rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Modeling wave propagation in boreholes to determine rock properties
  name:
    name part: Wu, Ru-Chuan.
    role:
      role term: creator
  name:
    name part: Berg, Robert R.
    role:
      role term: degree committee member.
  name:
    name part: Caputo, Michele
    role:
      role term: degree committee member.
  name:
    name part: Chan, Andrew K.
    role:
      role term: degree committee member.
  name:
    name part: Spencer, Terry W.
    role:
      role term: degree supervisor.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1986
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xii, 123 leaves : illustrations ; 28 cm
  abstract: Conventional methods for determining Poisson's ratio from full-waveform acoustic logs rely on measurement of the shear velocity. This measurement is subject to error from contamination by multiply reflected P-waves and pseudo-Rayleigh waves which arrive at the same time as the shear head wave. In slow formations where the shear head wave and pseudo-Rayleigh waves are not excited, the determination of formation shear wave traveltime must rely on other methods. A new method is presented for determining Poisson's ratio and shear velocity. This method can be implemented by recording the components of particle displacement on the borderline wall. The particle trajectory in the compressional head wave is rectilinear and is deflected with respect to the direction of propagation. The deflection is a sensitive function of Poisson's ratio, varying by more than 30 degrees over the range of Poisson's ratio encountered in rocks. In the polarization method all the measurements are made on the compressional head wave, the spatial resolution is greater than for velocity measurements, and the deflection is greatest in soft formations. To compare the different methods in extracting the attenuation (Q⁻¹) from full-waveform acoustic logs, the model Q's are incorporated in the algorithm. The algorithm is tested by recovering the model Q of the compressional head wave form synthetic waveforms. For a wide-band source, windowing the compressional head wave and using the spectral-ratio, slope method recovers model Q accurately. For a narrow-band source, windowing most of the P-wave train and using the spectral-ratio, peak-amplitude method recovers model Q approximately. The discrepancy between the extracted value and the model Q increases when the receiver spacing, z, increases in a high attenuation zone and when the dominant frequency of the source function increases.
  note: Reproduction of typescript.
  note: Ph. D. in Geophysics Texas A & M University 1986
  note: Includes bibliographical references (leaves 119-122).
  subject:
    topic: Geophysical well logging
  subject:
    topic: Shear waves
  subject:
    topic: Major geophysics
  classification: 622.159
  identifier: http://proxy.library.tamu.edu/login
  identifier: https://hdl.handle.net/1969.1/DISSERTATIONS-21991
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: https://hdl.handle.net/1969.1/DISSERTATIONS-21991
  record info:
    record content source: GOH
    record creation date: 861006
    record change date: 20220104090802.0
    record identifier: in00000015612
    language of cataloging:
      language term: eng