1887
Volume 39 Number 12
  • ISSN: 0263-5046
  • E-ISSN: 1365-2397

Abstract

Summary

Least Squares RTM (LSRTM) is a powerful inversion-based imaging algorithm which minimizes the data misfit between observed seismic recordings and forward-modelled synthetic data. The algorithm, which can be implemented in either data or image domains, carries a fundamental limitation because it is based on a linear inversion theory which cannot accommodate velocity refinement as part of its model update process. Successful application of LSRTM therefore requires highly accurate velocity information, and if the velocity model is in significant error, modelled events will not be aligned kinematically with the observed data, and the algorithm will tend to produce unsatisfactory results.

FWI is another inversion-based algorithm that enjoys widespread industry use. Unlike LSRTM, FWI poses its inverse problem within a non-linear framework whereby it updates the velocity model and associated wave paths throughout its iterative process, gradually aligning modelled events with observed events. With the recent convergence of FWI and LSRTM methodologies, FWI is not only being used as a velocity update tool, but also as a direct imaging tool, thereby achieving two key imaging goals, namely refining the velocity model and deriving a better-quality seismic image. The latter process, which is known as ‘FWI imaging’, has recently been gaining a lot of industry attention as it offers the possibility of high-quality imaging along with workflow simplification.

In this article we will compare and contrast LSRTM and FWI. We conclude that the process of generating the FWI-imaging essentially amounts to nonlinear, data-domain inversion. This recognition facilitates a ready comparison against the data-domain form of LSRTM, the latter being a linear, data-domain inversion.

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2021-12-01
2024-04-20
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References

  1. Cheng, C., He, Y. , Mao, J.
    and B.Wang , [2020]. Structure constrained least-squares migration of total reflection and its application, SEG Technical Program Expanded Abstracts: 3832–3835.
    [Google Scholar]
  2. Dai, W., and Schuster, G.T.
    [2009]. Least-squares Migration of Simultaneous Sources data with a Deblurring Filter.SEG Technical Program Expanded Abstracts: 2990–2994.
    [Google Scholar]
  3. Dai, W., Huang, Y. and Schuster, G.T.
    [2013]. Least-squares reverse time migration of marine data with frequency-selection encoding.Geophysics, 78(4), S233–S242.
    [Google Scholar]
  4. Dong, S., Cai, J., Guo, M., Suh, S., Zhang, Z., Wang, B. and Li, Z.
    [2012]. Least-squares reverse time migration: towards true amplitude imaging and improving the resolution, SEG Technical Program Expanded Abstracts: 1488.1–5.
    [Google Scholar]
  5. Fletcher, R.P., Nichols, D., Bloor, R. and Coates, R.T.
    [2016]. Least-squares migration — Data domain versus image domain using point spread functions:The Leading Edge, 35, 157–162.
    [Google Scholar]
  6. He, Y., Hao, F., Dong, S. and Wang, B.
    [2018]. Towards AV O Compliant Least Squares RTM Gathers, SEG Technical Program Expanded Abstracts: 4408–4412.
    [Google Scholar]
  7. He, Y., Xing, H., Huang, Y. , Liu, F. and Wang, B.
    [2021]. Inversion-based Imaging: FWI beyond Velocity.EAGE 82nd Conference and Exhibition
    [Google Scholar]
  8. Huang, R., Zhang, Z., Wu, Z., Wei, Z., Mei, J. and Wang, P.
    [2021]. Full-waveform inversion for full-wavefield imaging: Decades in the making, The Leading Edge, 40(5), 324–334.
    [Google Scholar]
  9. Lu, R., Lazaratos, S., Hughes, S. and Leslie, D.
    [2016]. Revealing overburden and reservoir complexity with high-resolution FWI, SEG Technical Program Expanded Abstracts: 1242–1246.
    [Google Scholar]
  10. Lu, S., Liu, F., Chemingui, N. and Orlovich, M.
    [2018]. Full wavefield migration by inversion, SEG Technical Program Expanded Abstracts: 4311–4315.
    [Google Scholar]
  11. Ma, Y. and Hale, D.
    [2013]. Wave-equation reflection traveltime inversion with dynamic warping and full-waveform inversion:Geophysics, 78(6), R223–R233.
    [Google Scholar]
  12. Ma, Y., Hale, D., Gong, B. and Meng, Z.
    [2012]. Image-guided sparse-model full waveform inversion:Geophysics, 77(4), R189–R198.
    [Google Scholar]
  13. Mao, J., Sheng, J., Huang, Y., Hao, F. and Liu, F.
    [2020]. Multi-Channel dynamic matching full-waveform inversion:SEG Technical Program Expanded Abstracts, 666–670.
    [Google Scholar]
  14. Michell, S., Shen, X., Brenders, A., Dellinger, J., Ahmed, I. and Fu, K.
    [2017]. Automatic velocity model building with complex salt: Can computers finally do an interpreter’s job?:87th Annual International Meeting, SEG, Expanded Abstracts, 5250–5254.
    [Google Scholar]
  15. Nemeth, T., Wu, C. and Schuster, G.T.
    [1999]. Least-squares migration of incomplete reflection data, Geophysics, 64(1), 208–221.
    [Google Scholar]
  16. Pratt, R.G., Shin, C. and Hicks, G.J.
    [1998]. Gauss-Newton and full Newton methods in frequency-space seismic waveform inversion:Geophysical Journal International, 133, 341–362.
    [Google Scholar]
  17. Roende, H., Bate, D., Mao, J., Huang, Y. and Chaikin, D.
    [2020]. New node acquisition design delivers unprecedented results with Dynamic Matching FWI – case study from the Gulf of Mexico, First Break, 73–78.
    [Google Scholar]
  18. Routh, P., Neelamani, R., Lu, R., Lazaratos, S., Braaksma, H., Hughes, S., Saltzer, R., Stewart, J., Naidu, K., Averill, H., Gottumkkula, V., Homonko, P., Reilly, J. and Leslie, D.
    [2017]. Impact of high-resolution FWI in the Western Blank Sea: Realing overburden and reservoir complexity, The Leading Edge, 36(1), 60–66.
    [Google Scholar]
  19. Sheng, J., Leeds, A., Buddensiek, M. and Schuster, G.T.
    [2006]. Early arrival waveform tomography on near-surface refraction data:Geophysics, 71(4), U47–U57.
    [Google Scholar]
  20. Shin, C. and Cha, Y.H.
    [2009]. Waveform inversion in the Laplace-Fourier domain:Geophysical Journal International, 177, 1067–1079.
    [Google Scholar]
  21. Schuster, G.T.
    [1993]. Least-squares cross-well migration:SEG Technical Program Expanded Abstracts, 110–113.
    [Google Scholar]
  22. Tang, Y.
    [2009], Target-oriented wave-equation least-squares migration/inversion with phase-encoded Hessian, Geophysics, 74(6), WCA95–WCA107.
    [Google Scholar]
  23. Tarantola, A.
    [1984]. Inversion of seismic reflection data in the acoustic approximation:Geophysics, 49, 1259–1266.
    [Google Scholar]
  24. Verschuur, D.J., Staal, X.R. and Berkhout, A.J.
    [2016]. Joint migration inversion: Simultaneous determination of velocity fields and depth images using all orders of scattering, The Leading Edge, 35(12), 1037–1046.
    [Google Scholar]
  25. Virieux, J. and Operto, S.
    [2009]. An overview of full waveform inversion in exploration geophysics:Geophysics, 74(6), WCC1–WCC26.
    [Google Scholar]
  26. Wang, B.
    [2014]. EAGE E-lecture: Least Squares Reverse Time Migration by Bin Wang: https://www.youtube.com/watch?v=PZEHGpiZJAY.
    [Google Scholar]
  27. Wang, B., He, Y., Cheng, C. and Liu, F.
    [2020]. Least Squares Migration in Complex Geology, SEG Technical Program Expanded Abstracts: Post-convention workshop 17.
    [Google Scholar]
  28. Wang, P., Gomes, A., Zhang, Z. and Wang, M.
    [2016]. Least-sqaures RTM: Reality and possibities for subsalt imaging:SEG Technical Program Expanded Abstracts: 4204–4209.
    [Google Scholar]
  29. Wang, P., Zhang, Z., Mei, J., Lin, F. and Huang, R.
    [2019]. Full-waveform inversion for salt: A coming of age, The Leading Edge38: 204–213.
    [Google Scholar]
  30. Warner, M., Ratcliffe, A., Nangoo, T., Morgan, J., Umpleby, A., Shah, N., Vinje, V., Štekl, I., Guasch, L., Win, C., Conroy, G. and Bertrand, A.
    [2013]. Anisotropic 3D full-waveform inversion:Geophysics, 78(2), R59–R80, doi: 10.1190/geo2012‑0338.1.
    https://doi.org/10.1190/geo2012-0338.1 [Google Scholar]
  31. Warner, M. and Guasch, L.
    [2016]. Adaptive waveform inversion. Theory, Geophysics, 81(6): R429–R445.
    [Google Scholar]
  32. Wong, M., Biondi, B. and Ronen, S.
    [2014]. Imaging with multiples using least-squares reverse time migration:The Leading Edge, 33(9), 970–976.
    [Google Scholar]
  33. Wu, R., Luo, J. and Wu, B.
    [2014]. Seismic envelope inversion and modulation signal model:Geophysics, 79(3), WA13–WA24.
    [Google Scholar]
  34. Xing, H., He, Y., Huang, Y. and Sheng, J.
    [2020]. Ultralong Offset OBN: Path to better subsalt image, SEG Technical Program Expanded Abstracts: 2938–2942.
    [Google Scholar]
  35. Yu, J., Lewis, L.J., Katz, J., Followill, F., Sun, H. and Schuster, G.T.
    [2003]. Autocorrelogram migration: IVSPWD test, Geophysics, 68(1), 297–307.
    [Google Scholar]
  36. Zeng, C., Dong, S. and Wang, B.
    [2014]. Least-squares reverse time migration: Inversion-based imaging toward true reflectivity, The Leading Edge33: 962–964, 966, 968.
    [Google Scholar]
  37. [2016]. Adaptive least-squares RTM with applications to subsalt imaging:The Leading Edge, 35(3), 253–257.
    [Google Scholar]
  38. Zhang, Y., Duan, L. and Xie, Y.
    [2015]. A stable and practical implementation of least-squares reverse time migration:Geophysics, 80(1), V23–V31.
    [Google Scholar]
  39. Zhang, Y., Ratcliffe, A., Roberts, G. and Duan, L.
    [2014]. Amplitude-preserving reverse time migration: From reflectivity to velocity and impedance inversion, Geophysics79(6), S271–S283.
    [Google Scholar]
  40. Zhang, Z., Wu, Z., Wei, Z., Mei, J., Huang, R. and Wang, P.
    [2020]. FWI imaging: Full-wavefield imaging through full-wavefield inversion, SEG Technical Program Expanded Abstracts:656–660.
    [Google Scholar]
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