Measurement-while-drilling assembly using gyroscopic devices and methods of bias removal
US6529834B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2000 |
| Grant date | Mar 4, 2003 |
| Priority date | — |
| Expiry date | Jan 3, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C19/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention provides a measurement-while-drilling (MWD) downhole assembly for use in drilling boreholes which utilizes gyroscopes, magnetometers and accelerometers for determining the borehole inclination and azimuth during the drilling of the borehole. The downhole assembly includes at least one gyroscope that is rotatably mounted in a tool housing to provide signals relating to the earth's rotation. A device in the tool can rotate the gyroscope and other sensors on the tool to one of a plurality of preselected positions and optionally lock the sensors. A processor in the tool combines measurements from the sensors taken at a plurality of positions at the same depth to determine the systematic bias in the sensors before further processing. Accelerometers in the MWD tool provide gravity measurements from which the toolface and inclination are determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.