Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 1Citation - Scopus: 1Assessing Seferihisar-Izmir (Turkiye) Geothermal Energy Prospects Through Marine Seismic and Field Geology Data Modelling(Pergamon-elsevier Science Ltd, 2025) Kilinc, Gizem; Cifci, Gunay; Gunaydin, Seda Okay; Hasozbek, Altug; Gurcay, Savas; Gungor, Talip; Cobanoglu, MelihSeferihisar (Izmir) is one of the most significant geothermal regions in the Aegean of Western Anatolia, Turkiye, due to its high geothermal gradient, extensive fault systems, and unique interaction between marine and meteoric waters that create distinct geothermal reservoirs. This study evaluates the geothermal potential and geological characteristics of the Seferihisar area by integrating marine seismic data with onshore geological observations. Specifically, this study combines: (i) geological and geochemical data from geothermal wells along the Tuzla Fault, (ii) high-resolution multichannel seismic reflection data from the Sigacik and Kusadasi Bays, and (iii) correlated onshore and offshore geological and geophysical datasets to develop a 2D conceptual cross-section and a 3D fault model. Geochemical analyses, including water geochemistry, XRF, and isotope studies, reveal that geothermal fluids in the region originate from a mix of meteoric and marine sources. Chloride concentrations in geothermal wells reach approximately ranging from 11,692 to 12,000 ppm, confirming significant seawater intrusion, while geothermometers estimate reservoir temperatures in the range of 220-280 degrees C. Isotopic data, such as He-3/He-4 ratios (similar to 0.9 Ra), suggest minor mantle involvement, and Ar-40/Ar-36 ratios ranging 301 that indicate crustal contributions to the geothermal fluids. These isotopic signatures provide critical insights into the sources and circulation dynamics of geothermal systems. Through integrated 2D conceptual cross-sections and 3D fault modeling, the study identifies the marine extension of the Tuzla Fault and its role in fluid dynamics, including up-flow and out-flow processes. The fault's continuities are linked to geothermal gradients and active fluid pathways, making the Tuzla Fault a critical target for geothermal exploration. The harmonized models suggest three potential drilling sites with high thermal gradients and fault-controlled fluid flow, optimizing the exploration strategy. Scaling and corrosion challenges in production wells are addressed through the application of inhibitors, which are integral to ensuring sustainable operation and long-term system performance. These multidisciplinary findings provide likely actionable insights into optimizing resource extraction, reducing environmental impact, and improving the long-term performance of geothermal systems. The study supports sustainable geothermal energy development in the Seferihisar region by addressing production challenges and guiding effective resource management.Article Effect of Degassing on Scaling in Hypersaline System: Tuzla Geothermal Field, Turkey(Springer Science and Business Media Deutschland GmbH, 2025) Tonkul, S.; André, L.; Baba, A.; Demir, M.M.; Regenspurg, S.; Kieling, K.A serious issue with geothermal power plants is the loss of production and decline in power plant efficiency. Scaling, also known as mineral precipitation, is one of the frequently-observed issue that causes this loss and decreasing efficiency. It is heavily observed in the production wells when the geothermal fluid rises from the depths due to a change in the fluid’s physical and chemical properties. Scaling issue in geothermal power plants result in significant output losses and lower plant effectiveness. In rare instances, it might even result in the power plant being shut down. The chemistry of the geothermal fluid, non-condensable gases, pH, temperature and pressure changes in the process from production to reinjection, power plant type and design, and sometimes the materials used can also play an active role in the scaling that will occur in a geothermal system. ICP–MS was used to evaluate the chemical properties of the fluids. On the other hand, XRD, XRF and SEM were used to investigate the chemical and mineralogical compositions of the scale samples in analytical methods. For the numerical approach, PhreeqC and GWELL codes were used to follow the chemical reactivity of the geothermal fluid in Tuzla production well. The novelty of this study is to determine potential degassing point and to characterize the mineralogical assemblage formed in the well because of the fluid composition, temperature and pressure variations. During production, geothermal fluids degas in the wellbore. This causes a drastic modification of the chemistry of the Tuzla fluids. This is why it is focused the calculations on the nature of the minerals that are able to precipitate inside the well. According to simulation results, the degassing point is estimated to be about 105 m depth, consistent with the field observations. If a small quantity of precipitated minerals is predicted before the boiling point, degassing significantly changes the fluid chemistry, and the model predicts the deposition of calcite along with smaller elements including galena, barite, and quartz. The simulation results are consistent with the mineral composition of scaling collected in the well. © The Author(s) 2024.Article Citation - WoS: 8Citation - Scopus: 8Structural Controls and Hydrogeochemical Properties of Geothermal Fields in the Varto(TÜBİTAK Scientific & Technological Research Council Turkey, 2021) Uzelli, Taygun; Sener, Mehmet Furkan; Dolek, Iskender; Baba, Alper; Sozbilir, Hasan; Dirik, Ramazan KadirVarto and the surrounding region have important geothermal fields, developing in strike-slip tectonic setting in East Anatolia, which resulted from the collision of the Arabian and Eurasian plates. The main structural elements in the area are the NE-trending sinistral and NW-trending dextral strike-slip fault segments and N-S trending extension zones. In order to determine fault-controlled geothermal circulation, it is very important to fully characterize the structural elements in these complex environments. The widely distributed volcanic rocks have fracture and crack systems that play an important role in surface infiltration, geothermal fluid, and groundwater circulation. Especially in areas where the fault segments intersect, hot springs outlets and natural resources easily come to the surface. In order to understand the flow paths of geothermal fluid along the faults in these geothermal systems, it is necessary to determine the stress state of the faults and to map the distribution of the structural elements. For this reason, we conducted a detailed study on the Varto Fault Zone, which has important geothermal fields in Eastern Anatolia. We present conceptual models of the geothermal fields in the Varto region that show favorable geothermal activity on the intersecting fault segments, fault bends, step-overs, and accompanying fracture-crack sets. As a result, we emphasize that the planes of strike-slip faults in transtensional areas are more favorable for secondary permeability and enhances the geothermal fluid circulation, and this can be supported by hydrogeochemical data.