Method and apparatus for measuring transient electromagnetic and electrical energy components propagated in an earth formation
US5955884A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1997 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Jun 26, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A single well transient electromagnetic ("TEM") apparatus and method is disclosed. The invention includes a wireline logging tool adapted for disposition in a borehole drilled in earth formations that has mounted thereon an electromagnetic transmitter and electric field transmitter for applying electromagnetic energy to the formation that will maximize the radial depth of penetration of the energy into the formation. The logging tool further includes an electromagnetic receiver and electric field receiver for detecting the electric field and magnetic field components created in the formation by the TEM transmitter. The electromagnetic transmitter and receiver preferably comprise three-axis electromagnetic coils, and the electric field transmitter and receiver preferably comprise three-axis electric dipole antenna elements. The tool may employ an array of the TEM transmitters and TEM receivers spaced axially along the tool in the borehole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.