A heat exchange circuit for a geothermal plant comprising a well excavated in the rock, a casing arranged inside the well, integral with it and comprising at least a first perforated section extending along a first portion of the well and at least a second perforated section extending along a second portion of the well, the perforated sections allowing the exit and the entry of a flow of geothermal fluid contained in an aquifer, an internal duct, located inside the casing in which a heat transfer fluid flows, wherein the well, the casing and the internal duct being arranged as a substantially closed ring, except for at least one surface interruption, at least one heat-exchange section at the bottom of the well between the first portion and the second portion of the well within which the geothermal fluid transfers heat to the heat transfer fluid.