Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
권호 표지
DOI QR코드

DOI QR Code

Case Study on Groß Schönebeck EGS Project Research in Germany

독일 그로스 쉐네벡 EGS 실증 프로젝트 연구사례

  • Min, Ki-Bok ;
  • Park, Sehyeok (Department of Energy Systems Engineering, Colloege of Engineering, Seoul National University) ;
  • Zimmermann, Gunter (Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Section 4.1 Reservoir Technologies & International Centre for Geothermal Research (ICGR))
  • Received : 2015.08.12
  • Accepted : 2015.08.26
  • Published : 2015.08.31
Download PDF
⟨ Previous Next ⟩

Abstract

This paper presents a case study of an enhanced geothermal system(EGS) demonstration project conducted in $Gro{\ss}$ $Sch{\ddot{o}}nebeck$, Northerm Germany, focusing on hydraulic stimulation. The project was conducted with doublet system in sandstone and volcanic formations at 4 - 4.4 km depth. Under normal faulting to strike-slip faulting stress regime, hydraulic stimulations were conducted at injection and production wells by massive waterfrac and gel-proppant fracturing. Injectivity index increased from $0.97m^3/(hr^*MPa)$ to $7.5m^3/(hr^*MPa)$ and productivity index increased from $2.4m^3/(hr^*MPa)$ to $10.1m^3/(hr^*MPa)$ by a series of hydraulic stimulations at both wells. After circulation tests through injection and production wells, however, productivity index decreased from $8.9m^3/(hr^*MPa)$ to $0.6m^3/(hr^*MPa)$ in two years. Slip tendency analysis for the stimulation in volcanic layer estimated the required pressure for shear slip and its preferred orientations and it showed reasonable match with actual stimulation results. Through the microseismicity observation for the stimulation of volcanic formation, only 80 seismic events with its moment magnitudes in -1.8<$M_W$<-1.0 were observed, which are unexpectedly low for EGS hydraulic stimulation.

본 논문에서는 독일 북부의 그로스 쉐네벡 지역에서 진행된 EGS 실증프로젝트를 수리자극 시험 중심으로 소개한다. 이 지역에서는 사암 및 화산암으로 이루어진 심도 4 - 4.4 km의 지층 내에 각각 1개의 주입정과 생산정을 갖는 순환 시스템을 구성했다. 정단층 및 주향이동단층 응력상태 하에서 물 또는 젤과 균열지지체를 주입하여 주입정과 생산정에서 각각 수리자극이 이루어졌으며, 그 결과 주입지수가 $0.97m^3/(hr^*MPa)$에서 $7.5m^3/(hr^*MPa)$로 증가하였고 생산성지수는$2.4m^3/(hr^*MPa)$에서 $10.1m^3/(hr^*MPa)$로 4.25배 증가했다. 그러나 주입정과 생산정을 연결하는 순환수리시험에서는 2년간 생산성지수가 $8.9m^3/(hr^*MPa)$에서 $0.6m^3/(hr^*MPa)$까지 감소했다. 화산암층에서의 수리자극에 대해 전단 미끄러짐 해석을 수행한 결과 전단균열의 발생 방향 및 요구되는 유체 압력을 실제 수리자극 결과와 유사하게 예측해 냈다. 화산암층에서의 수리자극 시 미소진동을 관측한 결과 모멘트 규모 -1.8에서 -1.0 범위의 미소진동이 80회 나타나 미소진동의 발생은 극히 미미했다.

Keywords

References

  1. Bertani, R., 2015, Geothermal Power Generation in the world 2010-2014 Update report, World Geothermal Congress, Melbourne, Australia, Paper No. 01001.
  2. BDEW, 2014, Press release on German Energy mix 2014 (date of issue: 29 Dec 2014, in German).
  3. Blocher, G., M. Cacace, T. Reinsch, N. Watanabe, 2015a, Evaluation of three exploitation concepts for a deep geothermal system in the North German Basin, Computers and Geosciences, 2015, 82, 120-129. https://doi.org/10.1016/j.cageo.2015.06.005
  4. Blocher, M.G., T. Reinsch, J. Henninges, H. Milsch, S. Regenspurg, J Kummerow, H Francke and G. Zimmermann, 2015b, Hydraulic history and current state of the deep geothermal reservoir Gross Schonebeck. Geothermics (in press).
  5. Blocher, M.G., G. Zimmermann, I. Moeck, W. Brandt, A. Hassanzadegan and F. Magri, 2010, 3D numerical modeling of hydrothermal processes during the lifetime of a deep geothermal reservoir. Geofluids, 10.3, 406-421. https://doi.org/10.1111/j.1468-8123.2010.00284.x
  6. Kwiatek, G., M. Bohnhoff, G. Dresen, A. Schulze, T. Schulte, G. Zimmermann and E. Huenges, 2010, Microseismicity induced during fluid-injection: A case study from the geothermal site at Gross Schonebeck, North German Basin. Acta Geophysica, 58.6, 995-1020.
  7. Legarth, B., E. Huenges and G. Zimmermann, 2005, Hydraulic fracturing in a sedimentary geothermal reservoir: Results and implications. International Journal of Rock Mechanics and Mining Sciences, 42.78, 1028-1041. https://doi.org/10.1016/j.ijrmms.2005.05.014
  8. Legarth, B., T. Tischner and E. Huenges, 2003, Stimulation experiments in sedimentary, low-enthalpy reservoirs for geothermal power generation, Germany. Geothermics, 32.4, 487-495. https://doi.org/10.1016/j.geothermics.2003.07.007
  9. Lund, J.W. and T.L. Boyd, 2015, Direct utilization of geothermal energy 2015 Worldwide review, World Geothermal Congress, Melbourne, Australia, Paper No. 01000.
  10. Min, K.B., W.S. Yoon and Y. Song, 2013a. Introduction to EGS Geomechanics special issue. Korean Journal of Rock Mechanics, Tunnel & Underground Space, 23.6, 455-456.
  11. Min, K.B., Y. Song and W.S. Yoon, 2013b, EGS Power Generation and Hydraulic Stimulation. Tunnel & Underground Space, 23.6, 506-520. https://doi.org/10.7474/TUS.2013.23.6.506
  12. Moeck, I., G. Kwiatek and G. Zimmermann, 2009a, Slip tendency analysis, fault reactivation potential and induced seismicity in a deep geothermal reservoir. Journal of Structural Geology, 31.10, 1174-1182. https://doi.org/10.1016/j.jsg.2009.06.012
  13. Moeck, I., H. Schandelmeier and H.G. Holl, 2009b, The stress regime in a rotliegend reservoir of the northeast german basin. International Journal of Earth Sciences 98.7, 1643-1654. https://doi.org/10.1007/s00531-008-0316-1
  14. Reinsch, T., S. Regenspurg, E. Feldbusch, A. Saadat, E. Huenges, K. Erbas, G. Zimmermann and J. Henninges, 2015, Reverse Cleanout in a Geothermal Well: Analysis of a Failed Coiled-Tubing Operation. SPE Production & Operations, Paper No.174080.
  15. Song. Y. and T.J. Lee, 2015, Geothermal Development in the Republic of Korea: 2010-2014 update, World Geothermal Congress, Melbourne, Australia, Paper No. 01008.
  16. Weber. J, B. Ganz, R. Schellschmidt, B. Sanner and R. Schulz, 2015, Geothermal energy use in Germany. World Geothermal Congress, Melbourne, Australia, Paper No. 01045.
  17. Zimmermann, G., G. Blocher, A. Reinicke and W. Brandt, 2011, Rock specific hydraulic fracturing and matrix acidizing to enhance a geothermal system-Concepts and field results. Tectonophysics, 503.1, 146-154. https://doi.org/10.1016/j.tecto.2010.09.026
  18. Zimmermann, G, and I. Moeck, 2008, Geothermal research well in Gross Schönebeck - from design to stimulation treatment, Brandenburg. geowiss. Beitr, 15, 1/2, 155-164 (in German).
  19. Zimmermann, G., A. Reinicke, W. Brandt, G. Blöcher, H. Milsch, H. Holl, I. Moeck, T. Schulte, A. Saadat and E. Huenges, 2008, Results of Stimulation Treatments at the Geothermal Research Wells in Gross Schonebeck, Germany. Proc 33th Workshop on Geothermal Reservoir Engineering, Standford University, Paper No. SGP-TR-185.
  20. Zimmermann, G. and A. Reinicke, 2010, Hydraulic stimulation of a deep sandstone reservoir to develop an enhanced geothermal system: Laboratory and field experiments. Geothermics, 39.1, 70-77. https://doi.org/10.1016/j.geothermics.2009.12.003
  21. Zimmermann, G., I. Moeck and G. Blocher, 2010, Cyclic waterfrac stimulation to develop an enhanced geothermal system (EGS)-conceptual design and experimental results. Geothermics, 39.1, 59-69. https://doi.org/10.1016/j.geothermics.2009.10.003
  22. Zimmermann, G., T. Tischner, B. Legarth and E. Huenges, 2009, Pressure-dependent production efficiency of an enhanced geothermal system (EGS): stimulation results and implications for hydraulic fracture treatments. In Rock Physics and Natural Hazards. Birkhauser Basel. 1089-1106.