Study on Oil and Gas Pipeline Leakage Real-Time Inspection System Based on Distributed Optical Fiber

2008 ◽  
Vol 381-382 ◽  
pp. 447-450 ◽  
Author(s):  
Y. Zhou ◽  
Shi Jiu Jin ◽  
H. Feng ◽  
Z.M. Zeng ◽  
Z.G. Qu

A new distributed optical fiber pipeline leakage detection technology based on Mach-Zehnder optical fiber interferometer theory is put forward. When using this technology, an optical fiber cable is laid along the pipeline. Noise from leaking point on the pipeline can be acquired by the optical fiber vibration sensor which was composed of three single mode optical fibers, thus, leakage occurred on the pipeline can be detected in real time. The detection principle and system construction are explained and in-site testing data is analyzed. With principle analysis and experimental results, it is demonstrated that the detection system’s measuring sensitivity and location accuracy for detecting leakage are high when adopting this technology.

Author(s):  
Hao Feng ◽  
Shijiu Jin ◽  
Yan Zhou ◽  
Zhoumo Zeng ◽  
Pengchao Chen

A distributed optical fiber system used to detect pipeline leakage and lawless excavation is put forward in this paper. This system is based on Mach-Zehnder optical fiber interferometer theory, which uses three monomode fibers in one optical fiber cable to compose two Mach-Zehnder interferometers. Vibrations from leakage point and lawless excavation along the pipeline can be acquired by the optical fibers, so the vibrations occurred on the pipeline can be detected in real time. In this paper, the principle and the system construction are introduced, and the way of the fiber cable to influence the sensitivity is studied. And also, the polarization on the optical path is studied in this paper, and a new technology to eliminate “Polarization Debilitating” is put forward. With principle analysis and experimental results, it is demonstrated that the detection system’s measuring sensitivity and location accuracy for detecting leakage and lawless excavation are greatly improved when adopting this technology, and furthermore the cost is very low.


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Nandhakumar P ◽  
Arun Kumar

AbstractOptical fiber communication is the backbone of the entire telecommunication industries in the world. In this work, the real-time backbone long-distance optical fibers (single mode) are tested and analyzed with two different wavelengths (1,310 nm and 1,550 nm) with the help of optical time domain reflectometer. Using these two different wavelengths, how the losses and events of the backbone optical fibers are changing are compared and analyzed. This work will give a way to study the nature of long-distance backbone optical fiber and understand the real-time application of the fiber optic communication.


Author(s):  
Zhigang Qu ◽  
Shijiu Jin ◽  
Yan Zhou ◽  
Jian Li ◽  
Dongjie Tan ◽  
...  

A new distributed optical fiber pipeline leakage pre-warning system based on the principle of Mach-Zehnder optical fiber interferometer and the method of its signal analysis are proposed in this paper. In this pre-warning system, an optical cable is laid in parallel with the pipeline in the same ditch and three single mode optical fibers in the optical cable build up the distributed micro-vibrant measuring sensor. Leakage and other abnormal events can be detected by the sensor in real-time and can be identified by using an “energy-pattern” method based on the wavelet packet analysis. The position of the leak point can be obtained by calculating the value of time delay of the two measuring signals through a correlation algorithm. This system detects various oil and gas pipeline leakages, and is especially suited for micro-leakage. At the end of this paper, experimental data obtained on oil field and the result of the signal analysis are presented. The data and the result of the signal analysis show that the measuring sensitivity and location precision of detecting leakage are improved when this technology is adopted, and abnormal events can be efficiently identified.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4865
Author(s):  
Kinzo Kishida ◽  
Artur Guzik ◽  
Ken’ichi Nishiguchi ◽  
Che-Hsien Li ◽  
Daiji Azuma ◽  
...  

Distributed acoustic sensing (DAS) in optical fibers detect dynamic strains or sound waves by measuring the phase or amplitude changes of the scattered light. This contrasts with other distributed (and more conventional) methods, such as distributed temperature (DTS) or strain (DSS), which measure quasi-static physical quantities, such as intensity spectrum of the scattered light. DAS is attracting considerable attention as it complements the conventional distributed measurements. To implement DAS in commercial applications, it is necessary to ensure a sufficiently high signal-noise ratio (SNR) for scattered light detection, suppress its deterioration along the sensing fiber, achieve lower noise floor for weak signals and, moreover, perform high-speed processing within milliseconds (or sometimes even less). In this paper, we present a new, real-time DAS, realized by using the time gated digital-optical frequency domain reflectometry (TGD-OFDR) method, in which the chirp pulse is divided into overlapping bands and assembled after digital decoding. The developed prototype NBX-S4000 generates a chirp signal with a pulse duration of 2 μs and uses a frequency sweep of 100 MHz at a repeating frequency of up to 5 kHz. It allows one to detect sound waves at an 80 km fiber distance range with spatial resolution better than a theoretically calculated value of 2.8 m in real time. The developed prototype was tested in the field in various applications, from earthquake detection and submarine cable sensing to oil and gas industry applications. All obtained results confirmed effectiveness of the method and performance, surpassing, in conventional SM fiber, other commercially available interrogators.


Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 521 ◽  
Author(s):  
Georgia Konstantinou ◽  
Karolina Milenko ◽  
Kyriaki Kosma ◽  
Stavros Pissadakis

We demonstrate a three-port, light guiding and routing T-shaped configuration based on the combination of whispering gallery modes (WGMs) and micro-structured optical fibers (MOFs). This system includes a single mode optical fiber taper (SOFT), a slightly tapered MOF and a BaTiO3 microsphere for efficient light coupling and routing between these two optical fibers. The BaTiO3 glass microsphere is semi-immersed into one of the hollow capillaries of the MOF taper, while the single mode optical fiber taper is placed perpendicularly to the latter and in contact with the equatorial region of the microsphere. Experimental results are presented for different excitation and reading conditions through the WGM microspherical resonator, namely, through single mode optical fiber taper or the MOF. The experimental results indicate that light coupling between the MOF and the single mode optical fiber taper is facilitated at specific wavelengths, supported by the light localization characteristics of the BaTiO3 glass microsphere, with spectral Q-factors varying between 4.5 × 103 and 6.1 × 103, depending on the port and parity excitation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. A. Perez-Herrera ◽  
M. Bravo ◽  
P. Roldan-Varona ◽  
D. Leandro ◽  
L. Rodriguez-Cobo ◽  
...  

AbstractIn this work, an experimental analysis of the performance of different types of quasi-randomly distributed reflectors inscribed into a single-mode fiber as a sensing mirror is presented. These artificially-controlled backscattering fiber reflectors are used in short linear cavity fiber lasers. In particular, laser emission and sensor application features are analyzed when employing optical tapered fibers, micro-drilled optical fibers and 50 μm-waist or 100 μm-waist micro-drilled tapered fibers (MDTF). Single-wavelength laser with an output power level of about 8.2 dBm and an optical signal-to-noise ratio of 45 dB were measured when employing a 50 μm-waist micro-drilled tapered optical fiber. The achieved temperature sensitivities were similar to those of FBGs; however, the strain sensitivity improved more than one order of magnitude in comparison with FBG sensors, attaining slope sensitivities as good as 18.1 pm/με when using a 50 μm-waist MDTF as distributed reflector.


2006 ◽  
Vol 60 (7-8) ◽  
pp. 176-179
Author(s):  
Aleksandar Kojovic ◽  
Irena Zivkovic ◽  
Ljiljana Brajovic ◽  
Dragan Mitrakovic ◽  
Radoslav Aleksic

This paper investigates the possibility of applying optical fibers as sensors for investigating low energy impact damage in laminar thermoplastic composite materials, in real time. Impact toughness testing by a Charpy impact pendulum with different loads was conducted in order to determine the method for comparative measurement of the resulting damage in the material. For that purpose intensity-based optical fibers were built in to specimens of composite materials with Kevlar 129 (the DuPont registered trade-mark for poly(p-phenylene terephthalamide)) woven fabric as reinforcement and thermoplastic PVB (poly(vinyl butyral)) as the matrix. In some specimens part of the layers of Kevlar was replaced with metal mesh (50% or 33% of the layers). Experimental testing was conducted in order to observe and analyze the response of the material under multiple low-energy impacts. Light from the light-emitting diode (LED) was launched to the embedded optical fiber and was propagated to the phototransistor-based photo detector. During each impact, the signal level, which is proportional to the light intensity in the optical fiber, drops and then slowly recovers. The obtained signals were analyzed to determine the appropriate method for real time damage monitoring. The major part of the damage occurs during impact. The damage reflects as a local, temporary release of strain in the optical fiber and an increase of the signal level. The obtained results show that intensity-based optical fibers could be used for measuring the damage in laminar thermoplastic composite materials. The acquired optical fiber signals depend on the type of material, but the same set of rules (relatively different, depending on the type of material) could be specified. Using real time measurement of the signal during impact and appropriate analysis enables quantitative evaluation of the impact damage in the material. Existing methods in most cases use just the intensity of the signal before and after the impact, as the measure of damage. This method could be used to monitor the damage in real time, giving warnings before fatal damage occurs.


Author(s):  
А.D. Меkhtiyev ◽  
◽  
E.G. Neshina ◽  
P.Sh. Madi ◽  
D.A. Gorokhov ◽  
...  

This article ls with the issues related to the development of a system for monitoring the deformation and displacement of the rock mass leading to the collapse of the quarry sides. Monitoring system uses point-to-point fiber-optic sensors. Fiber-optic sensors and control cables of the communication line are made based on the single mode optical fibers, which allows to measure with high accuracy the deformations and displacements of the rock mass at a distance of 30-50 km. To create fiber-optic pressure sensors, an optical fiber of the ITU-T G. 652.D standard is used. Laboratory sample is developed concerning the point fiber-optic sensor made based on the two-arm Mach-Zender interferometer using a single mode optical fiber for monitoring strain (displacements) with a change in the sensitivity and a reduced influence of temperature interference leading to zero drift. The article presents a mathematical apparatus for calculating the intensity of radiation of a light wave passing through an optical fiber with and without mechanical stress. A laboratory sample of single mode optical fibers based on the Mach-Zender interferometer showed a fairly high linearity and accuracy in the measurement and can be used to control the strain of the mass after appropriate refinement of its design. Mathematical expressions are also given for determining the intensity of the light wave when the distance between the fixing points of a single mode optical fiber changes depending on the change in the external temperature. A diagram for measuring strain using a point fiber-optic strain sensor is developed. Hardware and software package is developed, which can be used to perform a number of settings of measuring channels. The work is aimed at solving the production problems of the Kenzhem quarry of AK Altynalmas JSC.


2014 ◽  
Vol 40 (1) ◽  
pp. 89-93
Author(s):  
张金权 ZHANG Jinquan ◽  
李香文 LI Xiangwen ◽  
李东 LI Dong ◽  
张欣 ZHANG Xin ◽  
刘素杰 LIU Sujie ◽  
...  

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