Passive seismic monitoring in two carbon sequestration sites, a data driven approach

Passive seismic imaging during CO2 injection in geological formations gains more and more interest as part of an integrated monitoring approach. For two EU CO2 storage project sites, RECOPOL - Enhanced Coal-Bed Methane pilot site in Kaniów (Poland) and CO2SINK- CO2 injection in a saline aquifer in Ketzin (Germany), the Netherlands Geological Survey (TNO) has designed and implemented multi-component permanent seismic monitoring systems for both passive and active seismic observations. To process these passive seismic data, TNO developed a software package based on spectral-ratio preprocessing of the data and back-projection of seismic events. The approach is data driven in order to meet the variations in data quality caused by temporal and spatial changes in environmental site conditions. In this paper we present the processing workflow and initial results from both sites