Quick search Find article
Quick search
Find article

SH wavefields in cylindrical double-layered elastic media excited by a shear stress source applied to a borehole wall

Gui-Jin Yao1, Ke-Xie Wang1, Jun Ma1 and J E White2

Show affiliations


As a method of exciting shear waves in acoustic logging, the phenomenon of SH wave propagation along cylindrical double-layered elastic media surrounding a fluid-filled borehole, excited by an annular shear stress source applied to the borehole wall, is studied. The dispersion equation and excitation characteristics of guided waves and critical refracted head waves described by vertical branch cut integrals are theoretically and numerically analysed. It is found that the dispersion behaviour of guided waves as borehole radius tends to infinity is the same as that of Love waves in a half-space model with horizontally double-layered elastic media, and that the lowest-order guided waves have non-zero low cut-off frequencies. The transient full waveforms of the SH wavefield are calculated and compared with the sum of the waveforms of the component waves. Both are in good agreement.


PACS

91.30.Fn Surface and body waves

93.85.Fg Downhole methods

Subjects

Instrumentation and measurement

Environmental and Earth science

Dates

Issue 2 (June 2005)

Received 21 January 2005, accepted for publication 19 April 2005

Published 20 May 2005



View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.