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Why exactly do multiples need to be removed in direct seismic processing methods? And what about indirect methods?

ARTHUR B. WEGLEIN
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M-OSRP, Physics Department, University of Houston, 3507 Cullen Boulevard, Houston, TX. 77204, U.S.A.,
JSE 2022, 31(1), 1–18;
Submitted: 9 June 2025 | Revised: 9 June 2025 | Accepted: 9 June 2025 | Published: 9 June 2025
© 2025 by the Authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution -Noncommercial 4.0 International License (CC-by the license) ( https://creativecommons.org/licenses/by-nc/4.0/ )
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Abstract

Weglein, A.B., 2022. Why exactly do multiples need to be removed in direct seismic processing methods? And what about indirect methods? Journal of Seismic Exploration, 31: 1-18. This paper provides a new and detailed analysis on why multiples need to be removed in all current seismic processing methods - without any exception. We cast a wide and inclusive net - covering all direct methods and indirect methods. That includes methods that use multiples to estimate an image of an unrecorded primary, as well as within model-matching methods, for example, FWI. We include methods that require or do not require subsurface information. We conclude that all methods require multiples to be removed, either initially, or eventually within the method, and its application. A new migration method, Stolt-Claerbout III Migration for Heterogeneous and Discontinuous Media, plays an essential and fundamental role in that new insight, understanding and perspective. This is the first paper of a two-paper set, this one explaining “why” multiples are a pressing, and increasingly prioritized necessity and challenge, now and for the foreseeable future. The second paper describes “how” multiples are removed, with a tool- box perspective, and how to make cost-effective choices among options - and a recognition of both recent progress and challenges and open-issues.

Keywords
multiples
primaries
imaging
migration
direct and indirect
continuous and discontinuous velocity migration
FWI and smooth migration velocity
multiple removal
illumination
References
  1. Ben-Hadj-Ali et al. (2008, 2009), Biondi and Sava (1999), Biondi and Symes
  2. (2004), Brandsberg-Dahl et al. (1999), Chavent and Jacewitz (2011), Fitchner
  3. (2011), Guasch et al. (2012), Kapoor et al. (2012), Rickett and Sava (2002),
  4. Sava et al. (2005), Sava and Fomel (2003), Sirgue et al. (2009, 2010, 2012),
  5. Symes and Carazzone (1991), Tarantola (1987), Zhang and Biondi (2013).
  6. Many wrong velocity models can and will also satisfy a flat common-image-
  7. gather criterion, especially under complex imaging circumstances.
  8. Another type of indirect method, FWI, is a model matching methodology
  9. that can input any data set, consisting of primaries, free surface multiples
  10. and internal multiples. Among FWI references are Brossier et al. (2009),
  11. Crase et al. (1990), Gauthier et al. (1986), Nolan and Symes (1997), Pratt
  12. (1999), Pratt and Shipp (1999), Sirgue et al. (2010), Symes (2008), Tarantola
  13. (1984, 1986), Valenciano et al. (2006), Vigh and Starr (2008), Zhou et al.
  14. (2012). In practice, primaries are considered not enough, not full enough,
  15. and primaries and all multiples are apparently too much to match, a bit too
  16. full. And matching primaries and free surface multiples, are the perfect
  17. degree of fullness. Therefore, within current FWI practice, internal
  18. multiples are first removed and then primaries and free surface multiples are
  19. matched. Hence, an internal multiple removal is called for in FWI.
  20. The output from FWI is (at best) a smooth velocity
  21. model, and all multiples need to be removed when migrating
  22. with a smooth velocity model
  23. As was documented in a recent SEG/DGS Workshop on Velocity Model
  24. Building Saad et al. (2021) and the final/wrap-up presentation by Weglein
  25. (2021), FWI has been useful in providing an improved smooth velocity for
  26. migration. As we pointed out earlier in this paper, with a smooth migration
  27. velocity model, all multiples must be removed. Hence, within FWI today
  28. internal multiples need to be removed, and the use of the smooth velocity
  29. output from FYI, require all multiples to be removed in the use of that
  30. velocity in migration methods.
  31. Regarding AVO: AVO is a first term in a modeling equation for PP data
  32. run backwards - and, hence, is not a direct method, and assumes that multiples
  33. have been removed before the Zoeppritz equations are applied to estimate the
  34. relative changes in earth mechanical properties.
  35. Therefore, either initially or ultimately all multiples must be removed in
  36. all indirect seismic methods.
  37. We suggest the videos in the link below
  38. http://youtube.com/playlist?list=PL41Tzy Y 3tP VenlpnBQRJKurk Sbvmw6X Ws
  39. to complement the above analysis and conclusions.
  40. CONCLUSIONS
  41. All current migration velocity analysis methods can (at best) produce a
  42. smooth continuous migration velocity model. For direct seismic methods,
  43. that require subsurface information, for example, migration with a smooth
  44. velocity model, all multiples will cause false images that can masquerade as
  45. or interfere with structure - and need to be removed. To clearly analyze the
  46. role of primaries and multiples in imaging requires a new form of migration
  47. (that we label Stolt Claerbout III for heterogeneous media) that can image in
  48. a discontinuous medium without artifacts. With an accurate discontinuous
  49. velocity model, the new Stolt-Claerbout HI Migration for heterogeneous
  50. media, we showed that multiples cause no harm and provide no benefit. If
  51. (in the future) we could find an accurate discontinuous velocity model and
  52. used the Stolt-Claerbout III Migration for discontinuous media, we would
  53. have no reason to remove multiples. However, currently and for the
  54. foreseeable future, we are confined to (at best) improving a smooth
  55. approximate velocity, (e.g., output from FWI) and hence the absolute need
  56. to remove all multiples, before migration for structure and amplitude
  57. analysis, remains in place and of very high priority.
  58. To use a recorded multiple to estimate the RTM image of an unrecorded
  59. primary, we assume the recorded multiple consists of two subevents, one
  60. recorded and the other not recorded. Let’s further assume that the un-
  61. recorded subevent is an unrecorded primary. Then the recorded multiple, and
  62. the recorded subevent of the multiple, are used to estimate the image of an
  63. unrecorded primary subevent of the multiple. To satisfy the latter
  64. assumption, unrecorded subevents of the recorded multiple, that are (not
  65. unrecorded primaries but rather) unrecorded multiples, must be removed - since
  66. the unrecorded event is migrated with a form of RTM using a smooth velocity
  67. model. Furthermore, the original recorded multiple must be removed to image
  68. recorded primaries, again with a smooth velocity model. Hence, recorded
  69. and unrecorded multiples must be removed to image recorded and
  70. unrecorded primaries, respectively.
  71. The inverse scattering series is the only direct inversion method for a
  72. multi-dimensional earth, and in addition it doesn’t require any subsurface
  73. information (including velocity) to be known, estimated or determined. It
  74. contains distinct isolated task subseries that remove free surface and internal
  75. multiples. Only primaries are called for in task specific subseries for structure
  76. determination, parameter estimation and Q compensation, the latter without
  77. knowing, estimating or determining Q. If multiples were needed in the only
  78. direct multidimensional inverse method, the inverse scattering series, to
  79. achieve imaging and parameter estimation and Q compensation, it would not
  80. contain isolated task subseries whose sole purpose and existence is designed
  81. to remove them. Direct methods are purposeful, and do not remove events
  82. that are needed to carry out its purposes.
  83. For indirect methods, based on satisfying a criterium that only relate to
  84. primaries, e.g., CIG flatness, multiples must first be removed.
  85. FWI is model matching of primaries and multiples and currently is able
  86. (at best) to output a smooth velocity model for migration. Multiples must be
  87. removed when using a smooth velocity for migration. For the smooth
  88. migration velocity output of FWI to be useful, for imaging and inversion,
  89. multiples must first be removed.
  90. Hence, all direct and indirect seismic processing methods require all
  91. multiples to be removed, either initially or eventually.
  92. ACKNOWLEDGEMENTS
  93. We appreciate the encouragement and support of M-OSRP sponsors.
  94. Dr. J.D. Mayhan is thanked for his assist in preparing this paper. Dr. Jose
  95. Eduardo Lira and Dr. Jingfeng Zhang provided useful and constructive
  96. comments and suggestions.
  97. REFERENCES
  98. Anderson, J.E., Tan, L. and Wang, D., 2012. Time-reversal checkpointing methods for
  99. RTM and FWI. Geophysics, 77(4): S93-S103.
  100. Baumstein, A., Anderson, J.E., Hinkley, D.L. and Krebs, J.R., 2009. Scaling of the
  101. objective function gradient for full-wavefield inversion. Expanded Baster., 79th Ann.
  102. Internat. SEG Mtg., Houston: 2243-2247.
  103. Ben-Hadj-Ali, H., Operto, S. and Virieux, J., 2008. Velocity model building by 3D
  104. frequency-domain, full-waveform inversion of wide-aperture seismic data. Geophysics,
  105. 73(5): VE101-VE117.
  106. Ben-Hadj-ali, H., Operto, S. and Vireux, J., 2009. Efficient 3D frequency-domain full-
  107. waveform inversion (FWD with phase encoding. Extended Abstr., 71st EAGE Conf.,
  108. Amsterdam: P004.
  109. Biondi, B. and Sava, P., 1999. Wave-equation migration velocity analysis. Expanded
  110. Abstr., 69th Ann. Internat. SEG Mtg., Houston: 1723-1726.
  111. Biondi, B. and Symes, W., 2004. Angle-domain common-image gathers formigration velocity
  112. analysis by wavefield-continuation imaging. Geophysics, 69: 1283-1298.
  113. Brandsberg-Dahl, S., de Hoop, M. and Ursin, B, 1999. Velocity analysis in the common
  114. scattering-angle/azimuth domain. Expanded Abstr., 69th Ann. Internat. SEG Mtg.,
  115. Houston: 1715-1718.
  116. Brossier, R., Operto, S. and Virieux, J., 2009. Robust elastic frequency-domain full-
  117. waveform inversion using the Zi norm. Geophys. Res. Lett., 36 (20): L20310.
  118. Chavent, G. and Jacewitz, C., 1995. Determination of background velocities by multiple
  119. migration fitting. Geophysics, 60: 476-490.
  120. Claerbout, J.F., 1971. Toward a unified theory of reflector mapping. Geophysics, 36: 467-
  122. Crase, E., Pica, A., Noble, M., McDonald, J. and Tarantola, A., 1990. Robust elastic
  123. nonlinear waveform inversion: Application to real data. Geophysics, 55: 527-538.
  124. Fitchner, A., 2011. Full S seismic Waveform M modeling and Inversion. Springer-
  125. Verlag, Berlin.
  126. Gauthier, O., Virieux, J. and Tarantola, A. 1986. Two-dimensional nonlinear inversion of
  127. seismic waveforms. Geophysics, 51: 1387-1403.
  128. Guasch, L., Warner, M., Nangoo, T., Morgan, J., Umpleby, A., Stekl, I. and Shah, N.,
  129. Elastic 3D full-waveform inversion. Expanded Abstr., 82nd Ann. Internat. SEG
  130. Mtg., Las Vegas: 1-5.
  131. Kapoor, S., Vigh, D., Li, H. and Derharoutian, D., 2012. Full-waveform inversion for
  132. detailed velocity model building. Extended Abstr., 74th EAGE Conf., Copenhagen:
  133. W011.
  134. Liang, H., Ma, C. and Weglein, A.B., 2013. General theory for accommodating primaries
  135. and multiples in internal multiple algorithm: Analysis and numerical tests. Expanded
  136. Abstr., 83rd Ann. Internat. SEG Mtg., Houston: 4178-4183.
  137. Liu, F. and Weglein, A.B., 2014. The first wave equation migration RTM with data
  138. consisting of primaries and internal multiples: theory and 1D examples. J. Seismic
  139. Explor., 23: 357-366.
  140. Liu, F., Zhang, G.Q., Morton, S.A. and Leveille, J.P., 2011. An effective imaging
  141. condition for reverse-time migration using wavefield decomposition. Geophysics,
  142. 76(1): S29-S39.
  143. Lu, S.P., Whitmore, N.D., Valenciano, A.A. and Chemingui, N., 2011. Imaging of
  144. primaries and multiples with 3D SEAM synthetic. Expanded Abstr., 81st Ann. Internat.
  145. SEG Mtg., San Antonio: 3217-3221.
  146. Ma, C. and Zou, Y.L., 2015. A clear example using multiples to enhance and improve
  147. imaging: Comparison of two imaging conditions relevant to this analysis. The Leading
  148. Edge, 34: 814-816.
  149. Nolan, C. and Symes, W., 1997. Global solution of a linearized inverse problem for the
  150. wave equation. Comm. Part. Differ. Eqs., 22 (5-6): 127-149.
  151. Pratt, R.G., 1999. Seismic waveform inversion in the frequency domain, Part 1: Theory and
  152. verification in a physical scale model. Geophysics, 64: 888-901.
  153. Pratt, R.G. and Shipp, R.M., 1999. Seismic waveform inversion in the frequency domain,
  154. Part 2: Fault delineation in sediments using crosshole data. Geophysics, 64: 902-914.
  155. Rickett, J. and Sava, P., 2002. Offset and angle-domain common image-point gathers for shot-
  156. profile migration. Geophysics, 67: 883-889.
  157. Saad, A., ten Kroode, F., Jahdhami, M., Al Shuhail, A., Mansour, A., Vigh, D.,
  158. Verschuur, E., Schuster, G., Etgen, J., Vargas, J.E., Belaid, K., Delaijan,K, Guillaume,
  159. P., Al Kalbani, R. and Burley, T., 2021. SEG DGS workshop: Challenges & new
  160. advances in velocity model building. In: Virtual Workshop. SEG Conf. Web Page.
  161. https://seg.org/Events/V elocity-Model-Building.
  162. Sava, P. and Fomel, S., 2003. Angle-domain common-image leathers by wavefield
  163. continuation methods. Geophysics, 68: 1065-1074.
  164. Sava, P., Biondi, B. and Etgen, J., 2005. Wave-equation migration velocity analysis by
  165. focusing diffractions and reflections. Geophysics, 70(3): U19-U27.
  166. Sirgue, L., Barkved, O.I., van Gestel, J.P., Askim, O.J. and Kommedal, J.H., 2009. 3D
  167. waveform inversion on Valhall wide-azimuth OBC. Extended Abstr., 71st EAGE
  168. Conf., Amsterdam: U038.
  169. Sirgue, L., Barkved, O.I., Dellinger, J., Etgen, J., Albertin, U. and Kommedal, J.H., 2010.
  170. Full-waveform inversion: The next leap forward in imaging at Valhall. First Break, 28:
  171. 65-70.
  172. Sirgue, S., Denel, B. and Gao, F., 2012. Challenges and value of applying FWI to depth
  173. imaging projects. Workshop: From kinematic to waveform inversion - where are we
  174. and where do we want to go? A tribute to Patrick Lailly. 74th EAGE Conf.,
  175. Copenhagen.
  176. Stolt, R.H. and Weglein, A.B., 1985. Migration and inversion of seismic data.
  177. Geophysics, 50: 2458-2472.
  178. Stolt, R.H. and Weglein, A.B., 2012. Seismic Imaging and Inversion: Application of
  179. Linear Inverse Theory. Cambridge University Press, Cambridge.
  180. Symes, W.W., 2008. Migration velocity analysis and waveform inversion. Geophys. Prosp.,
  181. 56: 765-790.
  182. Symes, W.W. and Carazzone, J.J., 1991. Velocity inversion by differential semblance
  183. optimization. Geophysics, 56: 654-663.
  184. Tarantola, A. 1987. Inverse Problem Theory: Method for Data Fitting and Model Parameter
  185. Estimation. Elsevier Science Publishers, Amsterdam.
  186. Tarantola, A., 1984. Inversion of seismic reflection data in the acoustic approximation.
  187. Geophysics, 49: 1259-1266.
  188. Tarantola, A., 1986. A strategy for nonlinear elastic inversion of seismic reflection data.
  189. Geophysics, 51: 1893-1903.
  190. Valenciano, A., Biondi, B. and Guitton, A.,2006. Target-oriented wave-equation
  191. inversion. Geophysics, 71(4): A35-A38.
  192. Vigh, D. and Starr, E.W.,2008. 3D prestack plane-wave, full-waveform inversion.
  193. Geophysics, 73(5): VE135-VE144.
  194. Weglein, A.B., 2021. Wrap-up. Presentation given at the SEG(DGS Workshop:
  195. Challenges & New Advances in Velocity Model Building, Virtual Workshop,
  196. https://drive.google.com/drive/folders/1mwcO9feU41Bk_mPVkk7DHWA9ufqgveGj?u
  197. sp=sharing.
  198. Weglein, A.B., Mayhan, J.D., Zou, Y.L., Fu, Q., Liu, F., Wu, J., Ma, C., Lin, X.L. and Stolt,
  199. R.H., 2016. The first migration method that is equally effective for all acquired
  200. frequencies for imaging and inverting at the target and reservoir. Expanded Abstr., 86th
  201. Ann. Internat. SEG Mtg., Dallas: 4266-4272.
  202. Weglein, A.B., 2013. A timely and necessary antidote to indirect methods and so-called P-
  203. wave FWI. The Leading Edge, 32: 1192-1204.
  204. Weglein, A.B., 2016. Multiples: Signal or noise? Geophysics, 81(4): V283-V302.
  205. Weglein, A.B., 2017. A direct inverse method for subsurface properties: The conceptual
  206. and practical benefit and added value in comparison with all current indirect methods,
  207. for example, amplitude-variation-with-offset and full-waveform inversion. Interpretation,
  208. 5(3): SL89-SL107.
  209. Weglein, A.B., 2018. Direct and indirect inversion and a new and comprehensive
  210. perspective on the role of primaries and multiples in seismic data processing for
  211. structure determination and amplitude analysis. Ciencia, Tecnol. Futuro, 8(2): 5-21.
  212. Weglein., 2019a. A new perspective on removing and using multiples - they have the same
  213. exact goal - imaging primaries - recent advances in multiple removal. Presentation at
  214. the SEG KOC Workshop: Seismic Multiples - The Challenges and the Way Forward.
  215. Kuwait City, Kuwait.
  216. http://mosrp.uh.edu/news/ extended-version-weglein-key-note-20 19-seg-koc-workshop.
  217. Weglein, A.B., 2019b. A new perspective on removing and using multiples they have the
  218. same exact goal imaging primaries, recorded and unrecorded primari¢s recent
  219. advances in multiple removal. Inkited key-note address for the SEG/KOC Workshop:
  220. Seismic Multiples, the Challenges andthe way forward. Kuwait City, Kuwait.
  221. https://youtu.be/ sD89_418h1A.
  222. Weglein, A.B., 2020. YouTube video with interview of Arthur B. Weglein for the Bahia,
  223. Brazil student chapter of the EAGE.
  224. https://www. youtube.com/watch?v=iir4cuk50Cw&feature=youtu.
  225. Weglein, A.B., Aratijo, F.V., Carvalho, P.M., Stolt, R.H. Matson, K.H., Coates, R-T.,
  226. Corrigan, D., Foster, D.J. Shaw, S.A. and Zhang, H., 2003. Inverse scattering series
  227. and seismic exploration. Inverse Probl., 19(6): R27-R83.
  228. Weglein, A.B., Liu, F., Li, X., Terenghi, P., Kragh, E., Mayhan, J.D, Wang, Z.Q., Mispel,
  229. J., Amundsen, L., Liang, H., Tang, L. and Hsu, S.-Y., 2012. Inverse scattering series
  230. direct depth imaging without the velocity model: First field data examples. J. Seismic
  231. Explor., 21: 1-28.
  232. Whitmore, N.D., Valenciano, A.A., Lu, S.P. and Chemingui, N., 201la. Imaging of
  233. primaries and multiples with image space surface related multiple elimination. Extended
  234. Abstr.,73rd EAGE Conf., Vienna.
  235. Whitmore, N.D., Valenciano, A.A., Lu, S.P. and Chemingui, N., 2011b. Deep water
  236. prestack imaging with primaries and multiples. 12th Internat. Congr. Brazil. Geophys. Soc.,
  237. Rio de Janeiro.
  238. Zhang, H. and Weglein, A.B., 2009a. Direct nonlinear inversion of 1D acoustic media using
  239. inverse scattering subseries. Geophysics, 74(6): WCD29-WCD39.
  240. Zhang, H. and Weglein, A.B., 2009b. Direct nonlinear inversion of multiparameter 1D
  241. elastic media using the inverse scattering series. Geophysics, 74(6): WCD15—-WCD27.
  242. Zhang, Y. and Biondi, B., 2013. Moveout-based wave-equation migration velocity
  243. analysis. Geophysics, 78(2): U31-U39.
  244. Zhou, H., Amundsen, L. and Zhang, G., 2012. Fundamental issues in full-waveform
  245. inversion. Expanded Abstr., 82nd Ann. Internat. SEG Mtg., Las Vegas.
  246. Zou, Y.L. and Weglein, A.B., 2018. ISS Q-compensation without knowing, estimating or
  247. determining Q and without using or needing low and zero frequency data. J. Seismic
  248. Explor., 27: 593-608.
  249. Zou, Y.L., Fu, Q. and Weglein, A.B., 2017. A wedge resolution comparison between RTM
  250. and the first migration method that is equally effective at all frequencies at the target:
  251. tests and analysis with both conventional and broadband data. Expanded Abstr., 87th
  252. Ann. Internat. SEG Mtg., Houston: 4468-4472.
  253. Zou, Y.L., Ma, C. and Weglein, A.B., 2019. A new multidimensional method that
  254. eliminates internal multiples that interfere with primaries, without damaging the
  255. primary, without knowledge of subsurface properties, for offshore and on-shore
  256. conventional and unconventional plays. Expanded Abstr., 89th Ann. Internat. SEG Mtg.,
  257. San Antonio: 4525- 4529.
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