Multiple attenuation using 3D SRME<br/>&mdash;Optimization of Multiple Contribution Gather&mdash;

Abstract

This paper presents an optimization of multiple attenuation including three-dimensional Surface-Related Multiple Elimination (3D SRME). First of all, using marine 3D seismic data, we tested 3D SRME in terms of interval distance of the Multiple Contribution Gather (MCG) and the aperture parameter. The aperture parameter defines the ellipsoidal area for producing MCG. It is found that the optimal MCG interval is same as CMP interval and the aperture parameter should be set to the length that the ellipsoidal area includes neighboring sail lines. Moreover, the strategy of the aperture parameter presented in this paper will offer an optimized quality of 3D SRME. Subsequently, we conducted the comparison of 3D SRME and PRT. According to our results, 3D SRME performed better than PRT in near-to middle-offset records and effectively worked under circumstances where the diffracted multiple was observed or the difference of RMS velocity between primary and multiple reflection was small. Moreover, 3D SRME is expected to contribute to increase the accuracy of such cascaded processes as deconvolution or velocity analysis since it can be applied to the field-data. On the other hand, PRT showed superiority to 3D SRME on the far-offset records; therefore, it is considered advantageous for deep subsurface imaging. In conclusion, the implementation of PRT after 3D SRME can produce the best results owing to complementary attributes of each method.