Method and apparatus for directional well logging
US9360580B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 2009 |
| Grant date | Jun 7, 2016 |
| Priority date | — |
| Expiry date | Mar 20, 2033 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B49/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus are provided for making directional measurements toward a formation of different resistivity that is proximate to the borehole, but which is not penetrated by the borehole. The methods and apparatus include the use of at least one insulated gap and at least one magnetometer positioned within a non-magnetic housing that is disposed within a non-magnetic tubular. An electric current is applied across the insulated gap, which results in current leaking into the surrounding formations. When a formation of contrasting resistivity is proximate to the logging apparatus, the magnetometer detects a secondary magnetic field due to the contrasting formation. The direction of the secondary magnetic field can be used to determine the direction to the contrasting formation. The magnitude of the secondary magnetic field can be used to determine the distance position to the contrasting formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.