Page 242 - Geothermal Energy Systems Exploration, Development, and Utilization

218 4 Enhancing Geothermal Reservoirs

Frankfurt

Karlsruhe
Soultz Stuttgart

France Germany

Basal
Switzerland
Figure 4.15 Location of the Soultz site at the border between France and Germany.

1999–2004, three wells were drilled in granitic rock down to 5 km. Two wells (GPK2
and GPK4) will be used for production whereas the central well (GPK3) will be the
injection well. All the three wells were drilled from the same platform, whereas the
horizontal distance between the re-injection well and each of the production wells
is approximately 700 m at target depth (Figure 4.16).

1400m
Granite

GPK 2 GPK 4
Prod. Prod.
GPK 3
Inject.

600m 600m Open
hole
5000m / 200°C
Figure 4.16 Scheme of the borehole triplet (5 km depth) in
Soultz. Inject.: Injection well; Prod.: Production well.