Evaluation of a resistivity model derived from time-lapse well logging of a pilot-scale CO2 injection site, Nagaoka, Japan

► A rock physics model for resistivity at a CO2 injection site was constructed. ► A Waxman-Smits model was applied to fit the shaly sandstone log data. ► The effect of dissolved CO2 on the resistivity model was also considered. ► The model could estimate CO2 saturation at the site with sufficient accuracy.