1887
  1. Home
  2. Conferences
  3. Conference Proceedings
  4. 78th EAGE Conference and Exhibition 2016
  5. Conference paper

Abstract

Summary

We propose an anisotropic wavefield gradiometry technique to extract azimuthally anisotropic phase velocities from seismic noise that is dominated by a single surface wave mode. The method relies on a two-dimensional elliptical-anisotropic wave equation. This wave equation equates the spatial derivatives of the wavefield amplitudes with the temporal derivatives through the elements of a two-by-two matrix characterizing the medium parameters. The derivatives are evaluated using finite differences, and the system is inverted with a smoothness constraint. We test the procedure on ambient seismic noise recorded in a large and dense array installed over Ekofisk field. Because the station spacing is much larger cross-line then inline, the approximation error of the spatial finite difference results in an apparent anisotropy. From an experiment with synthetic isotropic plane waves, we define a Jacobian to correct the finite difference stencils. With the corrected finite difference stencils, we extracted anisotropic phase velocities at Ekofisk from as little as 10 minutes of seismic noise recordings. The azimuthal anisotropy forms a circular geometry around the production induced subsidence bowl. The methodology is a promising technique for studying changes in the subsurface geomechanical stress-state resulting from time-dependent phenomena operating at a short time-scales.

© EAGE Publications BV
Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201600627
2016-05-30
2024-04-26

  • From This Site

    /content/papers/10.3997/2214-4609.201600627
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Curtis, A. and J.O.A.Robertsson
    [2002] Volumetric wavefield recording and wave equation inversion for near-surface material properties, Geophysics, 67(5), 1602–1611.
     [Google Scholar]
  2. Eriksrud, M.
    [2010] Towards the optical seismic era in reservoir monitoring, First Break, 28, 105–111.
     [Google Scholar]
  3. Herwanger, J.V. and S.A.Horne
    [2009] Linking reservoir geomechanics and time-lapse seismics: Predicting anisotropic velocity changes and seismic attributes. Geophysics, 74(4), W13–W33.
     [Google Scholar]
  4. Huiskamp, G.
    [1991] Difference formulas for the surface Laplacian on a triangulated surface, Journal of Computational Physics, 95, 477–496.
     [Google Scholar]
  5. Kazinnik, R., B.Roy, A.Tura, L.Vedvik, and O.Knoth
    [2014] Near surface velocities at Ekofisk from Scholte and refracted wave analysis. SEG Technical Program Expanded Abstracts2014, 2036–2039.
     [Google Scholar]
  6. Langston, C.A.
    [2007a] Spatial gradient analysis for linear seismic arrays, Bulletin of the Seismological Society of America, 97(1B), 265–280.
     [Google Scholar]
  7. [2007b] Wave gradiometry in two dimensions, Bulletin of the Seismological Society of America, 97(2), 401–416.
     [Google Scholar]
  8. Lin, F.C. and M.H.Ritzwoller
    (2011). Helmholtz surface wave tomography for isotropic and azimuthally anisotropic structure. Geophysical Journal International, 186(3), 1104–1120.
     [Google Scholar]
  9. Liu, Y., and W.E.Holt
    [2015] Wave gradiometry and its link with Helmholtz equation solutions applied to USArray in the eastern U.S., Journal of Geophysical Research. Solid Earth, 120(8), 5717–5746.
     [Google Scholar]
  10. de Ridder, S.A.L. and B.L.Biondi
    [2015] Ambient seismic noise tomography at Ekofisk. Geophysics, 80(6), B167–B176.
     [Google Scholar]
  11. [2015] Near-Surface Scholte-Wave Velocities at Ekofisk from Short Noise Recordings by Seismic Noise Gradiometry. Geophysical Research Letters, 42(17), 7031–7038.
     [Google Scholar]
  12. de Ridder, S.A.L., B.L.Biondi, and D.Nichols
    [2015] Elliptical-Anisotropic Eikonal Phase-Velocity Tomography. Geophysical Research Letters, 42(3), 758–764.
     [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201600627
Loading
Anisotropic Seismic Noise Gradiometry by Elliptically-anisotropic Wave Equation Inversion - An Example Ekofisk
Conference Proceedings 2016, 1 (2016); https://doi.org/10.3997/2214-4609.201600627
/content/papers/10.3997/2214-4609.201600627
/content/papers/10.3997/2214-4609.201600627
Loading

Data & Media loading...

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error