Level sensor
US4747451A · kind A · utility
66Cited by
9References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1987 |
| Grant date | May 31, 1988 |
| Priority date | — |
| Expiry date | Aug 6, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/047
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system for controlling production in an oil well comprises a first level sensor mounted upon the outer surface of the tubing near the lower end of the tubing and a second level sensor mounted upon the outer surface of the tubing above the first level sensor. The first level sensor is tuned to a first electrical signal frequency. The second level sensor is tuned to a second electrical signal frequency. A control device at spaced intervals transmits electrical signals of the first and second frequencies down the oil well and senses the liquid level by detecting impedance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.