This EGS project, called ECOGI, is located in Northern Alsace within the Upper Rhine Graben. It produces geothermal steam to dry starch in a bio-refinery located close to the Rhine River. This geothermal project aims to exploit hot fluids (> 160 °C) at around 2 600 m depth at the cover-basement unconformity. Two deep boreholes (2.6 km deep) have been drilled for intersecting deep Triassic sandstone lying on fractured crystalline rocks. Due to a low natural injectivity index, the first well GRT-1 has been chemically and hydraulically soft stimulated. In this injection well, poststimulation injectivity was improved by a factor 5 leading to industrial flow rate higher than 70 L/s. Moreover, this soft stimulation program was carried out with no environmental nuisances. First, there was no induced seismicity event felt during hydraulic stimulation. Second, environmental free chemicals were used for dissolving specifically hydrothermal minerals sealing the pre-existing fractures. After those encouraging stimulation results, a second borehole has been drilled at Rittershoffen for targeting a production well which was quite successful with artesian flow conditions (> 40 L/s) at high temperature (> 160 °C). Thus, future operational hydraulic conditions with production flow rates higher than 70 L/s can be expected. As those soft stimulation data were never published and now belong to ESG, it is planned to deeply interpret them in the framework of the DESTRESS project.
Operator |
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Work Package No |
4 |
Location |
Rittershoffen, France |
Construction Year |
2 wells finished and stimulated in 2014 |
Foreseen Stimulation Techniques |
![]() THMC-Stimulation techniques performed 2013 |
Type of Use |
Heat for (green) chemical industry |
Soil Condition |
Fractured clastic rocks (SS) and fractured granite with high temperature geothermal resources |
Production Horizon |
Fractured Triassic sandstone and Carboniferous fractured granite |
Upper Depth (m) |
2600 |
Thickness (m) |
680 |
T (°C) |
>160 |
Salinity (g/l) |
~100 |
Contact |
Dr Albert GENTER, Deputy General Manager Phone: +33 (0)3 88 20 72 88 |