- Volume 26 Issue 2
In this paper, we perform a numerical analysis to evaluate the potential of fault reactivation during gas production from hydrate bearing sediments and the moment magnitude of induced seismicity. For the numerical analysis, sequential coupling of TOUGH+Hydrate and FLAC3D was used and the change in effective stress and consequent geomechanical deformation including fault reactivation was simulated by assuming that Mohr-Coulomb shear resistance criterion is valid. From the test production simulation of 30 days, we showed that pore pressure reduction as well as effective stress change hardly induces the fault reactivation in the vicinity of a production well. We also investigated the influence of stress state conditions to a fault reactivation, and showed that normal fault stress regime, where vertical stress is relatively greater than horizontal, may have the largest potential for the reactivation. We tested one simulation that earthquake can be induced during gas production and calculated the moment magnitude of the seismicity. Our calculation presented that all the magnitudes from the calculation were negative values, which indicates that induced earthquakes can be grouped into micro-seismic and as small as hardly perceived by human beings. However, it should be noted that the current simulation was carried out using the highly simplified geometric model and assumptions such that the further simulations for a scheduled test production and commercial scale production considering complex geometric conditions may produce different results.
Fault reactivation;Methane gas production;Hydrate;Induced earthquake;Coupled analysis;Geomechanics
- 김형목, J. Rutqvist, 2015, "호층 구조 가스하이드레이트 퇴적층에서 수직 생산정을 이용한 가스 회수생산 해석", 2015 한국암반공학회 춘계 총회 및 학술발표회 발표자료집, 2015년 3월, pp. 303-307.
- 임대희, 김정규, 송재준, 2013, "감압법을 이용한 가스하이드레이트 회수생산시 해저지반 거동예측에 관한 수치해석적 연구, 2013 한국암반공학회 추계 총회 및 학술발표회 발표자료집, 2013년 10월, pp. 206-211.
- Cappa, F. and J. Rutqvist, 2011, "Modeling of coupled deformation and permeability evolution during fault reactivation induced by deep underground injection of CO2", International Journal of Greenhouse Gas Control, Vol. 5, pp. 336-346. https://doi.org/10.1016/j.ijggc.2010.08.005
- Figueiredo, B., C.F. Tsang, J. Rutqvist, J. Bensabat, and A. Niemi, 2015, "Coupled hydro-mechanical processes and fault reactivation induced by CO2 injection in a three-layer storage formation", International Journal of Greenhouse Gas Control, Vol. 29, pp. 432-448.
- Gan, Q. and D. Elsworth, 2014, "Analysis of fluid injection-induced fault reactivation and seismic slip in geothermal reservoirs", Journal of Geophysical Research: Solid Earth, Vol. 199(4), pp. 3340-3353.
- Hanks, T.C and H. Kanamori, 1979, "A moment magnitude scale", Journal of Geophysical Research, Vol. 84, pp. 2348-2350. https://doi.org/10.1029/JB084iB05p02348
- Itasca, 2012, FLAC3D: Fast Lagrangian Analysis of Continua in 3 Dimensions, Version 4.0, Minneapolis, Minnesota, Itasca Consulting Group, pp.438. 2009.
- Kim, A.R., J.W. Lee and H.M. Kim, 2015, "A case study of test production of gas from hydrate bearing sediments on Nankai trough in Japan", Tunnel and Underground Space Vol. 25, No. 2, pp. 133-143. https://doi.org/10.7474/TUS.2015.25.2.133
- Kim, A.R. and H.M. Kim, 2016, "Scenario Analysis of Injection Temperature and Injection Rate for Assessing the Geomechanical Stability of CCS (Carbon Capture and Sequestration) System)", Tunnel and Underground Space Vol. 26, No. 1, pp. 12-23. https://doi.org/10.7474/TUS.2016.26.1.012
- Kim. H.M and J. Rutqvist, 2014, "Geomechanical model analysis for the evaluation of mechanical stability of unconsolidated sediments during gas hydrate development and production", Tunnel and Underground Space Vol. 24, No. 2, pp. 143-154. https://doi.org/10.7474/TUS.2014.24.2.143
- Kim. H.M, J. Rutqvist, and W.S. Bae, 2014, "Sensitivity analysis for fault reactivation in potential CO2-EOR site with multi-layers of permeable and impermeable formation", Geosystem Engineering, Vol. 17, No. 5, pp. 253-263. https://doi.org/10.1080/12269328.2014.972577
- Kim H.M., 2015, "Numerical analysis for geomechanical deformation of sea bed due to gas hydrate dissociation", J. Korean Soc. Miner. Energy Resour. Eng. Vol. 52, No. 2, pp. 148-157.
- Kim H.W., D.S. Cheon, B.H. Choi, H.S. Choi and E.S. Park, 2013, "Case Study on Stability Assessment of Pre-existing Fault at CO2 Geologic Storage", Tunnel and Underground Space Vol. 23, No. 1, pp. 13-30. https://doi.org/10.7474/TUS.2013.23.1.013
- Mazzoldi, A., A.P. Rinaldi, A. Borgia and J. Rutqvist, 2012, "Induced seismicity within geological carbon sequestration projects: Maximum earthquake magnitude and leakage potential from undetected faults", International Journal of Greenhouse Gas Control, Vol. 10, pp. 434-442. https://doi.org/10.1016/j.ijggc.2012.07.012
- Mohammedyasin, M.S., 2015, Deep-seated faults and hydrocarbon leakage in the Snohvit Gas Field, Hammerfest Basin, southwestern Barents Sea, Msc. thesis, Norwegian University of Science and Technology (NTNU) - Tronheim, p. 97.
- Moridis, G.J., M.B., Kowalsky and K. Pruess, 2008, TOUGH+HYDRATE v1.0 USER's MANUAL: A code for the simulation of system behavior in hydrate bearing geologic media, LBNL-149E, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
- Moridis, G.J., J. Kim, M.T. Reagan and S.J. Kim, 2013, "Feasibility of gas production from a gas hydrate accumulation at the UBGH2-6 site of the Ulleung basin in the Korean East Sea", Journal of Petroleum Science and Engineering, Vol. 108, pp. 180-210. https://doi.org/10.1016/j.petrol.2013.03.002
- NRC (National Research Council), 2013, Induced seismicity potential in energy technology, Washington D.C., The National Academies Press, p. 211.
- Rutqvist, J and G.J. Moridis, 2007, "Numerical studies of geomechanical stability of hydrate-bearing sediments", Offshore technology conference, 2007 May, Houston, Texas, U.S.A.
- Rutqvist, J., G.J. Moridis, T. Grover, S. Silpnagarmert, T. Collett and S.A. Holdich, 2012, "Coupled multiphase fluid flow and wellbore stability analysis associated with gas production from oceanic hydrate-bearing sediments", J. Petroleum Science and Engineering, Vol. 92-93, pp. 65-81. https://doi.org/10.1016/j.petrol.2012.06.004
- Rutqvist, J, A.P. Rinaldi, F. Cappa and G.J. Moridis, 2013, "Modeling of fault reactivation and induced seismicity during hydraulic fracturing of shale-gas reservoirs", Journal of Petroleum Science and Engineering, Vol. 107, pp. 31-44. https://doi.org/10.1016/j.petrol.2013.04.023
- Qui, K., K. Yamamoto, R. Birchwood, Y. Chen, C. Wu, C.P. Tan and V. Singh, 2013, "Evaluation of Fault Reactivation", Offshore Technology Conference, Houston, Texax, U.S.A., 30 April - 3 May 2012, OTC 22890.
- van Genuchten, M.T., 1980, "A closed-form equation for predicting the hydraulic conductivity of unsaturated soils," Soil Sci Soc Am J., Vol. 44, pp. 892-898. https://doi.org/10.2136/sssaj1980.03615995004400050002x