Where two or more reflections are more closely spaced than a quarter wavelength, a common situation for stratigraphic features of interest in petroleum exploration, the same half-cycles of the embedded wavelet tend to add; we call this the “thin-bed” case. In contrast, where they are close but separated by more than a quarter wavelength, different half-cycles tend to add; this is the “thick-bed” case. Many characteristics of seismic reflections differ in thinand thick-bed situations.
On unmigrated seismic sections the limits of horizontal resolvability are imposed by Fresnel-zone considerations. However, on migrated sections other factors become important, such as noise on the unmigrated section, spatial aliasing, migration aperture, and uncertainties imposed by velocity, stacking, and two-dimensional assumptions.
Figures & Tables
The publication of AAPG Memoir 26 opened up a whole new field to the exploration community. The material contained in that publication demonstrated the relationship of seismic data to the geology of the subsurface in greater detail than previously thought possible. In the years that have followed great effort has gone into refining and advancing the principles and methods of seismic stratigraphy. The goal of this Memoir 39 publication is to provide 15 papers which present and document the advances and refinements in seismic stratigraphic princples and methods that have occurred since the publication of Memoir 26. These articles help the geologist, geophysicist, and manager to keep abreast of this rapidly developing field and provide some guidelines for the evaluation of stratigraphically controlled prospects.