Pipeline Monitoring With Geotechnical Optical Fiber

Author(s):  
Christian Silva ◽  
Fabien Ravet

The 408 km × 34" PERULNG pipeline (operated by Hunt LNG Operating Company) is monitored in its first 62 km by a geotechnical fiber optic cable, since these first 62 km are exposed to major geohazard threats such as landslides, large river crossings, high slopes, bofedales, etc. The fiber optic cable geotechnical monitoring relies on the measurement of strain and temperature in the pipeline right-of-way. Due to the continuous and real-time monitoring of the duct, it was possible to detect a tension cracking near KP 25 + 600 as an abnormal temperature change was captured by the temperature sensing cable; also near KP 27 + 900 and KP 34 + 750 unusual cable stresses were detected which announced landslides of the rotational type in both locations. In these three cases, protection decisions could be taken to secure pipeline’s integrity.

2020 ◽  
Vol 57 (6) ◽  
pp. 871-881 ◽  
Author(s):  
Cheng-Cheng Zhang ◽  
Hong-Hu Zhu ◽  
Su-Ping Liu ◽  
Bin Shi ◽  
Gang Cheng

Distributed fiber optic sensing (DFOS) is gaining increasing interest in geotechnical monitoring. By using soil-embedded fiber optic cables, strain profiles as well as deformation patterns of geotechnical infrastructures can be captured. Probing the fiber optic cable–soil interfacial behavior is vital to the advancement of DFOS-based geotechnical monitoring and our understanding of the soil–inclusion interaction mechanism. To this aim, laboratory pullout tests were performed to investigate the progressive failure of the interface between micro-anchored cables and the surrounding sand. High-resolution strain profiles recorded using Brillouin optical time-domain analysis (BOTDA) not only elucidated the influence of anchorage on strain measurements, but also allowed the classical soil–inclusion interaction problem to be studied in detail. Interfacial shear stresses calculated from step-like strain profiles provided clear evidence of the contribution of each micro-anchor to the pullout resistance. The cable–soil contact is a combination of overall bonding and point fixation depending on the level of mobilized interfacial shear stress, and therefore the validity of measured strains is correlated to a three-stage process of interface failure. This study also shows that installing heat-shrink tubes on the fiber optic cable is a rapid, low-cost, effective approach to make an anchored DFOS system for deformation monitoring of earth structures.


Author(s):  
Priscila Pereira Teixeira ◽  
Wanderley Camargo Russo ◽  
João Luiz Torralbo Quintana ◽  
Ricardo Hoff

To ensure the integrity of pipelines in failure mode Geotechnical, TRANSPETRO and the TBG perform underwater inspections of pipelines in the main crossings of rivers, lakes, dams, canals and permanently flooded areas. The inspections are designed to locate guideline and measure the covering the pipelines from the margins and underwater depth, identify any exposure of the pipelines, map the occurrences of blocks of rock or debris on the channel and evaluate the anthropic influence on stability of the sections inspected. Among the crossings rivers inspected, in the Atibaia V, with approximately 27.3 m in length, was observed a high erosive potential, which resulted in the loss cover of 3 (three) pipelines of crossing river, besides the fiber optic cable. The lengths uncovered resulted in approximately 33.0 m, with suspended pipes, damage in the concrete jacket and presence of blocks of rocks in the channel. The pipeline in the most critical situation went vain of 6.0 m, with gap up to 0,2 m in relation the background. The crossing river was studied with bathymetric survey and designed cover the pipelines with mechanical protection and anti-erosive. The pipes were supported with sacks of granular material, sequentially, the margins and pipelines were protected with geotextile filled with concrete, installed with the help of divers. The working conditions of 4.0 m depth, currents of up to 0.8 m/s, temperature and low visibility waters were challenges overcome during execution, in which the divers took turns in short periods. Due to the characteristics of the bedrock, the blankets went stylized and stitched on the field by the team, with dimensions taken on site. After positioning the blankets in the background began the underwater concreting, which occurred in stages monitored by the volume pumped and divers strategically placed. The crossing river was re-inspected approximately 1 (one) year after their stabilization and was found in good conditions. The occurrence improved the procedures for geotechnical monitoring and treatment of pipelines uncovered in crossings rivers, being who the efficiency and safety of the work performed currently serve as a reference for the design of similar works.


Author(s):  
Ilham Sudrajat ◽  
Yasdinul Huda ◽  
Delsina Faiza

Based on the survey data of optical fiber service, the communication network uses optical fiber transmission medium is not maximal yet, because there are some errors in the network, such as the percentage of Network Post Dialing Delay in system is 97.5%, that means there is 2.5% of error a delay occurs in the network when making a call. This research was conducted by analyzing the fiber attenuation of fiber-optic communication systems performance on the link Padang-Bukittinggi in PT. Telkom Padang, SKSO division which uses single mode fiber optic cable types G655. Instrument in this study is the Power Meter and OTDR JDSU MTS-6000 type. Link Power Budget method is used to determine the performance of optical fiber communication systems caused by attenuation based on the value of the received power output. Obtained results on the link Padang-Bukittinggi highest attenuation occurs in core 5 with 26.7226 dB attenuation value and cable length 115 016 km, and in core 7 with 26.1812 dB and cable length 94 462 km. This value is still below of PT. Telkom standard with 28.10352 dB for core 5. While the attenuation value at 7 cores exceeds standard attenuation values​​, with 24.18186 dB, so the performance of the core is declared bad and needs to be evaluated. From optical fiber attenuation value, result of the link power budget analysis is obtained from the calculation of the value of Rx is smaller when compared with -27 dBm the value of Rx sensitivity, it can be said the performance of optical fiber communication systems on the link in the normal state and can be used to operate because the power output can be accepted by the receiver in the device. Keywords: fiber optic cable, optical fiber attenuation, SKSO, link power budget.


2020 ◽  
Vol 2 (2) ◽  
pp. 91-99
Author(s):  
Imam Mulyanto

The test has been successfully carried out on optical fibers to be used as a macrobending tilt sensor using SMF-28 single mode optical fiber. The optical fiber was molded with silicon rubber, then connected to a laser light and a power meter to see the intensity of the laser power produced. The principle is carried out using the macro bending phenomenon on single mode optical fibers, where the laser light intensity in the fiber optic cable will decrease if there is a bend or bending in the fiber optic cable. We can observe the power loss resulting from the macro bending process to find out how sensitive the optical fiber is to changes in a given angle. The resulting optical fiber sensitivity value is -0.1534o/dBm.


Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3094
Author(s):  
Preetam Suman ◽  
Deepak Kumar Singh ◽  
Fahad R. Albogamy ◽  
Mohammad Shibee

Agriculture and animals are two crucial factors for ecological balance. Human–wildlife conflict is increasing day-by-day due to crop damage and livestock depredation by wild animals, causing local farmer’s economic loss resulting in the deepening of poverty. Techniques are needed to stop the crop damage caused by animals. The most prominent technique used to protect crops from animals is fencing, but somehow, it is not a full-proof solution. Most fencing techniques are harmful to animals. Thousands of animals die due to the side effects of fencing techniques, such as electrocution. This paper introduces a virtual fence to solve these issues. The proposed virtual fence is invisible to everyone, because it is an optical fiber sensor cable, which is laid 12-inches-deep in soil. A laser light is used at the start of the fiber sensor cable, and a detector detects at the end of the cable. The technique is based on the reflection of light inside the fiber optic cable. The interferometric technique is used to predict the changes in the pattern of the laser light. The fiber cable sensors are connected to a microprocessor, which can predict the intrusion of any animal. The use of machine learning techniques to pattern detection makes this technique highly efficient. The machine learning algorithms developed for the identification of animals can also classify the animal. The paper proposes an economical and feasible machine-learning-based solution to save crops from animals and to save animals from dangerous fencing. The description of the complete setup of optical fiber sensors, methodology, and machine learning algorithms are covered in this paper. This concept was implemented and regressive tests were carried out. Tests were performed on the data, which were not used for training purposes. Sets of people (50 people in each set) were randomly moved into the fiber optic cable sensor in order to test the effectiveness of the detection. There have been very few instances where the algorithm has been unable to categorize the detections into different animal classes. Three datasets were tested for configuration effectiveness. The complete setup was also tested in a zoo to test the identification of elephants and tigers. The efficiency of identification is 94% for human, 80% for tiger, and 75% for elephant.


2018 ◽  
Vol 10 (1) ◽  
pp. 36-40
Author(s):  
Tio Hanif Yanuary ◽  
Lita Lidyawati

An optical fiber is a high-speed telecommunication transmission medium. Principally, an optical fiber is made of a very fine glass fiber material, which is able to transmit light waves using light reflection method on the surface of the fiber optics core. An underground installation of the fiber optics makes this device robust from external interferences. However, the fiber optic cable performance should always be checked to maintain performance during data transmission process. One way to test fiber optics cable performance is by using an Optical Time - Domain Reflectometer (OTDR) device. This device sends a light wave from one point of the fiber optics cable. The light wave then returns when reaching the other point of the fiber optic cable while carrying some measurement parameters especially the physical length and attenuation of a fiber optic cable. The evaluation of the fiber optics cable performance requires the preparation, installation, and configuration of the OTDR. In this paper, we conducted evaluation on the performances of fiber optics cable. The data generated by the performed evaluation indicated an occurring attenuation on the fiber optics cable along 64.402 km of its lengths.


Author(s):  
Fabien Ravet ◽  
Carlos Borda ◽  
Etienne Rochat ◽  
Marc Niklès

The present work introduces the technology background at the origin of FOPIMS (Fiber Optic Pipeline Integrity Monitoring Systems) with an emphasis on geotechnical monitoring. It shows how temperature sensing can be implemented to control soil erosion or dune migration through event localization and spatial quantification. Arctic pipeline monitoring project illustrates the application of soil erosion detection. Direct measurement of strain in soil also enhances environmental threat detection. Combined with temperature sensing, strain sensing composes the geotechnical monitoring system. Transandean pipeline monitoring examples are presented where the DITEST AIM was implemented for geohazard prevention. These study cases concern new pipeline installation as well as retrofit of existing lines. The technique successfully evidenced early events and allowed preventive measures to be taken. In some applications actual pipeline deformation need to be monitored. Such operation is achieved by measuring distributed strain along sensing cables attached to the structure. We show how such measurements complement the geotechnical measurements. We also describe a real implementation in seismic active area. As a whole, the work focuses on the technique principles, the installation and how the system is being implemented for pipeline preventive maintenance. We intend to present a comprehensive set of design guidelines based on real results and lessons learned from the various projects in what concerns geohazard detection and pipeline deformation monitoring.


This article examines the effect of longitudinal and thermoelastic deformation of an optical module on the technological reserve of an optical fiber. Analytical expressions are given for determining the lower limit of the technological margin of an optical fiber for various types of fiber-optic cable section along the axis.


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