Petrophysical characterization of in situ cores after CO2 injection and comparison with batch experiments of the German Ketzin Pilot site

At the Ketzin pilot site for geological CO2 storage in Germany, about 67,000 tons of CO2 were injected. Here we compare porosity and permeability from samples recovered prior to CO2 injection with core data drilled after 4 years of injection. Further batch experiments on Ketzin material under in situ p-T conditions over various time periods investigated by NMR relaxation and mercury injection porosimetry (MIP) complement the real in situ data. However, the observed changes between the different preinjection and post-injection well of the heterogeneous formation are only minor and have no effects on the injection behavior. The pore size related measurements of the batch experiments show only minor deviations The results are consistent with the logging data and confirm the data for the recovered in situ rock cores. Based on present data, the siliciclastic rocks of the Ketzin are not significantly affected by the injection of pure CO2 within this time. (C) 2017 The Authors. Published by Elsevier Ltd.