DRA DAS system
US11366243B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 2016 |
| Grant date | Jun 21, 2022 |
| Priority date | — |
| Expiry date | Apr 14, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V2210/1429
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is a system and method for improving the performance of downhole Distributed Acoustic Sensing (DAS) systems by simultaneous use of co-propagating and counter-propagating Distributed Raman Amplification (DRA). It uses a surface DRA system with a surface DAS system to combine their laser sources where the distal end of the downhole sensing fiber use uses a Wavelength Division Multiplexer (WDM) to optically split the DRA and DAS signals onto two optical fibers. The DAS fiber/signal is terminated with a low reflectance termination to minimize a potential back reflection whereas the DRA fiber is terminated with a high reflectance termination causing all the light to reflect back up the sensing fiber. This arrangement allows for simultaneous co and counter-propagating DRA of the DAS signals, both the transmitted pulse and the back scattered light, thus creating the maximum amount of gain possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.