Recent Developments in the European HDR Research Programme at Soultz-Sous-forets (France)

Abstract

The site at Soultz-sous-Forets (France)has been selected as the future European HDR research site (Garnish et al., 1994). An extensive testing program using a single well has been carried out since 1987 to characterize the rock mass at depth to 3590 m.

The hydraulic test carried out in 1993-1994 show the potential of this site for a future European Scientific Prototype. In particular they have shown that, in this part of the Rhine Graben, the fracture network in the basement is well developed, with a degree of permeability. While some fluid movement occurs naturally, hydraulic simulation has been shown to increase substantially the overall transmissivity. The site should therefore be suitable for testing the modified, step by step concept of HDR which has developed in recent years. The geological setting also offers other advantages, in terms of enhanced temperatures and relatively low stimulation pressures, a characteristic that may simplify the task of developing a circulation system.

A further deep well will be drilled late in 1994, with the aim of developing circulatior: between the well during the first part of 1995.