Method of evaluating a geological formation using a logging tool including slot antenna having two nonparallel elements
US5406206A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1993 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | Jul 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A slot antenna has a square aperture and two current probes at angles to each other in the aperture. The two current probes are excited simultaneously or separately with different signals. By adjusting the amplitude or phase of the signals in the current probes, the angle of the magnetic moment of the antenna can be adjusted. An array of such antennas in an electromagnetic propagation tool for a well-logging device simultaneously provides better standoff performance by adjusting tile magnetic moment to be parallel to a borehole axis, and better image response by adjusting the magnetic moment to be perpendicular to the formation bed. The array can be excited to function as an endfire and broadside array of an electromagnetic propagation tool.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.