Electrical imager operating in oil-based mud and low resistive formation
US8862406B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2012 |
| Grant date | Oct 14, 2014 |
| Priority date | — |
| Expiry date | Apr 19, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This disclosure relates to apparatuses and methods for reducing current leakage between a measure electrode and a logging tool body during borehole investigations in an earth formation involving electric current and non-conductive drilling fluid. The apparatus may include one or more transmitters disposed on a pad body, configured to inject an electric current into the earth formation, and coupled to the mandrel and one or more measure electrodes. The measure electrodes may be configured to receive current from the formation and coupled to a back plate of the pad body. The apparatus may be configured to maintain a selected ratio between pad body to logging tool body impedance and transmitters to logging tool body impedance sufficient to reduce current leakage between the earth formation and the logging tool body. The transmitter/mandrel and measure electrode/back plate may be electrically isolated from one another. The method may include using the apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.