Spherical Zoeppritz Explorer

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Source Code
Usage
Version History
Technical Notes
References

Usage

You will need to have the Java runtime environment (JRE) installed on your computer in order to use this software. As of Java Version 7 Update 51, you will also need to add https://www.crewes.org to the Java Exception Site List. This has been tested in Windows 10 using Microsoft Internet Explorer, Microsoft Edge and Mozilla Firefox.

To start the Spherical Zoeppritz Explorer click on the 'Launch' button above.

Version History

Chuck Ursenbach, 2005

Technical Notes

This Explorer is modeled after the CREWES Zoeppritz Explorer. In this application, however, reflection coefficients are calculated for both plane waves and spherical waves. It is useful for exploring the importance of including spherical wave effects in long-offset, post-critical AVO studies. Thus it is valuable when seeking to extract density properties.

The principle assumption in this calculation is that the wavelet is restricted to a specific form, namely, f(ν) = νⁿ exp(-nν/ν₀), where n is a non-negative integer and ν₀ is the dominant frequency. The wavelet is displayed at the top of the applet, in both time and frequency domains. Also displayed is the Ricker wavelet, to which it forms a close approximation for some values of n.

This Explorer also carries out a numerical integration, which allows for imperfection in the results. This imperfection will first be seen near 0 and 90 degree angles of incidence, as an erratic deviation of spherical-wave results from plane-wave results. The region of interest is generally at critical points in the 45 to 60 degree region, which will generally be affected negligibly. Potential errors will increase with α₁/(2Zν₀), which is a measure of sphericity.

References

Ursenbach, C.P., Haase, A.B., & Downton, J.E., 2005, "An efficient method for AVO modeling of reflected spherical waves", SEG Expanded Abstracts, Vol. 24