Si-geothermometry applied for the interpretation of three-components- mixtures in marine geothermal systems -exploration of the Gülbahce geothermal field, Western Anatolia/ Turkey

Abstract

The geothermal field of Gülbahce is located in western Anatolia/Turkey near Izmir. The University of Izmir IYTE is building-up a campus there. A pre-study was done to investigate whether the campus can be supplied with geothermal heat. Based on hydrogeochemical data, mixing calculations and a modified version of the SiO2-enthalpy diagram were applied to evaluate the reservoir temperature of three-components-mixtures. The temperature of the mixed outcrop water is 35°C. It consists of geothermal sea water, freshwater, and cold sea water. The fraction of freshwater was estimated to be 8%, The contents of Li and Si were interpreted to be generated by the reservoir temperature of 60°C in minimum - lower limit for low-temperature space heating - but to be maybe more than 100°C. This geothermal resource seems to be suitable, but exploitation will be difficult. One production well should satisfy the heat supply. Problems with scaling and corrosion are expected.