The objective of this on-site experiment was to quantify the geochemical impact on the Dogger aquifer (limestone) of the continuous reinjection of a cooled brine (40°C) over a typical time frame of 20 to 30 years. For that purpose, we first had to spend quite a long time for finding an accessible injection well and obtaining the required administrative authorizations for descending the tools down to more than 1,800 m below the ground level. Thanks to the collaboration of Chelles chaleur, a CORIANCE subsidiary operating the geothermal plant, and Syndicat Mixte pour la Geothermie de Chelles (SMGC, owner of the plant), we had the opportunity to perform this experiment on the injection well of a former geothermal doublet in Chelles (eastern suburbs of Paris). This well has been continuously used for reinjection over a period of 27 years. The results of this experiment, currently under interpretation, will provide a very precious baseline for assessing the chemical impact likely to be induced by the dissolved CO2 reinjection in an expected future CO2-DISSOLVED demonstration pilot. Moreover, the data acquired constitute an incomparable reference to evaluate the predictive capacity of our reactive transport models. This data acquisition campaign, carried out for the first time below the cased zone of the well, was performed by FLODIM, relying on their proprietary sonar survey system. The whole project team is very grateful to FLODIM, Chelles Chaleur, SMGC, and CORIANCE for making this unprecedented on-site experiment feasible.
Dernière mise à jour le 13.04.2016
