Method and apparatus for investigating drag and torque loss in the drilling process
US4760735A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1986 |
| Grant date | Aug 2, 1988 |
| Priority date | — |
| Expiry date | Oct 7, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B44/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Drilling conditions are analyzed by, for example, measuring the torque applied at the surface to the drill string and the effective torque acting on the drill bit. The applied torque and effective torque are compared to determine torque loss. Likewise, applied weight on the drill string and effective weight acting on the drill bit may be measured and compared to determine drag losses. These measurements and comparisons may be done in real-time to diagnose unfavorable drilling conditions. The torque or weight measurements may be used to calculate a variable coefficient of friction acting on the drilling string. Trends in the torque or weight losses, or in the value of the coefficient of friction, may be observed on a plot of these quantities as a function of depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.