CO2 Monitoring at the Ketzin Pilot Site with Joint Inversion: Application to Synthetic and Real Data

Summary To improve the imaging and the subsequent quantification of the injected CO2 at the Ketzin pilot site, as well as to improve knowledge about CO2 storage at Ketzin, we combine different geophysical techniques (e.g., seismics and geoelectrics) using joint inversion. The resulting 3D models of geophysical parameters, and their changes over time, can then be jointly interpreted to obtain reservoir parameters (e.g., pressure and saturation), using rock physics inversion. To accomplish this, a new joint inversion method using structural constraints was developed combining seismic full waveform inversion (FWI) and electrical resistivity tomography (ERT). The joint inversion combines the strength of the different techniques (e.g., high spatial resolution of seismics and the sensitivity of geoelectrics in terms of CO2 saturation), and results in models that are consistent with each other, with all data sets, and any a priori information. This new method is tested using realistic synthetic-, and real data from the Ketzin pilot site in Germany, and the results are presented.