Fluid–CO₂ injection in a hypersaline volcanic systems
a reactive transport and experimental evaluation with application to the Tuzla Geothermal Field, Türkiye
Serhat Tonkul (TU Delft - Reservoir Engineering, Izmir Institute of Technology)
Selçuk Erol (Middle East Technical University)
Alper Baba (Izmir Institute of Technology)
Simona Regenspurg (GFZ Helmholtz-Zentrum für Geoforschung)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
This study evaluates the CO2 sequestration capability of the Tuzla Geothermal Field (TGF) in northwest Türkiye under reservoir conditions (200 °C and 4.4 MPa). While ongoing studies at TGF have investigated CO2 co-injection primarily for geothermal heat extraction, the present study focuses on the associated potential for long-term CO2 storage. To this end, CO2–brine–rock interactions were examined through batch reactor experiments and reaction path modeling using the PhreeqC geochemical tool. The experiments revealed complex dissolution/precipitation reactions that altered reservoir properties, with mineralogical analyses (XRD, XRF, SEM, and EDS) showing the formation of secondary phases such as calcite, kaolinite, and Ca-rich aluminosilicates. These results indicate that the Tuzla reservoir rocks provide sufficient divalent cations to support mineral trapping under reservoir conditions. Overall, our findings highlight that, in addition to its promise for heat extraction, CO₂ co-injection at TGF offers an opportunity for permanent geological storage, thereby strengthening the dual benefits of this approach.
help_outline