The fundamental purpose of the exploration and reconnaissance phase is to determine if there exists a commercially exploitable geothermal resource. The first assignment is to perform a desk study, which entails collection and analysis of all available existing data regarding the geothermal field and the environment in order to define the resource and scope of the following exploration activities. The desk study is followed up by field work, which usually includes:

Geological mapping of important geological features in order to get acquainted to the geological structure of the geothermal system

Geochemical analysis of fluids from surface manifestations or shallow wells if available to get indications on the reservoir temperatures

Geophysical explorations, like resistivity measurements, gravity and seismic profiling where needed, to get better understanding of the subsurface features of the geothermal resource

Drilling of shallow exploration wells (usually 50-300 m) to measure temperature gradients in order to locate the up-flow zone of hot fluids in the geothermal reservoir