Logging while drilling apparatus with blade mounted electrode for determining resistivity of surrounding formation
US5339036A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 1993 |
| Grant date | Aug 16, 1994 |
| Priority date | — |
| Expiry date | May 21, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Measurement-while-drilling apparatus is disclosed for determining the resistivity of formations surrounding an earth borehole. An electrically conductive metal body, such as a drill collar on a drill string, is movable through the borehole. A transmitting toroidal coil antenna is disposed on the body and is energized to induce a current which travels in a path that includes the body and the formations. An electrode is disposed on the body, and an electrical signal resulting from said current is measured at the electrode to obtain an indication of the resistivity of the formations. In a disclosed embodiment, one or more electrodes can be mounted on a blade that is mechanically coupled to the body.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.