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

    IPC分类号: G02B6/36 G01D5/353 G01H9/00

    摘要: 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
    5.
    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

    申请人: Silixa Ltd.

    摘要: 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.

    ACOUSTIC ILLUMINATION FOR FLOW-MONITORING
    6.
    发明申请

    公开(公告)号:US20180149017A1

    公开(公告)日:2018-05-31

    申请号:US15877588

    申请日:2018-01-23

    申请人: Silixa Ltd.

    摘要: Externally generated noise can be coupled into a fluid carrying structure such as a pipe, well, or borehole so as to artificially acoustically “illuminate” the pipe, well, or borehole, and allow fluid flow in the structure or structural integrity to be determined. In the disclosed system, externally generated noise is coupled into the structure being monitored at the same time as data logging required to undertake the monitoring is performed. This has three effects. First, the externally generated sound is coupled into the structure so as to “illuminate” acoustically the structure to allow data to be collected from which fluid flow may be determined, and secondly the amount of data that need be collected is reduced, as there is no need to log data when the structure is not being illuminated. Thirdly, there are signal processing advantages in having the data logging being undertaken only when the acoustic illumination occurs.

    Method and System for Determining Downhole Optical Fiber Orientation and/or Location

    公开(公告)号:US20180052252A1

    公开(公告)日:2018-02-22

    申请号:US15784586

    申请日:2017-10-16

    申请人: SILIXA LTD.

    IPC分类号: G01V11/00 G01N21/68 G01N21/64

    摘要: A probe is provided that contacts the inner surface of the casing or other production tubing and imparts energy to the surface at the contact point, for example as heat energy or mechanical energy. Energy is imparted around the circumference of the casing, and a fiber optic distributed sensor located on the outer surface of the casing is used to measure and record the energy that it receives whilst the probe is moved to impart energy around the circumference. A record of energy versus position of the probe around the circumference can be obtained, from which maxima in the detected energy measurements can then be found. The position around the circumference which gave the maximum measurement should be the position at which the optical fiber of the fiber optic distributed sensor is located. In addition, an ultrasonic arrangement is also described, that relies on ultrasonic sound to provide detection.

    Submersible Pump Monitoring
    9.
    发明申请
    Submersible Pump Monitoring 审中-公开
    潜水泵监控

    公开(公告)号:US20170016312A1

    公开(公告)日:2017-01-19

    申请号:US15122038

    申请日:2015-03-02

    申请人: Silixa Ltd.

    摘要: In order to address the above noted problems, embodiments of the present invention use distributed acoustic sensing to monitor the fluid level in an ESP activated well so as to monitor the condition and performance of the ESP. Embodiments of the invention use the ESP as an acoustic source in order to monitor the annulus fluid level within the well and to monitor the frequency of the ESP. Additionally, embodiments of the present invention may use distributed acoustic sensing to monitor the flow rates of the production fluid above and below the ESP to determine the pump's efficiency. In particular, some embodiments utilise one or more optical fibers to measure the acoustic waves generated by the ESP, wherein the fiber cabling has already been deployed along the length of the well. As such, the present invention is a non-invasive, in-situ method for monitoring the condition and performance of an ESP.

    摘要翻译: 为了解决上述问题,本发明的实施例使用分布式声学感测来监测ESP激活的井中的液位,以便监测ESP的状况和性能。 本发明的实施例使用ESP作为声源,以便监测井内的环状液体水平并监测ESP的频率。 此外,本发明的实施例可以使用分布式声学感测来监测ESP上方和下方的生产流体的流量,以确定泵的效率。 特别地,一些实施例利用一根或多根光纤来测量由ESP产生的声波,其中光纤布线已沿着该孔的长度展开。 因此,本发明是用于监测ESP的状况和性能的非侵入式原位方法。

    Optical sensor and method of use
    10.
    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

    申请人: Silixa Ltd.

    IPC分类号: G01D5/353 G01M11/00 G01F1/66

    摘要: 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.

    摘要翻译: 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。