scholarly journals Physical Basis of Software-Based Leak Detection Methods

1998 ◽  
Author(s):  
Jim C. P. Liou
Keyword(s):  
Transient Flow ◽  
Detection System ◽  
Sudden Change ◽  
Leak Detection ◽  
The United States ◽  
Third Party ◽  
Detection Methods ◽  
Operational Experience ◽  
Flow Simulations ◽  
Long Time

There are many causes for a pipeline to leak. Third party punctures usually result in sizable leaks. The onset of such leaks generates a sudden change in the pipeline pressure and flow. Methods exist that rely upon these sudden changes for leak detection. Leaks previously undetected are not detectable by such methods. These pre-existing leaks are usually small in size but can exist for long time. The cumulation of leaked products may pose a greater hazard then the larger and sudden leaks. The operational experience of major pipeline company in the United States has demonstrated that all leak detection methods have their limitations, and that complementary leak detection methods should be used simultaneously (Mears 1993). Hence, we propose a leak detection system that uses, simultaneously, two independent but complementary methodologies: mass balance and transient flow simulations.

Improved Leak Detection by Method Diversity

1998 ◽  
Author(s):  
Ruprecht M. J. Pichler
Keyword(s):  
Transient Flow ◽  
Detection System ◽  
Type System ◽  
Leak Detection ◽  
Operating Conditions ◽  
Detection Methods ◽  
Special Focus ◽  
Oil Pipeline ◽  
Knowledge Based ◽  
Noise Factors

Leak detection systems for liquid pipelines are installed to minimize spillage in case of a leak. Therefore reliability, sensitivity and detection time under practical operating conditions are the most important parameters of a leak detection system. Noise factors to be considered among others are unknown fluid property data, friction factor, instrument errors, transient flow, slack-line operation and SCADA update time. The opening characteristics and the size of leaks differ considerably from case to case. Each software-based leak detection method available today has its particular strength. As long as just one or two of these methods are applied to a pipeline a compromise has to be found for the key parameters of the leak detection system. The paper proposed illustrates how a combination of several different software-based leak detection methods together with observer-type system identification and a knowledge-based evaluation can improve leak detection. Special focus is given to leak detection and automated leak locating under transient flow conditions. Practical results are shown for a crude oil pipeline and a product pipeline.

Detection of Trace Hydrocarbons and Toxic Components in the Environment

2012 ◽  
Author(s):  
Walter Knoblach ◽  
Peter W. Bryce
Keyword(s):  
Early Detection ◽  
Detection System ◽  
Leak Detection ◽  
Third Party ◽  
Chemical Pollution ◽  
Environmental Damage ◽  
Public Confidence ◽  
Late Response ◽  
Operational Experience ◽  
Right Of Way

The risk of hydrocarbon and toxic spills increases with the aging of oil and chemical plant related infrastructure. The need for early detection of hydrocarbon and toxic chemical pollution is paramount, particularly in view of potential environmental damage, cleanup costs, and the loss of public confidence in industry’s ability to quickly respond to leaks. Rigorous right-of-way monitoring, control of third party activities within proximity of pipelines, in conjunction with a robust preventative maintenance program is key to leak prevention. The first line of defense in the event of a leak is early detection and operational response to limit product loss from the pipe. Sophisticated mathematical modeling of flow regimes coupled with multiple pressure sensory relay devices in pipelines has increased the sensitivity of these leak detection technologies. However, despite these technological improvements significant leaks have occurred recently on major pipeline systems with damaging consequences. Operators are challenged to interpret and respond to leak alarms in the absence of corroborating information. Frequent false or ambivalent “indications” can foster complacency, and worse, inaction. The authors contend that reliance on a single technology for detecting leaks is imprudent and unacceptable in certain environments given the consequences of a late response to a loss of product from the line. Leak detection can be significantly enhanced by the application of molecular sensory technology in tandem with real time pipeline monitoring systems. The systems are synergistic and do not compete with each other. This paper describes the development of the LEOS® leak detection system, its application and operational experience in high sensitivity locations. Four distinct applications are described, including: an Arctic subsea pipeline, an arctic above ground pipeline, a river crossing, and a buried onshore pipeline right of way. In the latter, a situation is described where a hydrocarbon leak was discovered on an adjacent third party pipeline not directly monitored by the system.

scholarly journals A Synthetic Biology Approach Using Engineered Bacteria to Detect Perfluoroalkyl Substance (PFAS) Contamination in Water

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 801-807
Author(s):  
Nathaniel A Young ◽  
Ryan L Lambert ◽  
Angela M Buch ◽  
Christen L Dahl ◽  
Jackson D Harris ◽  
...  
Keyword(s):  
Synthetic Biology ◽  
Dna Sequences ◽  
Detection System ◽  
The United States ◽  
Detection Methods ◽  
Health Concern ◽  
Contaminated Water ◽  
Engineered Bacteria ◽  
Synthetic Biology Approach ◽  
Rhodococcus Jostii

ABSTRACT Introduction Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic compounds used industrially for a wide variety of applications. These PFAS compounds are very stable and persist in the environment. The PFAS contamination is a growing health issue as these compounds have been reported to impact human health and have been detected in both domestic and global water sources. Contaminated water found on military bases poses a potentially serious health concern for active duty military, their families, and the surrounding communities. Previous detection methods for PFAS in contaminated water samples require expensive and time-consuming testing protocols that limit the ability to detect this important global pollutant. The main objective of this work was to develop a novel detection system that utilizes a biological reporter and engineered bacteria as a way to rapidly and efficiently detect PFAS contamination. Materials and Methods The United States Air Force Academy International Genetically Engineered Machine team is genetically engineering Rhodococcus jostii strain RHA1 to contain novel DNA sequences composed of a propane 2-monooxygenase alpha (prmA) promoter and monomeric red fluorescent protein (mRFP). The prmA promoter is activated in the presence of PFAS and transcribes the mRFP reporter. Results The recombinant R. jostii containing the prmA promoter and mRFP reporter respond to exposure of PFAS by activating gene expression of the mRFP. At 100 µM of perfluorooctanoic acid, the mRFP expression was increased 3-fold (qRT-PCR). Rhodococcus jostii without exposure to PFAS compounds had no mRFP expression. Conclusions This novel detection system represents a synthetic biology approach to more efficiently detect PFAS in contaminated samples. With further refinement and modifications, a similar system could be readily deployed in the field around the world to detect this critical pollutant.

Pipeline Diagnostics With Ultrasonic Meters

2016 ◽  
Author(s):  
Nicole Gailey ◽  
Noman Rasool
Keyword(s):  
Real Time ◽  
Measurement Errors ◽  
Flow Measurement ◽  
Detection System ◽  
Leak Detection ◽  
The United States ◽  
Time Data ◽  
Critical System ◽  
Detection Systems ◽  
Transient Models

Canada and the United States have vast energy resources, supported by thousands of kilometers (miles) of pipeline infrastructure built and maintained each year. Whether the pipeline runs through remote territory or passing through local city centers, keeping commodities flowing safely is a critical part of day-to-day operation for any pipeline. Real-time leak detection systems have become a critical system that companies require in order to provide safe operations, protection of the environment and compliance with regulations. The function of a leak detection system is the ability to identify and confirm a leak event in a timely and precise manner. Flow measurement devices are a critical input into many leak detection systems and in order to ensure flow measurement accuracy, custody transfer grade liquid ultrasonic meters (as defined in API MPMS chapter 5.8) can be utilized to provide superior accuracy, performance and diagnostics. This paper presents a sample of real-time data collected from a field install base of over 245 custody transfer grade liquid ultrasonic meters currently being utilized in pipeline leak detection applications. The data helps to identify upstream instrumentation anomalies and illustrate the abilities of the utilization of diagnostics within the liquid ultrasonic meters to further improve current leak detection real time transient models (RTTM) and pipeline operational procedures. The paper discusses considerations addressed while evaluating data and understanding the importance of accuracy within the metering equipment utilized. It also elaborates on significant benefits associated with the utilization of the ultrasonic meter’s capabilities and the importance of diagnosing other pipeline issues and uncertainties outside of measurement errors.

Leak Detection Method Based on Pressure Wave Change

2006 ◽  
Author(s):  
XianYong Qin ◽  
LaiBin Zhang ◽  
ZhaoHui Wang ◽  
Wei Liang
Keyword(s):  
Pressure Wave ◽  
Detection System ◽  
Sudden Change ◽  
Leak Detection ◽  
Special Focus ◽  
Oil Pipeline ◽  
Scada System ◽  
Wave Change ◽  
Ole For Process Control ◽  
Pipeline Pressure

Reliability, sensitivity and detecting time under practical operational conditions are the most important parameters of a leak detection system. With the development of hardware and software, more and more pipelines are installed with advanced SCADA (Supervisory Control and Data Acquisition) system, so the compatibility of the leak detection system with SCADA system is also becoming important today. Pipeline leakage generates a sudden change in the pipeline pressure and flow. The paper introduces leak detecting methods according to the pipeline pressure wave change. In order to improve the compatibility of the leak detecting system, “OPC (Ole for process Control)” technology is used for obtaining the pressure signals from the distributed data collection system. Special focus is given on analysis of the pressure signals. It is successful to denoise the signals by means of wavelet scale shrinkage, and to capture the leak time tag using wavelet transform modulus maximum for locating the leak position accurately. A leak detecting system is established based on SCADA system. Tests and practical applications show that it locates leak position precisely. Good performance is obtained on both crude oil pipeline and product pipeline.

Remote and Intelligent Diagnostic Methods on Leakage Fault for Crude Oil Pipelines

2006 ◽  
Author(s):  
Lai-Bin Zhang ◽  
Zhao-Hui Wang ◽  
Wei Liang
Keyword(s):  
Real Time ◽  
Remote Monitoring ◽  
Data Exchange ◽  
Detection System ◽  
Leak Detection ◽  
Diagnostic Methods ◽  
Oil Fields ◽  
Detection Methods ◽  
Development Environment ◽  
Oil Pipelines

Oil and gas transportation pipelines are the key equipment in petroleum and chemical industry. At present, with the increase of transportation task in oil fields, real-time leak detection system becomes a demand that petroleum companies need to safeguard routines. At the heart of the leakage monitoring and detection procedures are the report of leakage event timely and of leakage point precisely. This paper presents a more realistic approach for using rarefaction-pressure wave technique in oil pipelines, which aims to two targets, one is the improvement of remote and intelligent degree, and the other is the improvement of the leakage location ability. This paper introduces a new scheme to meet the requirements of real time and high data transferring necessary for remote monitoring and leak detection methods for pipelines. The scheme is based on SCADA framework for remote pipeline leakage diagnosis, in which the Dynamic Data Exchange technology is utilized to construct the data-acquiring component to acquire the real-time information that could perform remote test and analysis. It also introduces a basic concept and structure of the remote leak detection system. Primarily, an embedded leak-detection package is designed to exchange the diagnostic information with the RTU data package of Modbus protocol, and then via fiber network, the SCADA-based remote monitoring and leak detection system is realized. Existing data acquisition apparatus applied in oil fields and city underground water pipeline is used, without changing the structure of pipeline supervisory system. This paper introduces the method of constructing DDE-based hot links between servers and client terminals, using Borland C++ Builder 6.0 development environment, and also explains the universality and friendliness of the method. It can easily access similar Windows’ applications simply by modifying Service names, Topic options and data Items. System feasibility was tested using negative-pressure data from oil-fields. Additionally, the applied results show that the whole running status of pipeline can be monitored effectively, and a higher automation grade and an excellent leak location precision of the system can be obtained.

High Sensitivity External Leak Detection for Liquid Fuel Pipelines

2004 ◽  
Author(s):  
David G. Parman ◽  
Ken McCoy
Keyword(s):  
Liquid Fuel ◽  
Risk Mitigation ◽  
Detection System ◽  
High Sensitivity ◽  
Leak Detection ◽  
Liquid Fuels ◽  
Detection Methods ◽  
Environmental Damage ◽  
Distributed Sensor ◽  
Environmentally Sensitive Areas

Pipeline risk mitigation in high consequence areas can be facilitated through the use of a high sensitivity external leak detection (HSELD) system. Such systems have been implemented for both off-site and on-site pipeline applications, including the Longhorn Pipeline (Texas) and the Madrid Barajas International Airport (Spain). We define high-sensitivity external leak detection as a leak detection system that will continuously and automatically detect very small amounts of liquid fuels and is physically independent of pipeline pumping operations. In addition, such systems monitor their own integrity on a continuous basis, without requiring periodic recalibration or operator interaction. The HSELD system we describe incorporates a distributed sensor cable, installed in a slotted PVC conduit which is run in close proximity to the pipeline. Many pipeline leaks start out as very small cracks or holes resulting from corrosion and wear. In their initial stages, such leaks go undetected by standard leak detection methods, but over time large volumes of liquid fuel may leak into the environment. In high consequence areas, such as above aquifers and other environmentally sensitive areas, the leak may go undetected until traces show up in water samples. The critical characteristic of an effective HSELD is its ability to detect and accurately locate very small volumes of liquid fuels, so that these small leaks can be identified, cleaned up and repaired before environmental damage is done.

scholarly journals Numerical Analysis of a Mobile Leakage-Detection System for a Water Pipeline Network

2021 ◽  
Vol 87 (1) ◽  
pp. 134-150
Author(s):  
Balbir Singh ◽  
Usman Ikhtiar ◽  
Mohamad Firzan ◽  
Dong Huizhen ◽  
Kamarul Arifin Ahmad
Keyword(s):  
Drag Coefficient ◽  
Detection System ◽  
Leak Detection ◽  
Detection Methods ◽  
Detection Accuracy ◽  
New Model ◽  
Pressure Drag ◽  
Pipeline Networks ◽  
Water Pipeline ◽  
And Control

The leakages in water pipeline networks sometimes negatively affect the environment, health, and economy. Therefore, leak detection methods play a crucial role in detecting and localizing leaks. These methods are categorized into internal and external detection methods, each having its advantages and certain limitations. The internal system has its detection based on the field sensors to monitor internal pipeline parameters such as temperature and pressure, thereby inferring a leak. However, the mobility of the sensing module in the pipeline is affected by the model drag coefficient. The low drag coefficient causes the module to quickly lost control in the pipeline leading to false detection. Therefore, this study is about designing and numerically analysing a new model to achieve a higher drag value of the sensing system. The drag value of various models is determined with the help of CFD simulations in ANSYS. The outcome of this study is a new model with a drag value of 0.6915. It was achieved by implementing an aerodynamic shape, a more significant surface contact area in the middle, and canted fins at the front of the . Both pressure, drag, and skin friction were increased, so a higher drag value of the sensing module can be achieved. Through this, the mobility and control of modules in the pipeline can be improved, improving leak detection accuracy.

Assessment of the Performance of Acoustic and Mass Balance Methods for Leak Detection in Pipelines for Transporting Liquids

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Jaqueline Costa Martins ◽  
Paulo Seleghim
Keyword(s):  
Mass Balance ◽  
Detection System ◽  
Experimental Tests ◽  
Leak Detection ◽  
Detection Methods ◽  
Working Fluid ◽  
Main Concern ◽  
Pressure Transducers ◽  
On Line ◽  
Reference Situation

On-line leak detection is a main concern for the safe operation of pipelines. Acoustic and mass balance are the most important and extensively applied technologies in field problems. The objective of this work is to compare these leak detection methods with respect to a given reference situation, i.e., the same pipeline and monitoring signals acquired at the inlet and outlet ends. Experimental tests were conducted in a 749 m long laboratory pipeline transporting water as the working fluid. The instrumentation included pressure transducers and electromagnetic flowmeters. Leaks were simulated by opening solenoid valves placed at known positions and previously calibrated to produce known average leak flow rates. Results have clearly shown the limitations and advantages of each method. It is also quite clear that acoustics and mass balance technologies are, in fact, complementary. In general, an acoustic leak detection system sends out an alarm more rapidly and locates the leak more precisely, provided that the rupture of the pipeline occurs abruptly enough. On the other hand, a mass balance leak detection method is capable of quantifying the leak flow rate very accurately and of detecting progressive leaks.

Leak Detection—Transient Flow Simulation Approaches

1995 ◽  
Vol 117 (3) ◽  
pp. 243-248 ◽  
Author(s):  
J. C. P. Liou ◽  
J. Tian
Keyword(s):  
Transient Flow ◽  
Flow Simulation ◽  
Leak Detection ◽  
Field Trials ◽  
Flow Conditions ◽  
Flow Measurements ◽  
Data Noise ◽  
Flow Simulations ◽  
Moderate Size ◽  
Detection Algorithms

The basis for and field trials of two leak detection algorithms by transient flow simulations are presented. Data noise in pressure and flow measurements are considered. Noise is found to limit leak detectability. The ability of the two algorithms to reliably detect small to moderate size leaks under steady and transient flow conditions is demonstrated.

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