Apparatus with capacitive electrodes for measuring subsurface electrical characteristics in the subsoil
US6731114B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2001 |
| Grant date | May 4, 2004 |
| Priority date | — |
| Expiry date | Jan 31, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to apparatus with capacitive electrodes for electrical prospecting in a borehole, the apparatus comprising at least two injection electrodes (16, 18), at least two measurement electrodes (28, 34), and a current generator (22) for applying an electrical current between the two injection electrodes. The current generator (22) delivers alternating current at a frequency of 5 kHz to 100 kHz and at a voltage of less than 1000 volts. At least one of the measurement or injection electrodes (16, 28) is placed in a borehole (12, 14) and presents an outer surface that is cylindrical and electrically conductive. The apparatus further comprises means (24) for measuring the current flowing through said injection electrodes, means (36, 36b) for measuring the potential difference between the measurement electrodes, and means for processing the measured current and potential difference to deduce therefrom the characteristics of the subsoil in which the borehole is situated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.