Publication in Geothermics scientific journal

"Modellingwater-rock interactions due to long-term cooled-brine reinjection in the Dogger carbonate aquifer (Paris basin) based on in-situ geothermal well data"

Authors:  Nicolas C.M. Marty; Virginie Hamm; Christelle Castillo; Dominique Thiéry; Christophe Kervévan

BRGM, 3 Avenue Claude Guillemin, Orléans Cedex 2,45064, France

ABSTRACT

An experimental campaign was conducted using bottom-hole geometry data from a 24-year-old injection well (∼1700 m deep) at a geothermal site exploiting the Dogger aquifer (Paris basin). A sonar tool was used to measure the geometry distortion of the open hole due to long-term reinjection of cooled brine. Reactive transport modelling was then performed. The calculated extent of carbonate dissolution at the well outlet was consistent with the sonar observations. The best fit to experimental results was obtained by considering partial CO2 degassing in the reinjected brine, which is consistent with the artesian mode doublet operation.