A 3D methodology for residual and diffracted multiple attenuation

Demultiple techniques such as 3D SRME and 3D wave equation modelling are able to model complex surface related multiples to a good extent, particularly in terms of their kinematics. However, the high frequency contents in the multiples model are often lacking due to stacking and/or convolutional operations. In addition, out-of-plane diffracted multiples are usually inadequately modelled by these techniques due to coarse streamer sampling. All these factors contribute in lowering the quality of any multiples model. Hence the demultiple process is not sufficient and some residual multiples are left in the data. These multiples would require further attenuation by a post demultiple process. This abstract proposes a novel post demultiple solution to attenuate both residual and diffracted multiples. The solution incorporates three main physical attributes that can be used to discriminate between primaries and residual multiples in moderate to deep water surveys: (i) amplitude range, (ii) frequency content and (iii) dip content. The proposed solution can be seen as a 3D frequency and dip dependent de-spiking process with Fourier based reconstruction to preserve primary signal.