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Experimental Study of Oil Pipeline Leak Processes  [PDF]
Agbakwuru Ahamefula Jasper, Gudmestad Tobias Ove, Bilstad Torleiv
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.37072
Abstract: This work provides a description of oil leak/spill processes from containment such as pipeline. Understanding of such processes is important in order to adequately estimate oil spills and to justify an appropriate emergency action for minimizing spills. Internal diameters of pipes used in the study are within 4 inches. Leaks are simulated from plastic pipeline oil containment fitted with valves. The leak response with time when upstream and downstream valves are operated is studied. Within the internal diameters of pipelines considered in the tests, two ranges of leak characteristics are evident; the “holding range” and the “flowing range” characteristics. The consequences of these characteristics in the oil industry operations have been discussed. The work suggests a spill estimation method based on this knowledge. Furthermore, in order to minimise spill in event of pipeline failure, it is observed that the optimum action on pipeline operational valves, is the immediate closure of upstream valve, followed by the downstream valve, nearly simultaneously. Future work will extend the test to larger diameter pipelines to attempt developing a mathematical approach for estimating limits of the “holding range” characteristics of pipelines given appropriate parameters and in-field test.
Leak Detection Modeling and Simulation for Oil Pipeline with Artificial Intelligence Method
Pudjo Sukarno,Kuntjoro Adji Sidarto,Amoranto Trisnobudi,Delint Ira Setyoadi
ITB Journal of Engineering Science , 2007,
Abstract: Leak detection is always interesting research topic, where leak location and leak rate are two pipeline leaking parameters that should be determined accurately to overcome pipe leaking problems. In this research those two parameters are investigated by developing transmission pipeline model and the leak detection model which is developed using Artificial Neural Network. The mathematical approach needs actual leak data to train the leak detection model, however such data could not be obtained from oil fields. Therefore, for training purposes hypothetical data are developed using the transmission pipeline model, by applying various physical configuration of pipeline and applying oil properties correlations to estimate the value of oil density and viscosity. The various leak locations and leak rates are also represented in this model. The prediction of those two leak parameters will be completed until the total error is less than certain value of tolerance, or until iterations level is reached. To recognize the pattern, forward procedure is conducted. The application of this approach produces conclusion that for certain pipeline network configuration, the higher number of iterations will produce accurate result. The number of iterations depend on the leakage rate, the smaller leakage rate, the higher number of iterations are required. The accuracy of this approach is clearly determined by the quality of training data. Therefore, in the preparation of training data the results of pressure drop calculations should be validated by the real measurement of pressure drop along the pipeline. For the accuracy purposes, there are possibility to change the pressure drop and fluid properties correlations, to get the better results. The results of this research are expected to give real contribution for giving an early detection of oil-spill in oil fields.
Oil/Gas Pipeline Leak Inspection and Repair in Underwater Poor Visibility Conditions: Challenges and Perspectives  [PDF]
Agbakwuru Jasper
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.35049
Abstract: Mechanical pressure clamps are examples of innovative tools commonly used in the oil and gas industry for arresting leaks from damaged oil and gas pipelines. However, if leaks result from pipeline rupture, clamps are not usually recommended. It is therefore obvious that inspection of the leaking pipeline is very crucial in deciding the strategy for repair. For subsea pipelines where underwater poor visibility is pronounced, this important aspect of the pipeline repair process becomes difficult to implement. The result is a repair-leak-repair cycle. This challenge is commonly found in repairs of old pipelines in unclear water conditions. Old pipelines and their vulnerability to fractures that often lead to ruptures are discussed. In this paper, the challenges and technologies available for visualisation and examination in such unclear water conditions are discussed. There appears to be a gap in the existing pipeline integrity management system with respect to inspection and repair of pipelines in unclear water conditions. This gap needs to be filled in order to minimise spills and pollution. For pipelines installed in unclear water condition, a perspective is suggested to extend the capability of existing remotely operated vehicles to employ the use of clear laminar water system or a related technique to provide integrity engineers and operators with close visual assess to inspect leaking pipelines and effect adequate repairs. This paper suggests that the use of optical eye as the main tool for examination remains valuable in managing the challenges in underwater pipeline repairs in unclear water condition.
Implementation of Optimal Pacing Scheme in Xinjiang's Oil and Gas Pipeline Leak Monitoring Network  [cached]
Peng Zhou
Journal of Networks , 2011, DOI: 10.4304/jnw.6.1.54-61
Abstract: Flow against Xingjian’s oil and gas pipeline leakage and the pipe network sudden burst pipe to pipeline leakage flow for the application objects, Optimal pacing scheme is designed in pipeline leak monitoring. Based on the property of Markov chain for network data, a new estimator with particle filter is proposed for congestion control in this paper. In the context of a reconfigurable transport protocol framework, we propose a QoS aware Transport Protocol (QSTP), specifically designed to operate over QoS (Quality of Service) enabled networks with bandwidth guarantee. The proposed scheme can adaptively adjust the network rate in real -time, so that it can efficiently avoid the traffic congestion. It proposes a Link Layer Adaptive Pacing (LLAP) scheme that adaptively controls the offered load into the network. The algorithms actively probe the underlay network and compute virtual multicast trees by dynamically selecting the least loaded available paths on the overlay network. The low computational complexity of the proposed algorithms leads to time and resource saving, as shown through extensive experiments. The Simulation results show that Network congestion avoidance strategy with optimal pacing scheme can efficiently improve the bandwidth utilization, Transmission Control Protocol (TCP) friendliness and reduce the packet drop rate in Pipeline Flux Leak Monitoring networks. Flood flow identified by the National Centre for testing: discussion group first proposed the use of particle filters to solve the new model can estimate the network congestion control problem. The results are sound, stable performance, efficiency 29%. Adaptive algorithm using the model proposed optimization scheme, to achieve accurate positioning of the leak, 0.05
Knowledge Discovery for Classification of Three-Phase Vertical Flow Patterns of Heavy Oil from Pressure Drop and Flow Rate Data  [PDF]
Adriane B. S. Serapi?o,Antonio C. Bannwart
Journal of Petroleum Engineering , 2013, DOI: 10.1155/2013/746315
Abstract: This paper focuses on the use of artificial intelligence (AI) techniques to identify flow patterns acquired and recorded from experimental data of vertical upward three-phase pipe flow of heavy oil, air, and water at several different combinations, in which water is injected to work as the continuous phase (water-assisted flow). We investigate the use of data mining algorithms with rule and tree methods for classifying real data generated by a laboratory scale apparatus. The data presented in this paper represent different heavy oil flow conditions in a real production pipe. 1. Introduction The design of oil production pipelines involves evaluation of flow lines subject to multiphase flow of oil, water, and gas, where oscillations in pressure, temperature, and phase concentration typically occur. Furthermore, the phases usually flow on different geometrical distributions inside the pipe, named flow patterns. The identification of flow patterns is essential for the economic evaluation of the project, such as pressure drop and flow rate along the pipeline. These aspects are critical on offshore production conditions, where extensive distances and high costs are involved. Flow pattern identification is an important step to design separation equipments, slug catchers, gas lift operations, wellhead gathering systems, and production management and control. With the discovery of heavy oil reservoirs the lack of tools and methodologies for flow pattern identification deserves attention because the existing multiphase flow correlations are made for low API oils, where the oil-water mixture may be treated as a single liquid phase with average properties. However, for water-continuous flow of heavy oil below bubble-point, three distinct phases are present, that is, oil, water, and gas, thus making the traditional approach of flow pattern classification and pressure drop prediction in three-phase flow may have poor accuracy. Basically, there are two types of models for flow pattern prediction: empirical and mechanistic. Empirical models are related to experimental data, where flow pattern maps are experimentally determined and analyzed with respect to mathematical relations representing the boundaries between the flow pattern regions. These relations depend on the amount of experimental data used and on the coordinate system in which the data are presented. Mechanistic models are based on balance equations [1]. Notwithstanding, these models are formulated to describe single or two-phase flows, and they cannot be highly extended for oil-gas-water mixtures, when the
Pipeline Leak Detection Techniques  [PDF]
Timur Chis, Ph.D., Dipl.Eng.
Annals. Computer Science Series , 2007,
Abstract: Leak detection systems range from simple, visual line walking and checking ones to complex arrangements of hard-ware and software. No one method is universally applicable and operating requirements dictate which method is the most cost effective. The aim of the paper is to review the basic techniques of leak detection that are currently in use. The advantages and disadvantages of each method are discussed and some indications of applicability are outlined.
Pipeline Leak Detection Techniques  [PDF]
Timur Chis
Computer Science , 2009,
Abstract: Leak detection systems range from simple, visual line walking and checking ones to complex arrangements of hard-ware and software. No one method is universally applicable and operating requirements dictate which method is the most cost effective. The aim of the paper is to review the basic techniques of leak detection that are currently in use. The advantages and disadvantages of each method are discussed and some indications of applicability are outlined.
Diagnosis and Localization of Pipeline Leak Based on Fuzzy Decision-making Method

FENG Jian,ZHANG Hua-Guang,

自动化学报 , 2005,
Abstract: A leak detection plays a key role in the overall integrity monitoring for a oil pipeline system. A fuzzy decision-making approach to pipeline leak localization is proposed in this paper. The two main methods, pressure gradient localization and negative pressure wave localization, are combined with fuzzy logical decision-making method to form a novel fault diagnosis scheme. The combination scheme can improve the precision of localization. An application example, 14km long oil pipeline leak detection and localization, is illustrated. This method is compared with others through practical experiments and its validity is confirmed by the results.
Crude Oil Pipeline Real-Time Security System

XU Nan-Shan,ZHOU Jun,

计算机系统应用 , 2012,
Abstract: In order to solve oil leakage and energy waste problems in current crude oil pipeline transmission,this paper proposes a B/S model based real-time security system for oil pipeline.The system realizes the pipeline data monitoring,pipeline leak detecting,energy-saving model and wax model.The design of the system,database and the main technology of the system are explained in detail in the paper.And with the friendly interface,stable communication,real-time monitoring,and high detection precision,this system really realizes automated monitoring and improves the level of automation of enterprise management.
Pipeline Potential Leak Detection Technologies: Assessment and Perspective in the Nigeria Niger Delta Region  [PDF]
Jasper Agbakwuru
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.28121
Abstract: This paper examines the advances in pipeline third party encroachment alert systems and leak control methods in the oil/gas industry. It also highlights the extent of spill/pollution issues in the Niger Delta region due to intended/unin- tended damages and suggests a possible method of control. It is believed that the best option to avoid pollution due to pipeline failure is to ensure that hydrocarbon does not exit from the pipeline. With the different methods considered in this review, acoustic monitoring of change in the operational sound generated from a given pipeline section is suggested to be practicable to identifying sound abnormalities of third party encroachments. One established challenge of the acoustic system for buried pipelines protection is attenuation of acoustic transmission. An attempt to check the performance of an acoustic transmission on steel pipelines submerged in water points to a similar research on plastic water pipelines that attenuation is small compared with pipe buried in soil. Fortunately, Niger Delta of Nigeria is made of wetland, swamps and shallow water and could therefore offer an opportunity to deploy acoustic system for the safety of pipelines against third party attacks in this region. However, the numerous configuration and quantity of oil installation in this region imply that cost of application will be enormous. It is therefore suggested that a combination of impressed alternating cycle current (IACC) which traces encroachment on the pipeline coating and an acoustic system be used to manage intended and unintended pipeline potential damages. The IACC should be used for flow lines and other short distance delivery lines within the oilfield, while the relatively large diameter and long length delivery, trunk and transmission lines should be considered for acoustic protection. It is, however, noted that further efforts are required to reduce cost and improve effectiveness of these systems.
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