Nuclear magnetic resonance sensing apparatus and techniques for downhole measurements
US6111408A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1997 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Dec 23, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N24/081
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus are disclosed for using nuclear magnetic resonance (NMR) techniques to obtain information relating to fluids present near geologic structures. A modular NMR tester which can be located within a standard modular logging tool is used for direct downhole NMR measurements of various parameters of fluid samples of geologic formations near the walls of a borehole. The tester has a vessel made of a non-conductive material and a surrounding permanent magnet that creates a uniform static magnetic field within the test chamber of the vessel. An RF coil is embedded in the walls of the vessel and is used to induce excitation field with a direction perpendicular to the static magnetic field. Fluids located proximate the borehole are introduced into a test chamber of the tester. NMR signals from the excited nuclei in the fluids are detected to obtain data for calculating a number of important fluid parameters and for the interpretation of wireline MRIL measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.