A three-dimensional numerical model of Yerköy (Yozgat) hydrogeothermal system, Central Anatolia, Türkiye

Yilmaz Turali E., Simsek S.

Journal of African Earth Sciences, vol.198, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 198
  • Publication Date: 2023
  • Doi Number: 10.1016/j.jafrearsci.2022.104815
  • Journal Name: Journal of African Earth Sciences
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Geobase, INSPEC
  • Keywords: Conceptual model, Fault controlled hydrogeothermal system, Natural state, Numerical model, Permeability, Temperature distribution
  • Hacettepe University Affiliated: Yes


© 2022 Elsevier LtdYerköy geothermal field which is located in the city of Yozgat in Central Anatolian Region, is one of the low temperature fields that is investigated for geothermal heating. In 2006, two exploration/production wells were drilled at 550 m and 750 m below the surface. The maximum bottom-hole temperatures ranged from 67 °C to 72 °C, respectively in these wells. These two exploration wells are provided the new information about the geothermal field and the reservoir of Yerköy. In this study, these well-data were evaluated for the first time together with the surface data obtained from the field. The aim of this study is to develop a conceptual model of the Yerköy geothermal system using these well data and geological, hydrogeological and hydrogeochemical studies and to simulate this model to define the three-dimensionally subsurface conditions. Numerical simulation was performed by using TOUGH2 Software. The calculated model results were compared with the measured static pressure and temperature in the wells for the calibration. According to the calibrated model, the permeability values of fractured rocks and fault are between 9.0 × 10−14 and 1.0 × 10−12 m2. The geothermal fluid with a mass flow of 18 kg/s with the enthalpy of 415 kJ/kg at the base boundary rises along the fault zones and transported into the fracture systems, which we define it as the reservoir in the immediate vicinity of the faults.