Main achievements from the multi-well EGS Soultz project during geothermal exploitation from 2010 and 2012

Albert Genter (1) , Nicolas Cuenot (1) , Bernd Melchert (2) , Wilfried Moeckes (1) , Guillaume Ravier (3) , Bernard Sanjuan (4) , Raphael Sanjuan (1) , Julia Scheiber (1) , Eva Schill (1) , Jean Schmittbuhl (5)

1 GEIE Exploitation Minière de la Chaleur
2 BGR - Bundesanstalt für Geowissenschaften und Rohstoffe
3 GroupeES - ESGéothermie
4 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
5 IPGS - Institut de physique du globe de Strasbourg

A research program based on a scientific and technical monitoring of the EGS Soultz power plant has been achieved during geothermal exploitation between 2010 and 2012. Several hydraulic circulation tests have been performed that involve one production well, GPK-2 and two reinjection wells, GPK-1 and GPK-3: a long term circulation for about 11 months in 2010, and two short term circulation tests in 2011. In 2012, a short term circulation test sharply stopped due to a serious down-hole pump failure. During the 2010 exploitation, geothermal fluid discharge from GPK-2 reached a volume of about 500 000 m3 by producing at 18 L/s for a temperature of 164°C. Tracer test was conducted and showed the good connection between GPK-3 and GPK-2. In 2010, more than 400 induced micro-seismic events of low magnitude occurred. In 2011, geothermal fluid discharge from GPK-2 reached a volume of about 300 000 m3 by producing at 24 L/s for a temperature of 159°C. The strategy was to increase the reinjection flow rate in the shallow well GPK-1 (3.6 km) and simultaneously minimize it in GPK-3 in order to decrease reinjection pressure. Induced seismic activity was seriously decreased with less than 10 microearthquakes in 2011. In 2012, GPK-4 well, a former production well was converted into an injection well but for a rather short period, due to the failure of the down-hole production pump. New improvements about Line Shaft Pump (LSP) technology were done and another pump was designed and tested before its setting in GPK-2. In parallel, many research works have been carried out for characterizing scaling and the natural radioactivity derived from natural brines circulating within a deep fractured granite reservoir. Down-hole pump technology was also tested in various geothermal conditions during exploitation. In 2010, the LSP worked for more than 300 days without any trouble. In 2011, occurrences of cuttings at higher flow rate, generated abrasion of the pump reinforcing its damaging. In 2012, serious damages occurred on its hydraulic part in terms of abrasion and corrosion. Environmental nuisances were also investigated in order to evaluate their impact on the local population and then on public acceptance. An opinion survey was conducted in close cooperation with the two neighbouring villages of Kutzenhausen and Soultzsous- Forêts showing the permanent need of information and communication at local scale.

Mots clés: EGS; Reservoir; Technology; Environment; Soultz-sous-Forêts; France

Domaines: Géochimie; Milieux et Changements globaux

Albert Genter, Nicolas Cuenot, Bernd Melchert, Wilfried Moeckes, Guillaume Ravier, et al.. Main achievements from the multi-well EGS Soultz project during geothermal exploitation from 2010 and 2012. European Geothermal Congress 2013, Jun 2013, Pise, Italy. 10 p. ⟨hal-00812959⟩