Fiberoptic tuned-induction sensors for downhole use
US9651706B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 2015 |
| Grant date | May 16, 2017 |
| Priority date | — |
| Expiry date | Jul 7, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of sensing electromagnetic (EM) fields downhole may include filtering a voltage signal induced in a coil antenna by an EM field to produce a filtered signal, said filtering being performed by a resonance tuning filter, and applying the filtered signal to a piezoelectric element to modify a strain of an optical fiber. A sensing system may include a cable deployed downhole and coupled to an interface unit. The cable has an optical fiber coupled to an array of downhole sensors, each sensor having a coil antenna coupled by a resonance tuning filter to a piezoelectric element that modifies a strain in the optical fiber in accordance with a signal induced in the coil antenna by an electromagnetic field. The interface unit measures a backscattered light to monitor the signal from each sensor in the array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.