Reverse time migration using water-bottom-related multiples |
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| Authors: | Yanbao Zhang Yike Liu Xuejian Liu Xiaopeng Zhou |
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| Institution: | 1. Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 China;2. Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 China
Institution of Earth Science, Chinese Academy of Science, Beijing, 10029 China |
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| Abstract: | Reverse time migration of multiples can be used to construct subsurface structures where primaries cannot illuminate well. However, the images generated using multiples suffer from severe artefacts due to the cross-talks created by interference among unrelated multiples. We developed a migration approach using water-bottom-related multiples to reduce these cross-talk artefacts. This approach first isolates primaries from the original data and predicts water-column primaries. The nth-order water-column multiples can be obtained by auto-convolving the water-column primaries n times, followed by convolving the nth-order water-column multiples with the primaries to extract the (n+1)th-order water-bottom-related multiples. The approach takes the nth-order water-column multiples as the secondary source and regards the (n+1)th-order water-bottom-related multiples as the receiver wavefield, followed by a cross-correlation imaging condition. Numerical examples from synthetic and field data sets reveal that our approach can provide images with substantially fewer cross-talk artefacts than conventional reverse time migration using multiples, as well as greatly improving shallow imaging compared with reverse time migration of primaries. |
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| Keywords: | Seismics Imaging Modelling Inversion |
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