Celebrating its 10th anniversary this year, Geo-Energie Suisse AG (GES) is a Swiss company focused on deep geothermal energy for electricity and heat production. The founding members include municipal utilities and regional energy supply companies from all over Switzerland. Geo-Energie Suisse employs ten people, and it is also supported by numerous external specialists.

The company aims to develop deep EGS projects in crystalline rocks through the use of multi-stage stimulation to increase the permeability of the rock while reducing the seismic risk. Haute-Sorne is the company’s most advanced project in Switzerland. Its setting shows many similarities with the Utah FORGE project, which makes the collaboration with the University of Utah-based team particularly exciting.

Geo-Energie Suisse core competencies reside in seismic risk assessments, seismic monitoring and real time seismic data processing and evaluation. At Utah FORGE, GES intends to test and validate new methods and downhole instruments and bring them to the next level of innovation. GES is also assisting in the design of the seismic monitoring program, as well as conducting numerical analyses of the seismic data.

The figure shows the results of resolution and sensitivity numerical modelling performed by GES to assess the optimal configuration of monitoring boreholes and sensors at Utah FORGE. Section-view (left) and map-view (right) of the monitoring boreholes and the first of two deep, highly deviated wells (16A(78)-32) that will be used to create the reservoir.

At the end of 2020, Geo-Energie Suisse succeeded in obtaining technical proof of its multi-stage stimulation concept. The successful demonstration took place in the Bedretto Underground laboratory for Geosciences and Geoenergy of the ETH Zurich in the Swiss Alps. Innovative sensors, measurement and control techniques were tested for the first time and enabled the observation and control of the hydraulic stimulations. These techniques increase safety when creating geothermal reservoirs in crystalline rock. In addition, a seismicity forecasting method, developed by ETH Zurich, was also successfully implemented in the demonstration project. GES will now validate the findings gained in the Bedretto Laboratory at the Utah FORGE test site in the high-temperature range.

This figure shows the spatial distribution of the microseismicity that occurred in 10 temporally staggered intervals and spatially isolated stimulation zones leading to permanent microcracks in the granite rock.

The stimulations were carried out by Geo-Energie Suisse AG in the Bedretto Laboratory of ETH Zurich in November and December 2020. © Geo-Energie Suisse. More pictures and videos here

The Swiss Federal Office of Energy supports the deep geothermal project in Haute-Sorne and especially the innovations that will substantially reduce the risk of induced seismicity for deep EGS projects. The Swiss, Utah FORGE and the international geothermal industry will be well served by such improvements in safety and the success of future EGS projects.

www.geo-energie.ch/ (French/German)