quality images. Careful processing that involved static corrections and more accurate velocity analysis were the key steps for successful imaging. These results were combined with bore-hole information for an integrated interpretation.