| Title | Amiata geothermal field (Italy): Modelling CO2 degassing dur-ing plant operation |
|---|---|
| Authors | P. de Montleau, A. Lenzi, P. Delbosco, O. kenshiro |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Geothermal production is often located in volcanic areas associated with natural emission of gas, among which is CO2. The fluid produced by the geothermal plants has of course also a content of gas. The objective of this analysis is to understand, using a fluido-thermo-dynamic numerical simulator, the reciprocal impact of the plant production and of the natural emissions in the surrounding areas. The area of interest is the deep reservoir of the Amiata zone (Tuscany, Italy). The model is made of a simplified 2D reservoir and its associated cap rock. The main assumption is that the CO2 is generated at a constant rate somewhere below the reservoir where it is entering and can escape to the atmosphere. The simulation consists in setting the natural state for which the CO2 is expelled to the atmosphere at the same rate as it is generated. Once the plant is set in production, it is observed that a gradual reduction of the natural degassing to the atmosphere up to the point where this reduction fully compensates for the plant emission. These mechanisms are of a particular importance to assess the impact of the geothermal plants in terms of gas emissions. |