1. Program topic: Geothermal Technology
Current status of the EGS Groß Schönebeck project within the North German basin: main achievements and perspectives
HUENGES1, E., A. SAADAT1, W. BRANDT1, B. LEGARTH1, T. TISCHNER², I. MOECK1, H. HOLL1, G.ZIMMERMANN1
GeoForschungsZentrum Potsdam (GFZ),
²Federal Institute for Geosciences and Natural Resources (BGR)
Program topic: Geothermal Technology
Add.: A. Förster, David Bruhn, S. Köhler et al.

2. Iceland Deep Drilling
Hannover
Bochum
Landau
Soultz
Basel
Larderello
Groß Schönebeck
Rhine Gr.
Molasse B.
Paris Basin
Mid-European Basin
Po Basin
Pannonian Basin
Hurter & Schellschmidt 2003

3. Southern Permian Basin
Hengill
Hannover
Bochum
Landau
Soultz
Basel
Larderello
Groß Schönebeck
Rhine Gr.
Molasse
Paris Basin
Southern Permian Basin
Po Basin
Pannonian Basin
Hurter & Schellschmidt 2003

4. Suitable for reservoir
Commercial
Potentially commercial
productive
hydrothermal
HotDry
Rock
Suitable for reservoir
enhancement*
High
natural permeability
Zero
* Hydrofracture, targeted injection, acid leaching, directional drilling, etc.
mod.from USGS

5. In-situ Geothermal Laboratory Groß Schönebeck
research borehole in sedimentary rocks
4.3-km deep, 150 °C with stimulated reservoir
drilling 2. well and concept to enhance mass-flow rate from the reservoir using a doublet
demonstration sustainable production with longterm circulation
geothermal power production in the North German Basin
methods:
hydraulic frac operation using gels, proppants, and hugh water injections
multidisciplinary process analysis

6. In-situ Geothermal Laboratory Groß Schönebeck

7. Operations overview open hole proppant frac with packer Jan/Feb 2002
production test / logging
m (frac 1)
m (frac 2)
open hole waterfrac
start Jan/Feb 2003
m, borehole instability
production test
cont. Nov/Dec 2003 m
production test / logging
preparation 2. well:
2004/2005
injection test & reservoir modelling
EU-tender for drilling services
Mining rights procedure
Design of drilling program & setup of the drillsite

8. productivity enhancement by hydraulic fracturing
creating zone of increased permeability
enlarging apparent wellbore radius
by-pass skin
improve inflow conditions

9. open hole proppant frac February 2002
concept:
open-hole stimulation
high-viscous fluid (HTU-Gel + citric acid)
proppant
result:
increase of productivity
not sufficient for economics
modelled 7 times higher productivity
Legarth et al., Geothermics, 2003

10. stimulation effect (proppant fracs)
BHTV
FMI
N E S W N
N E S W N
Flowmeter
SH:18,5°±3,7
Holl et al., EAGE, 2004

11. open hole waterfrac (Jan/Feb 2003)
well Groß Schönebeck / casing profile
max.
25 l/s
250 bar
Siltstone
Sandstone
Volcanics

12. waterfrac cont. (Nov/Dec 2003)
well Groß Schönebeck / casing profile
pre-perforated
liner
max.
80 l/s
500 bar

13. waterfrac Nov/Dec 2003
 HP triplex pumps
 80 l/s bei 500 bar
 4000 kW
 wellbore completion
 frac string installation
 1500 m³ storage
 acidization
 filter systems

14. production test Groß Schönebeck 1.12.03

15. Learning curve Groß Schönebeck
Huenges et al. 2004

16. Injection pressure & temperature around the wells
Injection well
Production well
1 Dm
0,5 Dm
thermal water loop with 75 m³/h

17. Step 1: Drill 2. well and realise the doublet
2006:
Drill 2.well (directional)
multifracturing
Commitment of the energy provider Vattenfall:
1. Primar productivity for 750 kW-power plant 2. Demonstration of sustainibility (circulation test)
Directional drilling concept 2.well

18. Step 2: Installation of the geothermal power plant
2007 Demonstration of geothermal power production (partner in industry Vattenfall Europe AG)
- demonstration - optimisation of the processes - Improving efficiency

19. Conclusions
EGS offer ways of increasing the potential of geothermal power generation for various geological environments:
Experiences with several hydraulic fracture treatments
Concept based on parallel fracs and transmissibility within the formation
In sedimentary rocks: e.g. Groß Schönebeck site since 2001, with 10 MW thermal 140 °C expected after drilling a second borehole

20. Seismic experiment Seismic parameters per line/star:
Autobahn
Seismic parameters per line/star:
Shot spacing = 800 m
50 x (20 m, 30 kg) = 40 km
Receiver spacing = 200 m
200 x 3C stations = 40 km