This website uses cookies to improve your experience. If you continue without changing your settings, you consent to our use of cookies in accordance with our cookie policy. You can disable cookies at any time.

×
Advanced search
Skip main navigation
Close Drawer MenuOpen Drawer Menu

Previous
Next
No AccessGEOPHYSICSVolume 83, Issue 4

Gas hydrate quantification using full-waveform inversion of sparse ocean-bottom seismic data: A case study from Green Canyon Block 955, Gulf of Mexico

Authors:
https://doi.org/10.1190/geo2017-0414.1

ABSTRACT

We present a case study of gas hydrate quantification using dense short-offset multichannel seismic (MCS) and sparse long-offset ocean-bottom-seismometer (OBS) data in lease block Green Canyon 955 (GC955), Gulf of Mexico (GOM), where the presence of gas hydrate was interpreted using logging while drilling (LWD) data acquired by the GOM Gas Hydrate Joint Industry Project Leg II expedition. We use frequency-domain full-waveform inversion (FWI) of seven OBS gathers to invert for a P-wave velocity model of an approximately 7 km long MCS profile connecting two LWD sites, GC955-H and GC955-Q. We build the starting model for FWI using traveltime inversion (TI) of the MCS and OBS data. In addition, we use the TI model for depth migrating the MCS stack. At the LWD sites, we constrain the hydrate saturation (Sgh) using sonic and resistivity logs. Unfortunately, as is typical of seismic quantification problems, the FWI model resolution is not sufficient to extrapolate the LWD-based Sgh. Therefore, we apply Backus averaging to the sonic log, at 60 m wavelength, bringing it within approximately 8% of the FWI model and make the assumption that averaging the sonic log is same as redistributing the gas hydrate within the Backus wavelength. In this manner, instead of Sgh, the FWI model is able to estimate the total gas hydrate volume. In the end, we use the FWI model and the migrated stack to constrain the locations and bulk volumes of free gas and gas hydrate. Our results demonstrate that with careful processing, reasonable estimates on locations and bulk volumes of submarine gas hydrate accumulations can be achieved even with sparse seismic data that are not adequate for amplitude-based assessments.

REFERENCES

  • Backus, G. E., 1962, Long-wave elastic anisotropy produced by horizontal layering: Journal of Geophysical Research, 67, 4427–4440, doi: 10.1029/JZ067i011p04427.JGREA20148-0227CrossrefWeb of ScienceGoogle Scholar
  • Bangs, N. L. B., D. S. Sawyer, and X. Golovchenko, 1993, Free gas at the base of the gas hydrate zone in the vicinity of the Chile triple junction: Geology, 21, 905–908, doi: 10.1130/0091-7613(1993)021<0905:FGATBO>2.3.CO;2.GLGYBA0091-7613CrossrefWeb of ScienceGoogle Scholar
  • Batzle, M. L., and Z. Wang, 1992, Seismic properties of pore fluids: Geophysics, 57, 1396–1408, doi: 10.1190/1.1443207.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Boswell, R., and T. S. Collett, 2011, Current perspectives on gas hydrate resources: Energy & Environmental Science, 4, 1206–1215, doi: 10.1039/C0EE00203H.EESNBY1754-5692CrossrefWeb of ScienceGoogle Scholar
  • Boswell, R., T. S. Collett, M. Frye, W. Shedd, D. R. McConnell, and D. Shelander, 2012a, Subsurface gas hydrates in the northern Gulf of Mexico: Marine and Petroleum Geology, 34, 4–30, doi: 10.1016/j.marpetgeo.2011.10.003.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Boswell, R., M. Frye, D. Shelander, W. Shedd, D. R. McConnell, and A. Cook, 2012b, Architecture of gas-hydrate-bearing sands from Walker Ridge 313, Green Canyon 955, and Alaminos Canyon 21: Northern deepwater Gulf of Mexico: Marine and Petroleum Geology, 34, 134–149, doi: 10.1016/j.marpetgeo.2011.08.010.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Boswell, R., C. Shipp, T. Reichel, D. Shelander, T. Saeki, M. Frye, W. Shedd, T. S. Collett, and D. R. McConnell, 2016, Prospecting for marine gas hydrate resources: Interpretation, 4, no. 1, SA13–SA24, doi: 10.1190/INT-2015-0036.1.AbstractGoogle Scholar
  • Brenders, A. J., and R. G. Pratt, 2007a, Efficient waveform tomography for lithospheric imaging: Implications for realistic, two-dimensional acquisition geometries and low-frequency data: Geophysical Journal International, 168, 152–170, doi: 10.1111/j.1365-246X.2006.03096.x.GJINEA0956-540XCrossrefWeb of ScienceGoogle Scholar
  • Brenders, A. J., and R. G. Pratt, 2007b, Full waveform tomography for lithospheric imaging: Results from a blind test in a realistic crustal model: Geophysical Journal International, 168, 133–151, doi: 10.1111/j.1365-246X.2006.03156.x.GJINEA0956-540XCrossrefWeb of ScienceGoogle Scholar
  • Brossier, R., S. Operto, and J. Virieux, 2009, Seismic imaging of complex onshore structures by 2D elastic frequency-domain full-waveform inversion: Geophysics, 74, no. 6, WCC105–WCC118, doi: 10.1190/1.3215771.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Bunks, C., F. M. Saleck, S. Zaleski, and G. Chavent, 1995, Multiscale seismic waveform inversion: Geophysics, 60, 1457–1473, doi: 10.1190/1.1443880.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Chand, S., T. A. Minshull, D. Gei, and J. M. Carcione, 2004, Elastic velocity models for gas-hydrate-bearing sediments: A comparison: Geophysical Journal International, 159, 573–590, doi: 10.1111/j.1365-246X.2004.02387.x.GJINEA0956-540XCrossrefWeb of ScienceGoogle Scholar
  • Chatterjee, S., G. Bhatnagar, B. Dugan, G. R. Dickens, W. G. Chapman, and G. J. Hirasaki, 2014, The impact of lithologic heterogeneity and focused fluid flow upon gas hydrate distribution in marine sediments: Journal of Geophysical Research: Solid Earth, 119, 6705–6732, doi: 10.1002/2014JB011236.CrossrefWeb of ScienceGoogle Scholar
  • Collett, T. S., 2002, Energy resource potential of natural gas hydrates: AAPG Bulletin, 86, 1971–1992.AABUD20149-1423Web of ScienceGoogle Scholar
  • Collett, T. S., M. W. Lee, M. V. Zyrianova, S. A. Mrozewski, G. Guerin, A. E. Cook, and D. S. Goldberg, 2012, Gulf of Mexico Gas Hydrate Joint Industry Project Leg II logging-while-drilling data acquisition and analysis: Marine and Petroleum Geology, 34, 41–61.CrossrefWeb of ScienceGoogle Scholar
  • Dai, J., H. Xu, F. Snyder, and N. Dutta, 2004, Detection and estimation of gas hydrates using rock physics and seismic inversion: Examples from the northern deepwater Gulf of Mexico: The Leading Edge, 23, 60–66, doi: 10.1190/1.1645456.AbstractGoogle Scholar
  • Delescluse, M., M. R. Nedimovic, and K. E. Louden, 2011, 2D waveform tomography applied to long-streamer MCS data from the Scotian Slope: Geophysics, 76, no. 4, B151–B163, doi: 10.1190/1.3587219.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Dutta, T., G. Mavko, T. Mukerji, and T. Lane, 2009, Compaction trends for shale and clean sandstone in shallow sediments, Gulf of Mexico: The Leading Edge, 28, 590–596, doi: 10.1190/1.3124935.AbstractGoogle Scholar
  • Gardner, G. H. F., L. W. Gardner, and A. R. Gregory, 1974, Formation velocity and density: Diagnostic basics for stratigraphic traps: Geophysics, 39, 770–780, doi: 10.1190/1.1440465.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Gassmann, F., 1951, Elastic waves through a packing of spheres: Geophysics, 16, 673–685, doi: 10.1190/1.1437718.GPYSA70016-8033AbstractGoogle Scholar
  • George, A., and J. Liu, 1981, Computer solution of large sparse positive definite systems: Prentice Hall.Google Scholar
  • Gray, S. H., J. Etgen, J. Dellinger, and D. Whitmore, 2001, Seismic migration problems and solutions: Geophysics, 66, 1622–1640, doi: 10.1190/1.1487107.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Haines, S. S., P. Hart, W. W. Shedd, and M. Frye, 2014a, Seismic investigation of gas hydrates in the Gulf of Mexico: 2013 multicomponent and high-resolution 2D acquisition at GC955 and WR313: Paper read at Offshore Technology Conference, Offshore Technology Conference, OTC-25318-MS, doi: 10.4043/25318-MS.CrossrefGoogle Scholar
  • Haines, S. S., P. E. Hart, T. S. Collett, W. Shedd, M. Frye, P. Weimer, and R. Boswell, 2017, High-resolution seismic characterization of the gas and gas hydrate system at Green Canyon 955, Gulf of Mexico, USA: Marine and Petroleum Geology, 82, 220–237, doi: 10.1016/j.marpetgeo.2017.01.029.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Haines, S. S., P. E. Hart, C. D. RuppelO'BrienT., W. Baldwin, J. White, E. Moore, P. Dal Ferro, and P. Lemmond, 2014b, Cruise report for P1–13–LA, U.S. Geological Survey gas hydrates research cruise: R/V Pelican April 18 to May 3, 2013, deepwater Gulf of Mexico, U.S. Geological Survey, doi: 10.3133/ofr20141080.CrossrefGoogle Scholar
  • Heggland, R., 2004, Definition of geohazards in exploration 3-D seismic data using attributes and neural-network analysis: AAPG Bulletin, 88, 857–868, doi: 10.1306/02040404019.AABUD20149-1423CrossrefWeb of ScienceGoogle Scholar
  • Helgerud, M. B., J. Dvorkin, and A. Nur, 2000, Rock physics characterization for gas hydrate reservoirs: Elastic properties, in G. D. HolderP. R. Bishnoi, eds., Gas hydrates: Challenges for the future, Annals of the New York Academy of Sciences, 116–125.CrossrefGoogle Scholar
  • Helgerud, M. B., J. Dvorkin, A. Nur, A. Sakai, and T. Collett, 1999, Elastic-wave velocity in marine sediments with gas hydrates: Effective medium modeling: Geophysical Research Letters, 26, 2021–2024, doi: 10.1029/1999GL900421.GPRLAJ0094-8276CrossrefWeb of ScienceGoogle Scholar
  • Holbrook, W. S., H. Hoskins, W. T. Wood, R. A. Stephen, and D. Lizarralde, 1996, Methane hydrate and free gas on the Blake ridge from vertical seismic profiling: Science, 273, 1840–1843, doi: 10.1126/science.273.5283.1840.SCIEAS0036-8075CrossrefWeb of ScienceGoogle Scholar
  • Hornbach, M. J., W. S. Holbrook, A. R. Gorman, K. L. Hackwith, D. Lizarralde, and I. Pecher, 2003, Direct seismic detection of methane hydrate on the Blake Ridge: Geophysics, 68, 92–100, doi: 10.1190/1.1543196.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Huo, Y. Y., and M. Zhang, 2009, Full waveform inversion of gas hydrate reflectors in Northern South China Sea: Acta Geophysica, 57, 716–727, doi: 10.2478/s11600-009-0011-z.CrossrefWeb of ScienceGoogle Scholar
  • Jaiswal, P., P. Dewangan, T. Ramprasad, and C. A. Zelt, 2012, Seismic characterization of hydrates in faulted, fine-grained sediments of Krishna-Godavari Basin: Full waveform inversion: Journal of Geophysical Research: Solid Earth, 117, B10305, doi: 10.1029/2012JB009201.CrossrefWeb of ScienceGoogle Scholar
  • Jaiswal, P., and C. A. Zelt, 2008, Unified imaging of multichannel seismic data: Combining traveltime inversion and prestack depth migration: Geophysics, 73, no. 5, VE269–VE280, doi: 10.1190/1.2957761.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Jaiswal, P., C. A. Zelt, and I. A. Pecher, 2006, Seismic characterization of a gas hydrate system in the Gulf of Mexico using wide-aperture data: Geophysical Journal International, 165, 108–120, doi: 10.1111/j.1365-246X.2006.02869.x.GJINEA0956-540XCrossrefWeb of ScienceGoogle Scholar
  • Jo, C.-H., C. Shin, and J. H. Suh, 1996, An optimal 9-point, finite-difference, frequency-space, 2-D scalar wave extrapolator: Geophysics, 61, 529–537, doi: 10.1190/1.1443979.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Kamei, R., R. GerhardPratt, and T. Tsuji, 2012, Waveform tomography imaging of a megasplay fault system in the seismogenic Nankai subduction zone: Earth and Planetary Science Letters, 317-318, 343–353, doi: 10.1016/j.epsl.2011.10.042.EPSLA20012-821XCrossrefWeb of ScienceGoogle Scholar
  • Kamei, R., and R. G. Pratt, 2013, Inversion strategies for visco-acoustic waveform inversion: Geophysical Journal International, 194, 859–884, doi: 10.1093/gji/ggt109.GJINEA0956-540XCrossrefWeb of ScienceGoogle Scholar
  • Kerr, R. A., 2004, Gas hydrate resource: Smaller but sooner: Science, 304, 946–948, doi: 10.1126/science.304.5673.946.SCIEAS0036-8075CrossrefWeb of ScienceGoogle Scholar
  • Kumar, P., T. S. Collett, K. Vishwanath, K. M. Shukla, J. Nagalingam, M. V. Lall, Y. Yamada, P. Schultheiss, and M. Holland, 2016, Gas hydrate-bearing sand reservoir systems in the offshore of India: Results of the India National Gas Hydrate Program Expedition 02, Fire in the ice: National Energy Technology Laboratory, 8.Google Scholar
  • Lailly, P., and D. Sinoquet, 1996, Smooth velocity models in reflection tomography for imaging complex geological structures: Geophysical Journal International, 124, 349–362, doi: 10.1111/j.1365-246X.1996.tb07025.x.GJINEA0956-540XCrossrefWeb of ScienceGoogle Scholar
  • Le Begat, S., H. Chauris, V. Devaux, S. Nguyen, and M. Noble, 2004, Velocity model estimation for depth imaging: Comparison of three tomography methods on a 2D real data set: Geophysical Prospecting, 52, 427–438, doi: 10.1111/j.1365-2478.2004.00427.x.GPPRAR0016-8025CrossrefWeb of ScienceGoogle Scholar
  • Lee, M. W., and T. S. Collett, 2012, Pore- and fracture-filling gas hydrate reservoirs in the Gulf of Mexico gas hydrate joint industry project leg II Green Canyon 955 H well: Marine and Petroleum Geology, 34, 62–71, doi: 10.1016/j.marpetgeo.2011.08.002.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Lee, M. W., D. R. Hutchinson, T. S. Collett, and W. P. Dillon, 1996, Seismic velocities for hydrate-bearing sediments using weighted equation: Journal of Geophysical Research-Solid Earth, 101, 20347–20358, doi: 10.1029/96JB01886.CrossrefWeb of ScienceGoogle Scholar
  • Liu, C., Q. Meng, X. He, C. Li, Y. Ye, G. Zhang, and J. Liang, 2015, Characterization of natural gas hydrate recovered from Pearl River Mouth basin in South China Sea: Marine and Petroleum Geology, 61, 14–21, doi: 10.1016/j.marpetgeo.2014.11.006.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Liu, X., and P. B. Flemings, 2006, Passing gas through the hydrate stability zone at southern Hydrate Ridge, offshore Oregon: Earth and Planetary Science Letters, 241, 211–226, doi: 10.1016/j.epsl.2005.10.026.EPSLA20012-821XCrossrefWeb of ScienceGoogle Scholar
  • Mackay, M. E., R. D. Jarrard, G. K. Westbrook, and R. D. Hyndman, 1994, Origin of bottom-simulating reflectors: Geophysical evidence from the Cascadia Accretionary Prism: Geology, 22, 459–462, doi: 10.1130/0091-7613(1994)022<0459:OOBSRG>2.3.CO;2.GLGYBA0091-7613CrossrefWeb of ScienceGoogle Scholar
  • Marfurt, K. J., 1984, Accuracy of finite-difference and finite-element modeling of the scalar and elastic wave equations: Geophysics, 49, 533–549, doi: 10.1190/1.1441689.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Mavko, G., T. Mukerji, and J. Dvorkin, 2009, The rock physics handbook, 2nd ed.: Cambridge University Press.CrossrefGoogle Scholar
  • McConnell, D., R. Boswell, T. Collett, M. Frye, W. Shedd, G. Guerin, A. Cook, S. Mrozewski, R. Dufrene, and P. Godfriaux, 2010a, Gulf of Mexico gas hydrate joint industry project leg II: Green Canyon 955 site summary: Initial scientific results of the Gulf of Mexico gas hydrates joint industry project leg IINational Energy Technology Laboratory, Department of Energy.Google Scholar
  • McConnell, D., T. S. Collett, R. Boswell, M. C. Frye, W. W. Shedd, R. Dufrene, P. Godfriaux, S. Mrozewski, G. Guerin, A. Cook, and E. Jones, 2010b, Gulf of Mexico gas hydrate joint industry project leg II: Initial results from the Green Canyon 955 site: Offshore Technology Conference, OTC-20801-MS.CrossrefGoogle Scholar
  • McConnell, D. R., Z. Zhang, and R. Boswell, 2012, Review of progress in evaluating gas hydrate drilling hazards: Marine and Petroleum Geology, 34, 209–223, doi: 10.1016/j.marpetgeo.2012.02.010.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Mienert, J., M. Vanneste, S. Bunz, K. Andreassen, H. Haflidason, and H. P. Sejrup, 2005, Ocean warming and gas hydrate stability on the mid-Norwegian margin at the Storegga Slide: Marine and Petroleum Geology, 22, 233–244, doi: 10.1016/j.marpetgeo.2004.10.018.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Milkov, A. V., and R. Sassen, 2002, Economic geology of offshore gas hydrate accumulations and provinces: Marine and Petroleum Geology, 19, 1–11, doi: 10.1016/S0264-8172(01)00047-2.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Minshull, T. A., S. C. Singh, and G. K. Westbrook, 1994, Seismic velocity structure at a gas hydrate reflector, offshore western Colombia, from full-wave-form inversion: Journal of Geophysical Research-Solid Earth, 99, 4715–4734, doi: 10.1029/93JB03282.CrossrefWeb of ScienceGoogle Scholar
  • Pecher, I. A., T. A. Minshull, S. C. Singh, and R. vonHuene, 1996, Velocity structure of a bottom simulating reflector offshore Peru: Results from full waveform inversion: Earth and Planetary Science Letters, 139, 459–469, doi: 10.1016/0012-821X(95)00242-5.EPSLA20012-821XCrossrefWeb of ScienceGoogle Scholar
  • Plaza‐Faverola, A., G. K. Westbrook, S. Ker, R. J. Exley, A. Gailler, T. A. Minshull, and K. Broto, 2010, Evidence from three‐dimensional seismic tomography for a substantial accumulation of gas hydrate in a fluid‐escape chimney in the Nyegga pockmark field, offshore Norway: Journal of Geophysical Research: Solid Earth, 115, B08104–B08127.Web of ScienceGoogle Scholar
  • Pratt, R., 1999, Seismic waveform inversion in the frequency domain. Part 1: Theory and verification in a physical scale model: Geophysics, 64, 888–901, doi: 10.1190/1.1444597.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Press, W. H., S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, 1992, Numerical recipes in C: The art of scientific computing, 2nd ed.: University Press.Google Scholar
  • Riedel, M., E. C. Willoughby, and S. Chopra, 2010, Geophysical characterization of gas hydrates: SEG.AbstractGoogle Scholar
  • Scales, J. A., P. Docherty, and A. Gersztenkorn, 1990, Regularization of nonlinear inverse problems-imaging the near-surface weathering layer: Inverse Problems, 6, 115–131, doi: 10.1088/0266-5611/6/1/011.INPEEY0266-5611CrossrefWeb of ScienceGoogle Scholar
  • Shedd, W., R. Boswell, M. Frye, P. Godfriaux, and K. Kramer, 2012, Occurrence and nature of “bottom simulating reflectors” in the northern Gulf of Mexico: Marine and Petroleum Geology, 34, 31–40, doi: 10.1016/j.marpetgeo.2011.08.005.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Shelander, D., J. Dai, G. Bunge, S. Singh, M. Eissa, and K. Fisher, 2012, Estimating saturation of gas hydrates using conventional 3D seismic data, Gulf of Mexico joint industry project leg II: Marine and Petroleum Geology, 34, 96–110, doi: 10.1016/j.marpetgeo.2011.09.006.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Shelander, D., J. C. Dai, and G. Bunge, 2010, Predicting saturation of gas hydrates using pre-stack seismic data, Gulf of Mexico: Marine Geophysical Researches, 31, 39–57, doi: 10.1007/s11001-010-9087-8.MGYRA70025-3235CrossrefWeb of ScienceGoogle Scholar
  • Singh, S. C., T. A. Minshull, and G. D. Spence, 1993, Velocity structure of a gas hydrate reflector: Science, 260, 204–207, doi: 10.1126/science.260.5105.204.SCIEAS0036-8075CrossrefWeb of ScienceGoogle Scholar
  • Sirgue, L., and R. G. Pratt, 2004, Efficient waveform inversion and imaging: A strategy for selecting temporal frequencies: Geophysics, 69, 231–248, doi: 10.1190/1.1649391.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Song, H. B., O. Matsubayashi, and S. Kuramoto, 2003, Full waveform inversion of gas hydrate-related bottom simulating reflectors: Chinese Journal of Geophysics-Chinese Edition, 46, 42–46.Web of ScienceGoogle Scholar
  • Tinivella, U., and F. Accaino, 2000, Compressional velocity structure and Poisson’s ratio in marine sediments with gas hydrate and free gas by inversion of reflected and refracted seismic data (South Shetland Islands, Antarctica): Marine Geology, 164, 13–27, doi: 10.1016/S0025-3227(99)00123-1.MAGEA60025-3227CrossrefWeb of ScienceGoogle Scholar
  • Vanneste, M., M. De Batist, A. Golmshtok, A. Kremlev, and W. Versteeg, 2001, Multi-frequency seismic study of gas hydrate-bearing sediments in Lake Baikal, Siberia: Marine Geology, 172, 1–21, doi: 10.1016/S0025-3227(00)00117-1.MAGEA60025-3227CrossrefWeb of ScienceGoogle Scholar
  • Virieux, J., and S. Operto, 2009, An overview of full-waveform inversion in exploration geophysics: Geophysics, 74, no. 6, WCC1–WCC26, doi: 10.1190/1.3238367.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Waite, W. F., J. C. Santamarina, D. D. Cortes, B. Dugan, D. N. Espinoza, J. Germaine, J. Jang, J. W. Jung, T. J. Kneafsey, H. Shin, K. Soga, W. J. Winters, and T. S. Yun, 2009, Physical properties of hydrate-bearing sediments: Reviews of Geophysics, 47, RG4003–RG4040, doi: 10.1029/2008RG000279.REGEEP8755-1209CrossrefWeb of ScienceGoogle Scholar
  • Wang, Z., 2001, Fundamentals of seismic rock physics. Geophysics, 66, 398–412, doi: 10.1190/1.1444931.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Weimer, P., 1990, Sequence stratigraphy, facies geometries, and depositional history of the Mississippi fan, Gulf of Mexico: AAPG Bulletin, 74, 425–453, doi: 10.1306/0C9B2321-1710-11D7-8645000102C1865D.CrossrefWeb of ScienceGoogle Scholar
  • Williamson, P. R., and M. H. Worthington, 1993, Resolution limits in ray tomography due to wave behavior: Numerical experiments: Geophysics, 58, 727–735, doi: 10.1190/1.1443457.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Winters, W. J., I. A. Pecher, W. F. Waite, and D. H. Mason, 2004, Physical properties and rock physics models of sediment containing natural and laboratory-formed methane gas hydrate: American Mineralogist, 89, 1221–1227, doi: 10.2138/am-2004-8-909.AMMIAY0003-004XCrossrefWeb of ScienceGoogle Scholar
  • Wood, W. T., J. F. Gettrust, N. R. Chapman, G. D. Spence, and R. D. Hyndman, 2002, Decreased stability of methane hydrates in marine sediments owing to phase-boundary roughness: Nature, 420, 656–660, doi: 10.1038/nature01263.CrossrefWeb of ScienceGoogle Scholar
  • Wood, W. T., P. E. Hart, D. R. Hutchinson, N. Dutta, F. Snyder, R. B. Coffin, and J. F. Gettrust, 2008, Gas and gas hydrate distribution around seafloor seeps in Mississippi Canyon, Northern Gulf of Mexico, using multi-resolution seismic imagery: Marine and Petroleum Geology, 25, 952–959, doi: 10.1016/j.marpetgeo.2008.01.015.MPEGD80264-8172CrossrefWeb of ScienceGoogle Scholar
  • Wood, W. T., P. L. Stoffa, and T. H. Shipley, 1994, Quantitative detection of methane hydrate through high-resolution seismic velocity analysis: Journal of Geophysical Research-Solid Earth, 99, 9681–9695, doi: 10.1029/94JB00238.CrossrefWeb of ScienceGoogle Scholar
  • Wu, R.-S., and M. N. Toksoz, 1987, Diffraction tomography and multisource holography applied to seismic imaging: Geophysics, 52, 11–25, doi: 10.1190/1.1442237.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Xia, G. Y., M. K. Sen, and P. L. Stoffa, 2000, Mapping of elastic properties of gas hydrates in the Carolina trough by waveform inversion: Geophysics, 65, 735–744, doi: 10.1190/1.1444772.GPYSA70016-8033AbstractWeb of ScienceGoogle Scholar
  • Yilmaz, O., 2001, Seismic data processing: SEG.AbstractGoogle Scholar
  • Yuan, J., and R. N. Edwards, 2000, The assessment of marine gas hydrates through electrical remote sounding: Hydrate without a BSR?: Geophysical Research Letters, 27, 2397–2400, doi: 10.1029/2000GL011585.GPRLAJ0094-8276CrossrefWeb of ScienceGoogle Scholar
  • Yuan, T., R. D. Hyndman, G. D. Spence, and B. Desmons, 1996, Seismic velocity increase and deep-sea gas hydrate concentration above a bottom-stimulating reflector on the northern Cascadia continental slope: Journal of Geophysical Research-Solid Earth, 101, 13655–13671, doi: 10.1029/96JB00102.CrossrefWeb of ScienceGoogle Scholar
  • Yuan, T., G. D. Spence, R. D. Hyndman, T. A. Minshull, and S. C. Singh, 1999, Seismic velocity studies of a gas hydrate bottom-simulating reflector on the northern Cascadia continental margin: Amplitude modeling and full waveform inversion: Journal of Geophysical Research-Solid Earth, 104, 1179–1191, doi: 10.1029/1998JB900020.CrossrefWeb of ScienceGoogle Scholar
  • Zelt, C. A., and R. B. Smith, 1992, Seismic traveltime inversion for 2-D crustal velocity structure: Geophysical Journal International, 108, 16–34, doi: 10.1111/j.1365-246X.1992.tb00836.x.GJINEA0956-540XCrossrefWeb of ScienceGoogle Scholar