Noise suppression and multiple attenuation using full-azimuth angle domain imaging: case studies

Abstract

The EarthStudy 360 Imager is an advanced depth imaging system that first maps the full recorded seismic data into the subsurface grid points and then decomposes the data into local angle domain (LAD) bins. It is based on specially designed diffraction operators using bottom-up ray tracing. In this article, we focus on the ability of the EarthStudy 360 Imager to attenuate different types of wave characteristics considered as both random and coherent noise – in particular, different orders of multiples, and non-reflection seismic events such as Rayleigh, refraction, diffraction and ‘side’ waves. The method is based on internal implementation of local slant stack (LSS) operators optimally designed for each primary ray pair associated with a given source-image point-receiver path and the corresponding seismic data event. The LSS is applied in the direction of the horizontal slowness components of the arriving rays at the acquisition surface, where the size of the LSS (the number of traces involved) is computed independently for each ray pair from its first Fresnel zone. Thus, primary reflection events sharing the same traveltime and the same surface directivity as the traced ray pairs are emphasized (highly weighted), while all other events (considered as noise) are simultaneously attenuated. We demonstrate our method in four different land data examples with different levels of geological complexities.