Shear Wave Logging In (Multilayered) Elastic Formations: An Overview
We perform the analysis of the dispersion and attenuation of the modes generated both by a dipole and quadrupole source in a fluid filled borehole surrounded by a (multilayered) elastic formation. The displacement-stress vectors are propagated through the layers using the Thomson-Haskell method. On...
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| Other Authors: | |
| Format: | Technical Report |
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Massachusetts Institute of Technology. Earth Resources Laboratory
2019
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| Online Access: | https://mit.atmire.com/handle/1721.1/121148 |
| _version_ | 1811086822434930688 |
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| author | Schmitt, D. P. Cheng, C. H. |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Schmitt, D. P. Cheng, C. H. |
| author_sort | Schmitt, D. P. |
| collection | MIT |
| description | We perform the analysis of the dispersion and attenuation of the modes generated both
by a dipole and quadrupole source in a fluid filled borehole surrounded by a (multilayered) elastic formation. The displacement-stress vectors are propagated through the layers using the Thomson-Haskell method. Only the well bonded configuration is investigated. In the time domain, we investigate the effects of the source center frequency on synthetic full waveform microseismograms computed using the discrete wavenumber method. Whatever the formation (fast or slow) and the configuration, the low frequency part of both the flexural and screw modes follows the virgin formation shear wave
characteristics. Their high frequency parts behave like that of the Stoneley wave excited
by a monopole source. As a result, the fundamental modes are very sensitive to the
properties of the inner layers at intermediate and high frequencies. In the presence of an invaded zone, the internal dynamics of the waveforms can be significantly modified, while the useful starting energy of the fundamental modes is shifted toward lower frequencies. The reverse phenomenon occurs when the borehole is cased. For this last configuration, it is only with low source center frequencies that multipole sources can log a slow formation shear wave due to the leaky character of the fundamental modes. |
| first_indexed | 2024-09-23T13:35:14Z |
| format | Technical Report |
| id | mit-1721.1/121148 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T13:35:14Z |
| publishDate | 2019 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/1211482019-04-12T20:30:45Z Shear Wave Logging In (Multilayered) Elastic Formations: An Overview Schmitt, D. P. Cheng, C. H. Massachusetts Institute of Technology. Earth Resources Laboratory Schmitt, D. P. Cheng, C. H. We perform the analysis of the dispersion and attenuation of the modes generated both by a dipole and quadrupole source in a fluid filled borehole surrounded by a (multilayered) elastic formation. The displacement-stress vectors are propagated through the layers using the Thomson-Haskell method. Only the well bonded configuration is investigated. In the time domain, we investigate the effects of the source center frequency on synthetic full waveform microseismograms computed using the discrete wavenumber method. Whatever the formation (fast or slow) and the configuration, the low frequency part of both the flexural and screw modes follows the virgin formation shear wave characteristics. Their high frequency parts behave like that of the Stoneley wave excited by a monopole source. As a result, the fundamental modes are very sensitive to the properties of the inner layers at intermediate and high frequencies. In the presence of an invaded zone, the internal dynamics of the waveforms can be significantly modified, while the useful starting energy of the fundamental modes is shifted toward lower frequencies. The reverse phenomenon occurs when the borehole is cased. For this last configuration, it is only with low source center frequencies that multipole sources can log a slow formation shear wave due to the leaky character of the fundamental modes. Massachusetts Institute of Technology. Full Waveform Acoustic Logging Consortium 2019-04-04T10:10:02Z 2019-04-04T10:10:02Z 1987 Technical Report https://mit.atmire.com/handle/1721.1/121148 Earth Resources Laboratory Industry Consortia Annual Report;1987-08 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Schmitt, D. P. Cheng, C. H. Shear Wave Logging In (Multilayered) Elastic Formations: An Overview |
| title | Shear Wave Logging In (Multilayered) Elastic Formations: An Overview |
| title_full | Shear Wave Logging In (Multilayered) Elastic Formations: An Overview |
| title_fullStr | Shear Wave Logging In (Multilayered) Elastic Formations: An Overview |
| title_full_unstemmed | Shear Wave Logging In (Multilayered) Elastic Formations: An Overview |
| title_short | Shear Wave Logging In (Multilayered) Elastic Formations: An Overview |
| title_sort | shear wave logging in multilayered elastic formations an overview |
| url | https://mit.atmire.com/handle/1721.1/121148 |
| work_keys_str_mv | AT schmittdp shearwavelogginginmultilayeredelasticformationsanoverview AT chengch shearwavelogginginmultilayeredelasticformationsanoverview |