bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Thrust Loads on Piping From Blowdown Stacks to Silencers at a Remote Distance Away
Authors: Botros Kamal K. , Martens Michael 
Published: January 2021

Abstract
Current trends in greenfield natural gas compression facilities and high-pressure gas transmission pipelines are designs for high pressure operation, e.g. PN150. At such high pressures, sound pressure level (SPL) of the noise generated during a planned blowdown can be as high as 165–175 dBA at 1 m distance away from the blowdown stack tip. Even double hearing protection would not be sufficient for an operator opening the blowdown valve at the blowdown assembly even for a short period of time. Blowdown silencers mounted on top of the blowdown stack are limited to the degree of noise suppression they offer (typically of the order of 30 to 40 dB), let alone the requirement for extensive support structures to hold the massive weight on the stack top. One innovation to alleviate this issue, is to place a silencer on a skid on a ground-level pad/support system, at a sufficient distance away from the blowdown stack. In this way, the blowdown valve operator would be exposed to a much lower SPL, as well as the silencer can be as large as desired being skid mounded on the ground. The main issue to be addressed is the dynamic thrust loads That would otherwise be afflicted on the various pipe segments of the piping connecting the blowdown stack top to the location of the blowdown silencer located distance away. Clearly this piping will include several above ground pipe segments, bends, tees and fittings that need to be adequately supported to withstand the dynamic loads as the blowdown valve opens. This paper presents a model approach based on solving the temporal-spatial governing equations in the form of 1-D hyperbolic differential equations, with boundary conditions accounting for the blowdown valve size and type, trim characteristics and opening time, upstream gas pressure and temperature, and downstream restriction equivalent orifice size at the inlet to the blowdown silencer. Results are presented for a case study of a single and dual blowdown assemblies equipped with reduced-bore ball valves (8″ × 6″), with lead piping of NPS 8 joining into NPS 12 header and finally splitting into two ground mounted silencers some 30 meters away. Thrust loads at each segment of these connecting piping were found to depend on whether one or dual blowdown valves are open simultaneously, upstream pressure, and more importantly the location of the choke point (Mach = 1) whether at the blowdown valve itself or at the silencer inlet diffuser orifice. The later was found to be the most critical parameter. The most important objective when designing such a system is to ensure that the choke point is at the silencer inlet orifice to minimize thrust loading on the blowdown valve(s) as well as along the entire lead piping.
Sand Dune Migration Monitoring for Pipeline Hazard Risk Mitigation: The Peru LNG Coastal Section Case
Authors: Ravet Fabien , Silva Christian , Gil Rodolfo , Maguire Simon , Rochat Etienne 
Published: January 2021

Abstract
Pipelines often cross challenging terrains where natural hazards are the main risk for their integrity. Environmental conditions can also worsen over the infrastructure lifetime. To reduce the risk of disasters, integrity programs are developed implementing tools for early detection of threats that can lead to a failure with dramatic social, environmental and economic consequences. Fiber optic (FO) monitoring solutions have been widely used and implemented as one of the most efficient prevention tools of these programs. These solutions include geotechnical monitoring, third party intrusion detection and eventually small or pinhole like leak detection.
FO based geotechnical monitoring has been successfully operated along the Sierra section of the Peru LNG pipeline since 2010, detecting minor landslides and erosion events. It has also been implemented along other hydrocarbon transport systems to allow the early detection of such events. However, these natural hazards are not the only ones threatening the pipeline. In fact, the coastal section experiences other phenomenon such as sand dune migration and eolian erosion that put the pipeline at risk. Recently, the FO monitoring was extended to the coastal region using the existing communication fiber optic cable to sense temperature changes. Very localized events are thermally detected, their spatial and temporal signature analyzed. The comparison of this data with thermal models identified sections that are close to be exposed or whose soil cover is less than 50cm over a spatial extension that does not exceed a couple of meters. Depth of cover of 10 to 30cm is estimated from such analysis. These results are confirmed by past and ongoing site inspections. Such positive results again illustrate the potential value of fiber optic sensing to mitigate geohazard risks. It not only enhances the efficiency of the integrity program detecting and localizing threats, it also improves and rationalizes the maintenance activities as focused surveys can be conducted.
Application of Risk and Reliability in Designing Facility Site Containment
Authors: Ballard Geoff , Ferdous Refaul , Payoe Anthony , Kulhawy Amanda 
Published: January 2021

Abstract
Enbridge is North America’s premier energy infrastructure company delivering the energy people need and want. Enbridge’s business value is asset intensive. With over 200 onshore liquids pipelines facility assets, operational safety and environmental protection are always top priorities. The embedment of risk management practices in business decisions is an effective way to appropriately optimize asset performance while avoiding catastrophic impacts to people and the environment. This includes understanding and managing these risk events and establishing barriers to prevent the impact.
Facility site containment is an independent protection layer that mitigates the consequences of a spill. The United States Environmental Protection Agency and the National Fire Code of Canada provide requirements to contain overland flow of a spill from liquids pipelines facility assets. Although there are specific volumetric requirements for spill containment for facility tanks, there are no specific volumetric requirements for spill containment for pipeline facility assets such as pumps, valves, etc. Industry typically employs an index-based approach to determine the specific design volumes using catastrophic rupture volumes and facility location. This approach has several shortcomings, including design inadequacy, inconsistency, and challenges with scalability.
A risk-based approach is appropriate in determining the required site containment volume based on oil spill history, facility assets, and environmental sensitivities. A probabilistic model can be created using historical facility oil spill data based on the Pipeline and Hazardous Materials Safety Administration’s (PHMSA’s) facility incident database to estimate the likelihood of a given size of release occurring. If available, company oil spill history can also be used or integrated with the PHMSA dataset. Combining the likelihood of the size of release occurring with the estimated consequence (by accounting for the volume of a release and the environmental sensitivity at the release location), it is possible to evaluate the risk of a release. This estimation of risk can then be leveraged to support facility site containment design to manage the risk to an acceptable level.
By informing facility site containment with volumetric requirements using reliability and consequence models and risk management principles, an organization can prudently balance pipeline safety and capital constraints to comply with federal regulations. This paper demonstrates this approach and describes:
• The value of available data and model development
• Reliability modeling and consequence assessment
• Risk-informed decision-making
• Future model enhancements
A Bayesian Approach for Effective Use of Multiple Measurements of Crack Depths
Authors: Koduru Smitha D. , Nessim Maher , Bott Steven , Al-Amin Mohammad 
Published: January 2021

Abstract
A Bayesian methodology was applied to use data from multiple inline inspection (ILI) runs and field measurements with non-destructive examination (NDE) tools to increase confidence in crack size estimates. Multiple crack depth measurements were used in two different ways — namely, to improve the characterization of ILI sizing error bias and to update the maximum depth distribution of individual crack features. This methodology was applied to selected datasets from an industrywide database for crack ILI data collected over a series of Pipeline Research Council International (PRCI) projects. The results of the approach are presented for two datasets, showing reduced variance in sizing error bias and improved confidence in crack depth estimates. In addition to the PRCI datasets, an additional dataset was collected and used to investigate the effect of multiple ILI runs on estimates of rate of detection and depth distribution of undetected features. The results of this analysis are also summarized.
Effects of Profile Data Grid on Deformation Capacity of Line Pipes
Authors: Asano Kanako , Watanabe Hidetaka , Mori Takeshi , Suzuki Nobuhisa , Arakawa Takekazu 
Published: January 2021

Abstract
The effects of the profile data grid on the compression or bending capacity of line pipes are discussed in this paper. An X65 600 mm line pipe and an X80 1200 mm line pipe are used in the sensitivity study. The initial profiles of the 600 mm line pipe are used for finite element analyses with different data grid sizes from 600 mm to 25 mm squares. Those of the 1200 mm line pipe are considered by varying the data grid from 1200 mm to 50 mm squares. With decreasing grid size, the compression or bending capacity tends to decrease and become stable when the data grid becomes 1/3 of the pipe diameter. The compression capacity is as small as 90% of that without profile data. The bending capacity of the 600 mm pipe pressurized to 60% SMYS decreases to 35%, while bending capacity of the 1200 mm pipe is 46% of that without profile data at the same pressure.
An Improved Methodology for Prioritizing Pipelines With Respect to Fatigue Cracking of Seam Weld Flaws
Authors: Turnquist Michael , Al-Otaibi Nader A. , Teshin Nauman , Al-Rabeeah Mohammed A. 
Published: January 2021

Abstract
The threat of pressure cycle induced fatigue cracking of flaws associated with the longitudinal seam weld continues to be a primary concern for pipeline operators. Cyclic pressure loading can cause initial manufacturing flaws in a seam weld to sharpen and grow over time. While this behavior is most prevalent in pre-1979 electric resistance welds (ERW) and electric flash welds (EFW), historical data also shows that submerged arc welds (SAW) have been observed to develop cracks at the toe of the weld, and those cracks have exhibited fatigue growth from transit fatigue, operating pressure cycles, or both.
When managing a large pipeline network, it is important to understand which pipelines exhibit higher priority with respect to seam weld fatigue cracking. While there are industry-accepted methodologies used to prioritize pipelines with respect to seam weld integrity (TTO-5 [1] and API RP 1176 [2] being the most well-known), these methodologies can be improved upon when specifically considering fatigue.
Saudi Aramco and Quest Integrity developed a detailed methodology to determine a prioritization for a group of pipelines specifically with respect to seam weld fatigue cracking. This improved methodology was specially tailored to consider additional data available in Saudi Aramco’s records to rank the likelihood for a fatigue failure to occur. This initial prioritization will be used to implement a more rigorous program to manage their assets. Additional data gathered in subsequent assessments can be included to refine the prioritization.
The primary metrics used to determine the prioritization are pressure cycle aggressiveness, predicted remaining life with respect to recent hydrostatic testing, and the API 1176 Annex B prioritization classification.
Life Expectancy of Decommissioned Pipelines Under External Corrosion: Probabilistic Modeling
Authors: Wong Chee , Dann Markus R. , Wong Ron 
Published: January 2021

Abstract
The typical service lives of operational energy pipelines are up to 50–70 years. The existing lines would subsequently be decommissioned and replaced with new lines. As one approach to dealing with a decommissioned line is by leaving the line untouched in the ground, there exists uncertainty in the structural integrity of decommissioned lines under external corrosion over time. This paper introduces reliability-based integrity assessment of decommissioned pipelines that remain in the ground. Two limit state functions are developed to quantify (i) formation of perforations under pitting corrosion, and (ii) thinning of pipe wall thickness under uniform corrosion and initiation of pipe yielding under soil and traffic loading. Corrosion occurrence and growth are modeled as stochastic processes to account for its spatio-temporal uncertainty. The reliability and safe remaining lifetime of an entire pipeline sections are determined using enhanced Monto-Carlo simulations. A sensitivity analysis is performed to identify the governing factors of the life expectancy. The proposed integrity assessment is illustrated on an example.
The Coarse Particle Influence on the Strength of Wax Deposition
Authors: Zhang Xun , Huang Qiyu , Zhang Yu , Li Yaping , Liu Xin 
Published: January 2021

Abstract
Wax deposition has always been an essential issue for flow assurance, especially in subsea pipelines. The coarse particles, which are usually measured in millimeters, will be carried out by oil flow during the deep-water oil fields production. However, due to insufficient understanding of the structure of wax deposits and the complexity of sandy crude oil deposition, the interaction between coarse particles and wax deposits in the pipeline have rarely been investigated.
In this paper, the effect of coarse particles on the yield stress of wax deposits has been studied. The sample was mixed at reversible structure temperature so that the impact of shear history could be eliminated, and the rapid particle settlement at high temperature could be avoided. Experimental results have found that there is a critical fraction in coarse particle influences, below which a small number of coarse particles added will lead to a slight increase in bulk yield stress. On the contrary, a dramatic decrease in yield stress when exceeding the critical mass fraction and increasingly marked enhancement of yield stress as the fraction increases.
This phenomenon has been explicated microscopically by the structural interaction between coarse particles and wax deposits. The interlock between wax crystals is the major contribution of the structure as the less particle fraction contains. Even though the silica sand is a typical non-colloidal particle, the asphaltene and resin could be absorbed on the surface of particles and forming a cluster of colloidal particles. As the fraction of particles slightly increased, the slip between colloidal particles and wax crystal interlock accelerates structural failure. Nevertheless, more particles involved the overall yield stress may depend on the friction and the adhesive force between solid particles. The subtle changes induced by coarse particles would have a harder deposit, which can hinder pig passing and affect pipeline pigging operations.
Crack Initiation and Propagation in Static Loaded Fracture Mechanics Tests in Steels Containing Atomic Hydrogen
Authors: Moore Philippa L. , Hoekstra Menno , Pargeter Alex 
Published: January 2021

Abstract
Hydrogen is well known to have a detrimental influence on the ductility of low alloy steels, reducing the fracture toughness. Standard test methods to characterize fracture toughness of steels in terms of ductile tearing resistance curves have not been developed to account for any hydrogen-driven contribution to the crack extension, Δa. Simply plotting J or CTOD against Δa is not necessarily appropriate for defining the initiation fracture toughness for tests performed in a hydrogen-charging environment. This paper explores a method to further analyse experimental data collected during fracture toughness tests, which allows the contribution of plasticity (i.e. when blunting precedes ductile tearing) to be considered separately from the initiation of crack extension (which could be by stable tearing and/or by hydrogen-driven crack extension). The principle is based on the assumption that a crack growing by a hydrogen-driven mechanism in a quasi-static fracture mechanics test performed in environment may not be associated with significant ductility in the plastic zone (which would accompany crack growth by stable tearing). The analytical method presented in this paper compares the different points of deviation from linear behavior of the components of J, to isolate the effects of ductility within the plastic zone from pure crack extension. In this way, the point of crack initiation can be defined in order to determine the relevant initiation fracture toughness; whether by blunting and stable tearing, or by hydrogen-driven crack growth. This approach offers a screening method which is illustrated using examples of fracture mechanics specimens tested in environments of varying severity (air, seawater with cathodic protection, and sour service). This method can be used to identify the relevant definition of initiation fracture toughness while allowing for a combination of ductile tearing, hydrogen-driven crack extension, or both, to be present during the test.
How Do I Ensure “Staff Competency” in My Pipeline Safety Management System?
Authors: Collins Karen , Unger Michelle , Dainis Amanda 
Published: January 2021

Abstract
Standards and regulations are clear: all staff who work on pipelines need to be both “competent” and “qualified.” Standards such as API 1173 are clear about competence within a safety management system: “The pipeline operator shall ensure that personnel whose responsibilities fall within the scope of the PSMS [Pipeline Safety Management System] have an appropriate level of competence in terms of education, training, knowledge, and experience.” The burden of defining and specifying competence falls on pipeline operators, but they have little guidance regarding the required skills, knowledge and levels of competency. Additionally, we are all biased — different operators will have different ideas and emphases on competencies, which will affect their decision-making. The only way to avoid these cognitive biases is to use consensus standards supported by rigorous surveys that capture the required competencies.
This paper explores some of the more common biases that can affect decisions and presents the results of a controlled, independent, survey aimed at both specifying and quantifying the necessary competencies needed by a specific engineer working within a PSMS: a pipeline integrity engineer. The paper identifies and ranks these necessary competences.
The survey was completed by 100 pipeline integrity engineers from 25 different countries. Its specific objective was to investigate the key skills and knowledge requirements needed in a junior engineering position (i.e., a pipeline engineer with less than three years of relevant experience) working under supervision to be ‘competent’. It listed eight core competencies (identified by subject matter experts) considered essential for a pipeline integrity engineer. Each of these core competencies contained a set of skills. Respondents were first asked to rank the eight core competences, and then rank the skills within the competency.
An analysis of the data provides insights into how 100 pipeline integrity engineers view the key skills required to be “competent.”
The results of the survey can assist pipeline companies in setting objective competency requirements for their engineering personnel, developing learning programs to address any gaps, and improve the overall safety of their pipeline system.
Manufactured Cracks in Pipe Used to Evaluate ILI Measurement Performance
Authors: Skow Jason , Krynicki Joseph W. , Peng Lujian 
Published: January 2021

Abstract
Recently, transmission pipeline operators have started designing pipe spools with manufactured cracks of very precise size and orientation for the purpose of qualifying measurement technologies. The manufactured cracks are very similar to naturally occurring cracks and can be made to have varied profiles and off-planar shapes (like hook cracks). The manufactured spools are installed on a transmission pipeline at either the pipe launcher, the receiver or in-line such that an in-line inpsection (ILI) tool passes through it during a transmission pipeline ILI field run. This produces highly valuable data to evaluate measurement performance because the crack sizes are precisely known, crack morphologies are similar to realistic cracks and the ILI tool is tested in field conditions. This paper describes the effect on the estimated ILI tool measurement performance for various combinations of manufactured cracks in a pipe spool. The cases described vary the number of manufactured cracks in the spool to estimate the value of each additional crack and vary the distribution of cracks sizes to compare the value of large versus small cracks.
Cross-Sectional Grain Size Homogeneity Effect on Structural Steel Fatigue Performance in Air and Hydrogen Environments
Authors: Stalheim Douglas , Slifka Andrew , Uranga Pello , Kang Dong-Hoon , Lucon Enrico 
Published: January 2021

Abstract
Structural steel mechanical properties of strength and ductility for a given microstructure are predominately driven by the average ferrite grain/packet size and by the through-thickness homogeneity of the ferrite grain/packet size in the final product. Fatigue performance, a ductility property, in air for applications of wind towers, bridges or high-rise buildings along within environments of high-pressure gaseous hydrogen for various pipeline systems is critical to the end-use design. Fracture and fatigue testing of a commercially produced low carbon 20 mm thick API X60 Sour Service steel had been completed which showed good and stable performance when compared to other commercially produced pipeline and structural steel microstructures. This commercially produced API steel was reported as “Alloy D” in prior published work. The microstructure was predominately polygonal ferrite with industrial quality of steel cleanliness, minimum of microstructural banding and a small but relatively homogenous through-thickness grain size required for a successful API X60 Sour Service specification/application. Based on the initial fatigue performance reported for the “Alloy D” through-thickness microstructure a more comprehensive study on the effect of the through-thickness grain size/homogeneity on fatigue was initiated. To isolate and study this effect of the, laboratory developed samples of a low carbon API X60 Sour Service steel with the same alloy design as “Alloy D”, which is characterized by a predominately single-phase polygonal ferrite microstructure with excellent cleanliness and no microstructural banding. Two sets of steels were made with the only difference being variations in average through-thickness and homogeneity of the final ferrite grain size.