Device for measuring the stresses applied in use to the downhole assembly of a drill pipe
US4294318A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1979 |
| Grant date | Oct 13, 1981 |
| Priority date | — |
| Expiry date | Oct 19, 1999 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/007
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
This device comprises a resilient stress-responsive member interconnecting two conduits which can be respectively coupled to upper and lower portions of the downhole assembly, and are surrounded by a protecting sleeve making up with one of said conduits, the lateral walls of an annular space. Annular elements secured to a first of said lateral walls, and slidable on the second of said lateral walls, form the end walls of said space and an intermediate annular piston integral with the second lateral wall, and slidable on the first lateral wall, divides the annular space into two annular chambers communicating respectively with the inner and outer spaces of the downhole assembly of the drill string, and having operative cross sections selected so as to compensate for the axial loads due to the hydrostatic pressure and bottom effect applied to the stress-responsive member.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.