Processing and imaging of seismic diffraction using multiparameter stacking attributes

Abstract

Conventional seismic processing and imaging techniques are tuned to enhance reflections while diffractions are considered as noise. However, diffraction imaging plays a key role in high-resolution characterization of small-scale subsurface structures. A key step of diffraction imaging and tomography is diffraction separation and enhancement especially in the full pre-stack data volume. In this work, we consider point diffractors and present a fast and robust workflow for pre-stack diffraction separation based on wavefront attributes which are determined using the common-reflection-surface (CRS) method. In the first stage, we use a zero-offset based extrapolation operator for pre-stack diffraction separation, which combines the robustness and stability of the zero-offset CRS processing with enhanced resolution and improved illumination of the finite-offset CRS processing. When finite-offset diffracted events are separated, in the second stage, we suggest a diffraction-based time migration velocity model building which provides high-quality diffraction velocity spectra. Applications of the new workflow to 2D~/~3D complex synthetic data reveal the high potential of diffractions for improved time imaging.