Integrated Assessment and Geoinformation Modeling of Geothermal Energy Potential for Sustainable Heat Supply in Turkmenistan

Abstract

The study comprehensively evaluated the geothermal energy potential of Turkmenistan and demonstrated the feasibility of its application for sustainable heat supply. Field investigations involved drilling wells at depths ranging from 600 to 2000 meters to collect representative samples of geothermal water. The measured wellhead temperatures averaged 57.4 °C, with maximum values reaching 83 °C, and discharge rates varied between 9 and 45 liters per second depending on geological conditions. Laboratory tests determined the specific heat capacity to be approximately 4.18 kJ/(kg·K) and thermal conductivity between 0.59 and 0.68 W/(m·K), confirming favorable heat transfer characteristics. A three-dimensional digital model of the temperature field down to 5000 meters depth was developed, identifying several areas with a predicted thermal potential exceeding 400 GJ/km². Experimental modeling of greenhouse heating systems validated the high energy efficiency of geothermal utilization, achieving heating capacities up to 395 kW and system efficiency factors up to 0.84. The estimated annual geothermal energy production was about 18.3 million Gcal, equivalent to saving up to 2.8 million tons of conventional fuel and reducing CO2 emissions by approximately 4.1 million tons per year.