Downhole methods and assemblies employing an at-bit antenna
US8581592B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2008 |
| Grant date | Nov 12, 2013 |
| Priority date | — |
| Expiry date | Dec 16, 2028 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/013
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Logging tools and methods employing an at-bit loop antenna to acquire azimuthal resistivity measurements proximate to the bit enable low-latency geosteering signals to be generated. In some embodiments, the at-bit antenna is part of a bottom hole assembly that includes a drill bit, a mud motor, and a resistivity tool. The mud motor is positioned between the at-bit antenna and the resistivity tool. The resistivity tool includes at least one loop antenna that is not parallel to the at-bit loop antenna. The at-bit antenna is part of an at-bit module that, in some embodiments, transmits periodic electromagnetic signal pulses for the resistivity tool to measure. In other embodiments, the at-bit module measures characteristics of electromagnetic signal pulses sent by the resistivity tool and communicates the measured characteristics to the resistivity tool via a short hop telemetry link.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.