A review of geophysical methods for geothermal exploration

Exploration of geothermal resources is important from the energy point of view. Geophysical methods are among the three main disciplines applied on the surface to explore geothermal resources, including geology and the chemistry of thermal fluids. This paper presents various geophysical methods of exploring geothermal reservoir. Some comparisons, advantages, and disadvantages of each method are discussed. It was found that, the most successful methods are aimed at parameters that are directly influenced by the geothermal activity, such as Geophysical well logs, self-potential, Geoelectrical and thermal methods, and are usually referred as direct methods. Other methods explore the physical parameters of the host rock, including magnetic properties, density and seismic velocity, and are usually referred as indirect or structural methods. It appears that, direct methods give information on parameters that are influenced by the geothermal activity, while the structural methods give information on geological parameters which may reveal structures or geological bodies that are important for the understanding of the geothermal system.