Electromagnetic induction method and apparatus for the measurement of the electrical resistivity of geologic formations surrounding boreholes cased with a conductive liner
US6294917A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 13, 1999 |
| Grant date | Sep 25, 2001 |
| Priority date | — |
| Expiry date | Sep 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Provided is a technique, including a method and a computer program product, to dynamically measure characteristics of geologic formations while hydrocarbons are being extracted therefrom. Specifically, the present invention allows measuring the resistivity of geologic formations in which a borehole has been formed therein and encased with a conductive casing, such as a conductive liner. This has been achieved by providing a method and computer program product that compensates for the effects of a conductive liner by measuring the characteristics of the geologic formation as a function of a ratio of two magnetic fields sensed by a receiver disposed in one of the boreholes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.