Enhanced wide aperture groove for antenna of downhole resistivity tool
US5157331A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 4, 1991 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | Oct 4, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/017
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In an electromagnetic propagating antenna circumferential groove disposed in an MWD resistivity tool mandrel and normally sealed with an epoxy resin non-conducting material forming an annular ring disposed in each of the plurality of circumferential grooves through which the electromagnetic energy from the antenna coil will propagate from the mandrel, each of the circumferential grooves comprises a pair of sidewalls interconnected by an annular flat base portion, each of the sidewalls further having disposed therein a plurality of circumferentially-spaced and longitudinally-disposed slots of uniform size having an open end communicating with each of the sidewalls and a closed end terminating longitudinally spaced from each of the sidewalls for forming a "zipper slot" configuration to the plurality of circumferential grooves, wherein the surface area of all of the plurality of zipper slots is preselected for cooperating with the surface area of each of the circumferential grooves for increasing the surface area of the grooves for permitting greater electromagnetic wave propagation from each of the antenna coils. In addition, the zipper slot configuration of the plurality of circumfe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.