Downhole magnetic position sensor
US5666050A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1995 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Nov 20, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/145
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A well apparatus for detecting the position of a moving element in a well. Downhole well tools normally comprise a magnetically permeable material which forms a Faraday Shield to interrupt the flux of a magnet positioned within the well tool. The invention attaches a magnet to a moving element surrounded by a magnetically permeable second element, and a magnetic sensor is positioned within a recess in the second element. The magnetic sensor detects the proximate position of the magnet and generates a signal. The signal can be transmitted to a surface controller for display or for generating a command signal to displace the moving element within the second element. A single wire can transmit signals from multiple sensors in a sensor array, and the absolute position and movement rate of the moving element can be identified by the sensor array. The magnet can comprise a permanent magnet or can comprise an electromagnet. The signal from the magnetic source can be modulated to communicate the signal through the second element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.