3D Geologic Model and Energy Potential Estimation of UAE Geothermal Systems Mubazzarah-Ain Faidha and Ain-Khatt

Abstract

In the United Arab Emirates (UAE) emerges several groups of hot springs classified as low-enthalpy. In this study, multiple geophysical and numerical investigations have been applied to better understand the geologic controls, depth and reservoir temperature, energy potential and future possible applications of the geothermal systems identified by these hot springs. The low-enthalpy geothermal systems were examined using densely spaced gravity and magnetic surveys to study the subsurface structure and geology. We have estimated the correlation between the density and the magnetic inversion results at the studied geothermal fields using a neural network trained estimation algorithm. Results from neural network classification helped to draft an initial geological structure, showing that these geothermal manifestations are structurally controlled. The thermal waters of the hot springs were sampled and tested for geochemical signatures indicating fluid origin and reservoir temperature. The thermal fluids are rich in Na and Cl with temperatures of surface discharge ranging from 32 oC to 49 oC. The geochemical and isotopic signature of the water suggests a meteoric origin. Reservoir temperature of sampled waters were estimated using cation geothermometers and showed values ranging from 56 oC to 87 oC. A 3D geothermal numerical simulation is developed using the geophysical and hydrochemical understanding in an attempt to reproduce these geothermal manifestations. The geothermal electricity potential was calculated for the main low-enthalpy geothermal fields using a stochastic Monte Carlo simulation and showed a value of 815 kWe for 25 years and 407 kWe for 50 years. These geothermal manifestations can be utilized for electricity generation using a binary-geothermal power plant or hybrid energy systems combining the geothermal energy with solar and/or wind.