| Abstract |
The Tatapani geothermal field is situated along the eastern margin of the Son-Narmada-Tapi (SONATA) lineament (Non-Orogenic geothermal province) in Central India, and is structurally bounded by major faults, including the Tatapani, Balrampur, and Lurgutta faults. The region, interpreted as part of a mid-continental rift system, comprises Archean-aged metamorphic assemblages such as quartzites, schists, granite-intruded gneisses, pegmatites, and amphibolites, in association with sedimentary units of the Gondwana Supergroup and the Chhotanagpur Granite Gneissic Complex. The surface geothermal anomaly extends over an area of 1 km2 with temperature gradient of 81°±36°C/km and heat flow of 219±87mW/m2 with recorded surface temperatures reaching close to 100℃. Geochemical thermometers estimate reservoir temperatures from 180℃ to 250℃ indicating a suitability for applications such as power generation and direct-uses. Twenty-six boreholes have been drilled across the Tatapani field, with five wells (maximum 350 m deep) discharging thermal fluids at a cumulative rate of ~1800 L/min and temperatures reaching 112.5 °C. Magnetotelluric studies have revealed a prominent conductive layer with hot upflow likely related to fault intersections. Subsurface reservoir volume is estimated on the integration of borehole temperature gradients with geological and geophysical logging datasets. Resource assessments by volumetric calculations and Monte Carlo simulations estimate a probable electric power output of ~9.1 MWe over a 30-year operational period considering key-parameters such as recovery factor, cut-off temperature, efficiency, and load factors. The findings delineate that the Tatapani geothermal field holds significant potential for sustainable energy production, with prospective applications in direct-use sectors such as geothermal cooling, tourism, and balneology. |