Apparatus and method for determining properties of anisotropic earth formations
US5886526A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Jun 16, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method is disclosed for determining the horizontal resistivity, vertical resistivity, and dip of formations surrounding a borehole, comprising the following steps: (a) suspending a logging device in the borehole; (b) transmitting electromagnetic energy from a transmitter location on the logging device, and receiving the transmitted electromagnetic energy at receiver locations on the logging device for a first transmitter-to-receivers spacing associated with the transmitter and receiver locations; (c) determining, from the received electromagnetic energy, measurement characteristics associated with the first transmitter-to-receivers spacing; (d) repeating steps (b) and (c) for a plurality of further transmitter-to-receivers spacings to obtain measurement characteristics for the plurality of further transmitter-to-receivers spacings; (e) generating a model of anisotropic formations that has horizontal resistivity Rh, vertical resistivity Rv, and a Dip angle with respect to a borehole reference; (f) selecting initial model values of Rh, Rv and Dip; (g) computing an error value from the differences, for each of a plurality of the transmitter-to-receivers spacings, between the measure…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.