LWD resistivity device with inner transmitters and outer receivers, and azimuthal sensitivity
US6377050B1 · kind B1 · utility
20Cited by
8References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1999 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Sep 14, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A borehole tool for logging resistivity of geologic formations, having at least two inner transmitters surrounded by at least two outer receivers. Each transmitter is sequentially excited, and measurements are taken at each of the receivers. The phase differences between these received signals are determined, once for each transmitter, and the two values are averaged to estimate the resistivity value of the surrounding formations. More than two receivers can be used. An azimuthal receiver array is also used to identify boundary transitions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.