Determining electrical conductivity of a laminated earth formation using induction logging
US6147496A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1997 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Jul 1, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method is provided for determining an electric conductivity of an earth formation formed of different earth layers, which earth formation is penetrated by a wellbore containing a wellbore fluid, is provided. The method includes the steps of: lowering an induction logging tool into the wellbore to a location surrounded by a selected one of the earth layers, the tool having a magnetic field transmitter effective to induce magnetic fields of different frequencies in the earth formation, and a magnetic field receiver effective to receive response magnetic fields and to provide a signal representative of each response magnetic field, at least one of the transmitter and the receiver having a plurality of magnetic dipole moments in mutually orthogonal directions. At least two of the different frequencies are selected, and for each selected frequency, the transmitter is operated so as to induce a magnetic field in the earth formation and the receiver is operated so as to provide a signal representing a response magnetic field, wherein the at least one of the transmitter and receiver is operated in the mutually orthogonal directions. The signals are combined in a manner so as to create a …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.