Method and apparatus for acoustic measurement of mud flow downhole
US4979112A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1990 |
| Grant date | Dec 18, 1990 |
| Priority date | — |
| Expiry date | Jul 17, 2010 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/107
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The flow rate of the drilling mud within a drill string is measured by measuring the doppler frequency shift in an acoustic signal propagated from a first acoustic transducer to a second acoustic transducer laterally separated from the first acoustic transducer. Each of the transducers are disposed within the principal flow of the drilling mud. The degree of doppler shift is a measure of the flow rate of the drilling mud between the two transducers. Variations in the flow rate of the drilling mud as measured by the transducers downhole are used to transmit information or commands from the well surface to a downhole microprocessor coupled to the output of the transducers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.