Method and apparatus for optimizing the reception pattern of the antenna of a propagating electromagnetic wave logging tool
US4940943A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1988 |
| Grant date | Jul 10, 1990 |
| Priority date | — |
| Expiry date | Apr 19, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A conventional electromagnetic logging device, having both MWD and wire line embodiments, and having a pair of cutouts spaced along the length of the tool mandrel, each cutout having a length of greater than 4.0 inches as measured along the longitudinal axis of the tool, is modified by adding a pair of full metal jackets around the pair of cutouts. The first metal jacket placed around the first cutout in the mandrel has an additional cutout therein having a length in the range of 1.0 to 4.0 inches and a depth in the range of 0.25 to 1.0 inch. A transmitting antenna is placed in the cutout in the first metal jacket. The second metal jacket placed around the second cutout of the tool mandrel has a pair of spaced cutouts therein, each having a length in the range of 1.0 to 4.0 inches and a depth in the range of 0.25 to 1.0 inch. First and second electromagnetic receiving antennas are placed in the first and second cutouts in the second metal jacket, respectively. In alternative embodiments, the walls of the cutouts in the full metal jackets are either parallel, diverging, converging or stair stepped. In further embodiments, the cutouts having lengths of 1.0 to 4.0 inches and depths of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.