The natural gas reservoir, that has existed for several million years, was discovered in 1951 by ENI (formerly AGIP) who used it until 1997, up to its economic depletion. The reservoir is located at a depth of 1.4 km and covers an area of 6 km2.
The geological structure is characterized by rocks dating back to the Pliocene
age ("Caviaga sands" formation) composed by alternate layers of sand and clay.
The reservoir is covered by a strong layer (several hundred meters) of clay
(the cap-rock) better known as "Clays of Santerno".
The peculiar geological features are particularly suitable for retaining gas and contribute to creating the ideal conditions to manage the storage activity in complete security.