Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling
In this paper, a finite element approach is applied to study the dispersion properties of non-leaky acoustic waves inside boreholes with off-centered LWD (logging while drilling) tools. Both soft and hard formation cases are studied with focus on phase velocity dispersions of Stoneley, dipole and qu...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Technical Report |
| Published: |
Massachusetts Institute of Technology. Earth Resources Laboratory
2012
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| Online Access: | http://hdl.handle.net/1721.1/68621 |
| _version_ | 1826212544427065344 |
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| author | Zheng, Yibing Toksoz, M. Nafi |
| author2 | Massachusetts Institute of Technology. Earth Resources Laboratory |
| author_facet | Massachusetts Institute of Technology. Earth Resources Laboratory Zheng, Yibing Toksoz, M. Nafi |
| author_sort | Zheng, Yibing |
| collection | MIT |
| description | In this paper, a finite element approach is applied to study the dispersion properties of non-leaky acoustic waves inside boreholes with off-centered LWD (logging while drilling) tools. Both soft and hard formation cases are studied with focus on phase velocity dispersions of Stoneley, dipole and quadrupole modes. When an LWD tool is off-centered, the dispersion curve of the Stoneley mode shifts to the lower phase velocity compared with that of a centered-tool condition. Meanwhile, the dipole dispersion curve splits into two curves with different phase velocities. This splitting phenomenon is also observed with the quadrupole mode. The splitting and shifting of the dipole mode are greater than those of the quadrupole mode. These new observations are important for interpreting acoustic LWD data accurately. |
| first_indexed | 2024-09-23T15:25:23Z |
| format | Technical Report |
| id | mit-1721.1/68621 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T15:25:23Z |
| publishDate | 2012 |
| publisher | Massachusetts Institute of Technology. Earth Resources Laboratory |
| record_format | dspace |
| spelling | mit-1721.1/686212019-04-11T06:24:53Z Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling Zheng, Yibing Toksoz, M. Nafi Massachusetts Institute of Technology. Earth Resources Laboratory Zheng, Yibing Toksoz, M. Nafi In this paper, a finite element approach is applied to study the dispersion properties of non-leaky acoustic waves inside boreholes with off-centered LWD (logging while drilling) tools. Both soft and hard formation cases are studied with focus on phase velocity dispersions of Stoneley, dipole and quadrupole modes. When an LWD tool is off-centered, the dispersion curve of the Stoneley mode shifts to the lower phase velocity compared with that of a centered-tool condition. Meanwhile, the dipole dispersion curve splits into two curves with different phase velocities. This splitting phenomenon is also observed with the quadrupole mode. The splitting and shifting of the dipole mode are greater than those of the quadrupole mode. These new observations are important for interpreting acoustic LWD data accurately. Massachusetts Institute of Technology. Earth Resources Laboratory Massachusetts Institute of Technology. Borehole Acoustics and Logging Consortium 2012-01-20T18:42:14Z 2012-01-20T18:42:14Z 2004 Technical Report http://hdl.handle.net/1721.1/68621 Earth Resources Laboratory Industry Consortia Annual Report;2004-10 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory |
| spellingShingle | Zheng, Yibing Toksoz, M. Nafi Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling |
| title | Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling |
| title_full | Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling |
| title_fullStr | Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling |
| title_full_unstemmed | Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling |
| title_short | Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling |
| title_sort | effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling |
| url | http://hdl.handle.net/1721.1/68621 |
| work_keys_str_mv | AT zhengyibing effectsoftooleccentricityonwavedispersionpropertiesinboreholeacousticloggingwhiledrilling AT toksozmnafi effectsoftooleccentricityonwavedispersionpropertiesinboreholeacousticloggingwhiledrilling |