Electromagnetic logging between borehole and surface
US8638103B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2009 |
| Grant date | Jan 28, 2014 |
| Priority date | — |
| Expiry date | Apr 7, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present disclosure relates to determining a property, such as resistivity, of an earth formation. A transmitter is disposed in a wellbore penetrating the formation, and a plurality of receivers are distributed on or near the earth's surface. The transmitter sends electromagnetic energy into the formation and the resulting signal, after passing through the formation, is detected by the array of receivers. The received signal is used to determine the property of the formation. This is often achieved using an inversion or numerical model of the formation being measured. The inversion takes into account changes in the background formation model due to transmitting from various locations. The measurements made on the formation can be performed while drilling the wellbore or subsequent to the drilling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.