1887

Abstract

Summary

In this study we propose a novel scheme to estimate shear wave anisotropic parameter using the virtual source method applied to a dataset acquired by a single ocean bottom seismometer for a line of air-gun shots beneath the sea surface. For the evaluation of the effectiveness of our method, we conduct numerical experiments for a 3D multi anisotropic layer model. We employ the virtual source method to the synthetic seismic data to generate cross-dipole data virtually acquired at every shot location. Finally we apply the layer stripping method to the virtual cross-dipole data to estimate an azimuthal angle of the anisotropy for each layer of the sub-seafloor structure below each air-gun location as a function of depth. Our results indicate that the orientation and the order of shear wave velocity anisotropy could be estimated for the usage of a monopole source without touching down the seafloor in the marine environment.

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/content/papers/10.3997/2214-4609.201801656
2018-06-11
2024-03-29
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References

  1. Bakulin, A., Calvert, R.
    , Shell International E&P, 2004, Virtual Source: new method for imaging and 4D below complex overburden: 74th Annual International Meeting, SEG, Expanded Abstracts, 1921–1924.
    [Google Scholar]
  2. , 2006, The virtual source method: Theory and case study: Geophysics, 71, SI139–SI150.
    [Google Scholar]
  3. , Shell International E&P, 2005, Virtual shear source: A new methods for shear-wave seismic surveys: 75th Annual International Meeting, SEG, Expanded Abstracts, 2633–2636.
    [Google Scholar]
  4. Bakulin, A., Mateeva, A., Calvert, R., Jorgensen, P., Lopez, J.
    , 2007, Virtual shear source makes shear waves with air guns: Geophysics, 72, P. A7–A11.
    [Google Scholar]
  5. Bakulin, A., Mateeva, A.
    , 2008, Estimating interval shear-wave splitting from multicomponent virtual shear check shots: Geophysics, 73, P. A39–A43
    [Google Scholar]
  6. Collino, F., Tsogka, C.
    , 2001, Application of the perfectly matched absorbing layer model to the linear elastodynamic problem in anisotropic heterogenous media: Geophysics, 66, P.294–307.
    [Google Scholar]
  7. Devaney, A.J., Oristaglio, M.L.
    , 1986, A plane-wave decomposition for elastic wave fields applied to the separation of P-waves and S-waves In vector seismic data: Geophysics, 51, P. 419–423.
    [Google Scholar]
  8. Nagai, Y., Tsuda, A., OzasaH., Hatanaka, H., Tanaka, K., Tagami, M., Sato, F., Takekawa, J., Mikada, H.
    , 2016, Towed Marine Dipole Source for Shear Wave Generation: 78th EAGE Conference and Exhibition, doi: 10.3997/2214‑4609.201600861.
    https://doi.org/10.3997/2214-4609.201600861 [Google Scholar]
  9. Ozasa, H., Takekawa, J., and Mikada, H.
    , 2017, Use of Virtual Dipole Shear Source in Offshore Shear Wave Exploration without Any Contact to the Seafloor, 79th EAGE Conference and Exhibition 2017, doi: 10.3997/2214‑4609.201701181.
    https://doi.org/10.3997/2214-4609.201701181 [Google Scholar]
  10. Saenger, E.H., Gold, N., Shapiro, A.
    , 2000, Modeling the propagation of elastic waves using a modified finite-difference grid: Wave Motion, 31, 77–92.
    [Google Scholar]
  11. Thomsen, L.
    , 1986, Weak elastic anisotropy: Geophysics, 51, 1954–1966
    [Google Scholar]
  12. Thomsen, L., Tsvankin, I., Mueller, M. C.
    , 1999, Coarse-layer stripping of vertically variable azimuthal anisotropy from shear-wave data : Geophysics, 64, P.1126–1138
    [Google Scholar]
  13. Kimura, T., Mikada, H., Araki, E.,Kodaira, S., Miura, S.
    , 2016, Wide-area distribution of S-wave anisotropy estimated by airgun surveys around seafloor-cabled seismometers in the Nankai Trough, Japan. SEG Technical Program Expanded Abstracts 2016: pp. 337–341.
    [Google Scholar]
  14. Winterstein, D.F, Meadows, M.A
    , 1991Shear-wave polarizations and subsurface stress directions at Lost Hills field : Geophysics, 56 P.1331–1348
    [Google Scholar]
  15. Watanabe, Y., Mikada, H., Takekawa, J.
    , 2017, Estimate azimuthal shear-wave anisotropy by applying virtual-source method with a line of air-gun shots and a single ocean-bottom seismometer: SEG Technical Program Expanded Abstracts2017: pp. 2476–2480
    [Google Scholar]
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