Determining the larmor frequency for NMR tools
US8686723B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2010 |
| Grant date | Apr 1, 2014 |
| Priority date | — |
| Expiry date | Jul 15, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/4625
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The Larmor frequency for an in situ nuclear magnetic resonance (NMR) tool is determined and used to acquire NMR data. An NMR tool is provided and placed in situ, for example, in a wellbore. An initial estimate of the Larmor frequency for the in situ NMR tool is made and NMR data are acquired using the in situ NMR tool. A spectral analysis is performed on the NMR data, or optionally, the NMR data are digitized and a discrete Fourier transform (DFT) is performed on the digitized NMR data. The modal frequency of the spectral analysis or DFT is determined, and the Larmor frequency for the in situ NMR tool is determined using the modal frequency. The NMR tool is modified to transmit at the determined Larmor frequency and then used to acquire further NMR data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.