bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stress-Strain Simulation of Viscoelastic Model of Sealing Disc Material for In-Pipe Detector
Authors: Wang Xingyu , Guo Yanbao , Zhang Zheng , Wang Deguo 
Published: December 2024

Abstract
In the pipeline inspection industry, polyurethane materials are chosen as the material for sealing discs in pipeline inspection detectors due to their excellent oil resistance, chemical stability, and mechanical stability. However, polyurethane materials are highly prone to generating interface frictional heat and adhesive wear during operation, presenting challenges in signal acquisition and detection. The simulation of frictional heat and adhesive wear necessitates the utilization of a viscoelastic model. Currently, the mechanical performance simulation of polyurethane materials often employs hyperelastic models, such as the Mooney-Rivlin model, which neglects the mechanical hysteresis losses induced by viscosity. This not only hampers the accurate evaluation of the sealing disc’s mechanical performance but also precludes the description of the generation of frictional heat and wear. In this study, compressive stress-strain tests and compression relaxation tests carried out on polyurethane materials. The generalized Maxwell model representing the viscoelasticity and the Mooney-Rivlin model representing the hyperelasticity were obtained. The Abaqus software’s “dynamic, explicit dynamics module” was employed to calculate the stress-strain distribution over time for the two models under different pressures. The models were constructed for polyurethane annular materials and steel annular materials using a face-to-face contact form, with a load range of 0.1 MPa to 0.5 MPa. In comparison with the hyperelastic model, differences in the stress-strain relationship over time were observed between the two models. Moreover, the material’s strain was found to be correlated with the change in stress. The viscoelastic model can provide a more accurate description of the material’s mechanical performance, with differences primarily manifested in the phase lag effect of the angle. This research opens up a new research direction for establishing a viscoelastic mechanical model for sealing discs in pipeline inspection detectors, enabling the possibility of studying the dynamic face-to-face friction model of viscoelastic materials (including frictional heat simulation and wear distribution calculations) through simulation calculations.
CO2 Dispersion Analysis Factors and Their Impacts on Pipeline Routing
Authors: Compton Nicola 
Published: December 2024

Abstract
Carbon capture and storage projects worldwide have grown by 48% in the last year [1]. This industry’s growth has also seen an increased need to transport carbon dioxide (CO2). The analysis performed and discussed in this paper is based on real project examples. The projects demonstrate how the application of dispersion analyses impacted significant project and pipeline routing decisions, with major potential capital and public safety implications. This is particularly relevant to our industry, which expects to increase the CO2 transport capacity significantly.
There are many hazards associated with CO2 due to the following properties: CO2 is colorless, odorless, heavier than air, is an asphyxiant and is an intoxicant. An uncontrolled release may spread undetected near the ground or in confined spaces.
With the rise in CO2 pipelines, challenges associated with pipeline routing need to be addressed. Ideally, pipelines should be routed in areas with sparse population densities due to the hazards to people associated with a CO2 release. Several factors affect how far from populated areas a pipeline should be routed. These include the most common local weather conditions (average temperature and average wind speed/direction), pipe size, the surrounding terrain, and the pipeline inventory.
This study will show the comparison of dispersion modelling results from three pipeline diameters (12″, 20″ and 36″) in a rural and an urban setting for four types of weather conditions, (stable and neutral atmospheric conditions for both summer high temperatures and winter low temperatures). The comparison of results will demonstrate the variables that must be considered at the early stages of pipeline routing.
Full-Scale Physical Modeling of Axial Soil-Pipe Interaction in Organic Soils
Authors: Jayasinghe Thushara , Wijewickreme Dharma 
Published: December 2024

Abstract
Organic soils (i.e., muskeg, peat deposits) cover 18% of the Canadian landscape and many energy pipelines cross these soil terrains over large distances. Thermal changes due to operational and environmental reasons pose a significant threat to the structural integrity and safety of pipeline systems in these soils. Engineering design of pipelines in muskeg terrains involves many challenges, mainly due to the lack of understanding of the mechanical behavior of organic soils. Such knowledge gaps have caused an absence of well-adapted soil-pipe interaction (SPI) assessment methodologies for pipeline design in organic soils, unlike the methods readily available for pipes buried in mineral sandy/clayey soils (e.g., PRCI guidelines [1]). In view of the above, a detailed research program is undertaken to study the soil-pipe interaction in organic soils. As a part of this program, a series of full-scale axial pipe displacement tests was conducted using a sand blasted 114 mm diameter steel pipe buried in organic soil simulating different H/D ratios, directly yielding axial p-y curves (i.e., soil springs). The “soil springs” representing muskeg are compared with those computed using equations given in PRCI guidelines [1] for pipes buried in clayey soils. Based on this, adjustments to these clay-based equations are proposed for generating axial soil springs for pipes buried in organic soils.
Performance of Terrain Mapping Estimation of Depth to Bedrock in Pipeline Construction Planning: A Case Study
Authors: Waddington Betsy , Toussaint Luc , Ghazali Rami , Baumgard Alex 
Published: December 2024

Abstract
Terrain mapping is the delineation of polygons with unique surficial geology, landforms and processes, and is often conducted at the start of a project to provide preliminary ground information, particularly in areas that have not been subject to significant development. Depth to bedrock, one of the attributes typically assigned to terrain mapping polygons, can be a key input in estimating rock excavation volumes through the design phase of a project. In this case study, design-level depth to bedrock estimation for three short new pipeline alignments routed through southeastern British Columbia are compared to detailed ground condition observations collected through construction. Possible causes of discrepancies are then discussed, leading to a review of the approach to conducting design-phase estimates for future projects.
Impact of Inline Isolation Tool on the Integrity of Onshore Pipelines
Authors: Debnath Suborno , Roy Kshama , Liu Tina , Yin Ole , Zhang Ken 
Published: December 2024

Abstract
Inline pressure isolation tools are widely used for offshore pipelines for planned maintenance and emergency repair work, e.g. valve replacement, repair, tie-ins. Design and engineering analysis of such tools for offshore application have been well developed. Although inline pressure isolation technology is widely used in offshore pipelines, its use in onshore application is limited. However, because of its capability of providing reliable in-line isolation with significantly reduced blown-down length and methane emission for integrity and capital projects that traditionally require pipeline outages, the inline pressure isolation tools are getting increased attention from the onshore pipeline operators in recent years. Consequently, there is a growing need for better understanding of applicability and limitations of using established offshore design rules for onshore applications and developing engineering assessment workflow to ensure successful execution and prevent potential irreversible damage to existing assets. One of the challenges for the application of pressure isolation tools to onshore pipelines is to better understand the pipelines stresses that are exerted by these tools during their operation. This paper investigates the impact of these tools on the integrity of onshore pipelines from stress perspective through leveraging 3-D continuum finite element (FE) analysis using Abaqus FE software, with consideration of actual loading and boundary conditions that onshore pipelines could involve. The FE model was first calibrated with a full-scale test to ensure accuracy and validity of the simulation. Subsequently, a total of 137 FE models were developed for a wide range of pipe sizes (NPS 10 to NPS 48) and wall thicknesses (4 mm to 26.4 mm). The resulting stresses were compared with the allowable stresses for the pipelines. Furthermore, a sensitivity study was performed for various pipe material properties to ensure that an adequate factor of safety is maintained throughout the analysis. Outcomes of the investigative study was fed into a streamlined assessment workflow that includes a series of simplified graphs for determining the allowable pressure for various pipe sizes for future applications. The results demonstrate advantages of using FE based streamlined approach over conservative case-by-case analytical solutions. The outcome of this study provides insights on the various stress conditions that could result from the inline isolation tool for onshore pipelines and could potentially impact pipeline integrity.
Fracture Toughness and Management of Cracking in Hydrogen Pipelines
Authors: Gallon Neil , Wynne Dominic , Baby Benjose 
Published: December 2024

Abstract
Due to the embrittlement effects of hydrogen on carbon steel, cracking has become a key technical focus for industry practitioners looking at the feasibility of converting existing pipelines to hydrogen operation. A prudent repurposing study should establish what crack size would be acceptable under hydrogen operation and at what rate it would grow through fatigue. This information allows for informed decision making when receiving baseline crack inspection data or considering what plausible crack-like anomalies could be present in the pipeline.
Although the potential repurposing of pipelines to hydrogen is new to the industry, the threat of cracking is not and there is extensive experience in the management of cracking. This experience includes quantifying acceptable crack sizes and the predicted remaining life of a pipeline. This quantification is based upon Engineering Critical Assessments, which rely for their inputs on knowledge of the crack dimensions and material properties (principally fracture toughness). For existing pipelines there is already a large body of work which helps define how to assess fracture toughness when different fracture toughness measurands (e.g. CTOD measurements or J-R curve data) or only Charpy V-notch tests are available. The applicability of these methods to a hydrogen pipeline is questionable.
This paper will explore what fracture toughness means in a hydrogen pipeline by comparing the different test methods and measurands, for example the threshold stress intensity factor (KIH) as defined in ASME B31.12 / ASTM E1681 as compared to fracture toughness measured under a rising load (ASTM E1820 type testing) and a potential “da/dt” threshold for crack growth under a static load. It will also illustrate some of the uncertainties around how to define fracture toughness in a rising load test, together with a discussion of the use of Charpy V-notch data in hydrogen service.
The paper will next illustrate what some of the uncertainties mean in terms of assessing cracks in hydrogen pipelines and demonstrate how the choice of test protocol and measurand can affect the critical crack size and detection capability. It will investigate the validity of the 50 ksi.in1/2 threshold stress intensity factor defined in ASME B31.12 and the implications of assuming this as a minimum fracture toughness value for a hydrogen pipeline.
In summary, the paper intends to provide an overview of quantifying the threat from cracking in H2 while showing how to establish a suitable operation window to meet remaining life expectations.
An Insight Into What it Takes to Validate Inline Inspection Tools for Reliable Hard Spot Identification and Measurement
Authors: Farnie Steven , Tindall Anthony 
Published: December 2024

Abstract
A hard spot is a localised area of increased hardness, defined in 49 CFR Part 192 as “an area on steel pipe material with a hardness greater than or equal to Rockwell 35 HRC (Brinell 327 HB or Vickers 345 HV10)”. Hard spots result in localised areas of increased residual magnetic field following magnetisation by an inline inspection tool run. These magnetic fields can be measured using a low or no field approach and used to detect and classify hard spots and to predict the hardness.
There are significant challenges in moving from pull test or dig data to creating a validated specification for hard spot inspection. The essential variables for hard spot inspection — sources of variation which must be controlled within defined limits for a successful result — are more numerous than for comparable inline inspection technologies. This is due to the two-step magnetization and measurement process and the range of factors related to the pipeline conditions, the hard spots themselves, and the inspection tool which could affect the magnitude of the residual field. The relative scarcity of hard spot examples and the difficulty in manufacturing hard spots to predictable tolerances means that the data required to validate across the range of all essential variables is not readily available.
This paper describes how Baker Hughes, in collaboration with industry partners, are using a multi modal approach to combine FEA, pull test and dig data to cover the essential variables required for inline inspection of hard spots and establish a validated POD, POI and POS specification.
Implementation and Optimization of a Multiphase, Transient Release Rate Model for Consequence Estimation
Authors: Middleton Steven , Svitich Aiden 
Published: December 2024

Abstract
The life safety consequences of CO2 pipelines and those carrying other toxic chemicals, unlike natural gas pipelines, are affected to a great extent by the outflow’s response to time and phase behaviour over a long timescale. Therefore, a critical part, of evaluating the hazard of releases is outflow modelling. To bridge this technical gap, as well as to produce a general model suitable for evaluating a range of product types, including natural gas and natural gas-hydrogen blends, a multiphase, transient release rate model is required. This paper outlines the enhancements applied to a method of characteristic-based flow solver, described by the University College of London, to facilitate its practical application to repeated simulations. These improvements include an adaptive grid and locally defined timestep; a REFPROP-derived equation-of-state property lookup table; a 1D wall heat-transfer treatment; a domain-extending boundary condition; and a numerical construct that uses a steady-state approximation of the conservation equations to extrapolate beyond the calculation domain to better approximate a semi-infinite pipeline.
The Blending of Hydrogen and Natural Gas by Direct Injection Into High-Pressure Large-Diameter Gas Transmission Pipelines
Authors: Curson Nigel 
Published: December 2024

Abstract
For many countries, blending hydrogen with natural gas into the existing gas transmission network is one of the critical steps towards energy transition. Blending allows relatively direct access to a market for hydrogen. It targets CO2 emissions associated with domestic and industrial consumption via existing connections. This is evidenced by the fact that in the EU 40% of households are connected to the gas network [1]. Blending has been trialled with medium-pressure, small-diameter public networks at relatively low volume flow rates for consumers, equivalent to a village. These first trials have proven hydrogen blending using a blending skid [2]; however, scaling a skid concept up from medium-pressure distribution diameters to transmission diameters and high pressures (32-inch and 85 barg, respectively) would require significant investment with sizeable equipment and a potentially disruptive intervention. Considerable economies can be obtained by injecting the hydrogen directly into the pipeline and using the pipeline itself as a mixer component. The challenges associated with this are achieving adequate mixing within a reasonable number of diameters downstream from the injection point, not exposing the inside surface of the pipeline to unacceptable percentages of hydrogen with the risk of embrittlement, and designing a nozzle or nozzles that are practical from a manufacturing perspective, allow inline inspection, don’t introduce a structural weakness, or have demanding construction or operational implications. This paper proposes various solutions with results backed by analytical modelling using Computational Fluid Dynamics (CFD).
Dent Safe Excavation Pressure and Fracture Reliability Assessment With Machine Learning
Authors: Tang Huang , Di Blasi Martin , Okoloekwe Chike , Yoosef-Ghodsi Nader 
Published: December 2024

Abstract
Dents can potentially cause cracking or pipeline leaks posing a threat to pipeline integrity. Engineering critical assessment of dents interacting with cracks plays an important role in the risk and integrity management of pipelines. It is not an easy task to conduct fracture assessment on a dent-crack defect due to the complexity of the stress field in the dent area. The failure assessment diagram (FAD) method has been widely used to conduct elastic-plastic fracture mechanics analysis of structural components [1, 2]. The FAD approach can be used to conduct fracture assessment for an arbitrary through-wall thickness stress distribution in a pipe with cracks. Finite element simulations are normally required to extract the stress distributions for a pipeline dent. However, the process is computationally demanding and tedious.
A machine learning-based methodology has been developed to improve the efficiency of the process of dent fracture assessment. The machine learning algorithms were trained using a dataset built from finite element simulations of dents. Through-wall thickness stress distributions at multiple critical locations with potential cracks in the dents were extracted for varied dent geometries at multiple pressure levels. The extracted stress distributions were used to calculate stress intensity factors (SIFs) for a wide range of crack dimensions based on the SIF solutions obtained from API 579 [3]. The output variable of the machine learning model was defined as the ratios of SIFs with and without dents. The inputs to the machine learning algorithms to train on include pipe and dent geometries, crack dimensions and pipe internal pressures. The model performance was evaluated through a three-way holdout method. It was shown that the trained machine learning models were able to effectively predict SIFs for dent-crack defects with varied dent geometries. The models were also shown to be robust when used to conduct Monte-Carlo simulations as part of a reliability assessment to develop a distribution of SIF accounting for uncertainties on the model input variables.
Dent fracture assessment with the trained machine learning models was employed in the determination of safe excavation pressure (SEP) based on a reliability analysis. The fracture assessment was conducted using the API 579 FAD approach. The effectiveness of the FAD method on the prediction of burst pressure limits for dent-crack defects was validated with full-scale tests. It was then shown that the machine learning model-based approach was effective in conducting reliability-based fracture assessment on dent-crack defects with the FAD method to determine SEPs corresponding to given reliability targets. The efficiency on the process of SEP determination has been significantly improved compared with the surrogate modeling approach using stress distributions extracted from the finite element simulations [4].
The Influence of Pipe Toughness in the Consequences of Third-Party Damage – A Comparison Between EPRG and Fracture Mechanics Methodologies
Authors: Anilkumar Suvarnalatha Vipin , Curson Nigel , Mcintyre Thomas , Alani Ali 
Published: December 2024

Abstract
Onshore and offshore pipelines provide one of the safest modes of transportation for oil and natural gas. Some offshore pipelines pass through areas where large vessels are active and risk third-party damage, particularly if the pipeline is not trenched. Most prominent ship traffic-related incidents are caused by anchoring in an emergency or indiscriminately. These incidents can cause bending, denting and gouging of the pipe wall leading to immediate rupture of the pipeline or fatigue failure over a short period if not remediated. Examples of severe pipeline damage incidents caused by anchor drop/drag damage include 2021 San Pedro Bay oil spill incident in USA [12] and the 2023 Baltic Sea gas pipeline incident in Finland [13].
In December 2022, an anchor was found to have damaged a 16-inch pipeline in the UK North Sea. The damage was not initially apparent, so the pipeline continued to operate for a few months until visual inspection revealed two severe dents. The pipeline was also displaced by 1.36m over a length of 30m. Gouges and cracking were expected but, initially, could not be confirmed. The Pipeline Defect Assessment Manual (PDAM) [6] recommends the use of European Pipeline Research Group (EPRG) methods [3,4] for assessing the tolerance and resistance of pipe to external damage by estimating the failure stress of a dent and gouge. However, the complexity of the interaction between a dent and a gouge, with the potential for cracking in the base of a gouge, limits the accuracy of this generalised method and demands a reasonable level of conservatism. An assessment of the dent using the methodology described in ASME B31.8 Appendix R revealed a high strain level (up to 12.7%) and a risk of material failure.
To establish whether a return to service is possible, an Engineering Criticality Assessment (ECA) was carried out based on the procedures given in BS 7910 [5]. The ECA results concluded that the dent is not expected to threaten the pipeline’s integrity during its service life.
This paper draws upon a case study to compare the EPRG dent/gouge model and the combination of Finite Element Analysis (FEA) and BS 7910 assessment methodology based on an arbitrary defect equal to a typical gouge and crack at the bottom of the gouge (this is an assumption specified in PDAM, based on the principle that it is hard to rule out the presence of a crack or limited dimensions).
Correlations were made between the low material test temperature and the pipeline ambient temperature to obtain a less conservative CVN value for use in the EPRG assessment. However, a more accurate and comprehensive methodology to calculate fracture toughness and assess the fracture resistance as per BS 7910 proved to be a more rational approach for assessing defects in a modern high-toughness line pipe.