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![]() | Reconciling processing and inversion: Multiple attenuation prior to wave-equation inversion | ![]() |
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We showed how different modes of multiple reflections present in Sigsbee2b data behave after migration. The multiple reflections we face are not surface-related; therefore, they can still persist after multiple attenuation during processing. As the model used to compute this dataset is based on a realistic geological setting, the same behavior is likely to happen in real data. We explored the separability of primaries from multiples after migration by applying simple filters. Once discriminated, primaries and multiples were submitted to a simultaneous, adaptive, non-stationary filtering to adjust amplitude and phase and decrease the cross-talk between them. The adapted multiples were then subtracted from the migrated data.
The inversion results show that, if the physics of the wave-propagation is not adequate to account for all the propagation modes in the migrated data, coherent noise - in our case multiples - will dominate the residual space, decreasing the efficiency of inversion. It is imperative, therefore, to make data satisfy the physical approximations by means of pre-processing that, in some sense reconciles processing and inversion.
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![]() | Reconciling processing and inversion: Multiple attenuation prior to wave-equation inversion | ![]() |
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