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Applied Geophysics

, Volume 16, Issue 2, pp 171–184 | Cite as

An improved fast converted-wave imaging method

  • Xiao Wu
  • Yang LiuEmail author
  • Yong Wang
  • Shi-Gang Xu
  • Wan-Li Jia
Seismic Migration/Inversion

Abstract

The conventional fast converted-wave imaging method directly uses backward P- and converted S-wavefield to produce joint images. However, this image is accompanied by strong background noises, because the wavefields in all propagation directions contribute to it. Given this issue, we improve the conventional imaging method in the two aspects. First, the amplitude-preserved P- and S-wavefield are obtained by using an improved space-domain wavefield separation scheme to decouple the original elastic wavefield. Second, a converted-wave imaging condition is constructed based on the directional-wavefield separation and only the wavefields propagating in the same directions used for cross-correlation imaging, resulting in effectively eliminating the imaging artifacts of the wavefields with different directions; Complex-wavefield extrapolation is adopted to decompose the decoupled P- and S-wavefield into directional-wavefields during backward propagation, this improves the efficiency of the directional-wavefield separation. Experiments on synthetic data show that the improved method generates more accurate converted-wave images than the conventional one. Moreover, the improved method has application potential in micro-seismic and passive-source exploration due to its source-independent characteristic.

Keywords

converted-wave fast imaging elastic wavefield separation directional wavefield separation 

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Copyright information

© The Editorial Department of APPLIED GEOPHYSICS 2019

Authors and Affiliations

  • Xiao Wu
    • 1
    • 3
  • Yang Liu
    • 1
    • 2
    • 3
    Email author
  • Yong Wang
    • 4
  • Shi-Gang Xu
    • 1
    • 3
  • Wan-Li Jia
    • 1
    • 3
  1. 1.State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum (Beijing)BeijingChina
  2. 2.Faculty of PetroleumKaramay Campus of China University of Petroleum (Beijing)Karamay, XinjiangChina
  3. 3.CNPC Key Laboratory of Geophysical ProspectingChina University of Petroleum (Beijing)BeijingChina
  4. 4.Sinopec Geophysical Exploration Institute of Jiangsu OilfieldJiangsuChina

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