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Shallow Water Multiple Elimination (SWME) on Broadband Data
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, cp-451-00838
Abstract
Surface Related Multiple Elimination (SRME) has been approved to be an effective demultiple tool for marine data processing. However, it breaks down when applied to shallow water data mainly because 1) missing or contaminated near-offsets lead to inaccurate multiple models; 2) the cross-talk of short-period multiples deteriorate the matching filter during the adaptive subtraction; 3) the spectrum of the multiple model is distorted by the extra source signature. This paper proposes a new approach that combines a model-based method and a conventional SRME to serve the means of shallow water multiple elimination (SWME). The advantages include: 1) replacing the water-bottom Green's functions with broadband wavelets predicts the correct amplitudes of the multiples; 2) limiting the aperture of the Green's functions to the distance where the critical reflection occurs suppresses the artefacts in the multiple model and lowers the cost; 3) Simultaneously subtracting both the receiver- and source- side water-bottom multiples significantly improves the efficiency; 4) a following SRME helps remove the residual non-water-bottom multiples. A broadband 2D line offshore Santos, Brazil is tested with the proposed approach. It has prominently outperformed the legacy processing that used SRME and Tau-P deconvolution years ago.