Preliminary Results of the Seismicity Induced During the Stimulation of the Vendenheim Enhanced Geothermal System (France)

Abstract

The European H2020 DEEPEGS project aims at demonstrating that enhanced geothermal systems can be developed and produce energy efficiently in different geological and geographical contextsacross Europe. Two main demonstrators are involved, one located in Iceland, in the Reykjanes peninsula and one located in France, at Vendenheim, in the Upper Rhine Graben. One of the project goal is to apply passive seismic monitoring to mitigate induced seismicity and to assess the geothermal reservoir development.We focus on the Vendenheim site, which is located in the northern suburb of Strasbourg (France). In 2018-2019, a well doublet was drilled and targets a fault in the granitic basement at ~4.6 kmdepth, where temperatures above 200°C were measured. The initial injectivity/productivity of the wells was too small and required stimulations to enhance the geothermal system and produce energy under economic conditions. These operations were monitored using a permanent seismic monitoring network completed by a temporary network. In total, nine stations recorded the seismicity induced by the operations. We present here preliminary results associated with the seismicity recorded during the hydraulic stimulation of the well VDH-GT2.