Apparatus for measuring weight, torque and side force on a drill bit
US4821563A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 15, 1988 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | Jan 15, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/007
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Apparatus is presented for measuring weight, torque and side force (bending) on a drill bit for oil and gas well drilling. Strain gages are located in radial holes in the wall of a drill collar sub for measuring each of the three parameters of weight, torque and bending. The holes are sealed by inner and outer plugs and a ring and bolt structure retains the plugs in place. For torque and bending measurements, the strain gages are arranged with symmetry of position beteween diametrically opposed holes. The strain gages are positioned in a novel array which departs from symmetry of position to minimized errors in the weight measurement caused by pressure changes in the drilling fluid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.