Method and apparatus for optical sensing

    公开(公告)号:US11022467B2

    公开(公告)日:2021-06-01

    申请号:US16474747

    申请日:2018-01-05

    Abstract: An improved optical fiber distributed acoustic sensor system uses an optical fiber having reflector portions distributed along its length in at least a first portion. The reflector portions are positioned along the fiber separated by a distance that is equivalent to twice the distance an optical pulse travels along the fiber in a single sampling period of the data acquisition opto-electronics within the sensor system. No oversampling of the reflections of the optical pulses from the reflector portions is undertaken. The sampling points for data acquisition in the sensor system are aligned with the reflections that arrive at the sensor system from along the sensing fiber. Adaptive delay componentry adaptively aligns the reflected optical signals (or their electrical analogues) with the sampling points. Control over the sampling points can re-synchronise the sampling points with the returning reflections. Reflection equalisation componentry may reduce the dynamic range of the returning reflections.

    Non-isotropic acoustic cable
    3.
    发明授权

    公开(公告)号:US10345139B2

    公开(公告)日:2019-07-09

    申请号:US15804657

    申请日:2017-11-06

    Applicant: Silixa Ltd.

    Abstract: Embodiments of the present invention address aliasing problems by providing a plurality of discrete acoustic sensors along a cable whereby acoustic signals may be measured in situations where the fiber optic cable has not been secured to a structure or area by a series of clamps. Acoustic sampling points are achieved by selectively enhancing the acoustic coupling between the outer layer and the at least one optical fiber arrangement, such that acoustic energy may be transmitted selectively from the outer layer to the at least one optical fiber arrangement. The resulting regions of acoustic coupling along the cable allow the optical fiber to detect acoustic signals. Regions between the outer layer and the at least one optical fiber arrangement that contain material which is acoustically insulating further this enhancement since acoustic waves are unable to travel through such mediums, or at least travel through such mediums at a reduced rate.

    Optical sensor and method of use
    4.
    发明授权
    Optical sensor and method of use 有权
    光学传感器及使用方法

    公开(公告)号:US09541426B2

    公开(公告)日:2017-01-10

    申请号:US14662940

    申请日:2015-03-19

    Applicant: Silixa Ltd.

    Abstract: An interferometer apparatus for an optical fiber system and method of use is described. The interferometer comprises an optical coupler and optical fibers which define first and second optical paths. Light propagating in the first and second optical paths is reflected back to the optical coupler to generate an interference signal. First, second and third interference signal components are directed towards respective first, second and third photodetectors. The third photodetector is connected to the coupler via a non-reciprocal optical device and is configured to measure the intensity of the third interference signal component directed back towards the input fiber. Methods of use in applications to monitoring acoustic perturbations and a calibration method are described.

    Abstract translation: 描述了一种用于光纤系统的干涉仪装置及其使用方法。 干涉仪包括光耦合器和限定第一和第二光路的光纤。 在第一和第二光路中传播的光被反射回到光耦合器以产生干涉信号。 首先,第二和第三干扰信号分量指向相应的第一,第二和第三光电探测器。 第三光电检测器通过不可逆的光学装置连接到耦合器,并且被配置成测量指向输入光纤的第三干涉信号分量的强度。 描述了用于监测声学扰动的应用的方法和校准方法。

    NON-ISOTROPIC ACOUSTIC CABLE
    5.
    发明申请
    NON-ISOTROPIC ACOUSTIC CABLE 有权
    非等级声学电缆

    公开(公告)号:US20160223389A1

    公开(公告)日:2016-08-04

    申请号:US15021319

    申请日:2014-09-04

    Applicant: SILIXA LTD.

    CPC classification number: G01H9/004 G01L1/242 G01M7/00 G02B6/4405 G02B6/4415

    Abstract: Embodiments of the present invention address aliasing problems by providing a plurality of discrete acoustic sensors along a cable whereby acoustic signals may be measured in situations where the fibre optic cable has not been secured to a structure or area by a series of clamps, as described in the prior art. Acoustic sampling points are achieved by selectively enhancing the acoustic coupling between the outer layer and the at least one optical fibre arrangement, such that acoustic energy may be transmitted selectively from the outer layer to the at least one optical fibre arrangement. The resulting regions of acoustic coupling along the cable allow the optical fibre to detect acoustic signals. Regions between the outer layer and the at least one optical fibre arrangement that contain material which is acoustically insulating further this enhancement since acoustic waves are unable to travel through such mediums, or at least travel through such mediums at a reduced rate.

    Abstract translation: 本发明的实施例通过沿着电缆提供多个离散的声学传感器来解决混叠问题,从而可以在光纤电缆未通过一系列夹具固定到结构或区域的情况下测量声信号,如 现有技术 通过选择性地增强外层和至少一个光纤布置之间的声耦合来实现声学采样点,使得声能可以从外层选择性地传输到至少一个光纤装置。 所产生的沿着电缆的声耦合区域允许光纤检测声信号。 外层和至少一个光纤布置之间的区域包含进一步声学绝缘的材料,因为声波不能穿过这种介质,或至少以降低的速率行进通过这种介质。

    Method and Apparatus for Optical Sensing
    6.
    发明公开

    公开(公告)号:US20240011823A1

    公开(公告)日:2024-01-11

    申请号:US18370963

    申请日:2023-09-21

    Applicant: Silixa Ltd.

    Abstract: The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

    LONG RANGE OPTICAL FIBER SENSING SYSTEMS
    7.
    发明公开

    公开(公告)号:US20230221151A1

    公开(公告)日:2023-07-13

    申请号:US17904599

    申请日:2021-02-19

    Applicant: Silixa Ltd.

    CPC classification number: G01D5/35364

    Abstract: A long range optical fiber sensor such as a distributed acoustic sensor has a sensing fiber located remotely from the interrogator, with a length of transport fiber path connecting the two. Because no sensing is performed on the transport fiber then the pulse repetition rate from the interrogator can be high enough such that the pulse repetition rate and pulse power are optimised according to the sensing fiber length and hence sensing frequency response and sensitivity are also optimised according to the sensing fiber length.

    Method and Apparatus for Optical Sensing
    8.
    发明申请

    公开(公告)号:US20190331523A1

    公开(公告)日:2019-10-31

    申请号:US16508522

    申请日:2019-07-11

    Applicant: Silixa Ltd.

    Abstract: The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

    Non-Isotropic Acoustic Cable
    9.
    发明申请

    公开(公告)号:US20180058916A1

    公开(公告)日:2018-03-01

    申请号:US15804657

    申请日:2017-11-06

    Applicant: Silixa Ltd.

    CPC classification number: G01H9/004 G01L1/242 G01M7/00 G02B6/4405 G02B6/4415

    Abstract: Embodiments of the present invention address aliasing problems by providing a plurality of discrete acoustic sensors along a cable whereby acoustic signals may be measured in situations where the fibre optic cable has not been secured to a structure or area by a series of clamps. Acoustic sampling points are achieved by selectively enhancing the acoustic coupling between the outer layer and the at least one optical fibre arrangement, such that acoustic energy may be transmitted selectively from the outer layer to the at least one optical fibre arrangement. The resulting regions of acoustic coupling along the cable allow the optical fibre to detect acoustic signals. Regions between the outer layer and the at least one optical fibre arrangement that contain material which is acoustically insulating further this enhancement since acoustic waves are unable to travel through such mediums, or at least travel through such mediums at a reduced rate.

    Non-isotropic acoustic cable
    10.
    发明授权

    公开(公告)号:US09823114B2

    公开(公告)日:2017-11-21

    申请号:US15021319

    申请日:2014-09-04

    Applicant: Silixa Ltd.

    CPC classification number: G01H9/004 G01L1/242 G01M7/00 G02B6/4405 G02B6/4415

    Abstract: Embodiments of the present invention address aliasing problems by providing a plurality of discrete acoustic sensors along a cable whereby acoustic signals may be measured in situations where the fiber optic cable has not been secured to a structure or area by a series of clamps, as described in the prior art. Acoustic sampling points are achieved by selectively enhancing the acoustic coupling between the outer layer and the at least one optical fiber arrangement, such that acoustic energy may be transmitted selectively from the outer layer to the at least one optical fiber arrangement. The resulting regions of acoustic coupling along the cable allow the optical fiber to detect acoustic signals. Regions between the outer layer and the at least one optical fiber arrangement that contain material which is acoustically insulating further this enhancement since acoustic waves are unable to travel through such mediums, or at least travel through such mediums at a reduced rate.

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