Invention Grant
- Patent Title: DRA DAS system
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Application No.: US16303370Application Date: 2016-07-22
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Publication No.: US11366243B2Publication Date: 2022-06-21
- Inventor: Mikko Jaaskelainen , Jason Edward Therrien , Seldon David Benjamin
- Applicant: Halliburton Energy Services, Inc.
- Applicant Address: US TX Houston
- Assignee: Halliburton Energy Services, Inc.
- Current Assignee: Halliburton Energy Services, Inc.
- Current Assignee Address: US TX Houston
- Agency: DeLizio, Peacock, Lewin & Guerra
- International Application: PCT/US2016/043478 WO 20160722
- International Announcement: WO2018/017111 WO 20180125
- Main IPC: G01V1/20
- IPC: G01V1/20 ; E21B47/135 ; G01V1/52

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.
Public/Granted literature
- US20200319358A1 DRA DAS SYSTEM Public/Granted day:2020-10-08
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