Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Fluid-CO2 Injection in a Hypersaline Volcanic Systems: A Reactive Transport and Experimental Evaluation with Application to the Tuzla Geothermal Field, Turkiye(Springer, 2026) Tonkul, Serhat; Erol, Selcuk; Baba, Alper; Regenspurg, SimonaThis study evaluates the CO2 sequestration capability of the Tuzla Geothermal Field (TGF) in northwest T & uuml;rkiye under reservoir conditions (200 degrees 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.Article Development and Validation of Regression Model via Machine Learning to Estimate Thermal Conductivity and Heat Flow Using Igneous Rocks from the Dikili-Bergama Geothermal Region, Western Anatolia(Pergamon-Elsevier Science Ltd, 2026) Ayzit, Tolga; Sahin, Onur Gungor; Erol, Selcuk; Baba, AlperThermal conductivity is a fundamental parameter that significantly influences the thermal regime of the lithosphere. It plays a crucial role in a variety of geological applications, including geothermal energy exploration, igneous system assessment, and tectonic modeling. In this study, a machine learning approach is used to predict the thermal conductivity of igneous rocks based on the composition of major oxides. A total of 488 samples from different regions of the world were analyzed. The thermal conductivity values ranged from 1.20 to 3.74 Wm(-1) K-1 and the mean value was 2.61 Wm(-1) K-1. The Random Forest (RF) algorithm was used, resulting in a high coefficient of determination (R-2 = 0.913 for training and R-2 = 0.794 for testing) and a root mean square error (RMSE) of 0.112 and 0.179, respectively. Significance analysis of the traits identified SiO2 (>40 %), Na2O (>15 %) and Al2O3 (>10 %) as the most influential predictors. The study presented results from the Western Anatolia region, where felsic rocks had the highest thermal conductivity (mean = 2.69 Wm(-)(1)K(-)(1)) compared to mafic (mean = 2.34 Wm(-)(1)K(-)(1)) and ultramafic rocks (mean = 2.39 Wm(-)(1)K(-)(1)). In addition, the study evaluated the predictive capabilities of machine learning models for the igneous rocks of the Dikili-Bergama region and compared the results with those of saturated models. Using these data, we calculated heat flow values of up to 400 mWm(-2) under saturated conditions in western Anatolia. These results highlight the value of integrating geochemical data with machine learning to improve geothermal resource exploration and lithospheric modeling.Article Citation - WoS: 16Citation - Scopus: 17Experimental Study and Kinetic Modeling of High Temperature and Pressure Co2 Mineralization(Elsevier Sci Ltd, 2024) Berndsen, Maximilian; Erol, Selcuk; Akin, Taylan; Akin, Serhat; Nardini, Isabella; Immenhauser, Adrian; Nehler, MathiasThe potential for in-situ CO2 sequestration was analyzed experimentally for one basaltic hyaloclastite sample from the Nesjavellir geothermal reservoir in Iceland and three metasedimentary rock samples from the K & imath;z & imath;ldere geothermal field in Turkey. Based on batch reaction experiments, this paper demonstrates the interaction between a CO2 gas-charged fluid and rock samples from these reservoirs. The experiments were conducted at 260 degrees C and 0.8 MPa, and 105 degrees C and 17 MPa for the basaltic and metasedimentary rocks, respectively. The experimental results indicate that CO2 sequestration within the glassy basaltic rocks is hampered by zeolite, chlorite, and anhydrite, which compete with carbonate minerals to uptake divalent cations at the P-T conditions applied. In contrast, the carbonation process for the metasedimentary rocks is inhibited by their mineralogical composition. Generally, these rocks are less reactive and provide an insufficient supply of divalent cations. The batch reactor experiments were numerically simulated with the PHREEQC geochemical modeling program. The simulations indicate that CO2 sequestration is feasible at the tested P-T conditions, provided that silicate and SO4 mineralization is suppressed for the basaltic rocks and that there is an effective source of divalent cations for the metasedimentary rocks.