Apparatus for measuring weight and torque on drill bit operating in a well
US6547016B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 2000 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Dec 12, 2020 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/007
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus for measuring the weight and torque on a drill bit operating down hole in a well. The apparatus comprises at least three pockets circumferentially spaced equidistantly around the drill collar of the drill string to which the drill bit is attached. Eight strain gages are equidistantly circumferentially spaced around each of the pockets so as to form first and second sets of strain gages. The strain gages in the first set are connected into one Wheatstone bridge while the gages in the second set are connected in a second bridge. Each of the strain gages that are oriented similarly within each of the pockets are connected in series within a single leg of a bridge so that the output voltage of the bridge is unaffected by bending in the drill string. The output of first bridge is used to determine the weight on the drill bit while the output of the second bridge is used to determine the torque on the drill bit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.