The Impact of Full-Azimuth Imaging on Resolving Subsurface Geology
By Gaby Yelin
E&P companies make huge investments in acquiring rich seismic data with wide azimuth and long offset, in an effort to obtain a more accurate definition of the reservoir, especially in fractured and sub-salt reservoirs. However, standard seismic imaging procedures that integrate or sum (stacking) seismic amplitude data for a large number of seismic events from energy arriving at different angles and all possible dips at each image point, result in smearing of the image along key subsurface objects. This is especially true in complex geological areas characterized by faults, pinchouts and material discontinuities. Consequently, standard discontinuity attributes (e.g. coherence, curvature, fault likelihood) can suffer from inaccuracy, instability, and considerable uncertainty when applied to poststack image volumes.
In this lecture we will discuss the benefits of a full-azimuth angle domain imaging system. The key advantage of this system is its ability to decompose and separate the wavefield into reflection and diffraction energy. Specular reflection stacks can be used to emphasize and interpret major continuous events and major discontinuities. On the other hand, diffraction stacks can be used to interpret and delineate high-resolution subsurface stratigraphic and structural features, such as small scale faults, tips and fractures. (Diffraction energy is often masked by reflection energy in conventional processing and methodologies.) This technology can be used to complement standard poststack oriented interpretation.
This presentation will feature Paradigm® EarthStudy 360®