Electromagnetic subsoil prospecting process using an asymptotic low frequency range
US4258322A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1978 |
| Grant date | Mar 24, 1981 |
| Priority date | — |
| Expiry date | May 8, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/108
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a sub-soil prospecting process a vertical magnetic field transmitter dipole and a receiver dipole are placed on the ground, away from each other. The receiver dipole is oriented to detect a radial horizontal magnetic field relative to the transmitter dipole. At low frequencies, the magnetic field detected assumes asymptotic values, and by measuring these values an apparent alternating current resistivity of the sub-soil is deduced. By varying the transmitter-receiver distance, and by simultaneously using a direct current electric prospecting process, a sub-soil model is determined which is less ambiguous than those supplied by electric or induction prospecting alone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.