1887

Abstract

Summary

Full waveform inversion (FWI) can provide high-resolution velocity models and find more details in velocities than ray-based tomography technologies. However, FWI requires a relatively accurate initial velocity model, data with good low-frequency signal content, and an accurate source signature. In our case we successfully apply FWI in a deep water area of offshore Angola. Our FWI benefits from a good initial velocity model created by ray-based high-definition tomography and variable-depth streamer data, which has good low-frequency signal content, and an accurately estimated source signature from near-field hydrophone data. We use reflected and diving waves from our 8 km offset data, enabling FWI to update the velocity as deep as approximately 5 km. The FWI updated velocity around shallow anomalies and faults is more accurately defined than the velocity from ray-based tomography. Even at the deeper Albian and shallow pre-salt levels, FWI is able to improve the velocity, producing a better migrated stack and improving gather flatness.

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/content/papers/10.3997/2214-4609.20141416
2014-06-16
2024-04-24
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References

  1. Guillaume, P., Lambare, G., Sioni, S., Carotti, D., Depre, P., Culianez, G., Montel, J-P., Mitouard, P., Depagne, S., Frehers, S., and Vosberg, H.
    [2011] Geologically consistent velocities obtained by high definition tomography. 81st SEG Annual Meeting.
    [Google Scholar]
  2. Ratcliffe, A., Jupp, R., Wombell, R., Body, G., Durussel, V., Fernandes, A., Gosling, B., and Lombardi, M.
    [2013] Full-waveform inversion of variable-depth streamer data: an application to shallow channel modelling in the North Sea. The Leading Edge, 32 (9), 1110–1115
    [Google Scholar]
  3. Shah, N., Warner, M., Nangoo, T., Umpleby, A., Stekl, I., Morgen, J., and Guasch, L.
    [2012] Quality assured full-waveform inversion: Ensuring starting model adequacy. 82nd SEG Annual Meeting.
    [Google Scholar]
  4. Soubaras, R.
    [2010] Deghosting by joint deconvolution of a migration and a mirror migration. 80th SEG Annual Meeting.
    [Google Scholar]
  5. Tarantola, A.
    [1984] Inversion of seismic reflection data in the acoustic approximation. Geophysics, 49, 1259–1266.
    [Google Scholar]
  6. Zhu, J., Perkins, R., Sen, P., Howe, S., Hiller, E., and Clough, J.
    [2013] Evaluation and joint inversion of TTI velocity models with walkaway VSP in deep-water offshore Angola. The Leading Edge, 32 (2), 194–198
    [Google Scholar]
  7. Ziolkowski, A., Parkes, G., Hatton, L., and Haugland, T.
    [1982] The signature of an air gun array: computation from near-field measurements including interactions. Geophysics, 47 (10), 1413–1421.
    [Google Scholar]
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