Gas Pipeline Failure Caused by In-Service Welding

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
A. Farzadi
Keyword(s):  
Failure Analysis ◽  
Gas Pipeline ◽  
Operating Conditions ◽  
Pipe Material ◽  
Natural Gas Pipeline ◽  
Repair Operation ◽  
Repair Procedure ◽  
Hydrogen Assisted Cracking ◽  
Major Factors ◽  
Material Information

In the research presented in this paper, a failure analysis had been carried out to identify causes of an incident, which had taken place after an operation to repair a leak in an interstate natural gas pipeline. In this operation, a partial encirclement reinforcement (patch) was welded to the carrier pipe according to an available hot taping procedure, while gas was flowing in the pipeline. The failure analysis commenced with preliminary steps of information gathering of background data regarding the repair operation and then several samples were extracted for macroscopic and microscopic metallurgical examinations. In addition to fractographic analyses of fracture surfaces, pipe material was examined because the pipeline had been in service for prolonged period and there was not any official material information available. The analyses disclose that hydrogen-assisted cracking, wrong design of branch connection, paint coating, and pipeline operating conditions were major factors contributing to the failure. The work undertaken also included development and recommendation of a repair procedure to avoid similar failures in the future.

Failure analysis of a natural gas pipeline subjected to landslide

2021 ◽  
Vol 119 ◽  
pp. 105009
Author(s):  
Akbar Vasseghi ◽  
Ebrahim Haghshenas ◽  
Aram Soroushian ◽  
Masoumeh Rakhshandeh
Keyword(s):  
Natural Gas ◽  
Failure Analysis ◽  
Gas Pipeline ◽  
Natural Gas Pipeline

scholarly journals Full-Scale Experimental Verification of the Explosion Shock Wave Model of a Natural Gas Pipeline

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Shaohua Dong ◽  
Yinuo Chen ◽  
Xuan Sun ◽  
Hang Zhang
Keyword(s):  
Shock Wave ◽  
Natural Gas ◽  
Wave Model ◽  
Full Scale ◽  
Gas Pipeline ◽  
Operating Conditions ◽  
Natural Gas Pipeline ◽  
Tnt Equivalent ◽  
The Absolute ◽  
Shock Wave Model

As developments in natural gas pipelines increasingly incorporate higher grades of steel, larger diameters, and higher pressures, the consequences of an accident caused by leakage, explosion, or ignition become progressively more severe. Currently, major technical obstacles include the quantification of the impact of an explosion shock wave of a high-strength, large-diameter natural gas pipeline, and the selection of a reasonable shock wave overpressure model appropriate to the operating conditions. In this paper, six models of shock wave overpressure theories, namely, the TNT equivalent method, the TNO method, the multienergy method, the British Gas method, the Shell method, and the Lee formula, were compared and analyzed to determine their applicability. A shock wave model adapted to the characteristics of a full-scale test was proposed, and the model verification of a full-scale blasting test was conducted on pipelines with diameters of 1422 mm and 1219 mm, respectively. Subsequent results indicated that the modifications to the TNT equivalent and the test parameters correlated with changes in the suitability of the model. Henrych’s formula calculation model of the British Gas method was found to correspond strongly with the measured value, in which the absolute value of the relative error was less than 30% and the absolute error within the range of 78 m to 800 m was no more than 0.05 MPa. Thus, the Henrych formula was adopted as the primary model formula for the shock wave overpressure calculations in this study. To further correct the error of the model, the trend between the curve obtained by the Henrych formula and the fitting curve of the measured value was compared and analyzed. The positive and negative compensations of the shaded area before and after the intersection point were carried out, and the new error correction overpressure model formula was obtained by fitting, with the error controlled within 15%.

Failure analysis of a natural gas pipeline

2018 ◽  
Vol 84 ◽  
pp. 167-184 ◽  
Author(s):  
Hadi Shabani ◽  
Narges Goudarzi ◽  
Mahdi Shabani
Keyword(s):  
Natural Gas ◽  
Failure Analysis ◽  
Gas Pipeline ◽  
Natural Gas Pipeline

Internal Corrosion Monitoring System Selection for Cross Country Natural Gas Pipeline: A Case Study of SHPPL

2015 ◽  
Author(s):  
Sandeep Vyas
Keyword(s):  
Natural Gas ◽  
Monitoring System ◽  
Gas Pipeline ◽  
Operating Conditions ◽  
Corrosion Monitoring ◽  
Compressor Station ◽  
Internal Corrosion ◽  
Monitoring Techniques ◽  
Natural Gas Pipeline ◽  
Pipeline Project

Reliance Gas Pipelines Limited (RGPL) is currently implementing a gas pipeline project from Shahdol, Madhya Pradesh to Phulpur, Uttar Pradesh for evacuation of gas produced from Coal Bed Methane (CBM) blocks owned by Reliance Industries Ltd. This pipeline will be hooked up with GAIL’s HVJ Pipeline at Phulpur. Over all Pipeline system includes 312 km (approx.) long trunk line, and associated facilities such as Compressor Station at Shahdol, Intermediate Pigging facilities, Metering & Regulating facilities at Phulpur and 12 No. Mainline valve stations. Gas produced from CBM blocks will be dehydrated within Gas Gathering Station facilities of CBM Project located upstream of pipeline Compressor station at Shahdol. Gas received at pipeline battery limit is dry and non-corrosive gas in nature, Internal corrosion is not expected in normal course of operation, however internal corrosion of the natural gas pipeline can occur when the pipe wall is exposed to moisture and other contaminants either under process upset conditions or under particular operating conditions. Even though internal corrosion is not expected during normal course of operations, to take care of any eventuality, it is proposed to implement Internal Corrosion Monitoring (ICMS) system in this project. ICMS will provide an efficient and reliable means of continuous monitoring internal corrosion. Internal Corrosion Monitoring (ICMS) system is used as a part of overall integrity management framework; to achieve two objectives viz., verify the corrosive behaviour of gas and to verify the efficacy of applied preventive actions. Philosophy involved in evaluating a suitable CM technique would include : • Applicable corrosion damage mechanisms, anticipated corrosion rates and probable locations. • Suitable CM technique and location based on process condition, system corrosivity, water content, pigging facilities, available corrosion allowance, design life, maintenance etc., • Measurement frequency. Some of the Corrosion Monitoring techniques used for pipeline and of relevance are: • Weight-loss Corrosion Coupons (CC), • Electrical Resistance probes (ER), • Linear Polarization Resistance Probe (LPR) • Ultrasonic Thickness Measurement (UT) • Sampling Points (SP) This paper discusses the merits / demerits of these corrosion monitoring techniques, considerations for selecting a specific technique for the Shahdol – Phulpur Gas Pipeline Project and highlights the implementation of the internal corrosion monitoring system.

scholarly journals Numerical Simulation of Natural Gas Pipeline Transients

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Abdoalmonaim S. M. Alghlam ◽  
Vladimir D. Stevanovic ◽  
Elmukhtar A. Elgazdori ◽  
Milos Banjac
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Computer Code ◽  
Gas Pipeline ◽  
Operating Conditions ◽  
Transient Effects ◽  
Natural Gas Pipeline ◽  
Transmission Pipeline ◽  
Variable Consumption ◽  
Isothermal Gas

Simulations of natural gas pipeline transients provide an insight into a pipeline capacity to deliver gas to consumers or to accumulate gas from source wells during various abnormal conditions and under variable consumption rates. This information is used for the control of gas pressure and for planning repairs in a timely manner. Therefore, a numerical model and a computer code have been developed for the simulation of natural gas transients in pipelines. The developed approach is validated by simulations of test cases from the open literature. Detailed analyses of both slow and fast gas flow transients are presented. Afterward, the code is applied to the simulation of transients in a long natural gas transmission pipeline. The simulated scenarios cover common operating conditions and abrupt disturbances. The simulations of the abnormal conditions show a significant accumulation capacity and inertia of the gas within the pipeline, which enables gas packing and consumers supply during the day time period. Since the numerical results are obtained under isothermal gas transient conditions, an analytical method for the evaluation of the difference between isothermal and nonisothermal predictions is derived. It is concluded that the nonisothermal transient effects can be neglected in engineering predictions of natural gas packing in long pipelines during several hours. The prescribed isothermal temperature should be a few degrees higher than the soil temperature due to the heat generation by friction on the pipelines wall and heat transfer from the gas to the surrounding soil.

Corrosive wear failure analysis in a natural gas pipeline

Wear ◽  
2007 ◽  
Vol 263 (1-6) ◽  
pp. 567-571 ◽  
Author(s):  
M.A.L. Hernández-Rodríguez ◽  
D. Martínez-Delgado ◽  
R. González ◽  
A. Pérez Unzueta ◽  
R.D. Mercado-Solís ◽  
...  
Keyword(s):  
Natural Gas ◽  
Failure Analysis ◽  
Corrosive Wear ◽  
Gas Pipeline ◽  
Natural Gas Pipeline

The Dynamic Simulation of a Long Distance Natural Gas Pipeline

2012 ◽  
Vol 268-270 ◽  
pp. 1244-1248
Author(s):  
Shan Bi Peng ◽  
En Bin Liu ◽  
Xiao Chun Du ◽  
Rong Lin Hong
Keyword(s):  
Natural Gas ◽  
Gas Pipeline ◽  
Operating Conditions ◽  
Pipeline System ◽  
Long Distance ◽  
Natural Gas Pipeline ◽  
Operation Conditions ◽  
Condition Change ◽  
Gas Market ◽  
The One

With the growth of the natural gas market, the long distance natural gas pipeline system is getting more and more important in nowadays. As a united and enclosed hydraulic system, the operation conditions of the whole line will be changed by the influence of the condition change in one station. On the one hand, the condition change made people analyze operation scheme more difficult, on the other hand, pipeline system operating conditions directly affect the relationship between the production and the sales of natural gas. Therefore, the operation of the gas pipeline must be optimized, which brings huge economic and social benefits. This paper constructed a simulation model of a long distance natural gas pipeline by TG.net, and then analyzed the change of the operating condition of the pipeline after a compressor station shut down, found out the regularity.

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