Characterization and Comparison of geothermal fluids geochemistry within the Kızıldere Geothermal Field in Turkey: New findings with power capacity expanding studies. (July 2021)

• Record Type: Journal Article
• Authors: Tut Haklıdır, Füsun S.; Şengün, Raziye; Aydın, Hakkı
• Is Part Of: Geothermics. Volume 94(2021)
• Publication Date: 2021-07
• Subjects: Geochemistry -- Geothermal reservoir -- Fluids -- Stable isotopes -- Western Anatolia -- Kızıldere; Hydrogeology -- Periodicals; Geothermal resources -- Periodicals; Énergie géothermique -- Périodiques; GEOTHERMAL ENGINEERING; GEOTHERMAL ENERGY; GEOTHERMAL EXPLORATION; Geothermal resources; Hydrogeology; Periodicals; Electronic journals; 621.44
• DOI: 10.1016/j.geothermics.2021.102110
• Languages: English
• ISSNs: 0375-6505

Abstract

Highlights: During the new and deep drilling studies, it was discovered that Kızıldere geothermal systems consist of four reservoirs. Geothermal waters from deep reservoirs have Cl − at levels between 92 mg/l and 100 mg/l while new deep wells have relatively higher Cl − than all production wells across the Kızıldere geothermal field. Silica concentrations in thermal waters reach up to 732 mg/l in the deep reservoir while the maximum silica level is 507 mg/l in the shallow reservoir and changes between 115 mg/l and 402 mg/l in re-injection wells. δ 13 C isotopes show that the origin of the CO2 gas is marble levels of metamorphic rocks at reservoirs at Kızıldere geothermal field. The source of sulfate in thermal waters might be due to the dissolution of gypsum or the oxidation of sulfides including pyrite and pyrrhotite. Abstract: The Kızıldere geothermal field is the first known high-temperature geothermal field in Turkey. The field is located in the Büyük 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 Kızıldere 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 Kızıldere geothermal reservoir is very heterogeneous due to vertically compartmentalized reservoir sections that require a unique injection-production configuration for a sustainable production lifetime.