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Estimating the amount of gas-hydrate using effective medium theory: a case study in the Blake Ridge

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Abstract

Estimating the amount of gas-hydrate and free-gas is difficult in deep seas even with scientific coring and downhole measurements. Well data may be incompatible between holes of a site as well as with depth in the same hole. In this paper, we demonstrate an approach to estimate saturation of gas-hydrate from seismic velocities at any site where data set is limited. The study is carried out in the outer Blake Ridge, which is one of the most intensively studied regions of natural gas-hydrate occurrences and a very distinctive example of studying geophysical signatures of gas-hydrate and free-gas in deep marine sediments. Although, downhole measurements from both vertical seismic profiles (VSPs) and sonic logs provide the most accurate and direct measurements of velocity, only VSP velocities at Ocean Drilling Program (ODP) Sites 994, 995, and 997 on the Blake Ridge are used to estimate the saturation of gas-hydrate and free-gas as sonic logs at ODP sites are not reliable. Here we derive a general trend of the background velocity with depth using the porosity and mineralogy from coring at discrete depth intervals. Saturations of gas-hydrate and free-gas are then estimated from this background velocity using the effective medium modeling. The porosity and mineralogical compositions are taken from four different depths at Site 995, as data quality is the best in this hole. Average saturations of gas-hydrate and free-gas at three holes are estimated as 10–14 and 2–3%, respectively.

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References

  • Ahlbrandt TS (2002) Future petroleum energy resources of the world. Int Geol Rev 44:1092–1104

    Article  Google Scholar 

  • Bonilla LL, Keller JB (1985) Acoustoelastic effect and wave propagation in heterogeneous weakly anisotropic materials. J Mech Phys Solids 33:241–261

    Article  Google Scholar 

  • Chand S, Minshull TA, Gei D, Carcione JM (2004) Elastic velocity models for gas-hydrate-bearing sediments-a comparison. Geophys J Int 159:573–590

    Article  Google Scholar 

  • Cholach PY, Schmitt DR (2006) Intrinsic elasticity of a textured transversely isotropic muscovite aggregate: Comparisons to the seismic anisotropy of schists and shales. J Geophys Res 111:B09410

    Article  Google Scholar 

  • Collett TS, Ladd J (2000) Detection of gas hydrate with downhole logs and assessment of gas hydrate concentrations (saturations) and gas volumes on the Blake Ridge with electrical resistivity log data. In: Paull CK, Matsumoto R, Wallace PJ, Dillon WP (eds) Proceedings of ODP, science results, vol 164, pp 179–191

  • Cook A, Goldberg D (2008) Stress and gas-hydrate-filled fracture distribution, Krishna–Godavari basin, India, In: Proceedings of the 6th international conference on gas hydrates, Vancouver, July 6–10

  • Dvorkin J, Nur A (1996) Elasticity of high porosity sandstones: theory for two North Sea data sets. Geophysics 61:1363–1370

    Article  Google Scholar 

  • Ecker C, Dvorkin J, Nur A (1998) Sediments with gas hydrate: internal structure from seismic AVO. Geophysics 63:1659–1669

    Article  Google Scholar 

  • Ecker C, Dvorkin J, Nur A (2000) Estimating the amount of gas hydrate and free gas from marine seismic data. Geophysics 65:565–573

    Article  Google Scholar 

  • Erickson SN, Jarrard RD (1998) Velocity-porosity relationships for water-saturated siliciclastic sediments. J Geophys Res 103:30385–30406

    Article  Google Scholar 

  • Ghosh R, Sain K (2008) Effective medium modeling to assess gas hydrate and free gas evident from the velocity structure in the Makran accretionary prism. Mar Geophys Res 29:267–274

    Article  Google Scholar 

  • Ghosh R, Sain K, Ojha M (2010) Effective medium modeling of gas hydrate-filled fractures using sonic log in the Krishna-Godavari basin, eastern Indian offshore. J Geophys Res. doi:10.1029/2009JB006711 (in press)

  • Guerin G, Goldberg D, Meltser A (1999) Characterization of in situ elastic properties of gas hydrate-bearing sediments on the Blake Ridge. J Geophys Res 104:17781–17795

    Article  Google Scholar 

  • Hamilton EL (1974) Prediction of deep-sea sediment properties: state of the art. In: Inderbitzen AL (ed) Deep-Sea sediments: physical and mechanical properties. Plenum, New York, pp 1–44

    Google Scholar 

  • Helgerud MB, Dvorkin J, Nur A (1999) Elastic-wave velocity in marine sediments with gas hydrates: effective medium modeling. Geophys Res Lett 26:2021–2024

    Article  Google Scholar 

  • Holbrook WS (2001) Seismic studies of the Blake Ridge: implications for hydrate distribution, methane expulsion, and free gas dynamics. In: Paull CK, Dillon WP (eds) Natural gas hydrates: occurrence, distribution, and detection. American Geophysical Union Geophys Mono 124, pp 307–315

  • Holbrook WS, Hoskins H, Wood WT, Stephen RA, Lizarralde D, Leg 164 Science Party (1996) Methane hydrate and free gas on the Blake Ridge from vertical seismic profiling. Science 273:1840–1843

    Article  Google Scholar 

  • Holland M, Schultheiss P, Roberts J, Druce M (2008) Observed gas hydrate morphologies in marine sediments. In: Proceedings of the 6th international conference on gas hydrates, Vancouver, July 6–10

  • Hornbach MJ, Saffer DM, Holbrook WS, Avendonk HJAV, Gorman AR (2008) Three-dimensional seismic imaging of the Blake Ridge methane hydrate province: Evidence for large, concentrated zones of gas hydrate and morphologicalyy driven advection. J Geophys Res 113:B07101. doi:10.1029/2007JB005329

    Article  Google Scholar 

  • Hornby BE, Schwartz LM, Hudson JA (1994) Anisotropic effective medium modeling of the elastic properties of shales. Geophysics 59:1570–1583

    Article  Google Scholar 

  • Hyndman RD, Moore GF, Moran K (1993) Velocity, porosity and pore-fluid loss from the Nankai subduction zone accretionary prism. In: Proceedings of the ocean drilling program, scientific results, vol 131, pp 211–220

  • Jakobsen M, Hudson JA, Minshull TA, Singh SC (2000) Elastic properties of hydrate-bearing sediments using effective medium theory. J Geophys Res 105:561–577

    Article  Google Scholar 

  • Kastner M, Claypool G, Robertson G (2008) Geochemical constraints on the origin of the pore fluids and gas hydrate distribution at Atwater Valley and Keathley Canyon, northern Gulf of Mexico. Mar Petro Geol 25:860–872

    Article  Google Scholar 

  • Klauda JB, Sandler SI (2005) Global distribution of methane hydrate in ocean sediment. Energy Fuels 19:459–470

    Article  Google Scholar 

  • Korenaga J, Holbrook WS, Singh SC, Minshull TA (1997) Natural gas hydrates on the southeast US margin: constraints from full waveform and travel time inversions of wide-angle seismic data. J Geophys Res 102:15345–15365

    Article  Google Scholar 

  • Kvenvolden KA (1998a) A primer on the geological occurrence of gas hydrate. In: Henriet JP, Mienert J (eds) Gas hydrates: relevance to the world margin stability and climate change, pp 9–30, Geol Soc Special Publications 37, London

  • Kvenvolden KA (1998b) Methane hydrate—a major reservoir of carbon in the shallow geosphere? Chem Geol 71:41–51

    Article  Google Scholar 

  • Lee MW (2000) Gas hydrates amount estimated from acoustic logs at the Blake Ridge, Sites 994, 995, and 997. In: Paull CK, Matsumoto R, Wallace PJ, Dillon WP (eds) Proceedings of ocean drilling program, scientific results, vol 164, pp 193–198

  • Lee MW, Collett TS (2008) Integrated analysis of well logs and seismic data to estimate gas hydrate concentrations at Keathley Canyon, Gulf of Mexico. Mar Petro Geol 25:924–931

    Article  Google Scholar 

  • Lee MW, Hutchinson DR, Collett TS, Dillon WP (1996) Seismic velocities for hydrate-bearing sediments using weighted equation. J Geophys Res 101:20347–20358

    Article  Google Scholar 

  • Mackay ME, Jarrad RD, Westbrook GK, Hyndman RD (1994) Origin of bottom simulating reflectors: geophysical evidence from the Cascadia accretionary prism. Geology 22:459–462

    Article  Google Scholar 

  • Makogon YF, Holditch SA, Makogon TY (2007) Natural gas hydrates—a potential energy source for the 21st century. J Petrol Sci Eng 56:14–31

    Article  Google Scholar 

  • Milkov AV (2004) Global estimates of hydrate-bound gas in marine sediments: how much is really out there? Earth Sci Rev 66:183–197

    Article  Google Scholar 

  • Nishizawa O (1982) Seismic velocity anisotropy in a medium containing oriented cracks: Transversely isotropic case. J Phys Earth 30:331–347

    Google Scholar 

  • Paull CK et al (1996) Proceedings of the Ocean drilling program. Sci Results 164:623

    Google Scholar 

  • Pecher IA, Holbrook WS, Sen MK, Lizarralde D, Wood WT (2003) Seismic anisotropy in gas hydrate-and gas-bearing sediments on the Blake ridge, from a walk away vertical seismic profile. Geophys Res Lett 30:1733. doi:10.1029/2003GL017477

    Article  Google Scholar 

  • Sayers CM (1994) The elastic anisotropy of shales. J Geophys Res B1 99:767–774

    Article  Google Scholar 

  • Sheng P (1990) Effective medium theory of sedimentary rocks. Phys Rev B 41:4507–4512

    Article  Google Scholar 

  • Sheng P (1991) Consistent modeling of the electrical and elastic properties of sedimentary rocks. Geophysics 56:1236–1243

    Article  Google Scholar 

  • Shipboard Scientific Party (1996) Site 995. In: Paull CK, Matsumoto R, Wallace et al (eds) Proceedings of ocean drilling program, initial reports, vol 164, pp 175–240

  • Sloan ED (1998) Clathrate hydrate of natural gases. Marcel Dekker, New York

    Google Scholar 

  • Sloan ED (2003) Fundamental principles and applications of natural gas hydrates. Nature 426:353–359

    Article  Google Scholar 

  • Tinivella U, Lodolo E (2000) The Blake Ridge bottom-simulating reflector transect: tomographic velocity field and theoretical model to estimate methane hydrate quantities. In: Paull CK, Matsumoto R, Wallace PJ, Dillon WP (eds) Proceedings of ocean drilling program, initial reports, vol 164, pp 273–281

  • Willis JR (1977) Bounds of self-consistent estimates for the overall properties of anisotropic composites. J Mech Phys Solids 25:185–202

    Article  Google Scholar 

  • Wood AB (1941) Text book of sound. Macmillan, Indianapolis, p 578

    Google Scholar 

  • Wyllie MR, Gergory AR, Gardner GHP (1958) An experimental investigation of factors affecting elastic wave velocities in porous media. Geophysics 23:459–493

    Article  Google Scholar 

Download references

Acknowledgments

We are grateful to the Director, NGRI for his kind consent to publish this work. The Ministry of Earth Sciences, Delhi and the Department of Science & Technology, Delhi are acknowledged for financial support. We are grateful to the Editor and two anonymous reviewers for their comments and suggestions.

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Correspondence to Kalachand Sain.

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Ghosh, R., Sain, K. & Ojha, M. Estimating the amount of gas-hydrate using effective medium theory: a case study in the Blake Ridge. Mar Geophys Res 31, 29–37 (2010). https://doi.org/10.1007/s11001-010-9084-y

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  • DOI: https://doi.org/10.1007/s11001-010-9084-y

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