Electromagnetic borehole surveying method
US6466020B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2001 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Mar 19, 2021 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/024
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus and method for surveying the path of a borehole includes two single-axis field sensors located at a radius centered at a fixed location. Guide wires are located along the earth's surface above the prescribed borehole path and the known electromagnetic field produced by current in the guide wires are detected by the sensors. Values of X and Y vectors at multiple locations on a spherical surface at the radial distance of the sensors are calculated and compared with measured values to define the location of the sensors on the spherical surface to permit the lateral spacing between the sensors and the desired borehole path to be determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.