Geothermal Exploration in Damt Geothermal Field, Dhala province, Western of Yemen

Abstract

Damt geothermal field is one of the five significant geothermal fields in Yemen, which are (Al lisi - Isbil, Al Qafr, Damt, Taiz and Red Sea lowland geothermal field). Damt geothermal field is located in Dhala province, in the east-western part of Yemen and 200 km away from the capital city, Sana’a. Geology and geothermal detailed explorations carried out by the Yemeni Geothermal Development Project (GDP) team and presents in this paper. The main geothermal manifestations and surface hydrothermal alteration mapped including thermal springs (some of them associated with gas discharge), hot domestic wells and Travertine outcrop (Harada) along with slight hydrothermal alteration. Geochemical study executed by GDP in cooperation with CNR and BGR in order to estimate the subsurface temperature and define the chemical properties of the fluid. Fifteen thermal springs and other hot or cold domestic wells analyzed in Italy and Germany laboratories whereas temperature, PH and conductivity were measured during field trips. Surface temperature ranges from 31°C to 52 °C and pH measurement ranges from 6.4 to 9.4. The results of the chemical analyses indicated that this water belongs to the Ca-bicarbonate-Cl-Na water type, which mainly caused the high erosion in the ground to form Travertine deposition. Moreover, the radon measurement shows that as the temperature increased the radon ratio decreased in hot springs and domestic wells in Damt. Traditionally, the geothermal potential in Damt like everywhere else in Yemen is restricted to direct uses for balneology purposes for many years (including bathing and swimming) which is in general estimated in 2020 to be 5.0 MWt and 100 TJ/yr. The geothermal resources in Damt should be better developed indirectly for power generation and used as well for greenhouse and CO2 or H2S gasses exploitation.