A ray model for head waves in a fluid-filled borehole

A model, suggested by tbe ray expansion of Roever et al., is constructed to rapidly generate the compressional and shear refracted arrivals, known as head waves, received from a point source on the axis of an ideal fluid-filled borehole. An impulse response is derived, and its frequency characteristics are investigated. The waves are compared to those obtained by the real axis integration method of Tsang and Rader, which results in a complete waveform, including the modes as well as the refracted arrivals. The ray model gives accurate results for the compressional head wave. The shear region of the complete waveform contains strong modal interference, making it difficult to evaluate the quality of the ray model shear wave. A useful filter results from insight provided by the basic structure of the model. This filter can be used to estimate the borehole diameter or formation compressional velocity. It can also remove the second and later compressional arrivals, thus providing an accurate estimate of the source pulse and and a relatively uncorrupted vie of the initial arrival in the shear region.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Engineering

Grantor

Rice University

Year dc:date.issued

1982

Author dc:creator

• Scheibner, David James

Advisor dc:contributor.advisor

• Parks, Thomas W.

Committee members dc:contributor.committeemember

• Johnson, Don H.
• Figueiredo, Rui J. P. de

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/104543

OAI identifier oai:identifier

oai:repository.rice.edu:1911/104543