Method and apparatus for correcting a shear wave slowness estimate from a sonic well tool and producing an output medium reflecting a true value of shear wave slowness
US5229939A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1992 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Feb 9, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/284
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A borehole correction software of a multipole sonic well tool adapted to be disposed in a borehole determines a true, corrected value of shear wave slowness from a measured uncorrected shear wave slowness value by first building a look up table comprising hole diameter, measured synthetic shear wave slowness and correction factor, and using the table in a system including the look up table and a multiplier to determine a bias, which bias is subtracted from the measured uncorrected shear wave slowness to produce an output medium reflecting a true, corrected value of shear wave slowness. The measured uncorrected shear wave slowness values are input to the look up table. For a given hole diameter, the measured uncorrected shear wave slowness is matched to a measured synthetic shear wave slowness, and a value of correction factor is determined from the table. The correction factor is multiplied by the measured uncorrected shear wave slowness, via the multiplier, and a bias figure is determined. The bias figure is subtracted from the measured uncorrected shear wave slowness value, and a true, corrected shear wave slowness figure is the result. A plurality of the true, corrected shear wa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.