METHOD OF DETERMINING VERTICAL AND HORIZONTAL RESISTIVITY, AND RELATIVE DIP IN ANISOTROPIC EARTH FORMATIONS HAVING AN ARBITRARY ELECTRO-MAGNETIC ANTENNA COMBINATION AND ORIENTATION WITH ADDITIONAL ROTATION AND POSITION MEASUREMENTS
US6819111B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2002 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Nov 22, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention is a method of determining horizontal and vertical resistivity in an anisotropic formation using a combination of orientable triaxial and array antennae conveyed downhole. Measurements are taken at various azimuthal angles about a measuring device at a given depth. Values at each azimuthal orientation can be fit to a curve to yield information on the surrounding formation. Multiple measurements at a given depth and azimuthal orientation can be weighted to obtain an average value. Values from the curve fitting process are used in subsequent inversion processing and reduce the uncertainty of the inversion processing result. Utilization of a three dimensional geometry enables a unique resolution of the orientation of the principle axis of anisotropy, and consequently of horizontal and vertical resistivity, and dip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.