Surface Multiple Attenuation Developments in the Clair Field

Abstract

Multiples are a key problem over the Clair area, mainly caused by the complexity in the overburden. The paper describes a much improved combination of demultiples techniques, which have been applied to the latest Clair South West HDOBC survey. The sequence consists a top-down approach removing successive multiples with PZ summation, Wavefield Extrapolation Multiples Modeling, GSMP and TauPQ deconvolution. Water bottom WEMM plays a key role, effectively predicting water layer multiples in a 3D sense. GSMP complements the results of the other techniques against short period multiples, but more importantly it also predicts other long period surface multiples which are cutting through at reservoir level. The results are a much improved level of multiples suppression, although some surface multiples contamination is still present, and internal multiples have not been attenuated.