Advertisement

Vulnerability of Seafloor at Shenhu Area, South China Sea Subjected to Hydrate Dissociation

  • Xin Ju
  • Fang Liu
  • Pengcheng Fu
Conference paper

Abstract

This study develops a hybrid model for investigating seafloor instability subjected to hydrate dissociation by combining the limit equilibrium slope stability analysis and numerical modeling of fluid flow and heat transport. This model is employed to study a slope configured according to the geological settings of hydrate reservoirs located at Shenhu area, South China Sea, under mild and sustaining warming scenarios. The vulnerable settings and the controlling factors are quantitatively identified through a parametric study. The results indicate that the slope is stable under the mild seafloor warming scenario in a short timescale. Under the sustaining warming scenario, the slope fails in the order of hundreds of years. The predicted slip onset is located at the top of the hydrate reservoir. The slope is particularly vulnerable to the presence of low permeable and tight sediments, and highly-concentrated hydrates. The permeability of the overburden layer plays a dominant role in determining the vulnerability of the slope, while the impact of the permeability, hydrate saturation, and porosity of the hydrate reservoir is secondary.

Keywords

Methane hydrate Seafloor instability THC coupled process South China Sea 

Notes

Acknowledgement

The work is supported by the Chinese National Natural Science Foundation (with grant No. 41572267, 51639008, and 51239010), and the Fundamental Research Funds for the Central Universities.

References

  1. 1.
    Mienert, J., Vanneste, M., Bünz, S., Andreassen, K., Haflidason, H., Sejrup, H.P.: Ocean warming and gas hydrate stability on the mid-norwegian margin at the storegga slide. Mar. Petrol. Geol. 22(1), 233–244 (2005)CrossRefGoogle Scholar
  2. 2.
    Song, Y., Yang, L., Zhao, J., Liu, W., Yang, M., Li, Y., et al.: The status of natural gas hydrate research in China: a review. Renew. Sustain. Energy Rev. 31(2), 778–791 (2014)CrossRefGoogle Scholar
  3. 3.
    Yu, X., Wang, J., Liang, J., Li, S., Zeng, X., Li, W.: Depositional characteristics and accumulation model of gas hydrates in northern South China Sea. Mar. Petrol. Geol. 56(3), 74–86 (2014)CrossRefGoogle Scholar
  4. 4.
    Matsumoto, R., Ryu, B.J., Lee, S.R., Lin, S., Wu, S., Sain, K., et al.: Occurrence and exploration of gas hydrate in the marginal seas and continental margin of the Asia and Oceania region. Mar. Petrol. Geol. 28(10), 1751–1767 (2011)CrossRefGoogle Scholar
  5. 5.
    Reagan, M.T., Moridis, G.J.: Dynamic response of oceanic hydrate deposits to ocean temperature change. J. Geophys. Res. Oceans 113(12), 1–21 (2008)Google Scholar
  6. 6.
    Stranne, C., O’Regan, M., Dickens, G.R., Crill, P., Miller, C., Preto, P., Jakobsson, M.: Dynamic simulations of potential methane release from East Siberian continental slope sediments. Geochem. Geophys. Geosyst. 17(3), 872–886 (2016)CrossRefGoogle Scholar
  7. 7.
    Mestdagh, T., Poort, J., De Batist, M.: The sensitivity of gas hydrate reservoirs to climate change: perspectives from a new combined model for permafrost-related and marine settings. Earth Sci. Rev. 169, 104–131 (2017)CrossRefGoogle Scholar
  8. 8.
    Sultan, N., Cochonat, P., Foucher, J.P., Mienert, J.: Effect of gas hydrates melting on seafloor slope instability. Mar. Geol. 213(1), 379–401 (2004)CrossRefGoogle Scholar
  9. 9.
    Nixon, M.F., Grozic, J.L.: Submarine slope failure due to gas hydrate dissociation: a preliminary quantification. Can. Geotech. J. 44(3), 314–325 (2007)CrossRefGoogle Scholar
  10. 10.
    Xu, W., Germanovich, L.N.: Excess pore pressure resulting from methane hydrate dissociation in marine sediments: a theoretical approach. J. Geophys. Res. Solid Earth 111(B1), B02104 (2006)CrossRefGoogle Scholar
  11. 11.
    Kwon, T.H., Cho, G.C.: Submarine slope failure primed and triggered by bottom water warming in oceanic hydrate-bearing deposits. Energies 5(8), 2849–2873 (2012)CrossRefGoogle Scholar
  12. 12.
    Masui, A., Haneda, H., Ogata, Y., Aoki, K.: Effects of methane hydrate formation on shear strength of synthetic methane hydrate sediments. In: The Fifteenth International Offshore and Polar Engineering Conference. International Society of Offshore and Polar Engineers (2005)Google Scholar
  13. 13.
    Wang, L., Wu, S.G., Li, Q.P., Wang, D.W., Fu, S.Y.: Architecture and development of a multi-stage Baiyun submarine slide complex in the Pearl River Canyon, northern South China Sea. Geo-Mar. Lett. 34(4), 327–343 (2014)CrossRefGoogle Scholar
  14. 14.
    Li, G., Moridis, G.J., Zhang, K., Li, X.S.: The use of huff and puff method in a single horizontal well in gas production from marine gas hydrate deposits in the Shenhu area of South China Sea. J. Petrol. Sci. Eng. 77(1), 49–68 (2011)CrossRefGoogle Scholar
  15. 15.
    Stone, H.L.: Probability model for estimating three-phase relative permeability. J. Petrol. Technol. 22(02), 214–218 (1970)CrossRefGoogle Scholar
  16. 16.
    Van Genuchten, M.T.: A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44(5), 892–898 (1980)CrossRefGoogle Scholar
  17. 17.
    Li, G., Li, X.S., Zhang, K., Li, B., Zhang, Y.: Effects of impermeable boundaries on gas production from hydrate accumulations in the Shenhu area of the South China Sea. Energies 6(8), 4078–4096 (2013)CrossRefGoogle Scholar
  18. 18.
    Thatcher, K.E., Westbrook, G.K., Sarkar, S., Minshull, T.A.: Methane release from warming-induced hydrate dissociation in the West Svalbard continental margin: timing, rates, and geological controls. J. Geophys. Res. Solid Earth 118(1), 22–38 (2013)CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  1. 1.State Key Laboratory of Disaster Reduction in Civil EngineeringTongji UniversityShanghaiChina
  2. 2.Key Laboratory of Geotechnical and Underground EngineeringTongji University, Ministry of EducationShanghaiChina
  3. 3.Lawrence Livermore National LaboratoryLivermoreUSA

Personalised recommendations