Method for formation evaluation while drilling
US6051973A · kind A · utility
46Cited by
32References
26Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 23, 1997 |
| Grant date | Apr 18, 2000 |
| Priority date | — |
| Expiry date | Dec 23, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N24/081
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A logging while drilling (LWD) and measuring while drilling (MWD) method and device are disclosed for reducing the sensitivity of NMR measurements to tool motions. The invention is based on NMR relaxation measurements determining longitudinal relaxation times T1 instead of the standard T2 measurements, and involves saturating a relatively wide sensitive region of the formation and processing NMR echo signals which originate approximately from the center of the sensitive region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.