bluuebunny/crossref_metadata_2025 huggingface dataset:
Association Between Geriatric Nutritional Risk Index and Critically Ill Patients With Pressure Injury: Analysis of the MIMIC‐IV Database
Authors: Zhang Yilei , Qin Chuan , Xu Li , Zhao Mengjia , Zheng Jinan , Hua Weilong , Wei Yutian , Zhang Guanghao , Huang Xiaoling , Chen Rundong
Published: December 2024

Aims and Objectives

To explore the relationship between the Geriatric Nutritional Risk Index (GNRI) and the occurrence of Pressure injury (PI) in elderly Intensive Care Unit (ICU) patients.

Background

PI represent a significant health concern within ICU, where the occurrence of such injuries is notably high among critically ill patients. However, few studies have explored the relationship between GNRI and PI.

Design

A longitudinal, single‐centre, retrospective study.

Methods

The study utilised GNRI calculation to identify PI occurrences. A comprehensive set of covariates was analysed, including demographic information, severity of illness scores, comorbidities, therapeutic interventions, vital signs and laboratory values. Statistical analysis involved descriptive statistics, logistic regression and receiver operating characteristic curves, supplemented by a doubly robust estimation method and propensity score modelling. This study follows the STROBE‐nut checklist.

Results

Among 5327 critically ill patients enrolled in the study, with a median age of 76 years, of which 2339 were females, representing 43.91% of the total study population. Binary logistic regression analysis revealed that with each unit increase in the GNRI, the likelihood of PI occurrence decreased by 3.7% in the fully adjusted model. Furthermore, there was a significant decrease in PI occurrence among patients deemed to have no risk compared to those identified as at‐risk.

Conclusions

GNRI emerges as a significant, independent predictor of PI risk in elderly ICU patients, underscoring the importance of nutritional assessment and management in this population.

Relevance to Clinical Practice

This study highlights the critical importance of nutritional assessment, specifically through GNRI, in early identification and prevention of pressure injuries among elderly ICU patients, underscoring the need for integrated nutritional strategies in clinical settings.

No Patient or Public Contribution

This is a retrospective cohort study, and no patients or the public were involved in the design and conduct of the study.
Divorce among more and less divorce‐prone populations following unilateral divorce laws
Authors: Andersson Linus , Saarela Jan , Uggla Caroline
Published: December 2024

Objective

This study analyzes heterogeneity in divorce rates after the 1987 transition from mutual consent to unilateral no‐fault divorce in Finland.

Background

Marriage and divorce legislation can impact divorce rates. However, some groups may be more responsive to changes in legal context than others. We propose that unilateral no‐fault divorce laws either (a) increase divorce more in more or less divorce‐prone groups, or (b) increase divorce equally across these groups.

Methods

We use population‐wide individual‐level register data from Finland to identify salient social groups with different divorce propensity, including ethno‐linguistic and religious affiliations with divergent divorce propensity and couples of different parental status, marriage length, and marital history. We use piecewise constant exponential survival models to estimate the association with divorce proneness before and after the introduction of mutual consent divorce laws.

Results

Divorce rates increase in all studied subgroups by about 60% in the years following unilateral divorce. We found no support for the hypothesis that groups that were either more or less divorce‐prone prior to the reform would be particularly responsive to divorce liberalization in the short‐to‐medium term.

Conclusions

The findings speak toward a universal rather than heterogeneous effect of divorce law liberalization.
Nationalist political elites and territorial disputes: A cross‐national investigation
Authors: Kwon Jaebeom , Kim Nam Kyu
Published: December 2024

This study explores the consequences of nationalist governing elites for states' territorial behaviours. We argue that political elites who promote nationalist ideologies and stoke nationalistic fervour are often more inclined to initiate or escalate territorial disputes with other nations. They are likely to perceive greater values of territory, while they underestimate the perceived costs associated with territorial disputes. Analysing all territorial claims from 1901 to 2001, our research reveals compelling evidence that nationalistic political elites are more likely to initiate territorial disputes and less likely to seek peaceful resolutions, particularly when the contested territory possesses intangible salience.
The gut microbiome and eating behavior outcomes: A systematic review
Authors: Chimera Bernadette , Hoobler Rachel , Deschasaux‐Tanguy Mélanie , Van Merris Eugenie , Roels Ophelia , Playdon Mary , Michels Nathalie , Huybrechts Inge
Published: December 2024

Background

Dysfunctional eating behaviors, and their modulators, are an important component in the prevalence of malnutrition. The gut microbiome, acting through the microbiota‐gut‐brain axis, is implicated as a modifiable factor in eating behavior. ObjectivesThis systematic review investigated the influence of the gut microbiome on human eating behavior and their modulators (appetite, satiety, energy/food intake, weight loss/gain).

Methods

Literature was retrieved from PubMed, Embase, and Web of Science until July 2022. In total, 37 studies were included, with interventions including pre/post/syn‐biotics. The primary outcome was eating behaviors, and their modulators.

Results

The gut microbiome was associated with eating behaviors, and their modulators, in 28 studies, particularly affecting appetite/appetite hormones, energy/food intake, and weight gain. Intake of probiotics and synbiotics were inconsistently related to appetite and appetite hormone levels, (n = 6 and n = 2 respectively). Prebiotic supplementation showed a consistent trend in the reduction of appetite (n = 4), regulation of appetite hormone levels (n = 10), and increase in self‐reported satiety (n = 4). Conversely, energy intake (n = 18) and weight gain/loss (n = 7) were inconsistently associated with probiotic interventions across studies, populations, and interventions. In terms of quality of evidence, most publications had a high risk or some concerns of risk of bias, with fewer than 25% falling into the low‐risk category.

Conclusion

This review provides an overview of the links between the gut microbiome and human eating behavior across human phenotypes. While explicit associations between specific microbiome taxa and eating behavior are identified, further evidence is needed to substantiate causal relationships. Future research with standardized methods and prospective designs is needed.
Editorial comment on “Prevention of allergies and infections by minimally processed milk in infants—The MARTHA feasibility and safety trial”
Authors: Alves Pedro Botelho , Khaleva Ekaterina , Eigenmann Philippe , Peters Rachel L.
Published: December 2024

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Tenosynovitis with psammomatous calcification—Analysis by scanning electron microscopy and energy‐dispersive x‐ray spectroscopy
Authors: Sonobe Yuta , Hasegawa Hiromasa , Hashimoto Kazuaki , Takamiya Hisatake , Yamawaki Yuka , Konishi Eiichi
Published: December 2024

Tenosynovitis with psammomatous calcification (TPC) is an extremely rare condition. It was first described as a characteristic subtype of idiopathic calcifying tenosynovitis, with only 40 cases reported to date. Here, we present a case of TPC affecting a female patient in her late teens, with no relevant medical history. She presented with discomfort and pain in the right first toe. A 10‐mm mushroom‐like calcified mass was observed in the metatarsophalangeal joint on radiographs. The surgical specimen revealed chronic synovitis with calcification. Numerous psammomatous bodies are observed in the synovium, often with granulomatous reactions. After removal of the mass, no recurrence has been observed for 5 years. Although the etiology of TPC has been suggested to be related to repetitive trauma to the tendon or peritendinous soft tissue, the composition and mechanism of calcification remain unclear because of its rarity. In this report, we also discuss the calcification mechanism in TPC, supported by scanning electron microscopy and energy‐dispersive x‐ray spectroscopy findings.
On the Possibility of Extending the Crack Length Criterion in the Master Curve Methodology
Authors: Sánchez Marcos , Cicero Sergio , Obermeier Florian , Serrano Marta , Chiu Yu-Lung , Altstadt Eberhard
Published: December 2024

The Master Curve (MC) methodology is a well-known approach utilized to characterize the ductile-to-brittle transition region (DBTR) of ferritic–pearlitic steels. This methodology was initially standardized in ASTM E1921 in 1997 and has undergone continuous evolution and improvement since its origin. However, the validity criterion for the crack aspect ratio (0.45 ≤ a0/W ≤ 0.55) has remained unchanged since its inception. It is worth noting that this criterion was originally established in accordance with standard ASTM E399, which characterizes fracture conditions under linear-elastic plane strain conditions, apparently for historical precedents rather than any scientific rationale. Furthermore, ASTM E1820, which is employed to characterize the fracture behavior of metallic materials in elastic–plastic conditions, permits a maximum crack length-to-width ratio of 0.70. In this context and considering that ASTM E1921 measures KJc (elastic–plastic) values of the fracture toughness, our research seeks to empirically demonstrate that the crack length-to-width criteria established in ASTM E1921 can be increased up to 0.60, without compromising the accuracy of the reference temperature calculations, at least for the specific datasets used in this work. Such a correction would offer significant advantages, especially when dealing with mini-C(T) specimens. Their subsize dimensions may result in the discarding of numerous specimens that could otherwise be effectively employed for reference temperature calculations. More research is recommended to provide additional validation of the crack aspect ratio upper limit proposed here, and even to explore the possibility of further extensions.
Turbulence Measurements in Axial Turbines Using Fast Response Aerodynamic Pressure Probes
Authors: Notaristefano Andrea , Persico Giacomo , Gaetani Paolo
Published: December 2024

Improving the comprehension of turbomachinery fluid-dynamics is vital to increase their performance and calls for the development or extension of advanced instrumentation. In this context, novel data acquisition and data reduction techniques have been recently developed at Politecnico di Milano for turbulence measurements performed with fast-response aerodynamic pressure probes (FRAPPs). These improvements address a gap in the capabilities of such probes, as turbulence data were among the few, yet very important, information they could provide only on a quality level. At first, the technique is validated against hot-wire measurements on a low-speed wind tunnel, where a combustor simulator is inserted with or without an upstream turbulence grid generator. Second, the developed methodology is applied downstream of both the stator and the rotor of a single-stage axial turbine, where the probe robustness and reliability are fully exploited to gain crucial flow information also in a harsh flow environment, where the use of hot wires might be critical. In this article, the measured turbulence intensity using FRAPP is compared among three different operating conditions obtained by changing the rotor rotational speed. Furthermore, the article explores the impact of nonuniform stage inlet conditions, which resemble the combustor outlet disturbances, on the stator and rotor flow features. The regions with the highest turbulence levels are observed in areas characterized by secondary flows, wakes, end-walls, and the residual swirl profile. The stator–rotor interaction contributes to the turbulence generation both downstream of the stator and the rotor. Additionally, an increase in blade loading corresponds to higher intensity in secondary flows, leading to elevated turbulence levels at the rotor exit. The injection of combustor nonuniformities has a diminished impact as the rotor load increases, given that the flow field becomes predominantly influenced by strong secondary flows.
Dent-Weld Interaction for Strain Assessment
Authors: Liu Taojun , Holliday Chris
Published: December 2024

Dents are an integrity threat to oil and gas pipelines. Due to the higher perceived risk of cracking associated with dents on welds, the acceptability thresholds for dents interacting with welds are more stringent than that for plain dents in the pipe body. Similar to the depth based criteria, when curvature strain assessment is utilized to determine dent acceptability, the acceptability threshold for a plain dent on the pipe body and a dent interacting with a weld is 6% (material specific limits are also available) and 4%, respectively.

When applying these screening criteria based on in-line inspection data, one practical challenge is to determine whether a dent is interacting with weld or not. Since weld interaction directly dictates the dent acceptability threshold, it affects repair decisions and hence may have a large impact on a pipeline operators’ budget and potentially pipeline safety. Overly conservative dent-weld interaction rules can cause unnecessary repair or investigation; whereas non-conservative dent-weld interaction rules may lead to injurious and non-compliant dents left in place unrepaired.

This paper presents a study of the dent-weld interaction rules from strain assessment perspective. A strain assessment database with greater than 9,000 dents, detected and measured by ILI, was utilized in this study to investigate the potential of applying existing dent-weld interaction criteria for strain assessment purposes. Recommendations are made with respect to applying such criteria for dent screening based on ILI data.
Performance-Based Seismic Assessment for Pipelines and Related Midstream Facilities
Authors: Farrow Kenny T.
Published: December 2024

The safety and reliability of pipelines and piping components for any infrastructure network are crucial, particularly in regions prone to seismic activity. Since midstream facilities play a key role in the energy supply and water conveyance chains, safeguarding these assets from earthquakes is paramount as the consequence of failure can be devastating, leading to, for example, possible immediate loss of life at facilities or complete loss of water supply across municipalities. Particularly for the latter, in a worst-case scenario, the complete loss of water supply would have significant chain-reaction effects in cases where water is required for post-earthquake response and recovery (e.g., firefighting, medical, sanitation, industrial cooling, potable water, etc.)

Seismic events pose unique challenges for pipelines and facility piping systems. Unlike buildings or bridges, pipelines are elongated structures that traverse diverse terrains, making their response to ground motion complex and site-specific. Specifically, these systems often span long distances, passing through different geological conditions and interacting with various structures. A performance-based seismic assessment addresses these challenges by moving beyond the traditional “life safety only” approach, which focuses solely on preventing collapse, using traditional seismic assessments that rely on prescriptive codes and standards to consider the functionality of the system after an earthquake. The ever-evolving field of earthquake engineering has paved the way for the use of this more sophisticated approach. Performance-based seismic design is particularly relevant for pipelines and facility piping, where continued operation is critical even in the aftermath of a seismic event. This methodology also addresses the fact that damaged sustained by pipeline assets may not be easily distinguishable and will require screening and triage based on measured ground shaking and observed condition of the asset.

Performance-based seismic design methodology offers a comprehensive understanding of the behavior and resiliency of pipelines and facility piping systems under seismic ground shaking, allowing for a more accurate evaluation of their performance, and required post-earthquake mitigations. This work summarizes a performance-based approach with distinct levels of assessment, ranging from visual inspection-level screening to detailed assessments based on site-specific response measurements (e.g., accelerometers, fiber optics), that facilitate quick interpretation and execution of pipeline asset mitigation strategies, as required.
Safety Culture: An Approach to Maturing Management Systems Through the Thoughtful Application of Human Factors
Authors: Hallihan Greg , Bentkowski Kaitlin , Shapiro Dan , Shironishi Mari , Sahney Reena
Published: December 2024

As the Southern California Gas Company (SoCalGas) matures its risk management practices, there is a desire to identify practical approaches to integrate human factors (HF) to strengthen the organization’s safety culture.

The Integrity Management department at SoCalGas has previously sought to mature its HF practice within the organization. However, these initiatives have been limited by the relative difficulty associated with measuring their direct impact, the complexity of adapting the breadth and depth of the relevant knowledge base to specific projects, the potential resource burden of implementation, and general ambiguity in what constitutes industry best practice. It was recognized that to effectively leverage HF for tangible improvements (e.g., improvement of operating procedures and processes to improve safety), future initiatives must be thoughtfully integrated with existing systems and processes, balancing best practice within organizational constraints. Considering this, SoCalGas and Jiva Consulting (Jiva) developed a novel approach with the following characteristics:

1. A significant scoping and planning stage prior to commencing the development of specific solutions, which included a detailed assessment of current gaps as a basis for developing a practical roadmap.

2. A detailed literature review to identify and leverage transferable practices from other industries and sectors.

3. A highly structured, multi-year approach that allowed for careful identification of key stakeholders to ensure the development of practical and sustainable processes through the implementation of multiple pilots.

4. The iterative development of a Human Factors ‘Toolkit’ (HFTK) comprised of:

• A Standardized Assessment Procedure to structure process implementation,

• A Body of Knowledge and Quick Reference Guide to effectively translate key knowledge,

• Assessment Forms to structure consistent data collection and analysis,

• Stakeholder engagement approaches to support issue validation and prioritization, and

• Presentation Materials for both staff training and organizational awareness.

This has allowed SoCalGas to effectively develop a unique approach to HF that is theoretically sound and systematic while remaining practical and allowing for continuous improvement. The approach has been through multiple pilots and has created conditions to mature overall subject matter literacy within the organization regardless of roles or baseline knowledge level — ranging from field-based personnel to office-based technical staff, including senior management.

The presentation of findings will outline how this approach addresses the complexities of implementing HF practices at SoCalGas via integration with the existing management system as well as early learnings from conducting its initial pilots.
Optimization of Fusion Bond Epoxy- Abrasion Resistant Overcoat Thicknesses for Trenchless Installations
Authors: Tsaprailis Haralampos , Granke Mike , Anthony Joseph
Published: December 2024

Trenchless installation such as horizontal directional drilling (HDD), direct steerable pipe thrusting, horizontal auger bore, and micro tunnelling have changed how gas and liquid pipeline utilities are installed worldwide. The current HDD technology has moved the limitation of length close to 5 km by creating an intersect method where two rigs drill from two sides towards each other. In 2022, a 4.7 km, 24-inch HDD crossing under Lake Sakakawea (North Dakota) was successfully designed and constructed. As the length increases, there is always a high risk of coating damage when pulling through rocks and gravel. The HDD trenchless construction technique uses a pilot hole (steerable system) along a predetermined alignment and profile to cross under road, rail, and watercourse crossings. When the pilot hole is enlarged by reaming operation, the pipeline is pulled through the bore profile. The subsurface investigation plays a vital role in HDD crossings. The project team should be aware of soil conditions to minimize potential damage to pipe coating during the installation.

In North American, fusion bond epoxy (FBE) with an abrasion resistant overcoat (ARO) is the primary pipeline coating system selected for horizontal directional drilling. Industry best practices specify the application methodology for these coating systems along with a minimum anti-corrosion barrier (FBE), but often neglect to specify a minimum, nominal, or maximum ARO thickness (i.e., the sacrificial overcoat).

Within this paper, the thickness requirements for FBE-ARO from various pipeline operators will be compared to establish an industry best range. This range of FBE-ARO thicknesses will be compared to the recommended thicknesses from the coating manufacturers. More importantly, a minimum, nominal, and maximum FBE and ARO thickness will be recommended based on laboratory testing from several qualification production tests, field observations, and the manufacturer’s recommendations. The laboratory testing included chemical (e.g., cathodic disbondment) and physical (e.g., impact, gouge) testing that was completed on mill coated pipe. Correlation to field data will also be presented based on various parameters collected from numerous pipeline horizontal directional drilling projects. The data provided will allow for a more informed decision-making process when specifying protective coating for future trenchless installations.
A Theory-Consistent Multi-Modal Fused Neural Network for Predicting Mixed Oil Length Range in Multi-Product Pipeline
Authors: Du Jian , Xu Ning , Zheng Jianqin , Liao Qi , Liang Yongtu
Published: December 2024

In the operation of a multi-product pipeline, a precise and effective prediction model for the contamination amount range is crucial to guide the formulation of the cutting plan. Existing methods, however, fail to extract clear feature correlations and overlook the implicit physical knowledge of mixed oil, leading to impractical prediction results. Therefore, this study integrating latent feature representations and scientific theory into the neural network to design a theory-consistent multi-modal fused neural network for predicting the mixed oil length range. The proposed model establishes a comprehensive feature representation of multi-dimensional features of mixed oil to extract ample feature correlations through a multi-modality feature fusion module. Subsequently, a theory-guided customized neural network is designed to incorporate the scientific theory into the forward and backward propagation. Additionally, a physics-consistent loss function is established by incorporating range difference constraints and data mismatch, intending to prevent the model from producing physically unreasonable results. Validation on real-world cases suggests that the proposed model surpasses advanced techniques and recent achievements, reducing Root Mean Squared Relative Errors by 31% and 36% in lower and upper limit prediction, respectively. The sensitivity analysis of model components suggests that both the multi-modality feature fusion and physical principles are crucial for model improvement.
Pipe Spring System: The MFL Identification, Characterization, and Assessment of Both Defects and Sleeve
Authors: Laughlin Shawn
Published: December 2024

A full encirclement laminated steel sleeve system has been designed, developed, tested, vetted by the industry, and utilized on North American regulated pipelines for permanent repairs of pipeline integrity threats. Pipeline integrity practitioners requested verification of various aspects of MFL based ILI inspections. This paper briefly reviews the details of the technology regarding the material, the mechanics and mitigation principles, and the field installation of the thin layer laminated steel sleeve system. We then address the MFL based ILI inspection topics. Three major topics have been investigated. These are: Verification that MFL based ILI can readily identify the volumetric metal which comprises the laminated steel sleeves system. Sleeves which were comprised of 2,4 and 8 layers of steel were temporarily installed on a pipeline system prior to a scheduled ILI run. The ILI provider was not informed prior to data collection. The pipeline operator maintains the in-house ability to quickly review vendor ILI data and provided initial assessment and analysis. This data has been collected the results are presented. Determination of the ability of MFL ILI based inspection to assess metal loss defects which have been permanently repaired with this technology. An ILI service provider created a series of various known calibration type defects and collected initial pull test data on unrepaired spool pieces. These defects were then repaired with the thin layer laminated steel sleeve system. The change in magnetic response between unrepaired and repaired runs has been evaluated for the various calibration type defects. The targeted goal of the effort is to build the algorithm or model to assess known defects after repair and installation of this sleeve system. These results are presented and discussed. Determination of the ability of MFL based ILI to inspect or verify that the magnetic response or magnetic signature of the laminated steel sleeve system can be assessed with sufficient consistency to indicate that that the sleeve displays no significant changes during service. This would provide confidence that the sleeve continues to effectively perform its intended mitigation. The results are presented and discussed.
Development of Probabilistic Reliability Models for Pure and Blended Hydrogen Pipelines
Authors: McAllister Lowell , Wright Chance , Bussiere Mathew
Published: December 2024

Growing demand for hydrogen and blended hydrogen / natural gas pipelines has introduced challenges that require engineering assessments and controls to ensure safe pipeline design, conversion, and operation. Quantitative risk assessment using probabilistic reliability models is a leading engineering assessment technique that is uniquely suited to addressing these challenges, even where limited historical experience and regulatory guidance exist. This paper presents developments that have been made to adapt the probabilistic reliability models commonly used to estimate the failure rates of conventional natural gas pipelines for application to pure and blended hydrogen pipelines. These developments are based on the latest research on the adverse effects of hydrogen on pipeline material performance (i.e. hydrogen embrittlement).

Hydrogen embrittlement has two primary effects on pipeline steel properties: a reduction in fracture toughness, and an increase in fatigue crack growth rate. Both effects are expected to increase the predicted failure rate of pipelines containing crack-like flaws. The extent to which these effects may significantly compromise the integrity of a pipeline asset is dependent on the extent of the embrittlement (as determined by the susceptibility of the pipeline material and the degree of hydrogen exposure) and the pipeline operating conditions (which influence both nominal and cyclic stress states). In any assessment, significant uncertainty may exist regarding the precise nature of hydrogen embrittlement mechanisms, and the material properties and existing damage conditions of the asset. However, probabilistic reliability models provide a means of systematically accounting for these uncertainties and can provide a quantitative basis to reduce those uncertainties as research advances.

This paper will discuss the use of empirical models to predict the extent of hydrogen-induced fracture toughness reduction and fatigue crack growth rate increase, the results of which have been characterized probabilistically herein. These models have been incorporated in a simulation of bi-directional crack growth (based on a variable amplitude, cyclic loading histogram input) to predict the time to reach a critical crack size. The probabilistic reliability model repeats these crack growth simulations in a Monte Carlo simulation to predict future failure rates for a prescribed evaluation period. A demonstration of the model predictions is also presented in this paper through a comparison of the predicted failure rates for a representative set of pipeline scenarios with varied hydrogen blend ratios and baseline predictions with a pure natural gas product. Finally, a description is given of the remaining gaps to be addressed in future research.
On the Changes in the Properties of an API 5L Steel Through Isothermal Artificial Aging
Authors: Velázquez Julio César , González-Arévalo Noe , Díaz-Cruz Manuel , Cervantes-Tobón Arturo
Published: December 2024

Despite the emergence of renewable energies, oil and gas will continue to be critical factors in economic growth, specially in developing countries. An immense amount of these hydrocarbons are moved using steel pipelines. However, these pipelines are becoming older each day and will continue in-service for several more years. Traditional inspections using “smart-pigs “ or UT techniques only help to obtain the size of the corrosion defects, they cannot measure in the field the mechanical properties of the material. In this context, studying the changes in the steel that can happen through years of service is necessary, but this is not a simple issue because the current real characteristics need to be compared with the original ones when the pipeline was built and commissioned. For this reason, an approximation based on an artificial aging method (isothermal method) can be helpful for estimating some mechanical characteristics. Likewise, the impact of these changes is assessed by computing the pipe failure pressure using semi-empirical models. The aforementioned mechanical characteristics are studied statistically with the purpose of determining the pipeline failure probability. Furthermore, the results of evaluating the changes in the corrosion susceptibility using electrochemical techniques are shown. Finally, the results point to the conclusion that the changes in the material properties could be significant, particularly when estimating the failure pressure of the pipe, this could lead to underestimate or overestimate the risk at the time of operation because the mechanical characteristics tend to show a more significant variance. Therefore, it would be recommended that the oil and gas industry propose to develop a methodology to monitor these changes.
Evaluating the Penetration Depth of Rock Falls on Buried Pipelines
Authors: Amini Mehdi , Wilson Paul , Rahman Mujib
Published: December 2024

Buried pipelines are usually less susceptible to rock falls compared to exposed utilities because soil cover protects them from direct rock fall impacts. However, in instances where pipelines are situated in mountainous terrains, the risk of rock falls penetrating through the protective cover becomes a concern. In these circumstances, the risk of rock fall to the pipeline should be assessed and managed. This paper, first, outlines a framework for assessing the rock fall risks to buried pipelines based on a general risk matrix. One of the key parameters in the matrix is the likelihood of rock fall penetration depth. To estimate this parameter, the penetration depth of the rock falls should be estimated and compared with the actual pipeline depth of cover. The existing theoretical relations commonly used to estimate rock fall penetration depth are then presented and critically reviewed in the paper. Finally, the penetration depths resulting from two actual rock fall incidents in the buried pipelines are back-calculated using theoretical relations and compared with the real measured penetration depths. The case histories occurred in a pipeline in 2006 and 2023. The comparison between theoretical estimations and the real measurements demonstrate that the existing theoretical relations generally underestimate the rock fall penetration depth. Therefore, relying only on the existing theoretical relations could lead to an underestimation of the rock fall risk. As a result of our study, we propose several recommendations to enhance the accuracy of estimating rock fall penetration depth and its associated likelihood in the risk calculations.
Increasing the Operational Reliability of an Onshore Pipeline Using Positive Displacement Pumps
Authors: Valle Marcus Felipe , Auras André Paegle
Published: December 2024

Positive displacement pumps excel in pumping fluids with high viscosities and high pour points efficiently across various flow rates and pressures. This article introduces a theoretical analysis of the results from computational simulations carried out to assess the use of a novel pumping system incorporating screw-type positive displacement pumps within a 120 km pipeline for fuel oil transfer in São Paulo, Brazil. To enhance the operational reliability of the pipeline, we explored a new pumping system configuration featuring positive displacement pumps. We selected the screw-type positive displacement pump following the recommendations of API STD 676 standard, considering the pipeline’s required flow rate and maximum permissible operating pressure. We undertook computational simulations with the Stoner Pipeline Simulator 9.8.0 (by GL Noble Denton), to verify the effectiveness of this innovative pumping system. These simulations demonstrated the feasibility and potential of the proposed system, particularly when integrated with a variable frequency drive, to boost the transportation efficiency and reliability of fuel oils.
Pipeline Defect Detection Using Artificial Intelligence-Based Active Acoustic Sensing
Authors: G. Dhasthagir Yaser A. , Chen Haobin , Bayati Farzaneh , Hugo Ron , Park Simon
Published: December 2024

This study presents an innovative AI-enhanced active acoustic sensing approach for continuous pipeline defect detection, overcoming limitations of conventional in-line inspection methods that include sparse inspection frequencies and extensive data analysis requirements. The proposed method introduces acoustic energy to detect circumferential notch-type defects. Numerical simulations are performed using Finite Element Analysis (FEA), and experiments performed using axial piezoelectric transducers and acoustic emission sensors. Due to the rapid attenuation at typical inspection frequencies, we excite the system close to natural resonance frequencies, improving defect detection accuracy. Our approach incorporates power spectral analysis and root mean square error (RMSE) computations against baseline references, with Z-score normalization addressing signal variations. The neural network model at the core of this AI methodology significantly boosts defect detection accuracy, proving its efficacy and reliability for enhancing pipeline structural health monitoring (SHM) and integrity management.
EMAT Reinspection Interval Considering POD and Undetected Cracks
Authors: Yan Jason , Zhang Billy , Zhang Shenwei , Upadhyaya Jay , Myden Kyle
Published: December 2024

Crack (or crack-like) anomalies are a major threat to the safety and structural integrity of oil and gas transmission pipelines. Pipeline operators commonly manage the crack threat by hydrostatic test (HT) and in-line inspection (ILI) using electromagnetic acoustic transducer (EMAT) or other inspection tools. As part of the ILI-based assessment, the determination of the re-inspection interval is critically important to assure the safe operation of pipelines.

A common method to determine the reinspection interval is to deterministically grow a hypothetical crack anomaly and determine the time to reach critical size, where the initial size of crack is typically assumed based on EMAT vendor specification. The limitation of this method is that the re-inspection interval is highly impacted by the vendor tool detection specification. The potential for any undetected cracks larger than the detection threshold are not properly considered.

The probability of detection (POD) of EMAT tools for cracks is not as high as magnetic flux leakage (MFL) tools for corrosion anomalies. Crack anomalies with size corresponding to 90% POD are usually more severe than corrosion anomalies with 90% POD. Therefore, the risk of missed (undetected) crack anomalies cannot be ignored when determining the re-inspection interval of EMAT runs. This paper describes a probabilistic method that considers the field verified tool POD to determine the EMAT re-inspection interval. The proposed method reflects reality better as it explicitly accounts for uncertainties associated with input parameters as well as the effect of missed cracks due to POD.

To quantify the risk of undetected crack anomalies, this paper systematically reviews the company’s historical EMAT reported and field found cracks, and develops the actual EMAT performance specification, i.e., POD curve, as a function of crack size and the proximity to a weld. Log-Logistic regression is employed to fit the data considering the unbalanced sample size of deep and shallow cracks.

Given the developed POD curve, various metrics are explored to characterize the severity of each ILI assessment path considering the EMAT reported crack population and size. As a result, a probabilistic metric is proposed to quantitatively characterize the risk due to EMAT undetected cracks, which can be used to prioritize the EMAT reinspection between lines more effectively. A safety check is also performed using the EMAT-field crack repair database. The proposed method could be used to determine the reinspection interval properly.

The details of the proposed generic framework are included in the paper, which could be used by feeding updated or other company-specific data. In addition, the line-specific hydrostatic test results before or after EMAT and real-time updated dig findings could also be built into the framework as prior knowledge to better prioritize the EMAT reinspection.
Design Considerations for a Sea Water Conveyance Pipeline in Chilean Mining: A Case Study
Authors: Martínez Héctor , Sanchez Maximiliano , Elorza Fernando
Published: December 2024

Chile, rich in mineral deposits, faces an acute water shortage in its arid mining regions. With increasing industrial and local demands, mining companies are aligning with the national mining policy for 2050 by investing in seawater conveyance infrastructure to reduce continental water consumption. The challenge lies in conveying this water from coastal facilities, traversing the challenging topography of the Andes to reach mining sites above 2,000 m.a.s.l, necessitating water conveyance pipeline infrastructure over extensions of 140 km. This paper focuses on the design complexities encountered in conveying seawater to a major copper mining operation in the region of Antofagasta, a hub of mining activity in Chile’s copper mining sector, addressing critical challenges associated with seawater corrosivity, variable flow capacities, energy efficiency, seismic risks, and steep topography.

For the case study presented, the pipeline is in API 5L X70 bare steel, with corrosion allowance, NPS 36″, as the result of life cycle cost analysis. The study details the approach to optimize the hydraulic design, incorporating historical data analysis for internal pipe roughness and corrosion rate determination due to seawater’s corrosive nature. The pump selection process is explored, emphasizing the need for strict tolerance specifications to ensure design capacity and energy efficiency in the face of the pipeline’s dynamic design requirements. Practical insights are shared regarding pump and electric motor, utilizing Variable Speed Drives (VSD) to accommodate multiple duty points throughout the pipeline’s operational life.

Given the seismicity of the project area, arising from the convergence of the Nazca and South American plates, the study underscores the necessity of a comprehensive seismic risk study to determine design parameters. Additionally, the pipeline’s route presents a unique construction challenge, due to steep elevation changes from coastal facilities to above 1,000 m.a.s.l through a coastal cliff range, within the first 30 km of the pipeline. The study addresses this by providing specific considerations for a specialized construction methodology suitable for high steep slopes.

In conclusion, this case study presents key multifaceted design considerations required for a seawater conveyance pipeline in Chilean mining. by tackling the issues of corrosivity, variable flow capacities along with energy efficiency, seismic risks and pipeline construction in steep topography, the paper offers valuable insights for engineers and stakeholders involved in similar projects. The comprehensive approach presented ensures the resilience and robustness of the pipeline infrastructure throughout its operational life, contributing to a sustainable water availability for the mining operation. The information is presented in general terms, as not to disclose private information.
Pipeline External Corrosion Model Validation
Authors: Ayello Francois , Ellinger Matthew , Liu Guanlan , Al-Beladi Shaker , Dakwar Naim , Krissa Len , Nelson Jocelyn
Published: December 2024

Establishing trust in corrosion models requires a robust validation process. This is difficult because large amounts of field data covering a wide range of operating conditions are needed. Relying on a few simple tests is insufficient, as a comprehensive validation demands a thorough comparison between corrosion model predictions and real-world observations. The present study by the Pipeline Research Council International presents the validation of a transmission pipeline external corrosion rate model (EC-01-13, Generic External Corrosion Growth Rate Distributions for Buried Pipelines). The validation was carried out by comparing the external corrosion rate model results with field data gathered by three oil and gas pipeline operators and covering over 400 miles of pipelines. Good agreement was found between modelled corrosion rates and ILI run comparison data.

This study has two main benefits to pipeline operators. First, the validation helped identify areas where the corrosion model may need to be adjusted to provide more accurate predictions for specific pipeline locations and operating conditions. Second, a simple set composed of 27 external corrosion rate distributions (as a function of pipeline exposure, mitigation, and time) have been generated by the external corrosion rate model and validated with the ILI data. This publication provides 27 reliable and simple external corrosion rate estimates that can be utilized by pipeline operators without the need for running the external corrosion model or using specialized software. The use of these validated external corrosion rate distributions may provide a more robust basis for decision-making in pipeline integrity management than using the traditional 16 mpy used for worst case scenarios. In addition, this publication provides a simple way to update the external corrosion rate distributions when new field data becomes available.
The Study on Low-Temperature Transportation of Waxy Crude Oil in Chemical Flooding Pipeline
Authors: Liu Wenchen , Huang Qiyu , Zhou Xiaolong , Lyu Yang , Yang Haoran , Zhang Zixin , Tian Jingru
Published: December 2024

At present, chemical flooding has become an important means to enhance oil recovery in Chinese oil fields. With the implementation of the “3060” carbon neutral policy, the low temperature transportation technology of high-water content crude oil has been implemented in major oil fields across China. However, there is a lack of research on low temperature transportation of crude oil in chemical flooding pipeline. In this paper, the rheometer and stirring method were used to study the rheological properties of oil-water mixtures of waxy crude oil in chemical flooding. The effect of hydrolyzed polyacrylamide (HPAM), petroleum sulfonate (PS) and HPAM/PS binary systems on the wall sticking of waxy crude oil during low temperature transportation was investigated by surface adhesion apparatus experiments for the first time. Finally, the interfacial tension (IFT) and contact angle (CA) of the chemical flooding oil/water/pipe wall system were measured by using a high-temperature and high-pressure optical contact angle measuring instrument. The interface wetting theory was used to deduce the adhesion mechanism of waxy crude oil during chemical flooding. The results showed that both HPAM and PS could advance the inversion point of the emulsion. Notably, the addition of HPAM after the inversion point increased the viscosity of oil-water mixture, whereas PS exhibited the opposite effect by decreasing it. Furthermore, the addition of HPAM increased the adhesion between oil droplets and pipe wall, consequently resulting in an elevation of the minimum safe transportation temperature (MSTT) in the range of 0 to 3°C. Conversely, the presence of PS correlated with a reduction in MSTT of 0 to 2°C. The simultaneous presence of both substances resulted in a mutual resistance phenomenon. The research results can provide theoretical guidance for low temperature transportation of waxy crude oil in chemical flooding pipeline.