Method and apparatus for determining resistivity of a formation
US10502859B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 2015 |
| Grant date | Dec 10, 2019 |
| Priority date | — |
| Expiry date | Jun 23, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and methods operable to determine a resistivity of a subterranean formation surrounding a wellbore. One such method includes using an apparent impedance function depending on a frequency variable and a plurality of unknown parameters, at least one of the unknown parameters depending on a formation impedance of the subterranean formation. The method also includes applying a voltage, at each of a plurality of frequency values, between electrodes of a resistivity tool that is disposed in the wellbore. The method also includes measuring, across the electrodes, a plurality of apparent impedance values, each corresponding to a different one of the frequency values. The method still further includes determining the unknown parameters based on the frequency values and the apparent impedance values, and estimating the formation resistivity based on an expression that includes at least one of the unknown parameters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.