An Automated Leak Detection and Location System in a Brazilian Liquid Ammonia Pipeline

2006 ◽  
Author(s):  
Emir Ceciliato ◽  
Claudia C. Magalha˜es ◽  
David G. P. Bueno
Keyword(s):  
Liquid Ammonia ◽  
Detection System ◽  
Main Idea ◽  
Ammonium Hydroxide ◽  
Leak Detection ◽  
Field Trials ◽  
Raw Material ◽  
Ratio Test ◽  
Human Intervention ◽  
Initial Field

Liquid ammonia is the basis of a variety of products, ranging from fertilisers, important intermediate chemical raw material (such as nitric acid and ammonium hydroxide), cosmetics, up to explosives. It is a very toxic product, requiring special care when transported. This paper shall present an automated leak detection system (i. e., without human intervention for shutting pumps down) for a short (approximately 6 kilometres long), 6 inch., liquid ammonia pipeline located at the city of Cubata˜o, state of Sa˜o Paulo, Brazil, within the bounds of a fertiliser producer. The pipeline runs from a Terminal (which is a port) down to a fertiliser complex, where the ammonia is used as raw material to produce ammonium nitrate. There is approximately 3.5 km of buried pipes, as well as 2.5 km of aerial ones. A special set of insulation layers is coating pipeline segments in order to keep ammonia in an undercooled temperature (and showing an undercooled liquid behaviour, as a consequence). The selected leak detection system is based on statistical concepts, using the SPRT (Sequential Probability Ratio Test) sampling technology. The main idea is to establish an automated procedure in which the LDS is capable of sending an alarm signal directly to the SCADA, to shut down pumps, without human intervention. The system architecture is covered, as well as the details on the pipeline hydraulics and ammonia transport properties (especially density and viscosity). Finally, initial field trials data are provided and analysed.

Leak Detection in a Pipeline Using Modified Line Volume Balance and Sequential Probability Tests

2006 ◽  
Author(s):  
Marti´n Di Blasi ◽  
Carlos Muravchik
Keyword(s):  
Dynamic Range ◽  
Detection System ◽  
Real Data ◽  
Leak Detection ◽  
Normal Operation ◽  
Ratio Test ◽  
Oil Pipeline ◽  
Probability Ratio ◽  
Volume Balance ◽  
Sequential Probability

The use of statistical tools to improve the decision aspect of leak detection is becoming a common practice in the area of computer pipeline monitoring. Among these tools, the sequential probability ratio test is one of the most named techniques used by commercial leak detection systems [1]. This decision mechanism is based on the comparison of the estimated probabilities of leak or no leak observed from the pipeline data. This paper proposes a leak detection system that uses a simplified statistical model for the pipeline operation, allowing a simple implementation in the pipeline control system [2]. Applying linear regression to volume balance and average pipeline pressure signals, a statistically corrected volume balance signal with reduced variance is introduced. Its expected value is zero during normal operation whereas it equals the leak flow under a leak condition. Based on the corrected volume balance, differently configured sequential probability ratio tests (SPRT) to extend the dynamic range of detectable leak flow are presented. Simplified mathematical expressions are obtained for several system performance indices, such as spilled volume until detection, time to leak detection, minimum leak flow detected, etc. Theoretical results are compared with leak simulations on a real oil pipeline. A description of the system tested over a 500 km oil pipeline is included, showing some real data results.

Leak Detection in a Pipeline Using Modified Line Volume Balance and Sequential Probability Tests

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Martín Di Blasi ◽  
Carlos Muravchik
Keyword(s):  
Dynamic Range ◽  
Detection System ◽  
Real Data ◽  
Leak Detection ◽  
Normal Operation ◽  
Ratio Test ◽  
Oil Pipeline ◽  
Probability Ratio ◽  
Volume Balance ◽  
Sequential Probability

The use of statistical tools to improve the decision process within leak detection is becoming a common practice in the area of computer pipeline monitoring. Among these tools, the sequential probability ratio test is one of the most named techniques used by commercial leak detection systems (Zhang and Di Mauro, 1998, “Implementing a Reliable Leak Detection System on a Crude Oil Pipeline,” Advances in Pipeline Technology, Dubai, UAE). This decision mechanism is based on the comparison of the estimated probabilities of leak or no leak observed from the pipeline data. This paper proposes a leak detection system that uses a simplified statistical model for the pipeline operation, allowing a simple implementation in the pipeline control system (Di Blasi, M., 2004, “Detección y localización de fugas en sistemas de transporte de fluidos incompresibles,” MS thesis, Universidad Nacional de La Plata, Buenos Aires, Argentina). Applying real-time recursive linear regression to volume balance and average pipeline pressure signals, a statistically corrected volume balance signal with reduced variance is derived. Its average value is zero during normal operation whereas it equals the leak flow under a leak condition. Based on the corrected volume balance, differently configured sequential probability ratio tests are presented to extend the dynamic range of detectable leak flow. Simplified mathematical expressions are obtained for several system performance indices, such as spilled volume until detection, time to leak detection, minimum leak flow detected, etc. Theoretical results are compared with leak simulations on a real oil pipeline. A description of the system tested over a 500 km oil pipeline is included, showing some real data results.

A Study of Multi-Method Based Subsea Pipeline Leak Detection System

2016 ◽  
Author(s):  
Yanyao Li ◽  
Tianyu Zhang ◽  
Weidong Ruan ◽  
Yong Bai ◽  
Chuntian Zhao
Keyword(s):  
Pattern Recognition ◽  
Detection System ◽  
Leak Detection ◽  
Recognition System ◽  
Economic Losses ◽  
Environmental Damage ◽  
False Alarms ◽  
Ratio Test ◽  
Balance Principle ◽  
Statistical Analysis Method

Pipelines are of most importance to subsea systems. The leakage of pipelines which may be caused by aging or corrosion will lead to serious environmental damage and significant economic losses. In this paper, a submarine pipeline leak detection system is developed to protect environment and also improve the safety of subsea system via quick detection and relatively correct location. The leak detection system includes data acquisition devices, wireless communication devices, the calculation part is also involved, like data processing module, leak detection module, pattern recognition module and positioning module. The corrected flow balance principle and a statistical analysis method, namely Wald’s Sequential Probability Ratio Test (SPRT), are used to decide whether it is leak-free or leak-present. Besides, a pattern recognition system is developed to minimize false alarms. The method of Hydraulic Grade Line was employed to locate the leakage. Our study provides a quick response to leak detection as well as leak location. A quick and convenient method to leak detection and location is provided by this paper.

PENGEMBANGAN BAHAN AJAR BERBASIS PENDEKATAN OPEN ENDED PADA MATERI FPB/KPK KELAS IV UNTUK MENINGKATKAN KEMAMPUAN PENALARAN SISWA DI SD NEGERI TAMBAKREJO 01 SEMARANG

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Ambar Widianingrum ◽  
Joko Sulianto ◽  
Rahmat Rais
Keyword(s):  
Data Analysis ◽  
Research And Development ◽  
Teaching And Learning ◽  
Analysis Data ◽  
Field Trials ◽  
Teaching Materials ◽  
Initial Field ◽  
Analysis Technique ◽  
Quantitative Descriptive ◽  
Stage 1

The purpose of this study was to describe the feasibility of teaching materials based on an open-ended approach to improve the reasoning abilities of fourth grade students in elementary schools. This type of research is research and development (Research and Development). The subjects of this study were 3 classroom teachers. The data analysis technique used is descriptive qualitative data analysis (data reduction, data presentation and conclusion) and quantitative descriptive data analysis. Based on the results of stage 1 media validation, it was obtained 84.8%, and the results of stage 2 media validation were obtained 94.8%. The result of material validation for stage 1 was obtained 84.6%, and validation for material for stage 2 was obtained 93.3%. The results of initial field trials obtained media 93.7% and material 92.3%. This shows that the teaching material is declared valid and suitable for use. Based on the results of this study, the suggestion that can be conveyed is that teaching materials based on an open-ended approach can be used as a tool for teaching and learning resources for students.

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.

scholarly journals Leak Detection Systems for Short Pipelines

2000 ◽  
Author(s):  
Renan Martins Baptista
Keyword(s):  
Detection System ◽  
Leak Detection ◽  
Low Complexity ◽  
Transient Model ◽  
Service Companies ◽  
Detection Systems ◽  
Volume Balance ◽  
Pipeline Networks ◽  
Phase Liquid ◽  
Flow Detection

This paper describes procedures developed by PETROBRAS Research & Development Center to assess a software-based leak detection system (LDS) for short pipelines. These so-called “Low Complexity Pipelines” are short pipeline segments with single-phase liquid flow. Detection solutions offered by service companies are frequently designed for large pipeline networks, with batches and multiple injections and deliveries. Such solutions are sometimes impractical for short pipelines, due to high cost, long tuning procedures, complex instrumentation and substantial computing requirements. The approach outlined here is a corporate approach that optimizes a LDS for shorter lines. The two most popular implemented techniques are the Compensated Volume Balance (CVB), and the Real Time Transient Model (RTTM). The first approach is less accurate, reliable and robust when compared to the second. However, it can be cheaper, simpler, faster to install and very effective, being marginally behind the second one, and very cost-efective. This paper describes a procedure to determine whether one can use a CVB in a short pipeline.

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