Patent · US Expired

Non-invasive detectors for wells

US6762601B2 · kind B2 · utility

1Cited by

8References

5Claims

0Family size

Assignee

Antech Limited · GB

Inventors

Antoni Miszewski · Missouri City, US
Simon Benedict Duckett · York, GB

Key dates

Filing date	Dec 17, 2002
Grant date	Jul 13, 2004
Priority date	—
Expiry date	Jan 7, 2023

Classification

Technology area (CPC G)Physics
CPC primaryG01V3/081
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

Detector circuitry for detecting magnetic field disturbances resulting from the movement of equipment through a pipe of magnetic material, the detector circuitry comprising a difference circuit fed with the outputs of two longitudinally spaced sensor means via respective DC blocking means, a saturating difference amplifier feeding an integrator and fed with the outputs of the difference circuit and the integrator, and indicating means fed from the integrator. The detector circuitry may also including level setting means and a comparator fed with the outputs of the integrator and the level setting means and feeding the indicating means. A second comparator may be connected in parallel with the first comparator and fed with the inverse of the output of the level setting means and the output of the integrator.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.