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Analysing the Effects of Least-squares Datuming on VSP Multiple Imaging
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
Interferometric transformations are widely applied to transform seismic data from one acquisition geometry to another. We used a correlation-type interferometric transformation to redatum vertical-seismic-profiling multiples into surface-seismic virtual primaries. Conventional redatuming, based on the cross-correlation of seismic traces, yields virtual surface-seismic records that suffer from correlation artefacts, wavelet distortion, and low-temporal resolution. These effects are mainly caused by the limited recording aperture, the band-limited nature of the source wavelet, and the coarse source-receiver sampling. Least-squares migration of the virtual surface-seismic gathers can partially enhance the seismic resolution and improve the quality of the final migrated sections. However, our results demonstrate that the least-squares datuming step remarkably helps suppress the cross-correlation artefacts, enhance the seismic resolution of the seismic events, and correctly deconvolve the source wavelet. Therefore, the obtained migrated sections suggest that least-squares datuming can be an essential processing step to apply to VSP surface-related multiples prior to imaging subsurface structures.