Method and apparatus for determining distance for magnetic and electric field measurements
US5218301A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 4, 1991 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Oct 4, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/24
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus for determining the distance from a relief borehole to a target well utilizes measurements of an electric field at the target well. The electric field is produced by injecting current into the earth near the wellhead of the target well, this current producing a target current in conductive material in the target well. The electric field corresponding to the target current is measured by means of sensors in the relief borehole, and this field measurement, together with a measurement of the alternating magnetic field at the relief well due to the target current, permits determination of the distance to the target well from the relief borehole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.