List of major events/results
- The fracture network has been explored down to 3900 m depth, where temperatures exceed 165°C. Within the volume which has been investigated (up to 1 km around the boreholes), the network appears to be stable and to have the desired properties.
- A series of hydraulic tests has been performed, including a forced circulation test of several months duration. This demonstrated that it is possible to circulate continuously about 25 l/s of water, at more than 140°C, between two boreholes 450 m apart without any water losses and requiring only 250 kWe pumping power compared with the thermal output of 10 MWth.
- Experience shows that such a loop can be managed nearly automatically, simply and without any noticeable environmental impact.
- All the activities during this phase led to an extended
improvement of knowledge and required technologies at the scale of the tests
performed:
- economical drilling performance through hard, hot and deep rocks ;
- stimulation and development of hot and very large "volumetric reservoirs";
- engineering for development / production adapted to Hot Dry Rock exploitation.
- Even though the performance obtained at Soultz is a significant advance on results achieved within the frame of previous experiments at other sites, they have relied on the continuous transfer of “know-how” from the teams involved in that earlier work and who now form part of the Soultz group.
- Based on the encouraging results of the circulation test 1997, the programme for the subsequent phase 1998-2001 was defined.