publications
Article
Deep reservoir temperatures of low-enthalpy geothermal systems in Tunisia: New constraints from chemistry of thermal waters  |
Di Napoli Rossolla, Aiuppa Alessandro, Fourré E., Jean-Baptiste P., Parello F., Allard P., Calabrese S., Gaubi E., BEN MAMMOU Abdallah, Valenza Mariano, 2012 |
Acta Vulcanologica, 24, 1-2, 43-50, Janvier 2012 |
Résumé
Tunisia is characterized by hot and warm groundwaters (temperature up to 75 °C) which represent the surface manifestation of geothermal
systems hosted in carbonate-evaporite rock sequences. The T-conditions of Tunisia deep thermal reservoirs are here evaluated
for the first time at the regional scale. The results here shown clearly highlight the limitations inherent in the application of
common geothermometric methods in the estimation of equilibrium temperatures in sedimentary environments. The modeling approach
proposed by Chiodini et alii (1995), which makes use of the ratios between dissolved HCO3, SO4 and F, provides the most reliable
results, and allows us to derive equilibrium temperatures up to 200 °C for the Tunisian thermal reservoirs. Very high equilibrium
pCO2 (100 bar) values are also estimated, likely indicative of the confined aquifer conditions
Tunisia is characterized by hot and warm groundwaters (temperature up to 75 °C) which represent the surface manifestation of geothermalsystems hosted in carbonate-evaporite rock sequences. The T-conditions of Tunisia deep thermal reservoirs are here evaluatedfor the first time at the regional scale. The results here shown clearly highlight the limitations inherent in the application ofcommon geothermometric methods in the estimation of equilibrium temperatures in sedimentary environments. The modeling approachproposed by Chiodini et alii (1995), which makes use of the ratios between dissolved HCO3, SO4 and F, provides the most reliableresults, and allows us to derive equilibrium temperatures up to 200 °C for the Tunisian thermal reservoirs. Very high equilibriumpCO2 (100 bar) values are also estimated, likely indicative of the confined aquifer conditions
