Method and apparatus for measuring defects in ferromagnetic tubing
US4492115A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1984 |
| Grant date | Jan 8, 1985 |
| Priority date | — |
| Expiry date | Apr 11, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/82
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for determining the extent of defects in ferromagnetic tubular elements comprising a continuous string for use in an oil or gas well is disclosed. The tubing trip tool measures tubing average wall thickness, local defects, such as corrosion pitting, and axial defects, such as sucker rod wear during removal of the tubing from the well. Tubing velocity is also measured, and couplings between tubing sections are detected and counted, in order to specify the axial location of defects on each tube, and also provide a profile of the condition of the overall string. 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.