bluuebunny/crossref_metadata_2025_split huggingface dataset:
Considering Roadway Traffic in Quantitative Risk Assessment for Natural Gas Pipelines
Authors: Lu Dongliang , Siraj Tammeen , Warhurst Karen , Dimitriadis Konstantinos , Towers Matt 
Published: December 2022

Abstract
Natural gas transmission pipeline systems can extend thousands of kilometers and traverse both populated and less populated areas. Traditionally, risk assessment of natural gas pipelines performed by TC Energy mostly focuses on evaluating the impact of pipeline failures to occupants of nearby structures. However, it is recognized that natural gas pipelines at road crossings or otherwise running in proximity to roads may also pose risks to motorists or other roadway users. Incidents of pipeline failures damaging road infrastructure, resulting in casualties, have been seen in the past.
This paper reports work undertaken to investigate the risk assessment of natural gas transmission pipelines considering the consequence of pipeline failures to roadway users in addition to occupants of nearby structures. Differences between how pipeline failure consequences should be evaluated for motorists travelling at a high speed in vehicles versus occupants of non-moving structures were investigated. Relevant factors that are unique to consequence assessment for roads, such as vehicle speed and relative position between roads and pipelines, were identified, and the way in which these unique factors can be incorporated in risk assessment was studied.
Based on the results from the study, TC Energy updated its System Wide Risk Assessment program to include consequence of pipeline failures associated with roads and roadway users. Data from a total of over 180,000 km of roadway segments across North America that are located in proximity to TC Energy’s over 90,000 km of natural gas transmission pipelines were analyzed. The societal risk with and without roads were evaluated and compared. The impact of considering roadway traffic in the risk assessment in different areas was assessed and the importance of proper consideration of roadway users in quantitative pipeline risk assessment was demonstrated. The methodology developed in the study is useful in advancing the overall accuracy of risk assessment for the pipeline industry, and particularly for pipeline operators in the US, provides a quantitative assessment tool to evaluate the risks associated with roadway driven Moderate Consequence Areas (MCA) and prioritize the integrity work accordingly.
Establishing Corrosion Growth Rates Based on MFL-C vs. MFL In-Line Inspection Run-to-Run Comparisons
Authors: Graf Eric , Ellinger Matthew , Harper William , Bubenik Thomas , Hickey Stacy , Moreno Pamela 
Published: December 2022

Abstract
Performing in-line inspection (ILI) run-to-run comparisons is a vital component of any pipeline integrity management program. A primary objective of ILI run-to-run comparisons is to establish corrosion growth rates along the length of a given pipeline segment that are defensible, justifiable, and realistic without being overly conservative.
Establishing realistic corrosion growth rates based on ILI data can be challenging, especially when considering different technologies are sometimes employed between the subsequent ILI tool runs. One example of this is a circumferential magnetic flux leakage (MFL-C) ILI survey followed by an axial magnetic flux leakage (MFL) ILI survey. While the two technologies are similar in that both can detect and characterize metal loss anomalies, they differ in the direction of the applied magnetic field. As a result, the tools may detect and characterize (i.e., size) the anomalies differently depending on the shapes and orientations of the anomalies.
This paper explores the differences observed in the detection and sizing of different anomaly types by the two technologies, how these differences contribute to calculated corrosion growth rates, and what considerations should be made when comparing MFL and MFL-C ILI data for the purpose of determining corrosion growth rates.
Review of Hydrogen Induced Cracking of Mid-Wall Defects
Authors: Podnar McMahan Tara , Bubenik Thomas , Padgett B. Nikki , Al-Muslim Husain , Beavers John , Kulkarni Satish 
Published: December 2022

Abstract
There is the potential to demand more of existing infrastructure and introduce uncommon integrity threats as a result of societal challenges to building new cross-country pipelines, the need to traverse more challenging terrain, and the momentum for a hydrogen economy increases. One such threat is hydrogen induced cracking (HIC) of mid-wall defects. HIC is commonly defined in the literature as cracking that initiates within the mid-wall from reformation of molecular hydrogen at mid-wall defects, such as stringers, or microscopic voids in the line pipe steel. In 2020, the Pipeline Research Council International, Inc. (PRCI) funded a project, PRCI Project NDE-1-10, to review the pipeline industry’s current understanding of mid-wall HIC and to identify a potential management strategy for HIC as an integrity threat.
The project included a literature review of key factors influencing HIC and of the capabilities of non-destructive inspection technologies (both in-line and in the field) to detect, identify, and size mid-wall defects and any potential radial cracking associated with HIC. A summary of the key factors as well as non-destructive inspection technologies with the potential to detect and size the mid-wall defects with radial cracking was compiled. As a result of the literature review, gaps in knowledge and experience with HIC were identified. It was determined that there is opportunity to better understand hydrogen exposure, both the amount of hydrogen present in the environment and the amount of time in which the line pipe materials are exposed, required to initiate HIC. The literature review also identified improvement opportunities related to non-destructive inspection technologies with the ability to reliably and consistently detect and size HIC.
A management framework was developed, based upon the key factors that were identified, data offered through case studies by the steering committee, as well as industry subject matter expert interviews and feedback. The framework is comprised of traditional integrity management components with a focus on threat susceptibility, integrity assessment, severity determination, and assessment response. Using the segment’s threat history, environmental factors, and pipe material factors, a high-level threat susceptibility process was developed that categorizes pipeline or dynamic segments into high-high, high, moderate, low, and not covered priorities. A response for each categorization was also developed that ranges from performing an integrity assessment as soon as practical to opportunistic monitoring. This paper provides a high-level summary of the key factors for the threat of HIC, the gaps identified through the literature reviewed as well as industry outreach, and the integrity management framework developed as a result.
Fatigue Threat to Natural Gas Pipelines: An Analysis Approach
Authors: Davis Brett , Hudgins Alex , Bhargava Yash , Patrick Brian , Myca Konrad 
Published: December 2022

Abstract
The United States Pipeline and Hazardous Material Safety Administration (PHMSA) published the amended gas pipeline federal safety standards (49 CFR 192) in October 2019. The updated regulations provide provisions for the execution of fatigue crack growth analyses and remaining life estimates. The fatigue threat has been extended to applicable pipeline segments within the standard for both integrity management, as well as MAOP reconfirmation approaches. Fatigue behavior and analysis of pipelines has been well studied throughout the industry and has been the subject of many publications. However, the practical application of such analyses, which incorporates the use of structural mechanics, fracture mechanics, material property assessments, uncertainty quantification, and risk analysis, requires a procedural approach that connects inputs and outputs, is scalable, and allows for prioritization of pipeline segments. A key component of this process is leveraging a simple method, used on the front-end of the larger fatigue assessment, for identifying and evaluating assets at risk of fatigue crack growth and subsequent ultimate failure from the fatigue threat. The current work outlines a mechanics-based process by which operators can gauge and prioritize pipeline segments based on the susceptibility to fatigue crack growth.
Line Pipe HAZ Softening Susceptibility and Response
Authors: Dinovitzer Aaron , Guest Stuart , Slumkoski Zoe , Tiku Sanjay , Zamil Shafayet , Khotenko Nick , Begg Darren 
Published: December 2022

Abstract
Unexpected girth weld failures have occurred in newly constructed pipelines with acceptable line pipe materials and weldments (i.e., API 5L and 1104 compliant) and yet these welds fabricated without significant discontinuities failed in a ductile manner with strain localized in the weldment region. Heat affected zone (HAZ) softening was identified as one of the contributing factors in these failures. This paper presents the result of a research project developing a “simple” HAZ softening susceptibility test (i.e. easier to do right than wrong) that may be used identify materials prone to HAZ softening. The test developed in a research project supported by the Pipeline Research Council International (PRCI) is intended as a line pipe material susceptibility test rather than a weld procedure acceptance test which could consider the impact of the heating cycles of multi-pass weld procedures.
The test development included the optimization of the welding procedure, sample configuration and support to produce repeatable results, as well as the definition of a testing procedure susceptibility metric considering local maximum and average through thickness softening. The performance of the testing procedure was demonstrated by considering 20 steels, ranging from X52-X70, steel chemical compositions and 1963–2020 manufacturing dates, designed to represent a range of HAZ softening susceptibilities. The development work demonstrated that the potential for HAZ softening cannot be exclusively related to steel chemistry and that the magnitude of softening is correlated to the size (e.g., width) of the HAZ.
The single pass weld test developed and described in this work successfully demonstrated the relative susceptibility of line pipe steels. In addition, Cross weld tensile testing employing digital image correlation was used to illustrate the process of strain accumulation and localization promoted by HAZ softening and is presented in this paper to describe the failure process of affected materials and estimate their residual strength. The single pass weld test results presented may be used in a material acceptance test or identify materials that require attention in to weld application or alternate welding procedures. These results provide opportunities to learn and reduce the risks associated with HAZ softening and this developing sound weldments that can better resist axial load.
Assessing Geohazard Probability of Pipeline Failure: Lessons and Improvements From the Last 10 Years
Authors: Newton Sarah , Van Hove Joel , Porter Michael , Ferris Gerald 
Published: December 2022

Abstract
Geohazards, consisting of geotechnical hazards where ground movements impact pipelines and hydrotechnical hazards where pipelines cross watercourses, can threaten pipeline integrity, causing leaks or ruptures. Given the vast geographies traversed by pipeline infrastructure, geohazard frequency can be high requiring triage of large inventories of identified geohazard sites. Since 2012, field screening probability of failure algorithms have been used to assess and prioritize geohazard threats to pipeline integrity. These algorithms were developed using empirical data from failure case histories, engineering judgement from geohazard professionals, and statistical rates of pipeline impact, exposure, and failure. When combined with consequences, the algorithms provide semi-quantitative risk assessments. The risk assessments are used to compare geohazard threats to other pipeline integrity threats to support cost-benefit decisions for pipeline operation. The algorithms have been applied to 243,000 sites on 440,000 km of oil and gas gathering, transmission, and distribution pipelines primarily in Canada and the United States.
In this paper, lessons learned from applying probability of failure algorithms to geohazard sites over the past 10 years are shared. The algorithms have proved successful in that their use has allowed pipeline operators to focus their integrity management effort on higher probability of failure sites. Use of the algorithms also allows operators to reduce investment on low probability of failure geohazard crossings. For example, the probability of failure assessments provide justification for less frequent reinspection intervals of low probability of failure sites, while providing clear means of advocating for the need to mitigate and monitor high probability of failure geohazard sites. Over the past decade, recalibration of the algorithms has reduced conservatism in earlier versions. As well, advancements in data collection, storage, and quality assurance have been undertaken to improve accuracy.
This paper describes the methods used to assess probability of failure for pipeline landslide and watercourse crossings. The use cases and limitations of the algorithms are also discussed.
Engineering Critical Assessment of Dents and Dents With Cracks Using Inline Inspection Data
Authors: Krishna Shree 
Published: December 2022

Abstract
Dented pipes with typical strain measurements greater than 6% are considered unacceptable, and further assessment using the finite element (FE) procedure is conducted. FE procedures are conducted using specific dent profiles based on the shape of indenters. The actual shape of a real dent differs from the simplified dent shapes that are assumed in engineering critical assessment, thereby compromising the accuracy, especially if there are two side-by-side dents. Several papers used simplified indenter profiles to generate strain and critical damage values. Such a simplified profile can generate non-conservative results, especially if there is an interaction with a nearby dent or residual stresses from the weld. These drawbacks are resolved using an innovative workflow outlined in this paper.
This paper elaborates on developing an approach by creating the dent surface from the ILI measurement data to evaluate the dented pipes. The results illustrate the importance of using accurate ILI measurement data to obtain dent strains and dent-based damage. Residual stress from the presence of weld adjacent to the dent can also be used conveniently by these approaches and is more amenable for the wider types of analyses. Approaches outlined in the paper will also illustrate how to analyze the dented pipes with cracks conveniently. The presence of cracks at the dent would significantly increase the stress intensity factor. Crack assessment for dents with cracks is a tedious FE procedure, which can be simplified using the polynomial stress distribution. Stresses from a dented profile with the cracks are obtained using this analysis which can thereby be used for crack assessment. Stress intensity factors of the cracks in the dent can be obtained using these approaches and can be further used for crack assessment. Finally, the remaining life of dented pipes with and without cracks is presented using the FE analyses results.
Application of Strain Based Assessment in Support of Operational and Mitigation Decisions
Authors: Liu Banglin , Wang Yong-Yi , Chen Xiaotong 
Published: December 2022

Abstract
A confirmed pipeline displacement due to ground movements often requires operational decisions regarding flow restriction and/or field mitigation. Some of the more frequently employed techniques for assessing the magnitude of the applied strain (strain demand), such as in-line inertial measurement unit (ILI IMU) or pipe-soil interaction analysis, may not be able to accommodate the timeframe for such decisions. The resulting lack of quantified strain demand and strain demand limit can potentially cause prolonged service interruptions or unnecessary field work under unfavorable access conditions.
A multi-leveled strain-based assessment (SBA) process is presented that was designed to support operational and mitigative decisions after confirmed pipe displacements. At the lower level, the methodology utilizes pipe locator data in conjunction with generalized pipe displacement profiles for quick determination of strain demands. At the higher level, conventional pipe-soil interaction analysis is used to refine the strain demand estimate as additional site data become available. The tensile strain capacity (TSC) is determined using one of three available options based on data availability. Integrity assessments can then be performed for both the current operating condition and future scenarios. For sites deemed safe at the moment of assessment, allowable movements at a future point can be established based on the margins between the strain demand and strain capacity. The allowable movements can be used in conjunction with geotechnical assessment to establish re-assessment intervals and trigger further field verification or mitigation activities.
An example SBA of a landslide in the Appalachian region is presented to illustrate the applications of the multi-leveled process with key considerations and some practical constraints in mind. Two gas transmission pipelines in a shared right of way were displaced after a slope movement. Pipeline A was shut-in immediately due to a larger displacement while Pipeline B remained in operation pending an integrity assessment. An initial lower-level SBA indicated neither pipeline had a sufficient margin between the strain capacity and the strain demand. Pipeline B was shut-in as a result. The initial assessment also pointed to different directions for refined assessments. Pipeline A, with the higher TSC and demand estimates, was subject to a refined pipe-soil interaction analysis to reduce the potential over-estimation of the strain demand. Pipeline B, with the lower TSC and demand estimates, was subject to in-ditch NDE in a controlled excavation, so that the TSC estimate can be updated with accurate weld-specific flaw information. The refined assessment indicated sufficient margins of safety for both pipelines. Consequently, both lines were returned to service, and a slide repair was implemented.
Understanding Principal Drivers to Burst Pressure and Local Deformation of Pipes With SCC Colonies
Authors: Wang Yong-Yi , Wang Alex , Leis Brian , Rapp Steven C. , Vervake Gary 
Published: December 2022

Abstract
Two pups with SCC colonies were removed from service. The most dominant cracks in the colonies are short and deep. One of the pups had a bulge in the area of the SCC colony. The two pups were subjected to hydrostatic burst tests and detailed post-test metallurgical examination. A companion paper covers the formation, dormancy, and growth of these SCC colonies using forensic analysis. This paper covers two main elements aimed at understanding the behavior of pipes with SCC colonies and supporting the work covered in the companion paper:
(1) Burst pressure prediction, and
(2) Analysis of the bulge.
Burst pressure predictions were made with available material properties and flaw dimensions measured by MPI, UT, and PAUT prior to the actual burst tests. After the burst tests, the predictions were updated with more relevant material property data and the flaw dimensions obtained from fracture surfaces exposed. The modified Ln-Sec, CorLAS™, MAT-8, and Level 2 of API 579 burst pressure models and the associated Charpy to fracture toughness correlations were used. Two flaw interaction rules, CEPA and PRCI-CRES, were used to determine the single equivalent crack dimensions for input into the burst pressure models. The burst pressure predictions were compared with the experimentally measured burst pressures.
Of the multiple factors affecting the burst pressure prediction, the selection of flaw interaction rules has the most prominent impact on the accuracy of the burst pressure prediction. The selection of burst pressure models has a secondary impact with the exception of API 579, which tends to give lower burst pressure predictions than other models.
The formation of the bulge was simulated under different longitudinal/axial loading conditions and two levels of internal pressure. It is shown that the level of the residual bulge has a strong dependence on the severity of SCC (length, depth, and spatial distribution), the level of maximum internal pressure before depressurization, and the longitudinal stress state. Compressive longitudinal stress reduces the level of internal pressure needed to produce a bulge of the same magnitude when the severity of SCC remains constant. Multiple possible conditions could have existed to produce the observed bulge.
Enhancement of Mechanical Damage Crack Evaluation
Authors: Rana Arnav , Tiku Sanjay , Piazza Mark , Burns Tim 
Published: December 2022

Abstract
This paper presents the results of a project undertaken to enhance previously developed tools being adopted in an industry recommended practice (API RP 1183) for pipeline mechanical damage (MD) integrity assessment and management. This project builds on MD assessment and management tools, developed on behalf of Pipeline Research Council International (PRCI), Interstate Natural Gas Association of America (INGAA), Canadian Energy Pipeline Association (CEPA), American Petroleum Institute (API), other research organizations and individual pipeline operators and were included in API RP 1183. The specific tasks in the current project included the assessment and improvement of indentation crack formation strain estimation methods, evaluation of the impact of ILI measurement accuracy on dent integrity assessment, and level of conservatism (safety factor) inherent in different levels of dent fatigue life assessment incorporated in API 1183.
A Comprehensive Fitness for Service Engineering Assessment of Gas Pipeline Dents
Authors: Debnath Suborno , Roy Kshama , Wickie Robert , Kohandehghan Alireza 
Published: December 2022

Abstract
Mechanical damages such as dents are one of the most common threats to the structural integrity of buried pipelines traversing high population areas or mountainous terrains. Dents are defined as local inward depression in the pipe surface caused by external forces that produce pipe wall plastic deformation and a disturbance in the curvature of the pipe. Since not all dents affect the fitness for service (FFS) of a pipeline, dents identified by in-line inspection (ILI) tools need to be properly evaluated to determine the severity. This article provides a methodological framework to carry out a comprehensive fitness for service engineering assessment of dented natural gas pipelines using finite element analyses. The assessment is based on the evaluation of the dent formation strain, plastic collapse, local buckling, and pressure cycling fatigue failure modes. This FFS engineering assessment methodology addresses the susceptibility of dents to ductile fracture damages and stress-corrosion cracking integrity threats that can develop due to high membrane and bending loads in a dented pipe. This FFS assessment methodology has successfully been utilized to assess dents identified by ILI in gas pipeline systems. The results and the associated interpretation and discussions of the FFS assessment findings are presented herein.