Method and system for determining formation anisotropic resistivity with reduced borehole effects from tilted or transverse magnetic dipoles
US6556015B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 2001 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Oct 11, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Systems and methods are provided for determining subsurface formation properties using an antenna system disposed within a borehole traversing the formation. A logging system includes a well tool implemented with an antenna system having transverse or tilted magnetic dipoles. One antenna implementation uses a set of three coils having non-parallel axes. Through mechanical or electromagnetic rotation of an antenna about its axis in order to maximize or minimize couplings, the systems and methods are used to estimate formation anisotropic resistivity, providing reduced borehole effects in vertical and small deviation wells. This invention may also be applied in deviated wells when the borehole is perpendicular to the strike direction, as is often the case in wireline logging.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.