1. Hydraulic stimulation of EGS: Comparison of the HDR-project Soultz
T. Tischner, R. Jung, J. Orzol
Hydraulic stimulation of EGS:
Comparison of the HDR-project Soultz
and the
GeneSys-project Hannover

2. Content
Basic concepts of both projects
Stress field
Stimulation operations
Hydraulic and seismic observations
Conceptual Models

3. HDR/EGS Pilot plant in Soultz The HDR base module 1.5 + 4.5 MWe
GPK 2
GPK 4
Crystalline rocks
Production
Production
1400 m
50 kg/s
50 kg/s
100 kg/s
GPK 3
5000m
Depth
600 m
600 m
200 o C

4. GeneSys: Original concept
Reinjection
Production zone
fault
Large Hydraulic Fracture

5. Stimulation Volpriehausen
Well Horstberg (GeneSys)
3600m
Salt
Sandstone
(Detfurth)
Sandstone (Volpriehausen)
Claystone
330 bar
450 bar
Stimulation Detfurth
(50 l/s, m3)
Stimulation Volpriehausen
(600m3)
Siltstone
4000m

6. Stress profile Horstberg (GeneSys) Soultz
Shearing is more likely in Soultz !
great stress differences in Horstberg

7. Hydraulic Stimulation
Soultz
Horstberg (GeneSys)

8. Stimulation: Shut in Soultz (GPK2) Horstberg High conductive structure
Wellbore storage: 1 m3/bar
Horstberg
High conductive structure
Wellbore storage: 100 m3/bar
(Large tensile fracture: m2)

9. Seismic events Soultz (GPK2) Horstberg 11 events: not localised

10. Injection tests after stimulation
Soultz (GPK2)
Horstberg
p ~
Formation linear flow
Infinite conductive fracture

11. Injection tests / wellbore storage
Soultz
(GPK2)
Horstberg
Wellbore storage:
(during stimulation)
1 m3/bar
(GPK 2)
100 m3/bar
Wellbore storage:
(below fracture pressure)
1 m3/bar
(GPK 2)
0.1 m3/bar
Soultz: Storage capacity
(stiffness) remains unchanged
Horstberg: Storage capacity
decreases drastically
after stimulation

12. Observations Soultz Horstberg Shearing Tensile fracturing
drastic change of storage
capacity
infinite conductive fracture
Horstberg
Shearing
constant (fairly high) storage
capacity
infinite conductive fracture

13. (hydro-frac bounded by faults)
Conceptual Models
Soultz (GPK2 and GPK3)
(hydro-frac bounded by faults)
Horstberg
Siltstone/
Clay Sh
Sandstone

14. Productivity/Injectivity
GPK GPK GPK Horstberg
Injectivity during
Stimulation [l/(s*bar)]:
0.4
0.08
Injectivity after
Stimulation [l/(s*bar)]:
(after 2 d)
Very effective hydraulic stimulation in Soultz !

15. Thank you for your attention !
Summary
very successfull hydraulic stimulations in Soultz
succesfull application of the waterfrac concept to sandstone:
Infinite conductive fracture !
Thank you for your attention !

17. GeneSys: Objectives Provide 2 MWth for direct use Single well concept
Sedimentary rocks with low permeability
Adoption water-frac technology to sediments

18. Shearing is more likely in Soultz !
Mohr-Circle
Shearing is more likely in Soultz !