bluuebunny/crossref_metadata_2025_split huggingface dataset:
In-Service Welding Onto Methane/Hydrogen Mixture Pipelines
Authors: Bruce William A. , Huising Otto Jan , Boring Matt , Amend Bill , Gould Melissa 
Published: December 2022

Abstract
The objective of the recently completed Phase 1 of a joint industry project (JIP) at DNV, the results of which are described in this paper, was to determine if welding onto an in-service pipeline that transports a mixture of methane and hydrogen results in an increased risk of hydrogen cracking and, if so, to develop guidance pertaining to measures that can be taken to mitigate the increased risk. The mechanisms and the extent to which steel line pipe can become charged with hydrogen when transporting methane/hydrogen mixtures were reviewed. An experimental program was undertaken to determine the extent to which elevated weld hydrogen levels can result during welding onto pipe pressurized with blends of hydrogen and methane (Task 2a) and from welding onto steel that has been exposed to high pressure blends for an extended period of time (Task 2b). The results of Task 2a showed various increases in weld hydrogen level, depending on the pipe wall thickness, the weld heat input, and the partial pressure of hydrogen. Reactions between the pipe contents, the line pipe steel base material, and surface oxides were also observed. Task 2b resulted in no significant increase in weld hydrogen level as the result of welding onto steel that had been exposed to a high pressure blend for an extended period of time.
Additional work is required to determine threshold conditions beyond which increased weld hydrogen levels do not occur and to quantify increases in weld hydrogen levels for a broader range of conditions, including higher and lower partial pressures of hydrogen.
Influence of Model Error as Epistemic Uncertainty in Reliability-Based Integrity Management
Authors: Koduru Smitha , Ibrahim Mahmoud , Shahzad Khurram , Hassanien Sherif 
Published: December 2022

Abstract
Uncertainties that influence the estimated probability of failure (PoF) are of two types: uncertainty due to inherent randomness of the physical properties and measurement error (termed ‘aleatory uncertainty’), and uncertainty due to lack of knowledge or simplification of physical processes represented in the empirical models (termed ‘epistemic uncertainty’). The objective of this study is to demonstrate the effects of epistemic uncertainty, represented as model error related to 1) reliability-based decision making for single features; 2) development basis of model error distributions; and 3) system wide reliability assessment.
In this study, the effect of model error is demonstrated with two approaches. First, the model error is estimated for various subsets of population features to demonstrate the effect of sub-populations on the model error distributions. Second, the epistemic uncertainty due to model error is separated in the estimation of failure probability. The effect of model error is represented by estimating the failure probability as an interval instead of a point estimate. The effect of using the range of failure probability, instead of a point estimate, on the reliability-based integrity management of both individual features and the system-wide decision-making is demonstrated.
Implementation and Validation of Reliability-Based Crack Assessment for Natural Gas Pipelines
Authors: Xiang Wei , Zhang Shenwei , Yan Jason , Sanjuan Riverol Elvis , Myden Kyle 
Published: December 2022

Abstract
Traditional in-line inspection (ILI)-based crack management programs use deterministic methods, where the calculated failure pressure ratio (FPR) and ILI-reported crack depth are compared with their respective thresholds. In recent years, TC Energy has developed a probabilistic crack assessment method, where annual probability of small leak (POSL) and probability of failure (POF, i.e., probability of burst) are evaluated. The mitigation plan is then made by comparing the annual POSL and POF with their respective thresholds. The advantage of the probabilistic method over deterministic method is that the former portrays reality better by explicitly accounting for the uncertainties associated with pipeline geometric and material properties, ILI-reported crack sizes, crack growth and burst pressure models.
This study demonstrates the safe implementation of the probabilistic assessment method for stress corrosion cracking (SCC) based on EMAT-reported ILI data and correlated dig data associated with three natural gas pipelines in Canada. Comprehensive validation was conducted by comparing the EMAT-based mitigation plan with the in-ditch assessment of a large set of dig data. Three key questions were addressed in the validation: (1) Does the probabilistic method capture all critical features identified in the field? (2) Whether the features avoided by the probabilistic method were unnecessary to excavate based on in-ditch assessment? (3) What is the benefit of the probabilistic method in comparison with the traditional deterministic method?
The examination indicates that the developed probabilistic assessment process captures all the critical SCC features identified in the field, and the digs avoided by the probabilistic method are confirmed to be unnecessary in the field. The result demonstrates that the reliability-based method can reduce a significant number of unnecessary digs without compromising safety.
The November 2021 British Columbia, Canada Storm: Observations and Lessons Learned From Assessing Pipeline Infrastructure Subject to Natural Disasters
Authors: Baumgard Alex , Thompson Matt , Van Hove Harmen , Sullivan Sean 
Published: December 2022

Abstract
In mid-November 2021, southwest British Columbia (BC), Canada was struck by a significant storm system dropping record rainfall over a 2-day period. This storm manifested resulted in significant impact and damage to critical infrastructure including bridges, highways, railways and pipelines, as well as leading to flooding that cut-off the most populated region of BC from the rest of Canada and an estimated rebuilding cost of $10 billion Cdn. This paper provides a background on the storm and the conditions that preceded it, remote sensing data that was gathered during and immediately following the event, mitigations that were implemented, and learnings needed to return the impacted pipelines into service.
Comprehensive Pipeline Record and Inspection Data Review and Assessment in Response to Safety Advisory on Girth Weld Strain-Induced Failures
Authors: Arbeau Craig , Clyne Alasdair , Bhatia Arti , Young Andy 
Published: December 2022

Abstract
Recent incidents outside Canada prompted the Canadian Energy Regulator (CER), the British Columbia Oil & Gas Commission (BCOGC) and the Alberta Energy Regulator (AER) to advise pipeline operators regarding the possibility of girth weld strain-induced failures in high strength pipe. In early 2020, the CER issued a Safety Advisory (SA) relating to the possibility of girth weld strain-induced failures in high strength (Grade X 70 or higher) steel line pipe. There was a concern that similar incidents could occur in Canada, given comparable conditions. Furthermore, the SA stated that.... “The CER expects that regulated companies can demonstrate that longitudinal strains resulting from loadings such as those described in Section 4.2.4 of CSA Z662-19 [essentially external loading over and above typical operating loads] have been accounted for in the design, construction and operation of pipelines where strain could potentially accumulate in under-matched girth welds”.
With respect to the SA, the failure causes were consistently linked to combinations of:
i) high strength pipe with a minimum tensile strength exceeding actual weld strength values,
ii) girth weld HAZ softening as a result of the welding process,
iii) loads applied to the pipeline causing additional longitudinal strain, and
iv) pipes welded with a standard bevel and alignment of approximately 45° between the heat affected zone (HAZ) and the root bead.
Emera New Brunswick (Emera) initiated an assessment of the 30 inch diameter, 145 km long, API 5L Grade X70 Brunswick Pipeline that evaluated:
i) pipeline material, welding and construction records with respect to specified requirements, and
ii) the propensity of the pipeline to external loading via the analysis of repeat inertial measurement unit (IMU) data and a geohazard review of locations exhibiting bending strain to understand the stability of the pipeline in relation to potential external loading.
This paper describes the systematic approach taken to address the potential concerns, the key results and recommendations of the study and how Emera has incorporated those findings into processes within its management system and protection programs.
Subset Simulation of Pipeline Corrosion, Crack, and Dent Defects Considering Multiple Limit States With Large-Scale Validation
Authors: Bandstra Daryl , Fraser Alex , Rojas Juan S. 
Published: December 2022

Abstract
Structural reliability is an engineering method that focuses on the calculation and prediction of the probability of failure for a structural system. Structural reliability is used by many pipeline operators to assess the probability of failure, and these probability of failure estimates are then used to manage safety, environmental, and operational risks for threats such as corrosion, cracking, and third-party damage. In the structural reliability approach, the probability of failure is obtained from a multi-dimensional integral, for which the solution is commonly estimated numerically using Direct Monte Carlo (DMC) simulation. DMC is straight-forward and robust but requires a significant amount of computational effort to estimate small probabilities, which are typical of threats to pipeline integrity. Subset Simulation is an approach that improves on the efficiency issues of DMC by representing the rare event probability as the product of a number of more frequent events, which are each estimated separately. Previous work published at IPC in 2020 by Bandstra and Fraser [1] showed very close agreement between DMC and Subset Simulation for a single defect reference case with a single limit state. This study extends that initial work by applying Subset Simulation to various failure models for a variety of pipeline defects. Subset Simulation is applied to the CSA corrosion model, PRCI MAT-8 crack model, and the EPRG dent failure model, and the performance is evaluated by comparing the results to DMC. For each of these comparisons, simulations are performed across a large-scale grid of validation cases that consider a range of pipeline and defect sizes. An approach that utilizes Subset Simulation to handle multiple limit states is also presented and applied for relevant failure models and the results are evaluated against DMC.
Prioritizing Retrofits of Non-Piggable Transmission Pipelines Using an Internal Corrosion Structural Reliability Model
Authors: Langlois-Rahme Gabriel , Bandstra Daryl , Iacobellis Vincent , Safari Miaad 
Published: December 2022

Abstract
Internal Corrosion (IC) is a time dependent threat to pipelines that leads to wall loss due to a reaction between pipe material and the products or contaminants being transported. Certain vintage pipelines are not piggable, meaning that Inline Inspection measurement tools cannot be used to measure IC defects. Furthermore, being older, these pipelines are more susceptible to time dependent threats such as IC due to their longer exposure time. Operators often need to prioritize retrofits between different non-piggable pipelines, and the approach described in this study uses a structural reliability approach to estimate the expected frequency of failure for non-piggable pipeline segments and ranks them accordingly.
This model captures the range of potential IC defect severity by using in-line inspection data from different pipeline asset types (e.g., Well Laterals, Transmission) to build empirical distributions of defect length and depth corrosion growth rate (CGR). These asset types serve as an indirect measure of gas quality as evidenced by differences in the defect distributions and anomaly densities. By characterizing CGR as a distribution for different asset types and using the industry standard Growth-by-Rule method to model defect depth, the model considers both asset type and pipe age when predicting the defect depth distribution in the current year. This projected depth distribution is used with physical and operating parameters (e.g., diameter, WT, pressure) in a structural reliability model to estimate the probability of failure for the segment under consideration.
The structural reliability-based prioritization approach described in this paper provides a methodology to utilize physical and operating parameters of an un-piggable pipeline together with information from inspected pipelines to rank the expected severity of a given un-piggable line. These segment ranks were finally compared to ranks generated using other heuristic methods to quantify the benefits of this more detailed analysis methodology.
Use of Carbon Composite Repair Technologies to Reinforce Crack-Like Flaws in High Pressure Pipelines
Authors: Futch David B. , Limon Sergio , Alexander Chris 
Published: December 2022

Abstract
Pipe body cracking and seam weld crack-like flaws can be encountered on virtually all pipeline systems and are traditionally repaired via a cutout, grinding, or full-encirclement metallic sleeves. Although the effectiveness of steel repair sleeves is well established, they have drawbacks when repairing out of roundness pipe and they can require large pipe excavations to find a suitable location for in-service welding. Moreover, finding a clean in-service welding landing zone can be difficult for vintage line pipe steel which have a higher probability of laminations and the potential of having seam weld defects in low frequency ERW/EFW pipe. Furthermore, safety is also a concern when welding onto an operational pipeline. An alternative to repairing planar flaws is the use of non-weldable, light weight, wet-lay carbon fiber composite system. A composite repair system has distinct advantages as it can contour to most pipe shapes, resulting in shorter repair lengths (and therefore shorter excavations), and no welding is required. Composite repair systems have historically been used to reinforce areas of external corrosion and dents; however, their use has not been fully extended to reinforce crack-like flaws. A study was conducted where three carbon-epoxy composite technologies were explored as an effective repair option for pipelines with crack-like defects.
A total of 35 reinforced external axial cracks were tested in base material and the longitudinal weld in 1960’s ERW pipe samples. Each crack was initiated by fatigue from a machined notch. Pressure cycle testing from 10%–72% SMYS showed that the carbon composite repair systems tested can effectively repair axial external crack-like defects in the pipe base and seam weld. The repaired cracks in the ERW bond line ranged from 45% to 55% wall thickness deep and all survived 25,000 test cycles with less than 10% wall thickness of additional growth. The aggressive test pressure cycles correlate conservatively to 600 to 1,000 years of fatigue life for normal gas pipeline operations, which demonstrated a fatigue life extension of 3 to 5 times when compared to unreinforced defects that leaked below 10,000 cycles. The contents of this paper and associated insights are valuable to the pipeline industry in extending the use of carbon composite repair technologies to reinforcing cracks and seam weld crack-like flaws based on full-scale testing and metallurgical assessment of post-tested fatigue growth of cracks.
Don’t Crack Up - Composite Repair of SSWC
Authors: Futch David B. , De Leon Christopher , Whalen Casey 
Published: December 2022

Abstract
Composite repairs have been extensively qualified and used to repair external corrosion and dents encountered on pipeline systems. More recently, test programs have explored extending the use of composite repairs to reinforce crack-like indications, including those found in low-frequency electric resistance welded (LF-ERW) pipe. This paper addresses repairing selective seam weld corrosion (SSWC) using composite repair systems, which is yet another extension for composite repairs. Current approved techniques for repair of SSWC include full encirclement steel sleeves and mechanical clamps, however, there can be challenges when repairing out of straight or out of round pipe and they can require large pipe excavations to find a suitable location for in-service welding. Finding a clean in-service welding landing zone becomes more difficult when considering vintage line pipe steel which have a higher probability of laminations.
SSWC results in a groove centered on the ERW bondline, which typically has lower toughness than the surrounding pipe. While corrosion is active, the groove remains relatively blunt. Therefore, a SSWC repair must minimize or eliminate the potential for sudden fracture along the seam. The chosen repair should reduce or eliminate the likelihood of crack formation at the stress concentration at the base of the SSWC groove.
In this study, fabricated SSWC-like features were reinforced with commercially available composite repair systems on vintage ERW pipe and subjected to cyclic pressure. Results have shown that composites can sufficiently reduce stress to prevent crack formation, providing a permanent repair option. Further corrosion is also mitigated by creating a barrier between the steel pipe and environment.
Exploratory Data Analyses on CFRP Wrapped HDD Overbend Subjected to Combined Loading
Authors: Davaripour Farhad , Roy Kshama , Maghoul Pooneh 
Published: December 2022

Abstract
Horizontal directional drilling (HDD) is one of the popular pipeline trenchless construction techniques for sites where surface excavations and conventional trenching are not desirable. An integral part of the pipeline design and construction process is to perform stress analysis on the HDD overbends, which can be subjected to significant cross-sectional deformations due to stresses/strains imposed by thermal expansion and internal pressure. This paper proposes a novel approach to reduce the stress range in the HDD overbends using carbon fibre reinforced polymer (CFRP) wraps. Although this reinforcement technique is primarily used in the pipeline industry for repairing damaged pipes, there is a handful of recent studies that showed the promising effect of using CFRP reinforcement on undamaged pipe bends. A total of 259 finite element analyses are conducted with a different combination of pipe diameter to thickness ratio, CFRP length and thickness, fibre orientation, and internal pressure. An exploratory data analysis is then performed to demonstrate the impact of each variable on the maximum equivalent stresses imposed on the HDD overbend. The finite element results show that multi-directional fibre orientation leads to the highest reduction of peak equivalent stress on the HDD overbend. Besides, an increase in CFRP thickness results in a greater reduction of stresses on the HDD overbend. However, CFRP length does not have a noticeable effect on decreasing the stresses on the HDD overbend.
The State of Dent Screening and Shape-Based Assessments: Discrepancies to Consider
Authors: Polasik Steven J. , Wu Shanshan , Bratton Joseph P. , Dotson Rhett , Sager Ryan 
Published: December 2022

Abstract
Dents in buried pipelines either caused by third party mechanical damage or introduced during pipeline construction remain a leading contributor to reportable pipeline releases. API Recommended Practice 1183 (API RP 1183) provides a modern, shape-based fatigue life assessment of pipeline dents that can be incorporated into a pipeline operator’s integrity management program. Specifically, in API RP 1183, dent shape information is obtained by analyzing in-line inspection (ILI) caliper data and is expressed using characteristic lengths and areas. Once obtained, these characteristic lengths and areas define not only the dent restraint condition, but also various fatigue growth parameters.
API RP 1183 provides multiple screening techniques that are intended to identify dents that are non-injurious and therefore do not require additional detailed assessments or response actions. These screening techniques both increase in complexity and decrease in conservatism. Three screening processes provided in API RP 1183 are: (1) a table with lower bound, conservative estimates of fatigue life, (2) a pipe geometry and spectrum severity indicator (SSI) approach, and (3) a pipe geometry and operational spectrum approach. When combined with the shape-based fatigue life assessment, multiple analysis approaches are described.
However, as more dents are being analyzed with the methods from the first edition of API RP 1183, discrepancies between the screening methods and the shape-based approach are being observed. The aim of this paper is to discuss those cases where the conclusions from the screening processes and the shape-based assessment are inconsistent. In other words, there are cases where the screening process “passes” a dent indicating the dent is non-injurious and can be monitored while the shape-based assessment dictates the dent is injurious and a response should be taken. After discussing the inconsistencies in these cases, the authors make recommendations on how operators should use API RP 1183 in its current form.
All Optical Multi-Sensor Well Monitoring System to Survey and Monitor Gas Storage Operations
Authors: Lee Allan , Barclay Christopher , Xu David , Paulsson Bjorn , Wylie Michael , He Ruiqing 
Published: December 2022

Abstract
Paulsson, Inc. (PI) has partnered with Pacific Gas & Electric (PG&E) and California Energy Commission (CEC) funded by the CEC grant PIR-19-001, to develop and apply cost-effective, all-optical Underground Gas Storage (UGS) reservoir surveying and monitoring technologies. This project was to determine the capabilities that fiber optic sensor technology may have in monitoring a natural gas wellbore and reservoir. The project goals and objectives include designing, prototyping, third party laboratory testing, building and installing a borehole all optical multi-sensor array into a well drilled at UGS facility. The optical sensor system has recorded a number of nearby small earthquakes which have provided the seismic sources that will be used for site characterization. The optical sensor array has also recorded large earthquakes in Japan, Peru and Fiji. The array will be used to characterize and monitor the gas injection and withdrawal operations for a number of months. The preliminary results of this project are discussed describing some potential applications for use.