bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing Risk Reduction: a Data-Driven Approach for Strategic Preventive and Mitigative Action Planning
Authors: Murray Jake
Published: December 2024

This paper presents an approach to empower risk management practitioners in navigating challenges posed by regulatory frameworks, aging infrastructure, and sustainability imperatives. The focus is on using quantitative risk assessment tools to identify, prioritize, and implement preventive and mitigative measures. The paper discusses tools, methods, and considerations that enable operators to synthesize risk assessment outputs, offering insights into feasible projects and evaluating their benefits in relation to costs.

Real-world applications across various energy sector operators emphasize the significance of quantitative risk modeling algorithms. The paper advocates for a data-driven decision-making framework, supporting the development of robust corporate risk management strategies. Example use cases highlight the integration of cost-benefit analyses and the application of the “As Low As Reasonably Practicable” (ALARP) criteria.

Key insights include principles for aggregating risk assessment results, process considerations for identifying candidate measures, and a methodology for consistent, actionable conversations about risk thresholds. The paper underscores the economic and operational advantages derived from specific risk mitigation measures, validating the ALARP principle’s efficacy in guiding investment decisions.

Conclusions offer strides in fortifying operational resilience and sustainability while keeping safety in the forefront. By leveraging quantitative risk modeling, data aggregation, and a consistent strategy for decision-making, the paper provides a practical approach for industry professionals to proactively address challenges and foster a culture of enhanced risk management.
Effect of Polyethylene Pipe on Wall Sticking of Waxy Oil in Low-Temperature Transportation
Authors: Zhang Yu , Huang Qiyu , Zhen Hanpeng , Zhang Xun , Wang Yijie , Xu Zhenkang
Published: December 2024

With the rapid development of the modern oil industry, oilfields have gradually transformed from a phase of high crude oil production to a period of high water cut. Consequently, heat transportation, which involves significant economic expenditure, is no longer feasible. Therefore, low temperature gathering and transportation technology has been proposed and applied. It enables the safe transportation of high water cut crude oil at temperatures below the pour point and the technical cost is increased pipe friction, which is less than heating loss. The low-temperature transportation of high water cut waxy crude oil was an energy conservation compared with heat transportation. In some oil fields, polyethylene (PE) pipes were used for low-temperature transportation of high water cut waxy crude oil in order to solve economic and environmental problem caused by pipeline corrosion. Unfortunately, few studies on effect of polyethylene pipe on wall sticking of waxy oil at low-temperature has been conducted. In this study, the critical velocity of wall sticking of waxy crude oil in the polyethylene pipes was found to be lower than that in the stainless-steel (SS) pipes in low-temperature transportation. The shear effect and structural strength of oil-wax gel, the most important factors to influence wall sticking of waxy crude oil, were calculated and compared. The shear effect was found to be similar in two pipes and the radial temperature gradient in polyethylene pipes was lower than that in stainless-steel pipes, which resulted in higher interface temperature in PE pipes. Under the influence of higher interface temperature, the solid wax content at oil-water interface in PE pipes was lower than that in SS pipes. The structural strength was affected by the solid wax content and strength enhanced with increase of the solid wax content. The strength of gelled oil in polyethylene pipes was lower than that in stainless-steel pipes, which implied that gelled oil sticking on wall was easier to be stripped from pipe wall in PE pipes. Therefore, the difference of radial temperature gradient in PE and SS pipes dominated the wall sticking process of waxy oil sticking and resulted in the lower wall sticking critical velocity of gelled oil in PE pipes.
Leveraging Advanced Technology and Data Integration in Managing Challenging Pipelines in Subsidence Areas
Authors: SooTot Josiah , Michels Connor , Curiel Fernando , Shafrova Svetlana
Published: December 2024

The contemporary landscape of the 21st-century pipeline industry is marked by continual technological progress such as high-resolution in-line inspection (ILI) and advanced monitoring systems. This paper elucidates the successful integration and application of cutting-edge technology for the identification and management of a pipeline situated within an active subsidence area. The term “subsidence” herein refers to ground sinking resultant from the expansion of subsurface cavities until surface level indications are seen. This phenomenon could be a result of pumping, fracking, and mining, including improper well completion practices.

This case study specifically delves into the utilization of different periodic and continuous monitoring techniques to address an active subsidence threat. The monitoring included satellite Interferometric Synthetic Aperture Radar (InSAR) techniques for subsidence measurement, where periodic satellite images are superimposed to reveal surface motion or deformation over time. Beyond conventional InSAR data collection, the operator implemented strain gages and subsidence prisms on the pipeline segment exposed to earth movement. This data, in conjunction with inertial mapping unit (IMU) bending strain analysis, enables real-time monitoring of bending (vertical and horizontal) and membrane strain components on the pipeline. The incorporation of a high strain trigger alarm serves to promptly notify the operator of potential issues.

The continuous data integration process aims to comprehensively understand and manage the subsidence threat by gathering diverse stakeholders at regular intervals to interpret and discuss the latest monitoring results. The proactive approach of the operator extends further into the realm of threat probability mapping solutions, demonstrating a creative and innovative methodology. This led to the strategic design of a pipeline reroute, diverting it away from the subsidence area and ensuring the sustained long-term operation of the pipeline.

The complexity of this process necessitates a series of analyses and discussions among subject matter experts (SMEs), reflecting a meticulous and innovative approach. The success of this endeavor not only secures the short-term integrity of the pipeline but also sets a precedent for long term identification and management of emerging threats within the industry. This study underscores the transformative power of integrating advanced technologies and creative problem-solving strategies in addressing and mitigating challenges in pipeline risk management.
Development and Application of Geobuffer System to Reduce the Impact of Ground Movements on Buried Pipes
Authors: Fathi Ali , Cheng Samuel , Kowis Jared , Hubert Yvan
Published: December 2024

This paper introduces an alternative solution for enhancing the performance of buried pipelines under various scenarios of ground displacements through the installation of Geobuffer elements. Installation of the Geobuffers allows for controlled modification of pipe’s boundary conditions based on the expected ground movement rate and direction. This modification enables the pipe to distribute the applied displacement more effectively, which prevents concentration of stress/strain.

The orthotropic properties of the Geobuffer make it flexible in one direction and stiff in the other orthogonal directions. As a result, it can accommodate large pipe movements without developing large reactive forces, while adequately resisting soil and overburden pressure. By using this method, the pipe maximum curvature and axial elongation are reduced significantly which results in lower longitudinal strain ranges and lower risk of subsequent failures. Reduction of the longitudinal strain accumulation rate also increases pipes life span in steady and slow ground movement scenarios (e. g., slope creep); and decreases probability of failure in episodic movement scenarios (e.g., fault slip).

This paper reviews the background and development stages of the Geobuffer system and continues with presenting its application on one pipeline crossing an axial/oblique landslide. The installation scope and layout were developed for this site based on the landslide and pipe characteristics and targeted tolerance level for future movements. The key design and development steps for this application are reviewed here, including design inputs, sizing and layout, performance evaluation analysis, installation, and the monitoring system. This paper concludes with a discussion of utilizing the Geobuffer system in the integrity management of pipelines and how it can offer value in certain areas.
Practical Solutions for Mountainous Pipeline Construction: Mechanically Stabilized Earth Retaining Walls on a Western Canadian Transmission Pipeline Project
Authors: Hou Wenzhu , Gartner Joseph , Baumgard Alex , Gauthier Dave , Otten Taco
Published: December 2024

Pipeline construction in various mountainous terrains presents unique challenges. When the deeper burial is needed for mitigating against geohazards, the conventional methods relying on shallow ditches can become impractical. Trenchless methods may not always be technically feasible or cost-effective. A transmission pipeline project in Western Canada encounters steep slopes, rocky terrains, and numerous environmental complexities. Narrow construction corridors across streams and gullies prone to geohazard risks pose additional intricacies to the design and pipeline construction. This paper presents two case studies from this project about application of Mechanically Stabilized Earth (MSE) retaining walls as an alternative solution to achieve the hydrotechnical and geotechnical dominant design intent for mitigating geohazard risks in challenging terrains. The first case study is on rocky ground. Concrete box culverts were installed beneath the MSE wall and the pipe at a creek crossing to convey surface water across the Right-of-Way (RoW) while maintaining a drivable forest road atop the pipeline. The second case study is on steep and colluvium mantled hillside slopes. The design incorporated a combination of culverts, headwalls, concrete swales, and riprap armoring to mitigate the potential scour from debris slides and flows. This paper presents practical tools and best practices of applying MSE retaining walls tailored to pipeline construction to resolve challenges in rugged terrains, promote a cost-effective engineering approach and minimize environmental impact. The presented case studies provide adaptable solutions to ensure the long-term integrity and resilience of pipelines in geohazard-prone landscapes.
Reducing Cost of ILI Inspections by Assessing and Improving Accuracy of Past Inertial Surveys
Authors: Czyz Jaroslaw A. , Joseph Joshua , Daiyan Nasser , Dewar Doug
Published: December 2024

Although IMU has been part of ILI surveys for 35 years, there is no standard method of reporting inertial mapping accuracy to operators. ILI vendors often report the accuracy of IMU runs as a standard tool specification rather than run-specific values, and when such specific values are reported, they can be easily misinterpreted. A method of assessing IMU survey accuracy explained in this paper could be adopted by the ILI industry to ensure reporting clarity and consistency between different vendors.

The error estimation is also the basis for producing a master pipeline listing using single or multiple IMU data sets. The presented method delivers more accurate pipeline centerline shape, improved odometer distance, and corrected GPS locations, particularly when data from multiple surveys is available. Incorporating master pipeline listings into an ILI vendor’s program will reduce operator costs. It produces more accurate dig locating and allows for accurate distance (chainage) calculations in the event of an odometer failure. It also eliminates the requirement for repeat high-accuracy GPS surveys of AGMs, valves and other pipeline features. It can even eliminate the need for collecting future IMU data, unless pipeline movement and bending strain monitoring are required, or there is a major re-route of the pipeline. Using the same distance for all future surveys would simplify data alignment, cross-reference, and movement analysis between runs. In the process of calculating master listing, more accurate data for pipeline movement analysis can also be delivered for the entire run. Evaluation and improvement of past inertial surveys accuracy is necessary for deciding whether additional GPS or IMU surveys are needed to produce master listing with the required accuracy.
River Crossing Reliability Screening Analysis Using a Bayesian Framework
Authors: Fowler Matthew , Sen Millan , Yoosef-Ghodsi Nader
Published: December 2024

Pipelines cross tens of thousands of river and stream crossings throughout North America. Scour of the riverbed material at these crossing locations can cause buried pipelines to become free-spanning and susceptible to vortex induced vibration fatigue or overstress failure. Current reliability assessment approaches require extensive (20+) site specific inputs, which correspondingly require detailed desktop review and/or field visits. Obtaining the data required to conduct these types of detailed assessments at every stream crossing is often neither feasible nor practicable for entire pipeline networks.

In this paper, the authors present a systemwide screening analysis approach to estimate the probability of failure of pipelines at river and stream crossings, requiring only 3 input variables but expandable to include more input variables. In this way, crossings that exceed a particular target can be prioritized for more detailed assessment. Moreover, a key strength of the model is modularity: the number of inputs can vary depending on the known characteristics of the crossing being assessed, which is beneficial at small streams where detailed inspections have not been conducted. Conversely, results are enhanced using additional inputs at crossings where more information is known.

The model uses historical industry failure observations as its basis and employs a Bayesian updating approach. Conditions that led to previous failures are compared to characteristics at crossings of interest to evaluate their probability of failure. A benefit of the approach is, unlike index-based models which can rely on subject matter expert judgement for index weightings, the Bayesian approach uses known data from historical failures as a fundamental basis. Distributions are fit to the historical failure data (e.g. bankfull width, measured depth of cover prior to failure, pipeline diameter) and the characteristics of the fitted distributions directly influence the response of the model, which eliminates the need for expert judgement in setting index factor weights.

In consideration that only minimal input data is required, the model was applied to all 5,000+ river crossings across Enbridge’s liquids pipeline mainline system. The screening model results were compared to the currently available detailed models results and showed reasonable agreement. It was also shown that approximately 90% of known stream crossings did not warrant detailed analysis under their current conditions.
New Specifications for Steel Pipeline Induction and Cold Bends (CSA Z245.16 and Z245.17)
Authors: Fernandez Marchi Pablo , Myschuk Fred , Xu Su , Mirabolghasemi Hamed
Published: December 2024

Steel pipe bends manufactured by induction or cold bending processes have become increasingly prevalent in the oil and gas pipeline industry, often replacing fittings in many applications. However, the absence of clear specifications for the manufacturing of these types of bends in the existing CSA standards prompted the development of new standards. In response, two new standards, CSA Z245.16:22 Induction bends, and CSA Z245.17:22 Cold bends were developed, and were published in August 2022. Notably, the CSA Z245.17:22 Standard, focusing on the manufacturing processes of factory-made cold bends designed primarily for integration into oil or gas pipeline systems, is the first of its kind. This is a significant development in the Canadian oil and gas pipeline industry, complementing the existing specification of CSA Z662 Oil and gas pipeline systems.

The main objective of these new standards is to establish clear and consistent requirements for factory-made induction and cold bends, distinct from the existing CSA Z245.11 Steel fittings standard. This differentiation is important because starting material and manufacturing processes qualification differ from those for fittings. The publication of these new bends standards provides clarification on the requirements specific to induction and cold bends.

This paper reviews the content and application of CSA Z245.16:22 and CSA Z245.17:22. It discusses the main requirements introduced and outlines a plan for future changes to the standards for their next edition in 2025.
Accounting for Measurement Uncertainty in Alternative Sampling Plans for Verification of Pipeline Material Properties
Authors: Ludlow Jed
Published: December 2024

The statistical formulations of alternative sampling plans to achieve “at least a 95% confidence level that material properties used in the operation and maintenance of the pipeline are valid” under US 49 CFR 192 have been studied previously. The resulting conservative lower bounds on yield strength (YS) have been presented under both frequentist and Bayesian approaches.

Every physical measurement of YS, whether in the field or in the laboratory, embodies at least two components of variation. First, the YS itself varies throughout the material under test across the many pipe joints in a population. Second, the measurement method has an associated uncertainty inherent in the technology employed to accomplish it. The observed results reported from the measurement method necessarily contain contributions from both sources of variation. The previous formulations for statistical lower bounds on YS remain conservative in the presence of measurement uncertainty by bounding the total material and measurement uncertainties taken together. But those bounds might be an overly conservative bound on YS if the measurement uncertainty is not negligible.

This paper presents a study of statistical approaches to developing a lower bound on YS that explicitly account for the presence of measurement uncertainty, separating out the effects of measurement uncertainty to arrive at a less conservative bound on just the YS variation. The study employs simulations of alternative sampling plans under various YS and measurement uncertainty conditions across a range of YS and measurement uncertainties that might be typical in actual pipeline applications. The study examines the effectiveness of the statistical approaches at separating the components of the combined uncertainty, recovering both the true lower bound on YS and the true associated measurement uncertainty. A comparison against truth is possible since full knowledge for the simulated populations is available. The resulting YS bounds are also compared against the more conservative statistical bounds developed previously that combine both sources of uncertainty into the bound.
Matching of Corrosion Features in Multiset Pipeline In-Line Inspection Data Utilizing Relative Point Positions
Authors: Ling Jiatong , Liu Zheng
Published: December 2024

Pipeline in-line inspection (ILI) stands out as an effective approach for comprehensively understanding the conditions of pipelines. Matching of corrosion features detected in multiset pipeline ILI is an essential prerequisite to determining corrosion growth. State-of-the-art methods for corrosion defect matching require the iterative process to find the optimal affine transformation or the extraction of individual defect attributes for matching model training. However, not only are these processes labor intensive, but the collection of substantial amounts of data is also challenging. To simplify the matching process, an automated method was proposed to match corrosion features that use the position of the features. This algorithm requires only the positions of detected corrosion points and applies to complex defect scenarios with high corrosion density. Firstly, triangles are constructed based on corrosion features. Secondly, local matching was employed to identify matching triangle pairs within two ILIs. Then, a global matching strategy was applied to refine the initially identified matches, filtering the false matches based on predefined requirements. Finally, the points in the final pairs of matched triangles serve as correspondences to determine the registration transformation. Experiments were conducted to validate the efficacy of the proposed method. The results demonstrate its reliability in accurately matching features within pipelines, which supports the integrity and risk assessment of pipeline systems.
Numerical Methods to Reduce Measurement Uncertainty and Lower CPM Leak Thresholds
Authors: Choquette Gary , Rans Rick , Petersen Warren
Published: December 2024

Within a pipeline system (gas or liquid), the measurement of inbound and outbound flow/energy should balance. In an ideal system, free of measurement or estimation error, a balance showing more product entering the system than exiting the system would indicate loss of product (potential leak or theft). Achieving an exact balance is, in practice, unachievable due to measurement uncertainty and accounting errors.

This paper describes novel and technically advanced analytic methods used to identify meter(s) that are the most probable contributors of a discrepancy as well as sub-sections of the system where unmeasured and inaccurately measured quantities are likely to exist. This allows the operator to initiate measures to reduce measurement uncertainty (thereby lowering the threshold of detection for measurement leaks) or identify subsections of the system where physical surveillance should be performed.

The methods presented here estimate the relative order of magnitude of measurement error/leak and have been validated on double blind simulated data.
An Investigation of Indicators for Determining Significant Changes in Dent Shapes Using Repeat ILI Data
Authors: Bankehsaz Morry , Sager Ryan , Wilde Andrew
Published: December 2024

The Pipeline and Hazardous Materials Safety Administration (PHMSA) has recently updated regulations for U.S. gas pipelines which went into effect in May 2023. As part of the new requirements for dent engineering critical assessments (ECA) detailed in 49 CFR § 192.712(c), a dent profile comparison shall be performed between the most recent and previous in-line inspections (ILIs) to identify significant changes in dent depth and shape. While the new initiative is essential to the integrity of the pipeline, either for new dent identification or ensuring the stability of the existing dents, a definition of “significant change” is not clarified in PHMSA regulations.

In this paper, various indicators are investigated to help pipeline operators screen for an identify dents that may have undergone significant material changes in terms of depth or shape across multiple inspections. Limits are investigated to effectively differentiate dents exhibiting altered shapes from those merely experiencing variations within the expected depth during successive inspections utilizing high-resolution ILI. The approach involves a comprehensive examination of diverse indicators, including ILI listing dimensions, curvature-based strain calculations, and direct comparisons of profiles. Through the application of this methodology to a dataset comprising 650 dents, the efficacy in systematically screening for and identifying dents that are new or have undergone substantial changes is demonstrated, thereby providing a valuable tool for proactive integrity management.

Discussion is also included on the factors that could lead to a change in dent shape and the importance of understanding the pipeline’s internal and external loading history.
Reliability-Based Evaluation of Corrosion Assessment Safety Factors for Pipelines Designed to Risk-Based Safety Class System
Authors: Adianto Riski , Koduru Smitha , Lu Dongliang
Published: December 2024

A risk-based pressure design approach for designing onshore transmission pipelines has been developed and incorporated in the Annex C of the 2023 edition of Canadian Standard Association (CSA) Z662 standard. This approach uses a set of hoop stress factors (termed class factors) calibrated for six consequence-based safety class system to design the required minimum wall thickness of the pipeline to limit the pipeline risk at a consistent acceptable level. This non-mandatory approach provides an alternative to the more established experience-based hoop stress factors (product of design and location factors) described in Clause 4.3.5 of the standard.

As written in the CSA standard, Clause 4.3.5 hoop stress factors are also used as safety factors to assess corrosion features as prescribed in Clause 10 of the standard. Following the same principle, Annex C class factors described in Clause C.5 are also prescribed to be used for the Clause 10 corrosion assessment. This paper evaluates the reliability implications of applying the class factors for corrosion assessment of pipelines designed to the Annex C safety class approach.

Three gas pipeline cases were considered in this evaluation, one in undeveloped area and the two others in developed areas. All pipelines were considered in two scenarios: 1) designed using the Clause 4.3.5 approach, and 2) designed using the Clause C.5 approach. Similar corrosion populations representative of decades-long operation were simulated for each scenario using information in public domain literature, and corrosion assessments to determine repairs were carried out using the approach described in Clause 10.10.2.5 of the CSA standard. In this assessment, each scenario utilized the corresponding hoop stress factors for the pipeline design as the corrosion safety factors (i.e. design and location factors for scenario 1, class factors for scenario 2). The implication of using these safety factors was evaluated by assessing the reliability of the pipelines with the remaining corrosion features that passed the Clause 10.10.2.5 assessments and subsequently their overall safety. Comparison was made between the Clause 4.3.5 and Clause C.5 scenarios to demonstrate the implied safety with both approaches.
A Probabilistic Method for Assessing Pipeline Strain Demand Using InSAR Ground Movement Data
Authors: Schell Colin A. , Paluchova Mirka , Lever Ernest , Groth Katrina M.
Published: December 2024

Ground movement hazards, such as landslides, ground settlement, and heave, pose a major threat to buried pipelines and resulted in $391M USD in property damages in the United States from 2002 to 2021. The dynamic nature of ground movement makes it necessary to actively model and predict pipeline integrity in order to maintain a reliable pipeline network. Strain-based design and assessment (SBDA) methods excel at predicting pipeline failure in the presence of large longitudinal strains that commonly result from ground movement hazards. Applying SBDA methods to operational pipelines requires the estimation of strain demand, the strain induced on the pipeline. Synthetic Aperture Radar (SAR) data, acquired by satellite, can be used to compute ground movement using SAR interferometry (InSAR). When combined with pipe-soil interaction (PSI) modeling, InSAR offers an attractive method for estimating strain demand; InSAR can cover large areas of interest and provide precise ground displacement measurements at a high spatial and temporal resolution.

This paper presents a probabilistic method for predicting pipeline strain demand using ground movement data computed with InSAR. Pipe-soil interaction models from prior research were integrated into a Bayesian network (BN) which accounts for the environmental effects on pipeline displacement. Model performance was tested using a landslide case study in which the predicted axial strain was within reason. However, the model needs further work to accurately predict bending strain. The high resolution of InSAR data and the use of BN models enable the probabilistic evaluation of strain demand without the need for finite element method (FEM) models. The proposed method can empower pipeline companies to perform pipeline integrity assessments with greater ease, promoting a fast and data-informed response to ground movement hazards.
Engineering Critical Assessment for MAOP Reconfirmation: Insights From a Project Instituted by a Consortium of Pipeline Operators
Authors: Alexander Tom , Mittelstadt Benjamin C. , Williams Dan , DeLong Terry , Maddin Kim , Jimenez Brian
Published: December 2024

Part 1 of the Gas Mega Rule (RIN-1) became effective July 1st, 2020. A key component of RIN-1 is the requirement for the reconfirmation of maximum allowable operating pressure (MAOP) for certain segments of gas transmission pipelines. Pursuant to 49 CFR §192.624, MAOP can be reconfirmed using one of six methods: hydrostatic test, pressure reduction, Engineering Critical Assessment (ECA) (as prescribed in 49 CFR §192.632), pipe replacement or pressure reduction for segments with small potential impact radius or an alternative technical assessment subject to notification in advance to the Pipeline Hazardous Materials Safety Administration (PHMSA) in accordance with 49 CFR §192.18.

The regulations in 49 CFR §192.632 specify the necessary elements for an ECA for MAOP reconfirmation, however they do not provide detailed instructions for executing an ECA. A Consortium of pipeline operators initiated a pilot project to develop ECAs for pipelines requiring MAOP reconfirmation, using the guidelines in 49 CFR §192.632. This initiative offered key insights into how pipeline operators can leverage established integrity management (IM) activities and principles to support ECA objectives. While certain consensus standards, such as American Society of Mechanical Engineers (ASME) standard B31.8S and American Petroleum Institute (API) recommended practice 1160 have long provided guidance on pipeline integrity management, it’s crucial to recognize the distinctly different objectives of integrity management and ECA, despite their significant technical overlap.

Pipeline operators have employed data integration and integrity assessment principles in these standards for integrity management for decades, and many of the activities supporting IM objectives are relevant to ECA objectives. Integrity management is an ongoing process, whereas ECA for MAOP reconfirmation is typically a one-time analysis confirming that the pipeline’s design and construction are suitable for operating at the established MAOP.

This paper will explore the similarities and differences between ECA and IM objectives, the assessment of relevant threats and conditions pursuant to 49 CFR §192.632 and examine data requirements that are relevant to each.
Study of Microstructural and Mechanical Evolutions of API X80 Heavy Gauge Large Diameter (OD1,219 mm×22 mm) Pipes and Their Weldability With Customised Niobium Microalloying
Authors: Han David
Published: December 2024

To explore the optimum application of niobium (Nb) element and study the influences of Nb in 22 mm-thick API X80 heavy gauge pipes with a large diameter, the investigation regarding 0.026 wt.% Nb difference, i.e. middle Nb (0.058 wt.%) and high Nb (0.084 wt.%), focuses on the correlations between microstructure, mechanical properties and weldability of the Nb-microalloyed X80 pipe steels. The Thermo-Calc software was used to predict the precipitation behaviours of equilibrium phases. Afterwards, the microstructures (grain size, precipitation and dislocation) and mechanical properties (strength and Charpy V-notch-/shear area-based ductile brittle transition temperatures), were analysed through multiple characterisation methods to verify the designed solid solution and precipitation of Nb during hot rolling, aiming at optimised performance of X80 pipes and their subsequent weldability. The weldability comparison of two Nb-level steels was conducted through welding thermal simulation. The positive factors that Nb has enable the improvement in weldability from the points regarding the combined controlling of prior austenite grain size, bainitic microstructure, and martensite-austenite constituent during single-pass welding thermal simulation. And these facts have led to the conclusions that the higher Nb X80 has a better performance after welding simulation. This study evidently clarifies the advantage of Nb addition in designing base material and its weldability for API X80 pipes with a heavy gauge and a large diameter, which can contribute to the safety during pipeline operation.
High-Frequency-Induction Welded Steel Pipes for the Future Hydrogen Gas Grid
Authors: Brauer Holger , Golisch Georg , Wackenhut Georg
Published: December 2024

Pipeline operators and pipe manufacturers need to consider the transport of hydrogen (compressed gas) to ensure the suitability of pipes and components for safe design. This article summarizes the status of hydrogen transport and storage in steel pipelines from the perspective of a steel pipe manufacturer. It reviews current standards, methods for testing pipeline materials and resulting requirements. The behavior of different high frequency induction welded steel pipe materials under hydrogen load is investigated and discussed on basis of fatigue requirements, crack growth behavior, hydrogen permeation and ductility. The article also gives insight to the importance of the inner surface of the pipe for hydrogen exposure. Comparative service life calculations are presented and evaluated based on crack propagation curves and different design curves, initial defects, and load scenarios.
Case Study: Leveraging API 1163 Validation and Verification to Manage SCC Using ILI Ultrasonics Crack Tool
Authors: Guajardo Rogelio , Urrea Santiago
Published: December 2024

A pipeline underwent two ultrasonic high-resolution (UTCD) inspection in consecutive years, revealing consistent anomalies but questionable depth accuracy. Despite adequate POD, the POI, especially depth accuracy, was in doubt due to feature underestimation. Subsequent API 1163 Level 2 validation indicated the tool did not meet published specifications.

The paper presents a case study demonstrating the application of API 1163 verification and validation to ensure pipeline safety. The authors underwent API 1163 verification for both inspections, followed by Level 1 validation confirming tool repeatability but unable to explain underestimation. Level 2 validation involved categorizing and analyzing features via systematic pattern analysis, identifying feature geometry as the main cause of underestimation. Historical data and simulations were utilized to understand the impact of feature geometry on recorded amplitudes and depth calculation. This study underscores the importance of systematic analysis in maintaining pipeline integrity.

Subsequently, ILI analysts developed a non-standard analysis procedure for the pipeline, focusing on features meeting specific criteria identified through pattern analysis. These features were then reevaluated, and depth compensations were applied, ultimately achieving Level 2 validation.
Utilizing Partial Safety Factors to Better Manage Stress Corrosion Cracking on Pipelines
Authors: Stewart Ryan , Dessein Thomas , Lamborn Lyndon , Vorontsov Vitaly , Rawlick Evelyn
Published: December 2024

Fitness for service assessments of stress corrosion cracking (SCC) crack fields must account for in-line inspection (ILI) tool measurement error. In deterministic assessments, the vendor-specified tool tolerance is typically added to the crack field depth and sometimes to the overall length. This methodology is very conservative and leads to a large number of false positives (resource outliers) when evaluated in the field. The resource outliers are defined as cases where the safety factor on the failure pressure (Pf) assessed using the ILI measurements is below 1.25 (Pf / MOP), but the field safety factor did not indicate a need for repair at this level.

In the present study, a semi-probabilistic model was calibrated to match lower percentiles (0.1th and 0.5th percentiles) drawn from distributions of predicted burst pressures generated using a full probabilistic model that is solved using Monte Carlo simulation. The Monte Carlo simulations account for measurement error in the ILI called wall thickness (WT), crack field depth, and crack field length, using probability distributions. The distributions are calibrated to reflect the difference between ILI measurements and field non-destructive examination (NDE) measurements. The calibration for length incorporates either the ratio between the total ILI-called total SCC field length and the NDE measurement of longest interacting length (LIL), or the ratio between the ILI-called LIL and the NDE LIL.

The semi-probabilistic model approximates the lower percentiles (0.1th and 0.5th percentiles) of the probabilistic burst pressure distributions using a deterministic evaluation of CorLAS™, incorporating partial safety factor (PSF) adjustments on the feature’s length and depth.

The PSFs are calibrated through an optimization which is run against probabilistic results generated for a comprehensive set of feature sizes and pipe attributes. The numerical optimization is done in two steps to ensure that a global optimum solution has been found. First, constrained global search is performed using simulated annealing and then steepest descent is used to fine tune to the best solution local to the outcome from the first step.

The performance of the model was evaluated to ensure a proper balance is achieved between the level of conservatism in the predicted failure pressure and the dig efficiency. When evaluated against historical digs, the results showed a more than 80% reduction in the number of recommended digs that were ultimately found to be false positives (resource outliers). Based on these historical field measurements, the expected probability of a false negative call (near miss) is less than 1 × 10−8.
Quantitative Risk Assessment for Residential Hydrogen Supply Trailer With 100% Purity
Authors: Yoho Gary P. , Fusco Jacqueline , Klashinsky Tyler , Munoz Eduardo , Fateminia Seyed Hamed , Fontenault Jeremy , Franey Tara
Published: December 2024

ATCO Gas & Pipelines plans to deliver 100% gaseous hydrogen to a residential dwelling in Alberta using a temporary supply trailer in 2024. This document introduces a quantitative risk assessment methodology designed for this specific application. The assessment systematically evaluates potential threats arising from equipment failure, improper operational procedures, vandalism, and adverse weather conditions. Additionally, it presents a thorough analysis of the consequences ensuing from the release of hydrogen, both in the presence and absence of ignition.

This residence, to be used as a show-home, will utilize pure hydrogen for space and water heating purposes and will serve as a proof-of-concept demonstration to the public, regulators, and industry that hydrogen for residential heating is a viable decarbonization option especially in the extreme cold temperatures experienced in Alberta. Although the equipment employed for this endeavor is conventional for natural gas operations, it’s pure hydrogen application and installation site deviate from the norm. Additionally, threats linked to hydrogen storage have traditionally been confined to industrial settings, where exposure concerns differ. The primary focus of this paper pertains to the vulnerabilities to which the trailer is exposed and the subsequent risk it imposes upon the surrounding residential development.

Numerous companies in the natural gas industry are currently investigating the potential of hydrogen as an alternative or supplemental fuel for domestic heating and cooking. They are examining the feasibility of blending hydrogen up to 20% with natural gas, as well as the application of 100% pure hydrogen. To facilitate a smooth and safe transition from natural gas to hydrogen, it is key to thoroughly understand the risks associated with delivering hydrogen to residential areas, homes, and surrounding communities. Conducting detailed quantitative risk assessments is an important step in this process, as it helps to identify and mitigate potential hazards linked to the use of hydrogen in these settings. This comprehensive approach ensures that the adoption of hydrogen as a residential fuel is both safe and efficient.
Composite Repair of Large-Size Diameter Pipe With Severe Metal Loss Defects
Authors: Yu Deli , Hossain Asad , Huang Hannah , Coker David , Turchet Stefan , Alexander Chris , Mally Timothy , Whalen Casey
Published: December 2024

A full-scale testing program was conducted to evaluate the use of carbon-epoxy composite repair technology to reinforce severe corrosion defects in large-diameter pipes. The technical elements associated with this program included reinforcing up to 85% deep corrosion defects in 24-inch diameter pipe samples, including integrating design equations, testing conditions, and performance subject to cyclic pressure and burst testing at elevated temperatures.

An objective of the test program was to evaluate changes in the composite design thickness considering a range of severe corrosion depths based on guidance provided in ASME PCC-2, as well as the pressure capacity reductions based on the methodology embodied in ASME B31G. The testing program also evaluated the ASME PCC-2 design guidance subjected to cyclic pressure conditions at 60°C (140°F).

The composite technology evaluated in this program has the potential to advance the effectiveness of composite repair while also addressing common severe corrosion defects to guarantee the operational life of a pipeline based on an optimized design configuration. This integration of knowledge based on results obtained in this program holds significant promise in guiding future composite repair procedures, structural reinforcement designs, and material choices, culminating in enhanced structural robustness and dependability of high-pressure transmission pipeline systems.
Phased Array Non-Destructive Error Measurement in the Characterization of Axially and Circumferentially Oriented Crack and Weld Defects in Transmission Pipelines
Authors: Catalano Joseph , Price Nicholas
Published: December 2024

Phased Array Ultrasonic Testing (PAUT) is among the most common non-destructive examination (NDE) methods for the characterization and sizing of pipeline defects. Where defects sized by PAUT cannot be removed by griding (internal/midwall defects or stacked defects) the practice of an operator was to add 1 mm depth to any PAUT reported values. If this assumed error is conservative, there may be significant impact to repair decisions, tool validation, and fatigue life calculations for crack defects or weld defects sized using PAUT. This impact is felt across the organization through higher integrity repair budget costs, an increase in required digs, and directly impacts workload for planning and execution groups. The purpose of the study was to verify whether the assumption to add 1mm depth to defects sized by PAUT was appropriate.

A comparison of PAUT measured sizing to ground (true) depths was conducted on over five hundred individual defects during integrity repair programs completed between 2020 and 2022 on a 1960’s vintage 317 MPa grade and 4.78 mm nominal wall thickness NPS 12 pipeline. The pipeline was selected as a candidate for the study due to the significant amount of available NDE data, particularly for axial/circumferential crack and girth/longseam weld defects. The influence of variables including technician conducting work, defect orientation, defect type, and longseam/girth weld interaction on the accuracy of measurements were assessed.
Refining the Hydrostatic Design Basis Assessment for Composite Pipes
Authors: Gilde Mohammad , Fujinaga Daniel , Ohaeri Enyinnaya George , Bussiere Mathew
Published: December 2024

This paper proposes a preliminary, supplementary testing approach aimed at refining the hydrostatic design basis assessment for composite pipes, which is crucial for oil and gas transportation under high-pressure conditions. The paper begins with an overview of existing standards and practices related to maximum allowable operating pressure and composite pipe longevity, highlighting limitations and opportunities for improvement. A short-term burst test based on the ultimate elastic wall stress (UEWS) principle is then proposed as a possible alternative to ASTM D2992 for requalifying family product variants. The proposed preliminary testing methodology is demonstrated by way of a limited demonstration test on two anonymized commercial composite pipe products. The demonstration test shows that, by using appropriate instrumentation, reliable strain field mapping, and robust statistical analysis, UEWS can offer a more practical means by which to requalify different product variations within the same family.
Numerical Modelling and Analysis of the Behaviour of Composite Flanges Joints With Conical Collar
Authors: Amar Manal , Boutahar Lhoucine , Chouiyakh Hajar
Published: December 2024

Glass fiber reinforced polymers, or GFRP, represents a kind of composite material being employed increasingly in different applications. It is frequently mixed with other materials to develop structures. Due to its excellent mechanical properties and resistance to chemical reactions, GFRP is used instead of metal pipes and bolted flanges in critical industrial sectors including the chemical, petroleum, and maritime industries.

The application of GFRP in bolted flange assemblies has, however, been the subject of limited published research, making the design of these joints difficult for the lack of specific standards. The understanding of the implications for the reliability of these flanges is limited since existing standards do not provide guidelines for the construction of GFRP bolted flange assemblies.

The modelling and finite element analysis of GFRP flange joints with a conical collar, according to ASTM D5421 and PS 15-69 standards, are the main purpose of this study. The NPS 4 and NPS 12 class 150 flange sizes were analysed to pinpoint the crucial components that need further consideration regarding to material selection, bolt tightening, sealing, and pressure limits.

The stated purpose was to figure out the most crucial places and their accurate locations through evaluating the deformations and stresses in the flange, gasket, and bolts. The overall aim of this global analysis is to highlight weaknesses within the assembly, with a view to optimize the design and ensure the reliability of the bolted GFRP flange assemblies.