A dispersive-wave processing technique for estimating formation shear velocity from dipole and Stoneley waveforms

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Geophysics

DOI:https://doi.org/10.1190/1.1443747· OSTI ID:37099

Tang, X M; Reiter, E C; Burns, D R ^[1]

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1. New England Research, Braintree, MA (United States)

A model-guided dispersive-wave processing technique has been developed to estimate formation shear-wave velocity from borehole acoustic logging waveforms. These waveform data can be the Stoneley waves in monopole logging or the flexural waves in dipole logging. In this technique, the waveform recorded on a given receiver is compared to the waveform from a second receiver that is numerically propagated to the given receiver`s position using a trial formation shear-wave velocity. The numerical propagation step uses the proper dispersion relation for the wave mode (dipole or Stoneley). The phase difference between the two waveforms is minimized by varying the shear velocity. The velocity value that minimizes the phase difference is chosen as the final shear velocity at which the waveforms attain the optimum phase match. In this procedure the dispersion effect is automatically accounted for by using the model theory and is demonstrated by a comparison with the results of the semblance method. Using this technique with a multiple-shot scheme to process array acoustic logging data, formation shear velocity can be estimated to the resolution of one receiver spacing (typically 0.5 ft (0.1524 m)). This result has been demonstrated by a field example in which the improved resolution in the shear velocity log is convincingly supported by the same character in the density log measured at one receiver spacing intervals. Shear velocity logs obtained using field Stoneley and dipole sonic data are also compared to demonstrate the ability of the technique to obtain high-resolution formation shear velocity logs from the dispersive logging waveforms. The new technique may find very useful applications in the determination of formation shear-wave properties using acoustic waveform logging.

• OSTI ID: 37099
• Journal Information: Geophysics, Journal Name: Geophysics Journal Issue: 1 Vol. 60; ISSN 0016-8033; ISSN GPYSA7
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
58 GEOSCIENCES
ALGORITHMS
ATTENUATION
BOREHOLES
IMAGE PROCESSING
PETROLEUM INDUSTRY
RESOLUTION
SEISMIC S WAVES
SEISMIC SURVEYS
SONIC LOGGING
WAVE PROPAGATION