Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations
In boreholes where formation shear velocity is lower than borehole fluid velocity neither refracted shear waves nor pseudo-Rayleigh waves can propagate. When frequency response of the sonde does not extend to low frequencies (e.g. 2 kHz) Stoneley waves are not excited efficiently. In such cases refr...
| 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/1721.1/75039 |
| _version_ | 1811073121672757248 |
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| author | Toksoz, M. Nafi Wilkens, R. H. Cheng, C. H. |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Toksoz, M. Nafi Wilkens, R. H. Cheng, C. H. |
| author_sort | Toksoz, M. Nafi |
| collection | MIT |
| description | In boreholes where formation shear velocity is lower than borehole fluid velocity neither refracted shear waves nor pseudo-Rayleigh waves can propagate. When frequency response of the sonde does not extend to low frequencies (e.g. 2 kHz) Stoneley waves are not excited efficiently. In such cases refracted P, leaking modes (PL) and fluid waves become dominant phases on a full waveform acoustic log. The P wave velocity can be determined from the first arrivals. Then, using synthetic microseismograms and a waveform
matching technique, formation shear wave velocity and attenuation can be determined. This method· is demonstrated using data from a well in the Baltimore Canyon Trough area of the Atlantic margin. |
| first_indexed | 2024-09-23T09:28:47Z |
| format | Technical Report |
| id | mit-1721.1/75039 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T09:28:47Z |
| publishDate | 2012 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/750392019-04-12T20:28:05Z Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations Toksoz, M. Nafi Wilkens, R. H. Cheng, C. H. Massachusetts Institute of Technology. Earth Resources Laboratory Toksoz, M. Nafi Wilkens, R. H. Cheng, C. H. In boreholes where formation shear velocity is lower than borehole fluid velocity neither refracted shear waves nor pseudo-Rayleigh waves can propagate. When frequency response of the sonde does not extend to low frequencies (e.g. 2 kHz) Stoneley waves are not excited efficiently. In such cases refracted P, leaking modes (PL) and fluid waves become dominant phases on a full waveform acoustic log. The P wave velocity can be determined from the first arrivals. Then, using synthetic microseismograms and a waveform matching technique, formation shear wave velocity and attenuation can be determined. This method· is demonstrated using data from a well in the Baltimore Canyon Trough area of the Atlantic margin. Massachusetts Institute of Technology. Full Waveform Acoustic Logging Consortium 2012-11-27T19:43:54Z 2012-11-27T19:43:54Z 1984 Technical Report http://hdl.handle.net/1721.1/75039 Earth Resources Laboratory Industry Consortia Annual Report;1984-08 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Toksoz, M. Nafi Wilkens, R. H. Cheng, C. H. Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations |
| title | Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations |
| title_full | Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations |
| title_fullStr | Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations |
| title_full_unstemmed | Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations |
| title_short | Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations |
| title_sort | determination of shear wave velocity and attenuation from waveforms in low velocity formations |
| url | http://hdl.handle.net/1721.1/75039 |
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