The data presented here contains PHREEQC geochemical modeling input and output files to model mineralogical-geochemical reactions due to the CO2 injection at the Ketzin CO2 storage site, Germany. The used modeling tool is PHREEQC version 3.4 (Parkhurst & Appelo, 2013), and the Pitzer database (PITZER.dat) is applied. The geochemical model is conducted to investigate the potential mineral precipitation in the reservoir.

The available characterization of the Stuttgart Formation (Norden & Frykman, 2013) and pristine formation fluid (Würdemann et al., 2010) is used in the models. Ketzin baseline (referred as to B, data collected by Würdemann et al. (2010) and post-CO2 injection (referred as to PI, previously unpublished observation data) brine solutions were sampled and analyzed under the surface (B-S and PI-S) and reservoir conditions (B-R and PI-R). Ketzin reservoir pressure and temperature data were obtained at the observation well Ktzi 202 at a depth of 650m before and after the CO2 injection (previously unpublished observation data).