Application of SOM Network in Ship Pipeline Leakage Detecting

2012 ◽  
Vol 468-471 ◽  
pp. 538-541 ◽  
Author(s):  
Hong Hao Yin ◽  
Hui Chen ◽  
Zhong Bo Peng

At present, ship pipeline leakage has become a great hidden risk of safe navigation and environmental pollution, but piping detecting technology mostly focuses on long-distance oil and gas pipeline, and does a little on the complicated pipeline system, for example, ship pipeline system. The frequently-used leakage detecting of negative pressure wave method, because the frequent adjustable pump or reset valve of ship pipeline system will also produce the negative pressure wave, may easily fail to report or even misreport. In order to monitor ship pipeline leakage effectively and greatly reduce fault alarm rate and missing alarm rate, SOM network (self-organizing feature map neural network) had been used to identify leakage from different working conditions. At first, the waveform characteristics of pressure and flow signals were analyzed by kurtosis calculating to obtain condition eigenvectors. From data sampling in terms of pipe working conditions, learning samples were obtained. Accordingly, the nonlinear mapping between SOM neural network inputs and outputs were well established via training. Afterwards, ship piping leakage was detected based on input eigenve

Author(s):  
Dongliang Yu ◽  
Bin Xu ◽  
Likun Wang ◽  
Dongjie Tan ◽  
Hongchao Wang ◽  
...  

As an important tool for the long-distance transportation of product oil, pipeline construction has being developed rapidly in recent years in the world. In the long-term running, leak will occur occasionally and seriously endanger the operation safety of the pipeline system, which may be caused by internal & external factors including pipe aging, mechanical damage, chemical corrosion, and natural disaster, etc. In order to timely find out and accurately locate the leakage, and reduce the economic loss and the accident risk, it is necessary to research into leak monitoring techniques and apply them in field. Compared with crude oil pipeline, due to multi-batch transportation, multi-distribution operation and frequent regulation, leak monitoring for product oil pipeline is much more difficult. Once leak occurs, the oil loss at the leakage point induces an oil pressure drop, causing negative pressure wave as well as acoustic wave. Through analyzing negative pressure wave signals and acoustic wave signals acquired by sensors, it can find out and locate the leakage. For interference signals like background noises in the product oil pipeline, wavelet packet decomposition technology is used to denoise the acquired negative pressure wave signals and acoustic wave signals, and extract the feature signals. Meanwhile, the signal velocity in product oil is calculated dynamically to improve the location accuracy. Field Tests indicate that the technology combining negative pressure wave and acoustic wave is accurate and reliable, and has good performance.


Author(s):  
Dongliang Yu ◽  
Laibin Zhang ◽  
Liang Wei ◽  
Zhaohui Wang

The appearance of a rupture, leak or damage in the long-distance oil & gas pipeline, which could cause a leak, usually generates a non-linear & chaotic negative pressure wave signal. By properly interpreting the negative pressure wave signature, it is possible to detect a leak along the pipeline. Most traditional noise reduction methods are established based on the linear system, which are not in line with the actual non-linear & chaotic situation. Therefore, the weak negative pressure wave signals, generated by small leaks, are often filtered out and cause false alarm and failure alarm. In order to resolve the problem, this paper uses the non-linear projective algorithm for noise reduction. First, the weak negative pressure wave signal series would be reconstructed using delay coordinates, in the high dimensional phase space, the background signal, the negative pressure wave signal and the noise signal are separated into different sub-spaces. Through the reconstruction of sub-spaces, the weak pressure wave signal can be isolated from the background signal as well as the random noise component reduced.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Boxiang Liu ◽  
Zhu Jiang ◽  
Wei Nie

Leakage problems are common in the water supply pipeline system, which will threaten the health of residents and cause economic losses. Negative pressure wave (NPW) technology calculates the time difference through the inflection point to locate the leak. However, due to the nonlinear and nonstationary characteristics of the pressure signal, it is difficult to obtain an accurate inflection point of the NPW by the traditional method. Therefore, the advantages of applying variational mode decomposition (VMD) in NPW technology are explored. Firstly, the correlation coefficient and permutation entropy (PE) are used for effective intrinsic mode function (IMF) component selection and parameter optimization. Thus, an adaptive denoising method based on VMD (AD-VMD) is presented. Then, to effectively separate the detail features of the NPW, a novel inflection point extraction method based on VMD (IPE-VMD) is proposed. Simulation and experimental results show that AD-VMD can effectively suppress noise interference and conserve the mutation characteristic of the leakage. IPE-VMD can obtain a distinct maximum peak at the inflection point and has good robustness to noise interference. This method can calculate the time difference precisely and stably. In addition, the accuracy of the leak location is verified. The average relative positioning error is 5.13%.


2021 ◽  
Author(s):  
Matthew Grimes ◽  
Nico Van Rensburg ◽  
Stuart Mitchell

Abstract This paper presents on a non-invasive, IoT-based method for rapidly determining the presence and location of spontaneous leaks in pressurized lines transporting any type of product (e.g., oil, gas, water, etc.). Specific applications include long-distance transmission lines, gathering networks at well sites, and offshore production risers. The methodology combines proven negative pressure wave (NPW) sensing with advanced signal processing to minimize false positives and accurately identify the presence of small spontaneous leaks within seconds of their occurrence. In the case of long-distance transmission pipelines, the location of the leak can be localized to within 20-50 feet. The solution was commercialized in 2020 and has undergone extensive testing to verify its capabilities. It is currently in use by several operators, both onshore and offshore.


2015 ◽  
Vol 74 (4) ◽  
Author(s):  
M. K. F. M. Ali ◽  
N. Md. Noor ◽  
N. Yahaya ◽  
A. A. Bakar ◽  
M. Ismail

Pipelines play an extremely important role in the transportation of gases and liquids over long distance throughout the world. Internal corrosion due to microbiologically influenced corrosion (MIC) is one of the major integrity problems in oil and gas industry and is responsible for most of the internal corrosion in transportation pipelines. The presence of microorganisms such as sulfate reducing bacteria (SRB) in pipeline system has raised deep concern within the oil and gas industry. Biocide treatment and cathodic protection are commonly used to control MIC. However, the solution is too expensive and may create environmental problems by being too corrosive. Recently, Ultraviolet (UV) as one of the benign techniques to enhance mitigation of MIC risk in pipeline system has gained interest among researchers. An amount of 100 ml of modified Baar’s medium and 5 ml of Desulfovibrio vulgaris (strain 7577) seeds was grown in 125 ml anaerobic vials with carbon steel grade API 5L-X70 coupons at the optimum temperature of 37°C and pH 9.5 for fifteen days. This was then followed by exposing the medium to UV for one hour. Results from present study showed that UV radiation has the ability to disinfect bacteria, hence minimizing the risk of metal loss due to corrosion in steel pipeline. 


Author(s):  
Wei-Liang Jin ◽  
Jian-Wen Shao ◽  
En-Yong Zhang

Submarine pipeline system is a main pattern in collection and transmission of offshore oil and gas, which sends oil and gas from offshore oil/gas field to land, and it plays an important role in the production of oil and gas. Because of the complicated and harsh condition in which pipeline system works, such as impulsion, corrosion and free-spanning vibration, failure of submarine pipeline system occurs occasionally, it causes oil leakage, environment pollution and economic losses. Health monitoring is a feasible and effective manner to ensure submarine pipeline safe and reliable during service, especially when all factors affecting pipeline failure are not still entirely realized or controlled. The basic strategy of a new real-time monitoring system for long distance submarine pipeline is introduced in this paper, which has the function of diagnosis and auto-alarm. In this system, a new distributed optical fiber sensor (DOFS), which uses optical time domain reflectometry theory based on Brillouin backscatter, is applied to monitor the strain and temperature along the pipeline. To be used for long distance submarine pipeline, this system applies Wavelength Division Multiplex (WDM) technology and series DOFSs in series so as to extend the measure scope for long distance submarine pipeline. By using signal processing system to analyze the outcome data of sensor, the strain along the pipeline can be obtained. If the strain reaches the alarm setting, the system will send out caution and meanwhile accurately give the damage position. The system can also analyses vibration frequency of pipeline, if free-spanning vibration occurs, caution will also be given, so that the operator can take some measures in time to avoid the failure of pipeline. In this paper, the makeup of distributed optical fiber sensor and developing principle are specified, system development, application and construction in engineering are analyzed as well. The brand new practical system can not only be used for submarine oil and gas pipeline but also for land oil and gas transfer system, city coal gas transfer system, electricity-transmission cable and so on. This system can be widely used in many prospects of other industries.


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