Characterization and Comparison of geothermal fluids geochemistry within the Kızıldere Geothermal Field in Turkey: New findings with power capacity expanding studies

Abstract The Kizildere geothermal field is the first known high-temperature geothermal field in Turkey. The field is located in the Buyuk Menderes Graben (BMG), Western Anatolia (Turkey). There are four production sections (reservoir-I, II, III, and IV) with different rock compositions and geochemical characteristics in the production area. Identifying and characterizing these production units may give a good insight into field development plans for a sustainable production. This study aims to characterize production sections of the Kizildere geothermal field using geology, hydrogeochemical properties such as chemistry, stable isotope, and non-condensable gas compositions. The results of gas and water analysis showed that geothermal fluids are of a meteoric origin in all producing sections. It was also found from the analyses that more intensive water-rock interactions take place as the reservoir temperature irises. Based on the different geochemical characteristics of each producing section, we thought that impermeable sediments like mica-schists and chlorite-schists lying between the reservoir units act as a seal. In light of this study, it can be concluded that the Kizildere geothermal reservoir is very heterogeneous due to vertically compartmentalized reservoir sections that require a unique injection-production configuration for a sustainable production lifetime.