Acoustic body wave dampener
US6082484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Dec 1, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/523
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An acoustic attenuator suppresses acoustic signals traveling along the body of a measurement-while-drilling (MWD) tool, making it possible to obtain acoustic measurements relating to underground formations. Shaped cavities (spherical or cylindrical) filled with a fluid have a resonance frequency that is tuned to be within the band of interest thereby attenuating acoustic signals traveling through the body at these resonance frequencies. The staggered arrangement of the cavities increases the path length for the acoustic signals and provides further attenuation. Attenuation may also be accomplished by use of a composite consisting of cylindrical layers of two different materials with thicknesses that attenuate selected frequencies. Additional attenuation is provided by lengthening the path length of a seismic signal passing through the more competent of the two materials of the composite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.