Method and apparatus for measuring axially extending defects in ferromagnetic elements
US4792756A · kind A · utility
13Cited by
37References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 4, 1987 |
| Grant date | Dec 20, 1988 |
| Priority date | — |
| Expiry date | May 4, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/904
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for determining the extent of axially extending defects in ferromagnetic elements, such as tubing comprising a continuous string for use in an oil or gas well is disclosed. The tubing trip tool detects axial defects, such as sucker rod wear during removal of the tubing from the well. A saturating magnetic field and a fluctuating magnetic field are applied to the tubing and the magnitude of the induced fields and the changes are measured to quantify defects in the tubing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.