Subsurface formation parameters from tri-axial measurements
US6584408B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 2001 |
| Grant date | Jun 24, 2003 |
| Priority date | — |
| Expiry date | Jun 28, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Systems and methods are provided for determining various subsurface formation parameters from electromagnetic measurements. Formulas are disclosed for field components in a coordinate system tied to the logging tool. Closed form expressions for a magnetic field distribution in a homogeneous anisotropic medium are derived from Moran-Gianzero formulas. A complete coupling of a tri-axial system of transmitters and receivers is derived in the tool coordinate system, allowing direct inversion of the measurements for horizontal and vertical conductivity and dip and strike (dip-azimuth) angles. Closed form expressions for these four quantities in the low frequency limit are also derived.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.