Geophysics and Geophysical Exploration (지구물리와물리탐사)

Korean Society of Earth and Exploration Geophysicists (한국지구물리·물리탐사학회)
권호 표지
DOI QR코드

DOI QR Code

Reverse-time Migration using Surface-related Multiples

자유면 기인 겹반사파를 이용한 거꿀시간 참반사 보정

  • Lee, Ganghoon (Department of Energy Resources Engineering, Inha University) ;
  • Pyun, Sukjoon (Department of Energy Resources Engineering, Inha University)
  • 이강훈 (인하대학교 에너지자원공학과) ;
  • 편석준 (인하대학교 에너지자원공학과)
  • Received : 2018.01.11
  • Accepted : 2018.02.21
  • Published : 2018.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

In the traditional seismic processing, multiple reflections are treated as noise and therefore they are eliminated during data processing. Recently, however, many studies have begun to consider multiples as signals rather than noise for seismic imaging. Multiple reflections can illuminate an area where primary reflections are not able to cover, thus it is allowed that a smaller number of shots and receivers are used for imaging large areas. In order to verify this, surface-related multiples were used for reverse-time migration (RTM), and then we compared the results with conventional RTM images which are generated from primary reflections. To utilize multiples, we separated multiples from whole seismic data using surface-related multiple elimination (SRME) method. Numerical examples confirmed that the migration using multiples can image wider area than the conventional migration, particularly in the shallow subsurface layers. In addition, the migration of multiples could eliminate the acquisition footprints.

전통적인 탄성파 탐사 자료처리 분야에서 겹반사파(multiple)는 잡음으로 취급되어 제거한 후 자료처리를 수행한다. 그러나 최근 겹반사파를 잡음이 아닌 하나의 신호로 인식하고 이를 영상화에 이용하는 연구가 많이 이루어지고 있다. 겹반사파는 일차 반사파(primary reflection)가 도달하지 못하는 지점까지 도달할 수 있어 적은 수의 송신원과 수신기로도 더 넓은 범위를 영상화 할 수 있다. 이를 검증하기 위해 본 연구에서는 영상화 기법 중 하나인 거꿀시간 참반사 보정(reverse-time migration)을 이용하여 겹반사파 자료를 영상화한 후 일차 반사파를 사용한 전통적인 거꿀시간 참반사 보정 결과와 비교하였다. 겹반사파를 독립적으로 사용하기 위해 자유면 기인 겹반사파 제거(surface-related multiple elimination; SRME)기법을 사용해 탄성파 자료에서 겹반사파를 분리하였다. 수치 예제를 통해 겹반사파를 이용한 참반사 보정 결과가 일차 반사파를 이용한 전통적인 참반사 보정 결과보다 더 넓은 범위를 영상화 할 수 있음을 확인하였고, 특히 천부 지층에서 두드러진 효과가 나타나는 것을 알 수 있었다. 또한 겹반사파를 이용한 참반사 보정은 자료취득 흔적(acquisition footprint)에 의한 영상 왜곡이 제거됨을 확인할 수 있었다.

Keywords

References

  1. Aminzadeh, F., Burkhard, N., Long, J., Kunz, T., and Duclos, P., 1996, Three dimensional SEG/EAGE models-an update, The Leading Edge, 15, 131-134. https://doi.org/10.1190/1.1437283
  2. Baysal, E., Kosloff, D. D., and Sherwood, J. W. C., 1984, A two-way nonreflecting wave equation, Geophysics, 49, 132-141. https://doi.org/10.1190/1.1441644
  3. Berkhout, A. J., and Verschuur, D. J., 1997a, Estimation of multiple scattering by iterative inversion, Part I: Theoretical considerations, Geophysics, 62, 1586-1595. https://doi.org/10.1190/1.1444261
  4. Berkhout, A. J., and Verschuur, D. J., 1997b, Estimation of multiple scattering by iterative inversion, Part II: Practical aspects and examples, Geophysics, 62, 1596-1611. https://doi.org/10.1190/1.1444262
  5. Berkhout, A. J., and Verschuur, D. J., 2003, Transformation of multiples into primary reflections, 73rd Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 1925-1928.
  6. Berkhout, A. J., Verschuur, D. J., and Romijn, R., 2004, Reconstruction of seismic data using the focal transformation, 74th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 1993-1996.
  7. Berkhout, A. J., and Verschuur, D. J., 2006, Imaging of multiple reflections, Geophysics, 71, SI209-SI220. https://doi.org/10.1190/1.2215359
  8. Bube, K. P., and Langan, R. T., 1997, Hybrid l1/l2 minimization with applications to tomography, Geophysics, 62, 1183-1195. https://doi.org/10.1190/1.1444219
  9. Cheong, S., Koo, N., Kim, W., Lee, H., Shin, W., Park, K., and Kim, J., 2009, Optimal Rejection of Sea Bottom, Peg-leg and Free-surface Multiples for Multichannel Seismic Data on South-eastern Sea, Korea, Geophys. and Geophys. Explor., 12, 289-298. (In Korean with English abstract)
  10. Claerbout, J. F., 1971, Toward a unified theory of reflector mapping, Geophysics, 59, 467-481.
  11. Dedem, E. V., and Verschuur, D. J., 2005, 3D surface-related multiple prediction: A sparse inversion approach, Geophysics, 70, V31-V43. https://doi.org/10.1190/1.1925752
  12. Etienne, R., 2016, EAGE E-Lecture: Reverse Time Migration: How Does It Work, When To Use It, https://youtu.be/ywdML8ndYeQ, (November 15, 2016)
  13. Foster, D. J., and Mosher, C. C., 1992, Suppression of multiple reflections using the Radon transform, Geophysics, 57, 386-395. https://doi.org/10.1190/1.1443253
  14. Guitton, A., and Verschuur, D. J., 2004, Adaptive subtraction of multiples using the L1-norm, Geophys. Prospect., 52, 27-38. https://doi.org/10.1046/j.1365-2478.2004.00401.x
  15. Hampson, D., 1986, Inverse velocity stacking for multiple estimation, 56th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 422-424.
  16. Herrmann, P., Mojesky, T., Magesan, M., and Hugonnet, P., 2000, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 1953-1956.
  17. Kaelin, B., and A. Guitton, 2006, Imaging condition for reverse time migration, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 2594-2598.
  18. Kim, T., and Jang, S., 2012, Optimization for Multiple Attenuation of Marine Seismic Reflection Data, J. Korea Inst. Mineral Mining Eng., 49, 281-291. (In Korean with English abstract)
  19. Lee, G. H., Pyun, S., Park, Y., and Cheong, S., 2016, Improvement of Reverse-time Migration using Homogenization of Acoustic Impedance, Geophys. and Geophys. Explor., 19, 76-83. (In Korean with English abstract) https://doi.org/10.7582/GGE.2016.19.2.076
  20. Li, Z., Li, Z., Wang, P., and Zhang, M., 2016, Reverse time migration of multiples based on different-order multiple separation, Geophysics, 82, S19-S29.
  21. Liu, Y., Chang, X., Jin, D., He, R., Sun, H., and Zheng, Y., 2011, Reverse time migration of multiples for subsalt imaging, Geophysics, 76, WB209-WB216. https://doi.org/10.1190/geo2010-0312.1
  22. Lopez, G. A., and Verschuur, D. J., 2015a, Closed-loop surfacerelated multiple elimination and its application to simultaneous data reconstruction, Geophysics, 80, V189-V199. https://doi.org/10.1190/geo2015-0287.1
  23. Lopez, G. A., and Verschuur, D. J., 2015b, 3D Focal Closed-Loop SRME for shallow water, 85th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 4418-4422.
  24. Miley, M. P., J. Paffenholz, K. Hall, and S. Mitchell, 2001, Optimizing surface-related multiple elimination on a synthetic subsalt data set, 71st Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 1277-1280.
  25. Peacock, K. L., and Treitel, S., 1969, Predictive deconvolution: Theory and practice, Geophysics, 34, 155-169. https://doi.org/10.1190/1.1440003
  26. Robinson, E. A., 1957, Predictive decomposition of seismic traces. Geophysics, 22, 767-778. https://doi.org/10.1190/1.1438415
  27. Sacchi, M. D., and Ulrych, T. J., 1995, High-resolution velocity gathers and offset space reconstruction, Geophysics, 60, 1169-1177. https://doi.org/10.1190/1.1443845
  28. Scales, J. A., Gersztenkorn, A., and Treitel, S., 1988, Fast lp solution of large, sparse, linear systems: Application to seismic travel time tomography, J. Comput. Phys, 75, 314-333. https://doi.org/10.1016/0021-9991(88)90115-5
  29. Taner, M. T., 1980, Long period sea-floor multiples and their suppression, Geophys. Prospect, 28, 30-48. https://doi.org/10.1111/j.1365-2478.1980.tb01209.x
  30. Trad, D., Ulrych, T., and Sacchi, M., 2003, Latest views of the sparse Radon transform, Geophysics, 68, 386-399. https://doi.org/10.1190/1.1543224
  31. Verschuur, D. J., 1991, Surface-related multiple elimination, an inversion approach, Ph. D. thesis, Delft University of Technology
  32. Verschuur, D. J., Berkhout, A. J., and Wapenaar, C. P. A., 1992, Adaptive surface-related multiple elimination, Geophysics, 57, 1166-1177. https://doi.org/10.1190/1.1443330
  33. Verschuur, D. J., 2006, Seismic multiple removal techniques: Past, present and future, EAGE publications.
  34. Wang, Y., Chang, X., and Hu, H., 2013, Simultaneous reverse time migration of primaries and free-surface related multiples without multiple prediction, Geophysics, 79, S1-S9.
  35. Wang, Y., Zheng, Y., Zhang, L., Chang, X., and Yao, Z., 2014, Reverse time migration of multiples: Eliminating migration artifacts in angle domain common image gathers, Geophysics, 79, S263-S270. https://doi.org/10.1190/geo2013-0441.1
  36. Zhang, D., and Schuster, G. T., 2013, Least-squares reverse time migration of multiples, Geophysics, 79, S11-S21.