1887
  1. Home
  2. A-Z Publications
  3. Geophysical Prospecting
  4. Volume 37, Issue 8
  5. Article
Volume 37 Number 8
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Data from offshore Norway is used to study applications of elastic VSP modelling in detecting shear waves and observing the effects of successive mode conversion in field‐recorded VSP data. The shear‐wave velocities and densities from log data are used in conjunction with compressional wave velocities determined from surface seismic and log data in the VSP modelling.

The time domain non‐normal incidence elastic VSP modelling technique of Aminzadeh and Mendel is used as the modelling algorithm. Two surface seismograms are computed first. One is the vertical component and the other is the horizontal component for plane waves that have specified incident angles. A downward continuation method is then applied to generate seismograms at different depth points. The collection of these seismograms constitutes non‐normal incidence VSPs. Both vertical and horizontal components of VSP data can be obtained by this procedure.

In this paper non‐normal incidence VSPs are generated for a 12.5° incident plane wave. The modelling results of layered earth systems of thin layers and thick layers are both compared with field data, and the effect of mode conversions in thin layers is observed. Several events in the field data can be explained by this elastic VSP modelling.

Comparison of the model data and field data enabled a probable tube wave or out‐of‐plane event to be identified, the removal of which significantly improved the final VSP section. This study also shows how the VSP data helped the interpretation of the surface 3D data.

Loading

Article metrics loading...

/content/journals/10.1111/j.1365-2478.1989.tb02239.x
2006-04-27
2024-04-25

  • From This Site

    /content/journals/10.1111/j.1365-2478.1989.tb02239.x
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Aminzadeh, F.1986. A recursive method for the separation of upgoing and downgoing waves of vertical seismic profile data. Geophysics51, 2206–2218.
    [Google Scholar]
  2. Aminzadeh, F. and Mendel, J.M.1985. Synthetic vertical seismic profiles for non‐normal incidence plane waves. Geophysics50, 127–141.
    [Google Scholar]
  3. DiSiena, J.P. and Gaiser, J.E.1983. An application of Ga&lcarperin's polarization position correlation technique. 53rd SEG meeting, Las Vegas , Expanded Abstracts, 522–524.
    [Google Scholar]
  4. Frasier, C.1970. Discrete‐time solution of plane P‐SV waves in a plane layered medium. Geophysics35, 197–219.
    [Google Scholar]
  5. Omnes, G.1980. Logs from P and S vertical seismic profiles. Petroleum Technology32, 1843–1849.
    [Google Scholar]
  6. Wrolstad, K.H.1986. Offset‐dependent amplitude analysis by lithological modelling of data from offshore Norway. 56th SEG meeting, Houston , Expanded Abstracts, 341–346.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/j.1365-2478.1989.tb02239.x
Loading
  • Article Type: Research Article

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error