Extended Resolution by 3-D Holographic Seismic Imaging

摘要

Holography represents a method of recording on a plane (the hologram) a pattern due to the interference of a reference beam with light diffracted from an object. When the hologram is illuminated, the entire picture of the object in three dimensional space is obtained as a virtual image. An essential principle is that a seismogram is a hologram. The understanding of this principle opens up new vistas in seismic exploration, and in particular justifies important cost saving measures in acquisition and processing methods. When a hologram is illuminated or a seismic section is migrated, each depicts the entire image of the unattainable object. Moreover, any part of the hologram also depicts the entire image of the object. The same is true in the seismic case if conventional migration is replaced by holographic seismic imaging, also known as holistic migration. Holistic migration is a process in which any part of the seismic section produces the entire image of the subsurface. Holistic methods allow wavefield images to achieve resolution beyond that predicted by conventional digital processing techniques. The image might not be quite as clear, but the same fine structure will be present. The implication is that in a seismic survey the number of shot points and detectors can be greatly reduced without adversely affecting the results. Holographic seismic imaging provides the extended resolution needed to attain a better image of the subsurface.