| Title | Geothermal Repurposing of Depleted Hydrocarbon Wells: Case Studies in Italy |
|---|---|
| Authors | Scrocca D., Alimonti C |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Depending on the local geothermal gradient, depleted oil and gas wells may have downhole temperatures high enough to support the geothermal exploitation of the reservoir fluids. Consequently, when hydrocarbon wells approach depletion and geothermal potential is identified, converting them into geothermal wells can be a viable alternative to permanent closure, otherwise eliminating any opportunity for repurposing the existing infrastructure. Several possible technologies have been proposed so far to harvest the geothermal heat in mature hydrocarbon fields, which include: 1) coproduction of the residual hydrocarbons alongside the hot formation water, 2) open loop system developed reconfiguring existing wells to operate as paired injectors and producers, and 3) closed loop system installing Borehole Heat Exchangers in the existing wells or connecting existing well with new lateral well segments. These different approaches require varying levels of intervention, ranging from using wells in their current configuration to extensive workover operations up to drilling new wells. In this contribution, we discuss the pros and cons of the different possible solutions based on some case studies in Italy, where about 850 active wells with different operational status are in onshore hydrocarbon concessions. Since wells are generally drilled in basins characterized by low heat flow, the temperatures of these wells are generally medium to low. However, our case studies demonstrate that many currently depleted wells can be repurposed to produce fluids with proper temperatures for various direct applications, including district heating. |