Revising the static geological reservoir model of the upper triassic stuttgart formation at the ketzin pilot site for CO2 storage by integrated inverse modelling

Abstract

The Ketzin pilot site for CO2 storage in Germany has been operated from 2007 to 2013 with about 67 kt of CO2 injected into the Upper Triassic Stuttgart Formation. Main objectives of this undertaking were assessing general feasibility of CO2 storage in saline aquifers as well as testing and integrating efficient monitoring and long-Term prediction strategies. The present study aims at revising the latest static geological reservoir model of the Stuttgart Formation by applying an integrated inverse modelling approach. Observation data considered for this purpose include bottomhole pressures recorded during hydraulic testing and almost five years of CO2 injection as well as gaseous CO2 contours derived from 3D seismic repeat surveys carried out in 2009 and 2012. Inverse modelling results show a remarkably good agreement with the hydraulic testing and CO2 injection bottomhole pressures (R2 = 0.972), while spatial distribution and thickness of the gaseous CO2 derived from 3D seismic interpretation exhibit a generally good agreement with the simulation results (R2 = 0.699 to 0.729). The present study successfully demonstrates how the integrated inverse modelling approach, applied for effective permeability calibration in a geological model here, can substantially reduce parameter uncertainty.