Drillstring radar
US6778127B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Nov 4, 2002 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Nov 4, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/885
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A drillstring radar comprises a measurements-while-drilling instrument for mounting just behind the drill bit and downhole motor of a drill rod. The instrument includes a radar system connected to upward-looking and downward-looking horn antennas. These are used to electronically probe the interface of a coal seam with its upper and lower boundary layers. A dielectric constant sensor is included to provide corrective data for the up and down distance measurements. Such measurements and data are radio communicated to the surface for tomographic processing and user display. The instrument also includes a navigation processor and drill bit steering controls. The radio communication uses the drillstring as a transmission line and F1/F2 repeaters can be placed along very long runs to maintain good instrument-to-surface communication. A docking mechanism associated with the instrument and its antenna array allows the instrument to be retrieved back inside the drillstring with a tether should the drill head become hopelessly jammed or locked into the earth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.