The Use of Hydrotesting and EMAT Inline Inspection Technology for the Integrity Management of Stress Corrosion Cracking (SCC) in Gas Pipelines

Author(s):  
Pedro M. Hryciuk ◽  
Eduardo Carzoglio ◽  
Jose A. Minellono ◽  
Leonardo Martinetto ◽  
Pedro M. Guillen ◽  
...  

This paper describes the activities and stages completed as part of the Integrity Management Program for SCC in the natural gas system of Transportadora de Gas del Norte (TGN-Argentina) which started in 2000. This document focuses in a pipeline section of the system, which suffered an in-service failure in 2002 due to high pH SCC. This event triggered a series of activities, whose results are detailed in this paper. These activities involved soil analysis to determine the susceptibility to develop SCC along the system pipelines. For susceptible sections, the program included hydrostatic testing to levels of 100% and 110% of SMYS followed by replacement of degraded coating. The paper also details the experience in the use of new internal inspection tools with EMAT technology. The capability of the EMAT tool to detect and size SCC defects and the possibility of discriminating between SCC colonies that have been recoated and those that may still be active due to degraded coating is discussed. Finally, the severity of SCC cracks detected by in-line inspection is assessed using API 579 methodology, and the feasibility of using this assessment results to determine the critical SCC defect sizes for detection by ILI tools is analyzed.

Author(s):  
Joe Paviglianiti ◽  
Alan Murray ◽  
Tijani (TJ) Elabor

As a result of numerous stress corrosion cracking incidents in the 1980s and early 1990 the National Energy Board (NEB) held an Inquiry1 in 1995 on the SCC failure mechanism and how to prevent failures. One of the recommendations of the Inquiry was Companies were to develop a SCC management program to proactively identify and mitigate SCC. Based on the apparent success of the SCC programs in significantly reducing SCC failures, the NEB revised its Onshore Pipeline Regulations in 1999 (OPR-99)2 to require companies to develop an integrity management program (IMP) for all hazards. This paper discusses the evolution of integrity management program (IMP) requirements and evaluates incident rates and other performance metrics to determine if there is evidence that IMPs have contributed to the improvement of safety of pipelines. The paper highlights the challenges associated with gathering incident and IMP performance metrics and evaluating the data to determine if there is a correlation between the implementation of IMP and pipeline safety. In addition, the analysis discusses the challenges associated with comparing data between different countries and regulatory jurisdictions. Suggestions for future improvement are identified.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3400
Author(s):  
Jie Xing ◽  
Peng Wu

Bidirectional coupling systems for electricity and natural gas composed of gas units and power-to-gas (P2G) facilities improve the interactions between different energy systems. In this paper, a combined optimization planning method for an electricity-natural gas coupling system with P2G was studied. Firstly, the characteristics of the component model of the electricity-natural gas coupling system were analyzed. The optimization planning model for the electricity-natural gas coupling system was established with the goal of minimizing the sum of the annual investment costs and the annual operation costs. Based on the established model, the construction statuses for different types of units, power lines, and pipelines and the output distribution values for gas units and P2G stations were optimized. Then, the immune algorithm was proposed to solve the optimization planning model. Finally, an electricity-natural gas coupling system composed of a seven-node natural gas system and a nine-node power system was taken as an example to verify the rationality and effectiveness of the model under different scenarios.


Author(s):  
Toby Fore ◽  
Stefan Klein ◽  
Chris Yoxall ◽  
Stan Cone

Managing the threat of Stress Corrosion Cracking (SCC) in natural gas pipelines continues to be an area of focus for many operating companies with potentially susceptible pipelines. This paper describes the validation process of the high-resolution Electro-Magnetic Acoustical Transducer (EMAT) In-Line Inspection (ILI) technology for detection of SCC prior to scheduled pressure tests of inspected line pipe valve sections. The validation of the EMAT technology covered the application of high-resolution EMAT ILI and determining the Probability Of Detection (POD) and Identification (POI). The ILI verification process is in accordance to a API 1163 Level 3 validation. It is described in detail for 30″ and 36″ pipeline segments. Both segments are known to have an SCC history. Correlation of EMAT ILI calls to manual non-destructive measurements and destructively tested SCC samples lead to a comprehensive understanding of the capabilities of the EMAT technology and the associated process for managing the SCC threat. Based on the data gathered, the dimensional tool tolerances in terms of length and depth are derived.


2016 ◽  
Vol 48 ◽  
pp. 257-264 ◽  
Author(s):  
Lin Zhu ◽  
Le Zhang ◽  
Junming Fan ◽  
Peng Jiang ◽  
Luling Li

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