Reduction of tool mode and drilling noise in acoustic LWD
US9115568B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2009 |
| Grant date | Aug 25, 2015 |
| Priority date | — |
| Expiry date | Sep 23, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/46
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A downhole measurement tool includes at least one regular receiver and at least one reference receiver externally deployed on a tool body. The reference receiver is configured to be acoustically isolated from the borehole, for example, via an isolation structure including a high-impedance cap and a low-impedance gap. The reference receiver may be deployed in a linear array with the regular receiver(s) and may be substantially identical to the regular receiver(s) such that it has substantially the same sensitivity to tool mode signals and internal drilling noise as do the regular receivers. Received waveforms may be processed so as to remove tool mode arrivals and/or drilling noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.