One of Europe’s leading geothermal developers is exploring the potential of a poorly developed geothermal reservoir that is also targeted for public water supply in France. The context is not dissimilar to the Yarragadee aquifer in Perth which is used to provide 25% of the public water supply and is also targeted by 26 geothermal and injection wells.
To assess the impact of injection of geothermally cooled water on the aquifer, Rockwater constructed a comprehensive geological model of the target aquifer in France. The geological model incorporated a major fault displacing the porous sandstone intervals.
Numerical groundwater flow and heat transport modelling was used to estimate the likely impact of injection on nearby production bores used for potable water supply. To provide a probabilistic the numerical model was run multiple time using a Monte-Carlo approach.
Another aspect of the study included geochemical modelling using the PHREEQC code of precipitation/dissolution reactions caused by the cooling of the geothermal water down to very low temperatures after circulation through a heat pump.
The Rockwater study was used to estimate the optimum injection temperature and ensure no detrimental impact on the nearby bores used for water supply. The study was completed in line with the local regulatory framework and produced in French to be included in a public tender.
Rockwater is leading in geothermal modelling.
