NMR magnet system for well logging
US4717876A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1986 |
| Grant date | Jan 5, 1988 |
| Priority date | — |
| Expiry date | Aug 13, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic structure for producing a substantially uniform magnetic field in a region external to the structure. The field produced has a predetermined magnitude but with all of its first and second order partial derivatives with respect to spatial coordinates being equal to zero at any selected point within the uniform region. The structure includes a pair of elongated magnets which are magnetized along their longitudinal axis. The magnets are spaced from each other with their corresponding end poles facing each other. A pair of annular cylindrical magnets which are magnetized in a radial direction are mounted on the end faces of each of the elongated magnets. Another annular cylindrical magnet, also having its magnetization oriented in a radial direction is located on the midplane between the two elongated magnets. The combined effect of these magnets is to create a uniform toroidal field. This field is particularly suitable for use in NMR oil well logging applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.