1887
Volume 65, Issue 3
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Reverse‐time migration gives high‐quality, complete images by using full‐wave extrapolations. It is thus not subject to important limitations of other migrations that are based on high‐frequency or one‐way approximations. The cross‐correlation imaging condition in two‐dimensional pre‐stack reverse‐time migration of common‐source data explicitly sums the product of the (forward‐propagating) source and (backward‐propagating) receiver wavefields over all image times. The primary contribution at any image point travels a minimum‐time path that has only one (specular) reflection, and it usually corresponds to a local maximum amplitude. All other contributions at the same image point are various types of multipaths, including prismatic multi‐arrivals, free‐surface and internal multiples, converted waves, and all crosstalk noise, which are imaged at later times, and potentially create migration artefacts. A solution that facilitates inclusion of correctly imaged, non‐primary arrivals and removal of the related artefacts, is to save the depth versus incident angle slice at each image time (rather than automatically summing them). This results in a three‐parameter (incident angle, depth, and image time) common‐image volume that integrates, into a single unified representation, attributes that were previously computed by separate processes. The volume can be post‐processed by selecting any desired combination of primary and/or multipath data before stacking over image time. Separate images (with or without artifacts) and various projections can then be produced without having to remigrate the data, providing an efficient tool for optimization of migration images. A numerical example for a simple model shows how primary and prismatic multipath contributions merge into a single incident angle versus image time trajectory. A second example, using synthetic data from the Sigsbee2 model, shows that the contributions to subsalt images of primary and multipath (in this case, turning wave) reflections are different. The primary reflections contain most of the information in regions away from the salt, but both primary and multipath data contribute in the subsalt region.

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2016-08-25
2024-04-24
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References

  1. AudebertF., FroidevauxP., HuardI., NicoletisL. and Svay‐LucasJ.2000. A multi‐angle toolbox for resorted amplitude images and AVA‐gathers. 70th SEG Meeting, Calgary, Canada, Expanded Abstracts, 1020–1023.
  2. BiondiB. and SymesW.W.2004. Angle‐domain common‐image gathers for migration velocity analysis by wavefield‐continuation imaging. Geophysics69(4), 1283–1298.
    [Google Scholar]
  3. CaoJ. and McMechanG.A.2010. Multiple prediction and subtraction from apparent slowness relations in 2D synthetic and field ocean‐bottom cable data. Geophysics75(6), V89–V99.
    [Google Scholar]
  4. CavalcaM. and LaillyP.2005. Prismatic reflections for the delineation of salt bodies. 75th SEG Meeting, Houston, USA, Expanded Abstracts, 2550–2553.
  5. ChangH. and McMechanG.A.2009. 3‐D, 3‐C full‐wavefield elastic inversion for anisotropic parameters: a feasibility study with synthetic data. Geophysics74(6), WCC159–WCC175.
    [Google Scholar]
  6. ChattopadhyayS. and McMechanG.A.2008. Imaging conditions for prestack reverse‐time migration. Geophysics73(3), S81–S89.
    [Google Scholar]
  7. ClaerboutJ.F.1971. Toward a unified theory of reflector mapping. Geophysics36, 467–481.
    [Google Scholar]
  8. DengF. and McMechanG.A.2008. Elastic true amplitude prestack depth migration. Geophysics73(4), S143–S155.
    [Google Scholar]
  9. DickensA. and WinbowG.A.2011. RTM angle gathers using Poynting vectors. 81st SEG Meeting, San Antonio, USA, Expanded Abstracts, 3019–3113.
  10. DoumaH., YingstD., VasconcelosI. and TrompJ.2010. On the connection between artifact filtering in reverse‐time migration and adjoint tomography. Geophysics75(6), S219–S223.
    [Google Scholar]
  11. FayeJ.P. and JeannotJ.P.1986. Prestack migration velocities from depth focusing analysis. 56th SEG Meeting, Houston, USA, Expanded Abstracts, 438–440.
  12. HuaB. and McMechanG.A. 2003. Parsimonious 2‐D prestack Kirchhoff depth migration. Geophysics68(3), 1043–1051.
    [Google Scholar]
  13. JinH. and McMechanG.A.2014, Comparison of methods for extracting ADCIGs from RTM. Geophysics79(3), S89–S103.
    [Google Scholar]
  14. JinH., McMechanG.A. and NguyenG.2015. Improving input/output performance in 2D and 3D angle‐domain image gathers from reverse‐time migration. Geophysics80(2), S65–S77.
    [Google Scholar]
  15. KabbejA., BainaR. and DuquetB.2005. Data driven automatic aperture optimization for Kirchhoff migration. 75th SEG Meeting, Houston, USA, Expanded Abstracts, 1890–1893.
  16. KaelinB. and GuittonA.2006. Imaging condition for reverse time migration. 76th SEG Meeting, New Orleans, USA, Expanded Abstracts, 2594–2598.
  17. KlokovA. and FomelS.Selecting an optimal aperture in Kirchhoff migration using dip‐angle images. Geophysics78(6), S243–S254.
    [Google Scholar]
  18. LiuZ.1997. An analytical approach to migration velocity analysis. Geophysics62(4), 1238–1249.
    [Google Scholar]
  19. MacKayS. and AbmaR.1992. Imaging and velocity estimation with depth‐focusing analysis. Geophysics57(12), 1608–1622.
    [Google Scholar]
  20. MontelJ.P. and LambaréG.2013. Wave equation angle domain common image gather asymptotic analysis. 83rd SEG Meeting, Houston, USA, Expanded Abstracts, 3757–3761.
  21. NguyenB.D. and McMechanG.A.2013. Excitation amplitude imaging condition for prestack reverse‐time migration. Geophysics78(1), S37–S46.
    [Google Scholar]
  22. NguyenB.D. and McMechanG.A.2015. Five ways to avoid storing source wavefield snapshots in 2D elastic prestack reverse‐time migration. Geophysics80(1), S1–S18.
    [Google Scholar]
  23. OpertoM.S., XuS. and LambaréG.2000. Can we quantitatively image complex structures with rays? Geophysics65(4), 1223–1238.
    [Google Scholar]
  24. PaffenholzJ., McLainB., ZaskeJ. and KeliherP.J.2002. Subsalt multiple attenuation and imaging: observations from the Sigsbee2B synthetic dataset. 72nd SEG Meeting, Salt Lake City, USA, Expanded Abstracts, 2122–2125.
  25. SavaP. and FomelS.2003. Angle‐domain common‐image gathers by wavefield continuation methods. Geophysics68, 1065–1074.
    [Google Scholar]
  26. SavaP. and FomelS.2005a. Coordinate‐independent angle‐gathers for wave equation migration. 75th SEG Meeting, Houston, TX, USA, Expanded Abstracts, 2052–2055.
  27. SavaP. and FomelS.2005b. Wave equation common‐angle gathers for converted wave. 75th SEG Meeting, Houston, TX, USA, Expanded Abstracts, 947–951.
  28. SavaP. and FomelS.2006. Time‐shift imaging condition in seismic migration. Geophysics71(6), S209–S217.
    [Google Scholar]
  29. StorkC.1992. Reflection tomography in the postmigrated domain. Geophysics57, 680–692.
    [Google Scholar]
  30. SunR.J. and McMechanG.A.2001. Scalar reverse‐time depth migration of prestack elastic seismic data. Geophysics66, 1519–1527.
    [Google Scholar]
  31. SunR.J., McMechanG.A., LeeJ.S., ChowJ. and ChenC.H.2006. Prestack scalar reverse‐time depth migration of three‐dimensional elastic seismic data. Geophysics71, S199–S207.
    [Google Scholar]
  32. SunW. and FuL.Y.2013. Two effective approaches to reduce data storage in reverse time migration. Computers & Geosciences56, 69–75.
    [Google Scholar]
  33. SymesW.W.2007. Reverse‐time migration with optimal checkpointing. Geophysics72(5), SM213–SM221.
    [Google Scholar]
  34. TabtiH., GeliusL.J. and HellmanT.2004. Fresnel aperture prestack depth migration. First Break22(3).
    [Google Scholar]
  35. VyasM., NicholsD. and MobleyE.2011. Efficient RTM angle gathers using source directions. 81st SEG Meeting, San Antonio, USA, Expanded Abstracts, 3104–3108.
  36. WangB., PannK. and MeekR.A.1995. Macro velocity model estimation through model based globally‐optimized residual‐curvature analysis. 65th SEG Meeting, Houston, USA, Expanded Abstracts, 1084–1087.
  37. WangW. and McMechanG.A.2015. Vector‐based prestack elastic RTM. Geophysics80(6), S245–S258.
    [Google Scholar]
  38. WhitmoreN.D. and LinesL.R.1986. Vertical seismic profiling depth migration of a salt dome flank. Geophysics51, 1087–1109.
    [Google Scholar]
  39. XieA. and WuR.S.2002. Extracting angle domain information from migrated wavefields. 72nd SEG Meeting, Salt Lake City, USA, Expanded Abstracts, 1360–1363.
  40. XuS., ChaurisH., LambaréG. and NobleM.2001. Common‐angle migration: A strategy for imaging complex media. Geophysics66, 1877–1894.
    [Google Scholar]
  41. XuS., ChenF., TangB. and LambaréG.2014. Noise removal by migration of time‐shift images. Geophysics79(3), S105–S111.
    [Google Scholar]
  42. XuS. and LambaréG.2004. Fast migration/inversion with multi‐valued ray fields Part I: method, validation tests and application to 2D Marmousi. Geophysics69(5), 1311–1319.
    [Google Scholar]
  43. XuS., LambaréG. and CalandraH.2004. Fast migration/inversion with multi‐valued ray fields Part II: application to SEG/EAGE salt model. Geophysics69(5), 1320–1328.
    [Google Scholar]
  44. XuS., ZhangY. and TangB.2011. 3D angle gathers from reverse time migration. Geophysics76(2), S77–S92.
    [Google Scholar]
  45. YanR. and XieX.2009. A new angle‐domain imaging condition for prestack reverse‐time migration. 79th SEG Meeting, Houston, USA, Expanded Abstracts, 2784–2788.
  46. YanR. and XieX.2011. Angle gather extraction for acoustic and isotropic elastic RTM. 81st SEG Meeting, San Antonio, USA, Expanded Abstracts, 3141–3146.
  47. YanR. and XieX.2012. An angle‐domain imaging condition for elastic reverse‐time migration and it's application to angle gather extraction. Geophysics77(5), S105–S115.
    [Google Scholar]
  48. YoonK., GuoM., CaiJ. and WangB.2011. 3D RTM angle gathers from source wave propagation direction and dip of reflector. 81st SEG Meeting, San Antonio, USA, Expanded Abstracts, 3136–3140.
  49. YoonK. and MarfurtK.J.2006. Reverse‐time migration using the Poynting vector. Exploration Geophysics37, 102–107.
    [Google Scholar]
  50. ZhangY., ZhangG. and BleisteinN.2005. Theory of true amplitude one‐way wave equations and true‐amplitude common‐shot migration. Geophysics70(4), E1–E10.
    [Google Scholar]
  51. ZhangQ. and McMechanG.A.2010. 2D and 3D elastic wavefield vector decomposition in the wavenumber domain for VTI media. Geophysics75(3), D13–D26.
    [Google Scholar]
  52. ZhangQ. and McMechanG.A.2011a. Direct vector‐field method to obtain angle‐domain common‐image gathers from isotropic acoustic and elastic reverse‐time migration. Geophysics76(5), WB135–WB149.
    [Google Scholar]
  53. ZhangQ. and McMechanG.A.2011b. Common‐image gathers in the incident phase‐angle domain from reverse time migration in 2D elastic VTI media. Geophysics76(6), S197–S206.
    [Google Scholar]
  54. ZhangY., SunJ. and GrayS.2007. Reverse‐time migration: Amplitude and implementation issues. 77th SEG Meeting, Expanded Abstracts, 2145–2149.
  55. ZhuX. and McMechanG.A.2012. Elastic inversion of seismic reflection data using phase variation with angle. Geophysics77(4), R149–R159.
    [Google Scholar]
  56. ZhuX. and McMechanG.A.2013. Amplitude and phase versus angle for elastic wide‐aperture data in the t‐p domain. Geophysics80(1), N1–N9.
    [Google Scholar]
  57. ZhangY., XuS., TangB., BaiB., HuangY. and HuangT.2010. Angle gathers from reverse time migration. The Leading Edge29, 1364–1371.
    [Google Scholar]
  58. ZhuX. and WuR.‐S.2010. Imaging diffraction points using the local image matrices generated in prestack migration. Geophysics75(1), S1–S9.
    [Google Scholar]
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  • Article Type: Research Article
Keyword(s): Common‐image gathers; Imaging conditions; Multipathing; Reverse‐time migration

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