Gradient-based single well ranging system for SAGD application
US10429534B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 2013 |
| Grant date | Oct 1, 2019 |
| Priority date | — |
| Expiry date | Oct 4, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/082
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A tool, method and system for ranging between two wellbores. The target wellbore includes a conductive member disposed within a portion of the target wellbore. An investigative wellbore includes an electromagnetic gradiometer positioned within the wellbore, as well as emitter electrode and return electrode spaced apart along an investigative wellbore, preferably in the process of being drilled. The position of the emitter electrode and the return electrode are selected to optimize current transmission to the target wellbore in order to enhance the electromagnetic field emanating from the conductive member at a desired point along the conductive member. Where the electrodes and gradiometer are carried by a drill string, gap subs are positioned along the drill string to minimize conduction of current along the drill string therebetween. In some embodiments, the gradiometer is positioned between the emitter and return electrodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.