Enel Generation and Energy Management (GEM), the main electric producer in Italy, is
particularly engaged in the development of renewable energies and, among these, high
temperature geothermal resources have been explored and exploited in Italy since the
beginning of last century.
Exploration activities started in the Larderello and Travale areas (Tuscany) and
then, in the second half of the last century, were extended to several other areas
of potential interest in central and southern Italy. These activities were mainly
and widely carried out in Tuscany and Latium regions, with the integration of many
surface surveys (geological, geophysical etc.) and drilling activities. Many
geophysical methodologies were performed and tested on the base of the geological
features and the depth of the potential targets.
Unfavorable reservoir characteristics together with others logistical or
environmental problems hindered geothermal development in many of these areas.
At the present Enel is operating 32 power generation units, only in Tuscany
(Larderello, Travale and Amiata areas), with a total capacity of about 700 MW
The highest costs in the geothermal exploration are related to the drilling
activity, particularly when the geothermal reservoirs are deep (> 2500 m) and
characterized by fractures-controlled permeability. These cases are very frequent in
the deep metamorphic reservoirs of the main geothermal areas in Italy.
The reconstruction, as detailed as possible, of the structural-geological model and
the location, prior to drilling, of promising targets for the wells (high fractured
levels) are at the present the main purposes of the surface exploration.
Different geological systems need different geosciences technologies, depending on
which physical parameter is better defined and able to discriminate geothermal
signatures (acoustic impedance, resistivity contrast, etc.).
Seismic surveys (2D and more recently 3D) are providing encouraging results for the
deep target individuation in the metamorphic reservoir of Larderello-Travale areas.