Practical considerations - book

ADVERTISEMENT
From SEG Wiki
Jump to: navigation, search
Other languages:
English • ‎español
Digital Imaging and Deconvolution: The ABCs of Seismic Exploration and Processing
DigitalImaging.png
Series Geophysical References Series
Title Digital Imaging and Deconvolution: The ABCs of Seismic Exploration and Processing
Author Enders A. Robinson and Sven Treitel
Chapter 14
DOI http://dx.doi.org/10.1190/1.9781560801610
ISBN 9781560801481
Store SEG Online Store

Deconvolution with multiple gates (or windows) commonly is used to correct for absorption loss of high frequencies. This approach requires that the deconvolution operators be derived from windows that are smaller than usual. Some of those windows might be too short to meet the requirements necessary for the statistical assumption that the reflectivity be random within the window. In addition, use of short windows often results in phase distortions at the zones of overlap. However, some processing systems include methods for designing smoothly varying minimum-phase inverse filters that correct for those deleterious effects.

One beneficial effect of Q-filter use is that the resulting wavelet tends to vary less in time than does the original wavelet. That is because the higher frequencies become more and more attenuated so that the wavelets become smoother and smoother. As a result, the conditions for designing a deconvolution operator for a single window are better satisfied.

Clearly, many other factors can obscure the information that one can extract from reflection amplitudes (Toksöz and Johnston, 1981[1]). Corrections are made for the effects of spherical divergence and raypath curvature. The gain of the recording instruments is taken into account. Ray-directivity effects and amplitude-variation-with-offset (AVO) effects can be considered. Migration corrects for reflector curvature and other geometric factors. After these corrections, the following effects remain: (1) effects caused by energy losses from absorption, scattering, transmissivity losses, and peg-leg multiples, and (2) effects caused by source strength, source coupling, geophone sensitivity, geophone coupling, and source-receiver offsets. Although the effects in group 1 are difficult to determine, usually they are relatively constant along a line and therefore do not obscure lateral variations. For high multiplicity of CMP data, the effects in group 2 can be compensated for by the use of surface-consistent amplitude corrections.


References

[2]
[3]
[4]

Continue reading

Previous section Next section
Useful attenuation mechanisms Appendix O: Exercises
Previous chapter Next chapter
Phase Input-output Models

Table of Contents (book)

Also in this chapter

External links

find literature about
Practical considerations - book
SEG button search.png Datapages button.png GeoScienceWorld button.png OnePetro button.png Schlumberger button.png Google button.png AGI button.png
  1. Toksöz, M. N., and D. H. Johnston, eds., 1981, Seismic wave attenuation: SEG Geophysics Reprint Series No. 2.
  2. Whaley, J., 2017, Oil in the Heart of South America, https://www.geoexpro.com/articles/2017/10/oil-in-the-heart-of-south-america], accessed November 15, 2021.
  3. Wiens, F., 1995, Phanerozoic Tectonics and Sedimentation of The Chaco Basin, Paraguay. Its Hydrocarbon Potential: Geoconsultores, 2-27, accessed November 15, 2021; https://www.researchgate.net/publication/281348744_Phanerozoic_tectonics_and_sedimentation_in_the_Chaco_Basin_of_Paraguay_with_comments_on_hydrocarbon_potential
  4. Alfredo, Carlos, and Clebsch Kuhn. “The Geological Evolution of the Paraguayan Chaco.” TTU DSpace Home. Texas Tech University, August 1, 1991. https://ttu-ir.tdl.org/handle/2346/9214?show=full.