Acoustic logging systems and methods employing multi-mode inversion for anisotropy and shear slowness
US9529105B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2012 |
| Grant date | Dec 27, 2016 |
| Priority date | — |
| Expiry date | Jun 27, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V2210/74
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Acoustic logging systems and methods are provided with multi-mode inversion for at least vertical shear slowness and shear anisotropy. At least some method embodiments acquire waveforms for multiple acoustic wave modes as a function of tool position in a borehole, derive position-dependent mode dispersion curves from the waveforms, match the derived dispersion curves with parameterized dispersion curves to determine a vertical shear slowness and a shear anisotropy as a function of position, and displaying a borehole log that represents at least one of the vertical shear slowness and the shear anisotropy as a function of position. The objective function employed for the inversion is evaluated across multiple wave propagation modes and mud slownesses and may employ an adaptive, frequency-dependent weighting based on distance between the derived dispersion curves and the parameterized dispersion curves.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.