Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data
Phase velocity and attenuation of guided waves have been estimated from multireceiver, full waveform, acoustic logging data using the extended Prony's method. Since a formation affects velocity and attenuation, estimating these quantities is important in evaluating the formation properties....
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Technical Report |
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Massachusetts Institute of Technology. Earth Resources Laboratory
2012
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| Online Access: | http://hdl.handle.net/1721.1/75082 |
| _version_ | 1811085681660788736 |
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| author | Ellefsen, K. J. Cheng, C. H. Duckworth, G. L. |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Ellefsen, K. J. Cheng, C. H. Duckworth, G. L. |
| author_sort | Ellefsen, K. J. |
| collection | MIT |
| description | Phase velocity and attenuation of guided waves have been estimated from multireceiver,
full waveform, acoustic logging data using the extended Prony's method. Since a formation
affects velocity and attenuation, estimating these quantities is important in evaluating
the formation properties. The estimation is performed using an array processing
technique which requires two steps: (1) the traces for all receivers are transformed into
the frequency domain, and (2) for each frequency the extended Prony's method is used
to determine the presence of a guided wave propagating past the array of receivers. The
guided wave properties estimated by the Prony's method include amplitude, attenuation,
and phase change which is related to phase velocity. An important assumption
in this array processing technique is that the formation, borehole fluid, and tool are
homogeneous along the receiving array. For synthetic data, the phase velocities and attenuation of the tube wave and two modes of the pseudo-Rayleigh wave are accurately
estimated over many frequencies, with the exception that the low amplitude of the second
mode causes its attenuation estimate to be somewhat less accurate. For laboratory
data, very good estimates of the phase velocities of the tube wave and three modes of the pseudo-Rayleigh wave are obtained. Since the materials used in the laboratory
experiment had very large quality factors, the attenuation could not be estimated. For
field data, the dispersion of the tube wave and the velocity of the pseudo-Rayleigh wave
at its cutoff are very close to those predicted by another, independent method. Accurate
attenuation estimates could not be made because the data are noisy and consist of only
eight traces. |
| first_indexed | 2024-09-23T13:13:51Z |
| format | Technical Report |
| id | mit-1721.1/75082 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T13:13:51Z |
| publishDate | 2012 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/750822019-04-11T01:22:17Z Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data Ellefsen, K. J. Cheng, C. H. Duckworth, G. L. Massachusetts Institute of Technology. Earth Resources Laboratory Ellefsen, K. J. Cheng, C. H. Duckworth, G. L. Phase velocity and attenuation of guided waves have been estimated from multireceiver, full waveform, acoustic logging data using the extended Prony's method. Since a formation affects velocity and attenuation, estimating these quantities is important in evaluating the formation properties. The estimation is performed using an array processing technique which requires two steps: (1) the traces for all receivers are transformed into the frequency domain, and (2) for each frequency the extended Prony's method is used to determine the presence of a guided wave propagating past the array of receivers. The guided wave properties estimated by the Prony's method include amplitude, attenuation, and phase change which is related to phase velocity. An important assumption in this array processing technique is that the formation, borehole fluid, and tool are homogeneous along the receiving array. For synthetic data, the phase velocities and attenuation of the tube wave and two modes of the pseudo-Rayleigh wave are accurately estimated over many frequencies, with the exception that the low amplitude of the second mode causes its attenuation estimate to be somewhat less accurate. For laboratory data, very good estimates of the phase velocities of the tube wave and three modes of the pseudo-Rayleigh wave are obtained. Since the materials used in the laboratory experiment had very large quality factors, the attenuation could not be estimated. For field data, the dispersion of the tube wave and the velocity of the pseudo-Rayleigh wave at its cutoff are very close to those predicted by another, independent method. Accurate attenuation estimates could not be made because the data are noisy and consist of only eight traces. Massachusetts Institute of Technology. Full Waveform Acoustic Logging Consortium 2012-11-29T17:42:05Z 2012-11-29T17:42:05Z 1987 Technical Report http://hdl.handle.net/1721.1/75082 Earth Resources Laboratory Industry Consortia Annual Report;1987-13 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Ellefsen, K. J. Cheng, C. H. Duckworth, G. L. Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data |
| title | Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data |
| title_full | Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data |
| title_fullStr | Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data |
| title_full_unstemmed | Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data |
| title_short | Estimating Phase Velocity and Attenuation of Guided Waves in Acoustic Logging Data |
| title_sort | estimating phase velocity and attenuation of guided waves in acoustic logging data |
| url | http://hdl.handle.net/1721.1/75082 |
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