Fluid Pressure Variation in a Sedimentary Geothermal Reservoir in the North German Basin: Case Study Groß Schönebeck

  • Ernst Huenges
  • Ute Trautwein
  • Björn Legarth
  • Günter Zimmermann
Part of the Pageoph Topical Volumes book series (PTV)


The Rotliegend of the North German basin is the target reservoir of an interdisciplinary investigation program to develop a technology for the generation of geothermal electricity from low-enthalpy reservoirs. An in situ downhole laboratory was established in the 4.3 km deep well Groß Schönebeck with the purpose of developing appropriate stimulation methods to increase permeability of deep aquifers by enhancing or creating secondary porosity and flow paths. The goal is to learn how to enhance the inflow performance of a well from a variety of rock type in low permeable geothermal reservoirs. A change in effective stress due to fluid pressure was observed to be one of the key parameters influencing flow properties both downhole, and in laboratory experiments on reservoir rocks. Fluid pressure variation was induced using proppant-gel-frac techniques as well as waterfrac techniques in several different new experiments in the borehole. A pressure step test indicates generation and extension of multiple fractures with closure pressures between 6 and 8.4 MPa above formation pressure. In a 24-hour production test 859 m3 water was produced from depth indicating an increase of productivity in comparison with former tests. Different depth sections and transmissibility values were observed in the borehole depending on fluid pressure. In addition, laboratory experiments were performed on core samples from the sandstone reservoir under uniaxial strain conditions, i.e., no lateral strain, constant axial load. The experiments on the borehole and the laboratory scale were realized on the same rock types under comparable stress conditions with similar pore pressure variations. Nevertheless, stress dependences of permeability are not easy to compare from scale to scale. Laboratory investigations reflect permeability variations due to microstructural heterogeneities and the behavior in the borehole is dominated by the generation of connections to large-scale structural patterns.


Formation Pressure Lateral Strain Reservoir Rock Uniaxial Strain Geothermal Reservoir 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Baumgärtner, J., Jung, R., Hettkamp, T., and Teza, D. (2004), The status of the hot dry rock scientific power plant at soultz-sous-forêts, Z. Angew. Geol. 2, 12–17.Google Scholar
  2. Bourne, S.J. (2003), Contrast of elastic properties between rock layers as a mechanism for the initiation and orientation of tensile failure under uniform remote compression, J. Geophys. Res. B: Solid Earth. 108(8), ETG 14-1-ETG 14–12.Google Scholar
  3. Cinco Ley, H. and Samaniego, F. V. (1981), Transient pressure analysis for fractured wells, J. Petroleum Technology, 1749–1766.Google Scholar
  4. Economides, M. J. and Nolte, K. G. (1989), Reservoir Stimulation, Schlumberger Educational Services, Houston, Texas.Google Scholar
  5. Faulkner, D. R. and Rutter, E. H. (2003), The effect of temperature, the nature of the pore fluid, and subyield differential stress on the permeability of phyllosilicate-rich fault gouge, J. Geophys. Res. B: Solid Earth 108(5): ETG 2-1–2-12.CrossRefGoogle Scholar
  6. Ghalambor, Ali and Economides, M. J. (2002), Formation damage abatement; a quarter-century perspective, SPE J. 7, 1, 4–13.Google Scholar
  7. Gueguen, Y., David, C., and Gavrilenko, P. (1991), Percolation networks and fluid transport in the crust, Geophys. Res. Lett. 18(5), 931–934.Google Scholar
  8. Gueguen, Y., Chelidze, T., and Ravalec, M. L. E., (1997), Microstructures, percolation thresholds, and rock properties, Tectonophysics 279, 23–35.CrossRefGoogle Scholar
  9. Gueguen, Y., Gavrilenko, P., and Ravalec, M. L. E. (1996), Scales of rock permeability, Survey in Geophys. 17, 245–263.CrossRefGoogle Scholar
  10. Heiland, J., (2003), Permeability of triaxially compressed sandstone: Influence of deformation and strainrate on permeability, Pure Appl. Geophys. 160(5–6), 889–908.CrossRefGoogle Scholar
  11. Henninges, J., Zimmermann, G., Büttner, G., Schrötter, J., Erbas, K., and Huenges, E. (2005), Wireline distributed temperature measurements and permanent installations behind casing, Proc. World Geothermal Congress 2005, Antalya, Turkey, 24–29 April, 2005.Google Scholar
  12. Huenges, E., Holl, H. G., Legarth, B., Zimmermann, G., Saadat, A., and Tischner, T. (2004), Hydraulic stimulation of a sedimentary geothermal reservoir in the North German basin: Case study Groß Schönebeck, Z. Angew. Geol. 2, 24–27.Google Scholar
  13. Legarth, B., Tischner, T., and Huenges, E. (2003), Stimulation experiments in sedimentary, low-enthalpy reservoirs for geothermal power generation, Germany, Geothermics 32, Pergamon Press, 487–495.CrossRefGoogle Scholar
  14. Park, A. J., Tuncay, K., Laroche, M., Comer, J. B., and Ortoleva, P.JJ. (2001), Comparing observed overpressuring and fracturing characteristics of siliciclastic and carbonate sediments and basin. RTM 3-D simulation predictions. In american Association of Petroleum Geologists 2001 Annual Meeting: Annual Meeting Expanded Abstracts, Am. Assoc. Petroleum Geologists, 151. pp.Google Scholar
  15. Trautwein, U. and Huenges, E. (2005), Poroelastic behaviour of physical properties in Rotliegend Sandstones under uniaxial strain, Internat. J. Rock Mechanics and Mining Sciences 42, 7–8, 924–932.Google Scholar
  16. Vinciguerra, S., Meredith, P. G., and Hazzard, J. (2004) Experimental and modeling study of fluid pressure-driven fractures in Darley Dale sandstone, Geophys. Res. Lett. 31(9), L09609 1–4.CrossRefGoogle Scholar
  17. Yardley, B. W. D. (2001), Rock controls on fluid regimes in the crust, Yardley Bruce W. D. Earth system processes; programmes with abstracts, 53 pp. Geolog. Soc. Am. Geolog. Soc. London, International.Google Scholar
  18. Zimmermann, G., Reinicke, A., Holl, H. G., Legarth, B., Saadat, A., and Huenges, E. (2005a), Well test analysis after massive waterfrac treatments in a sedimentary geothermal reservoir, Proc. World Geothermal Congress 2005, Antalya, Turkey, 24–29 April, 2005.Google Scholar
  19. Zimmermann, G., Burkhardt, H., and Engelhard, L. (2003), Scale dependence of hydraulic parameters in the crystalline rock of the KTB, Pure Appl. Geophys. 160, 1067–1085.CrossRefGoogle Scholar
  20. Zimmermann, G., Burkhardt, H., and Engelhard, L. (2005b), Scale dependence of hydraulic and structural parameters in fractured rock, from borehole data (KTB and HSDP). In Petrophysical Properties of Crystalline Rocks (Harvey, P.K., Brewer, T.S., Pezard, P.A., and Petrov, V.A., eds), Geolog. Soc. London, Special Publications 240, 37–45.Google Scholar
  21. Zoback, M.D., Barton, C.A., Brudy, M., Castillo, D.A., Finkbeiner, T., Grollimund, B.R., Moos, D.B., Peska, P., Ward, C.D., and Wiprut, D.J. (2003), Determination of stress orientation and magnitude in deep wells, Internat. J. Rock Mechanics and Mining Sciences. 40(7–8), 1049–1076.CrossRefGoogle Scholar

Copyright information

© Birkhäuser Verlag 2006

Authors and Affiliations

  • Ernst Huenges
    • 1
  • Ute Trautwein
    • 1
  • Björn Legarth
    • 1
  • Günter Zimmermann
    • 1
  1. 1.GeoForschungsZentrum PotsdamPotsdamGermany

Personalised recommendations