bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison Between Yield Strength Results Obtained From Methods Using Both Flattened and Non-Flattened Specimens
Authors: Nayyar Pratham , Dimopoulos Dimitris , Walsh William 
Published: January 2021

Abstract
Tensile properties of API 5L large diameter pipes are typically determined with the use of full thickness flattened strap samples extracted in the transverse direction with respect to the longitudinal pipe axis (TPA) [1, 2, 3, 4]. It has been well established that the process of sample flattening has a significant influence on determination of the yield strength of the pipe [5, 6]. The flattening process is sensitive to a number of variables such as method of flattening, equipment used, number/sequence of strokes, and operators conducting the flattening. As a result, issues with repeatability are frequently encountered and despite several efforts, the industry lacks any type of official standard for universal use.
Historically, the industry has been focused on ensuring that the actual strength of pipes was safely higher than the specified minimum. Recently, there has been interest to also establish an upper limit on pipe strength particularly in the longitudinal direction with respect to the pipe axis (LPA) in order to avoid under matching between pipe and girth weld properties. These new requirements create the need for enhanced process control to minimize the variation due to flattening.
Samples obtained from longitudinally welded (SAWL) and helically welded (SAWH) seam Grade X70M line pipe of various nominal wall thickness to diameter (t/D) ratios were flattened using different procedures, measured for curvature, and tensile tested, all in controlled laboratory environments with minimized repeatability variation. Special attention was given to the definition and measurement of different types of curvatures observed through the range of different t/D ratios and effort was made to assess criteria for curvature measurement prior to testing. Additionally, non-flattened specimens were tensile tested using round bar and full ring expansion test methods, and a comparison between the results obtained from both flattened and non-flattened specimen methods was made.
The sample transverse yield strength results confirmed the expected variation between samples flattened by different methods. In addition, a much greater variation was observed when comparing the yield strength results between flattened and non-flattened samples. Considerations of extending the use of non-flattened specimens as a production test and benefits or limitations associated with such practice are discussed.
A Hybrid Method Based on SVM Integrated Improved PSO Algorithm for Electrical Energy Consumption Forecasting of Crude Oil Pipeline
Authors: Xu Lei , Hou Lei , Zhu Zhenyu , Li Yu , Lei Ting 
Published: January 2021

Abstract
Electrical energy consumption forecasting of crude oil pipelines plays a critical role in energy consumption target setting, batch scheduling, and unit commitment. For actual crude oil pipelines, because of its uncertainty, nonlinearity, intermittency, fluctuations and complexity, it is challenging to establish the electrical energy consumption forecasting model. And it is difficult to describe the non-linear characteristics of electrical energy consumption forecasting by traditional methods. Therefore, a novel hybrid electrical energy consumption forecasting system based on the combination of support vector machine (SVM) and improved particle swarm optimization (IPSO) is proposed, which includes four parts: data pre-processing part, optimization part, forecasting part, and evaluation part. In the pre-processing stage, in order to avoid large deviation caused by sampling stochasticity of small samples, the training set and the test set are divided by stratified sampling method. During the modeling process, the non-linear relationship in electrical energy consumption forecasting is efficiently represented by support vector machine, and the parameters of support vector machine regression are optimized by the improved particle swarm optimization algorithm. According to the established IPSO-SVM model, evaluation part is conducted to make a comprehensive evaluation for this framework. By comparing the evaluation indicators of IPSO-SVM with that of eight state-of-the-art forecasting methods, the effectiveness of IPSO-SVM method is evaluated. Based on the operation data of four crude oil pipelines in China, the results show that the proposed IPSO-SVM hybrid model has the best forecasting performance than other benchmark models, and its forecasting results are the closest to the actual data. It is concluded that the proposed approach can be an efficient technique for electrical energy consumption forecasting of crude oil pipelines.
Pipe Sleeve Repair Analysis of Axial Surface Cracks to Improve Remaining Life
Authors: Thorwald Greg , Kolovich Carolyn 
Published: January 2021

Abstract
The industry widely uses steel repair sleeves to repair defects in pipelines. This paper focuses on the types of repairs used for crack-like defects where there may be concerns of crack propagation in service from operating pressure cycles. The length of the repair sleeve, the pressure at the time of the repair, and the fillet welds of a Type B sleeve can all effect the future integrity of the repair.
Type B sleeves (fillet weld connecting the sleeve to the pipe) are widely used in the pipeline industry to repair crack-like flaws. Current standards require a minimum of two inches of sleeve material past the edge of a defect. A case study is presented to show if this length is adequate under various operating conditions to ensure the defect does not propagate in service to extend beyond the fillet welds. A pipe with a surface crack and the sleeve repair are modeled using finite element analysis to compute the crack front stress intensity. Contact interaction between the pipe’s outside surface and the sleeve’s inside surface provides the load path from the pipe to the sleeve. The contact interaction is varied from frictionless to fully bonded to vary the amount of crack opening permitted by the sleeve. The stress intensity is compared for each case to quantify the effect of the sleeve repair on reducing the hoop stress and reducing the crack’s stress intensity.
Operators often take a pressure reduction during an in-service repair both for safety reasons and to assist with obtaining a tight fit-up between the carrier pipe and the steel sleeve. An additional benefit of a pressure reduction can be gained in relation to in-service crack growth. A case study is presented that shows how a pressure reduction can extend the fatigue life of a resident defect. Comparing the crack front stress intensity shows the effect on the crack of the pressure reduction when the sleeve is applied. Fatigue crack propagation analysis of several cases shows how the pressure reduction effects the crack growth rates. The analysis method can be used to examine trade-offs between the amount of pressure reduction on fatigue life versus operational requirements.
On-Water Liquid Leak Detection Technology Evaluation
Authors: Apps Chris , Derakhshesh Marzie , Salmatanis Nikolaos , Greaney Carrie 
Published: January 2021

Abstract
The pipeline industry is directing their efforts toward reducing the environmental impact of their operations, improving pipeline performance, preventing and minimizing releases, and addressing evolving regulatory requirements. One key type of technology that helps with these efforts is related to detecting the presence of liquid hydrocarbons on the surface of water, either inside facilities or when crossing waterbodies. C-FER Technologies (1999) Inc. (“C-FER”), under contract to Pipeline Research Council International (PRCI) and in partnership with various pipeline operators, has completed a comprehensive research project to help operators assess the performance of various external leak detection technologies when identifying the presence of liquid hydrocarbon products on the surface of water in a controlled lab environment. Some of these results are presented in this paper.
Improved Semi-Quantitative Reliability-Based Method for Assessment of Pipeline Dents With Stress Risers
Authors: Virk Amandeep Singh , Langer Doug , Woo Janine , Yoosef-Ghodsi Nader , Kainat Muntaseer 
Published: January 2021

Abstract
Dents, especially those interacting with stress risers, can pose integrity threats to pipeline systems. Regulations in Canada and the United States mandate the repair of dents based on depth and interaction with stress risers, however, there have been cases in the past where dents that have passed these criteria have ended up in loss of containment. Recent industry’s recommendations regarding dent integrity analysis are predominantly based on strain, and the dent-fatigue models have been proven to be limited in their application. Additionally, these models or methodologies are generally deterministic which may not fully account for uncertainties associated with pipe properties and in-line inspection (ILI) tool measurement.
Enbridge Liquid Pipelines Inc. had previously presented a framework to support system wide dent assessment with an efficient probabilistic-based calibrated semi-quantitative analysis method for dents (SQuAD), which elicits potentially injurious features from thousands of features within a system in a reasonable analysis timeframe. This paper expands on the authors’ previous work and presents several improvements that have since been made to the SQuAD model to address the limitations in the initial version of the model.
The previous version of SQuAD was strain-based and did not explicitly account for pressure-cycling induced, fatigue-based failure quantitatively. An approximate circle fitting method was adopted for estimating the dent’s radii of curvature in order to calculate strains. In the improved model, filtering techniques have been employed to reduce the noise in the ILI-reported data while preserving the dent shape. Furthermore, a simplified FEA process has been developed to calculate the stresses within a dent due to pressure cycles, thus the fatigue-based Probability of Failure (PoF) of a dent can now be estimated using S-N approach. The filtered data allows for better accuracy in quantifying the radius of curvature of dents as reported by ILI tools, which are used for calculating dent strain as recommended in the updated version of ASME B31.8, Appendix R. Finally, the feasibility of applying this improved SQuAD model is discussed from an operator’s perspective.
The improvements allow the enhanced SQuAD model to be used as an effective screening tool on a system-wide basis as part of a comprehensive, reliability-based dent assessment framework.
High-Pressure Natural Gas Pipeline in Geohazard Region of Papua New Guinea Sustains Mw7.5 Earthquake: Key Factors of Successful Outcome
Authors: Albrecht Robert , Calame John , Cook Mike , Falcon Ignacio , Lee Patrick 
Published: January 2021

Abstract
ExxonMobil PNG Limited (EMPNG) operates the Papua New Guinea Liquefied Natural Gas Project (PNG LNG), an integrated LNG project comprising wellpads, gathering lines, gas conditioning plant, onshore and offshore export pipelines, liquefaction plant and marine terminal in Papua New Guinea (PNG). The PNG LNG project is a joint venture with participation by ExxonMobil, Oil Search Limited (OSL), Kumul Petroleum, Santos, JX Nippon Oil and Gas Exploration and Mineral Resources Development Company, and began production in 2014. The highlands of PNG presents a challenging physical environment, with high rainfall, steep terrain, active tectonics and seismicity, and ongoing landsliding and erosion. The PNG LNG onshore gas and condensate pipelines confront these physical challenges by having to traverse approximately 150 km of steep volcanic, mudstone and Karstic highlands along the Papuan Fold and Thrust Belt, the modern leading edge of active mountain-building, plus an additional 150 km in Karstic lowlands. During design, construction and operations of the pipelines, ExxonMobil has addressed these challenges in partnership with the engineering, construction and specialist consulting communities.
On February 25th, 2018 (UTC) a Magnitude 7.5 earthquake struck the PNG highlands. The event, along with its approximately 300 aftershocks, caused widespread community impact, landsliding and damage to over 1000s of km2, and was centered directly under the highlands portion of the PNG LNG pipelines. The pipelines however, did not lose containment or pressure, and, following inspections and repairs to the PNG LNG gas conditioning plant, PNG LNG production was restored within seven weeks of the main shock.
This technical paper and companion oral presentation discuss the key factors of this successful outcome, in particular the sustained condition of the gas and condensate pipelines. Contributing factors to the pipeline’s success include route selection, pipe material specification, early commitment to field studies, careful assessment of geohazards, high awareness of off-ROW community impacts, micro-routing during construction, and active geohazard management during startup and operations. The paper demonstrates that, with respect for the host community, thoughtful engineering, careful construction and ongoing surveillance, pipelines can be safely and successfully designed, constructed and operated in remote and extreme geohazardous environments.
Electromagnetic Induction Post Heating to Reduce NDE Delay Times of Welding In-Service Repairs
Authors: Hagel Liam , Prescott Jonathan , Kohandehghan Alireza , Guest Stuart , Lepine Sean 
Published: January 2021

Abstract
When a pipeline requires a repair, a pressure-containing steel sleeve or an emergency repair fitting is often fillet welded to the in-service pipe to return the pipeline to normal service conditions. During welding, the flowing product rapidly quenches the fillet weld, promoting the formation of high hardness and low ductility microstructures in the heat-affected zone. The rapid cooling rates also limit the mobility of diffusible hydrogen introduced from the welding electrodes. The hydrogen can be trapped in the weld metal and heat-affected zone and concentrated in specific locations throughout the weld based on the welding deposition sequence. Fillet welds also contain inherent locations of geometric stress concentration at the weld toes and root locations. The elevated hydrogen concentration in the in-service weld, combined with the geometrical stress concentrations at the location of crack-susceptible microstructures, can increase the likelihood of forming a hydrogen-induced crack. Delayed non-destructive examination (NDE) is often employed to wait a sufficient time for any cracks to form so they can be detected.
To reduce hydrogen concentration at the locations of stress concentration and NDE delay times, post-heating can be applied to the in-service weld. Elevating the temperature within the weld can enable hydrogen diffusion and reducing the cracking propensity. The rapid heat removal due to flowing product requires post-heating techniques with high energy outputs that will not overheat the steel surfaces. Electromagnetic induced current (induction heating) methods can produce sufficient thermal energy in the electrically conductive steel pipe and sleeve. Coupled numerical finite element analysis (FEA) models were utilized to simulate various induction cable arrangements and thermal convection coefficients, representative of various pipeline products. The analysis of the induction heating arrangements for the studied thermal convection coefficient was conducted to achieve a minimum temperature of 120 °C in the fillet weld root and toes to enable sufficient thermal driving force for hydrogen diffusion while ensuring the pipe and sleeve surface temperature does not exceed 200 °C. An optimal induction heating procedure was found to which could achieve the target temperatures within a reasonable heating time such that NDE delay times of in-service welds can be reduced by 5–6 times.
Stress Corrosion Cracking “Like-in-Kind” Reliability Approach for Pipelines Without Crack Tool In-Line Inspection
Authors: Elsisi Amal , Lee Winston Y. W. , Tomar Pushpendra , Williams Dan 
Published: January 2021

Abstract
Gas transmission pipeline operators increasingly rely on Electro-Magnetic Acoustic Transducer (EMAT) technology to reliably detect, identify and size stress corrosion cracking (SCC) anomalies in their pipeline system. However, scheduling EMAT in-line inspection (ILI) on every pipeline in the system is not always practicable or achievable in an expeditious manner. A means of conducting a preliminary assessment of the SCC threat on pipelines without EMAT ILI data in an objective and quantifiable manner is useful for understanding the threat level and for prioritizing or deciding on outstanding EMAT inspections. A wealth of system-specific SCC field data from historical integrity excavations across the pipeline system typically exists in a pipeline operator’s dataset and can be readily leveraged for quantitatively estimating the SCC threat reliability in other, similar (“like-in-kind”) parts of the pipeline system. This system-specific data, based on actual SCC findings from integrity excavations, is an improved and more granular alternative to applying industry-wide SCC statistics to estimates of SCC reliability levels on pipelines without EMAT ILI data.
This paper presents a robust and direct limit state approach for estimating the SCC reliability level in pipelines that have not yet had an EMAT ILI completed by leveraging system-wide SCC field findings from historical integrity excavations.
Separation Characteristics of an X65 Linepipe Steel From Laboratory-Scale to Full-Scale Fracture Tests
Authors: Davis Bradley J. , Michal Guillaume , Lu Cheng , Linton Valerie 
Published: January 2021

Abstract
Separations are small fissures that form along the rolling-plane of some steels when sufficient stresses are created to open planes of weakness in the material. In the pipeline industry, separations have been observed on the fracture surfaces of tensile, Charpy, and drop-weight tear tests — the key tests for determining the fracture arrest capabilities of line pipe steels. When compared, the separation appearance between lab-scale tests and full-scale fracture test are noticeably dissimilar. Therefore, the influence separations have on the fracture behaviour may not clearly scale between lab-scale and full-scale tests.
In this study, the separation severity of Charpy, DWTT, and full-fracture propagation test fracture surfaces was measured and compared. Two full-scale burst tests were carried out with pipes containing a CO2/N2 mixture. Fracture surfaces were observed along the length of the pipe and captured when the separation appearance changed. For each pipe section, the corresponding lab-scale test surfaces were compared.
With the separations measured across all fracture faces, the separation appearance of the full-scale test surfaces did not provide the same values as the lab-scale tests. However, the lab-scale tests did capture the trend in separation severity for each pipe section. Only the lab-scale test surfaces showed a correlation in separation severity.
Stress Analysis of Buried Pipelines Under Thaw Settlement of Permafrost Zone Based on Moisture-Heat-Stress Coupled Analysis
Authors: Jiang Jinxu , Zhang Hong , Liu Jianping , Chen Pengchao , Liu Xiaoben 
Published: January 2021

Abstract
Permafrost thawing caused by the hot crude pipeline is a major threat to the safe operation of buried pipelines in permafrost zone. In this paper, the process of thawing and consolidation of frozen soil is considered, and a three-dimensional (3D) finite element model of buried pipelines in permafrost zone is established using ABAQUS. The calculation of thaw settlement displacement of frozen soil based on moisture-heat-stress coupled was carried out, and the deformation and stress of buried pipelines were analyzed. The effects of ground temperature, oil temperature, thermal conductivity of insulation material and soil distribution along the pipeline on the vertical displacement and longitudinal stress of buried pipelines in frozen soil were studied. Research results show that in thaw-unstable soil, the vertical displacement and stress of the pipeline increase significantly with the increase of the average ground temperature, and change on ground temperature amplitude has a little effect on the vertical displacement and longitudinal stress of the pipeline in thaw settlement zone. It is 1/3 of the vertical displacement of the pipeline without a heat insulating layer. When the thermal conductivity of the insulation material is less than 0.4 W/m °C, the vertical displacement of the pipeline in the thawing zone can be further reduced by reducing the thermal conductivity of the insulation material. When clay and sand appear alternately along the pipeline, the vertical displacement and longitudinal stress of the pipeline can be reduced by reducing the length of clay section. This study has certain reference value for optimizing the design parameters of buried pipelines in permafrost zone and reducing the impact of differential thaw settlement of frozen soils on the safe operation of pipelines.
Integration of Multiple ILI Technologies for Robust Understanding of Unique Anomalies on a Pipeline
Authors: Shie Taylor , Lutz Andrew , Taverna Paul 
Published: January 2021

Abstract
Pipeline operators have many choices when selecting inline inspection (ILI) vendors and technologies. No single technology has a one hundred percent probability of detection, identification, and sizing for all anomaly types. Operators must match the threats on their system to the existing capabilities of the ILI technologies to achieve the goals defined by the company’s integrity management program. It is sometimes necessary to run multiple technologies to effectively assess all threats in a pipeline. Multiple technologies may be run during the same timeframe or they may be run at different times during the life of the pipeline to meet program goals.
Shell Pipeline Company, LP (SPLC) has a pipeline that is comprised of low frequency electric resistance welded (LFERW) pipe from Youngstown Sheet and Tube, seamless pipe from National Tube, double submerged arc welded (DSAW) pipe from Kaiser, and high frequency electric resistance welded (HF-ERW) pipe. The LF-ERW pipe was installed in 1948 while the HF-ERW was installed during relatively recent replacement projects. The DSAW pipe was installed in 1952 with the seamless pipe being installed in both 1948 and 1952.
From 2015 through 2018, SPLC executed an extensive integrity management program. This included: an axial magnetic flux leakage (AMFL) inspection, two circumferential magnetic flux leakage (CMFL) inspections, two deformation inspections, an electro-magnetic acoustic transducer (EMAT) inspection, an ultrasonic crack detection (UTCD) inspection, an ultrasonic wall measurement (UTWM) inspection, and a hydrotest. A dig campaign of nearly 100 excavations was completed as a result of these surveys. One of the focuses of the paper will be the comparison of EMAT to UTCD for Likely Cracks, Possible Cracks and Unlikely Cracks that have been field verified.
This paper also shares some of the unique anomalies found through the dig campaign identifying the effectiveness of each technology and their combination for integrity purposes. The paper shows the benefits of combining ILI technologies to properly characterize, assess and mitigate reported anomalies and ensure there are no blind spots in the integrity management program. Case studies including dent with gouge (e.g. AMFL + Deformation), manufacturing, and cracking anomalies as well as the analytics of ILI versus field findings are presented and discussed in the paper. The paper concludes with the knowledge creation resulting from multiple ILI technology integration assisted with subject matter expert experience and analytics to provide a robust understanding of unique anomalies in pipelines.