Closed-Loop Systems for Geothermal Energy Exploitation from Hydrocarbon Wells: An Italian Case Study

Geothermal energy resources associated with disused hydrocarbon wells in Italian oilfields represent a considerable source of renewable energy. Using the information available on Italian hydrocarbon wells and on-field temperatures, two simplified closed-loop-type systems models were implemented in the Python environment and applied to a selected hydrocarbon well (Trecate4) located inside the Italian Villafortuna–Trecate field (Northwestern Italy). Considering the maximum extracted working fluid temperatures, Coaxial WBHE turned out to be a better performing technology than the U-tube version. The obtained outflow temperatures of the working fluid at the wellhead for Coaxial and U-tube WBHEs of 98.6 °C and 84 °C, respectively, are both potentially exploitable for ensuring a multi-variant and comprehensive use of the resource through its application in sectors such as the food industry, horticultural and flower fields.