Modelling acid stimulation in the enhanced geothermal system of Soultz-sous-Forêts (Alsace, France)

•The re-injection of fluid can cause the dissolution/precipitation of minerals and may have a impact on porosity/permeability.•A modelling approach is considered to discuss different scenarios in terms of acid choice, amount and duration of injection.•The approach is based on the code KIRMAT, using single-porosity and double-porosity models.•The modelling results showed that chemical stimulation could significantly increase porosity and permeability.•But for both models, the improved zones are only present within a few metres of the reinjection well.