bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure Surge Relief Options in Terminal Design
Authors: Zhou Alan X. L. , Cabrejo Victor , Yu David 
Published: December 2014

Terminals are an integral part of a pipeline system. Typically, petroleum products are transported from an initiating terminal to various delivery terminals along the pipeline. Operation safety is paramount in transporting petroleum products in the pipeline industry. Safety can affect the performance and economics of a pipeline system. While effective operation safety requires well-trained operators, operational procedures, and compliance with regulatory requirements, the best way to ensure operation safety is to implement safety systems during the design stage of the pipeline system. A pressure relief system is an important component of an engineered safety system. This system is intended to prevent catastrophic failure of the transport system due to overpressure conditions that can occur under abnormal operating conditions.
This paper discusses pressure surge relief as it applies to the design of pipeline terminals. Different pressure surge relief devices such as pressure relief valves and pressure surge vessels are considered and their advantages and disadvantages are discussed. The effects of transport rates, piping configurations, and other equipment operation, such as pumps and valves, on pressure surge relief system, are evaluated.
One of the primary objectives of this paper is to discuss pressure surge events, device simulations, and key parameters to consider when selecting a pressure surge relief system for a terminal design to ensure that the piping system and hydraulic components remain safe during abnormal operating conditions. Although the analyses presented in this paper are applicable across a broad range of operating conditions and equipment and devices in terminal system designs, it is not possible to cover all situations. As such, sound engineering principles and engineering judgment should always be applied in an engineering design.
Excavation Assistance System Design Based on Human Factors: Functional and Technical Analysis
Authors: Perinet Romuald , Lecchi Maxime , Marmeys Thierry , Pognonec Gaël , Herchin Nicolas 
Published: December 2014

External interference is the first cause of incidents on gas transmission pipelines in Europe in terms of frequency. The large majority of pipe breaks are indeed due to excavation works. Prevention barriers exist: slabs, warning tapes, surveillance patrols, public awareness campaigns, … but third party activities are gradually increasing and additional barriers are needed. Furthermore, incidents also occur on works contracted by gas companies themselves and specific barriers are missing for these particular situations. In this context, embedded systems for excavators can be interesting solutions to prevent the driver from hitting pipelines. However, studies conducted in the past have shown the limitations of such systems available on the market.
Thus, the CRIGEN (GDF SUEZ research center dedicated to gas and new energies) has worked on the specification of an embedded system, using an approach combining human factors and a functional analysis. This global method has been built to ensure that the potential solution will meet the need and that it will not have detrimental effects on the actual human organization which represents in itself a barrier.
This paper presents the main results of the work including the different methodologies and tools that have been used, but also the way they have been combined. The strong contribution of the human factors oriented analysis is detailed through: the identification of the hazardous situations to address, the identification of bias involved in incidents and the resulting safety functionalities for the system. Technical aspects of the method are also shown in the document, which includes a functional analysis and a benchmark of technologies of interest for the system. This allows a rather objective evaluation of several systems’ options combining different architectures and technologies. As a conclusion, a generic system architecture is proposed. This architecture mainly relies on existing tools and on a supervision unit. It is thought not to disturb the driver’s work but to help him digging in safer conditions by warning him in case of drift.
Tandem Flux-Cored Arc Welding for High Strength Line Pipe
Authors: Penniston Christopher J. , Huntley Robert M. 
Published: December 2014

The benefits of mechanized welding for pipeline construction are well known, as reflected by the high industrial acceptance and usage of its variations. However, the engineering and qualification costs associated with the preparation of alternative acceptance criteria for typical pulsed and short-circuit MIG (GMAW-P and GMAW-S) girth welds can make the implementation of mechanization too costly and/or time consuming for small projects.
A multi-wire welding technology, employing a high-deposition consumable that possesses excellent positional capability, along with paired digitally controlled asynchronous inverter power sources, is presented.
Trials were performed on CSA Z245.1 914 mm (NPS 36) OD × 20.4 mm WT Grade 483 heavy wall high strength line pipe. One variant used an 8-head internal welding machine for the root pass, and a conventional single torch short-circuit GMAW hot pass in a compound narrow-groove configuration. A second variant utilized an externally applied controlled short-circuit GMAW-S process for the root pass in a factory-style pipe bevel configuration. Both variants employed fill and cap passes using tandem pulsed gas-shielded flux-cored arc welding (T-FCAW-G/P), using rutile consumables, with the “bug and band” MOW II mechanized welding system.
Basic mechanical testing was performed on the first weld variant, along with single-edge notched bend (SENB) crack tip opening displacement (CTOD) tests, and results are presented.
A productivity comparison is then shown, using weld data from the second weld variant against alternative processes, showing considerably lower fill and cap pass arc time using the T-FCAW-G/P process.
Given the process’s low tendency for the formation of planar discontinuities, the process is appealing for the use of “workmanship” acceptance criteria.
With further procedure development and fine-tuning of the process, tandem flux-cored arc welding may prove viable, particularly for “short” pipelines, where the costs of comprehensive engineering critical assessment/fitness-for-purpose weld procedure qualification and associated engineering work aren’t justified; as a higher productivity alternative to single wire flux-cored arc welding for mechanized tie-in welding; as a much higher productivity alternative to SMAW for tie-ins; or with a narrow groove design, mainline applications for longer-distance projects.
Field Testing of Negative-Wave Leak Detection Systems
Authors: Siebenaler Shane , Tervo Eric , Vinh Paul , Lewis Chris 
Published: December 2014

The pipeline industry is improving its ability to detect and locate leaks through emerging technologies. There has been a variety of research in recent years aimed at further development of sensor-based technologies for leak detection. A key obstacle to retrofitting existing pipelines with leak detection technologies is the cost and risk of installing hardware, particularly those sensors that require excavation near the pipe. There are many advantages to employing leak detection systems that can leverage existing instrumentation access locations. One such technology may be negative-wave leak detection systems. Negative-wave technologies work by measuring dynamic pressure changes in the pipe. It should be noted that some negative-wave systems require line modifications to accommodate multiple transmitters. While such systems have been on the market for many years, there is insufficient data available about their performance under various pipeline operating conditions for widespread adoption.
In an effort to close many information gaps on the performance envelope of negative-wave technologies, a PRCI-funded field test was performed on a 41-kilometer segment of a 30-inch diameter heavy crude oil pipeline. Products from three suppliers were installed at either end of the test segment. Actual commodity withdrawals were conducted at a remote valve site approximately 21 kilometers into the segment during various operations to test the systems’ abilities to detect the withdrawals without direct user interaction. These test points included withdrawals during steady-state flowing, pump startup, and shutdown conditions.
Data were collected from each system to determine their abilities to detect leaks under various conditions, abilities to locate the leak, false alarm rates, and response times. This test provided significant insight into the performance of such systems over the range of conditions tested. The key focus of this paper is the approach for conducting such multi-vendor commodity withdrawals. This project required some unique considerations for its execution. Such considerations are also documented to provide input to others who are considering such a test.
Shallow Dents: Updates to the UKOPA Dent Management Strategy
Authors: Lockey Aaron , Palmer-Jones Roland , Jackson Neil , Ellis Roger 
Published: December 2014

Pipelines can be dented, but shallow dents with depths less than 2% of the pipe diameter have only recently begun to be reported reliably by high resolution in-line geometry inspections. Most thin-walled onshore pipelines around the world are found to contain these shallow dents, many on welds of unknown toughness, or subject to severe pressure cycling.
Much of the existing guidance for dent management was published before such shallow dents were being reported, and did not necessarily consider them. Furthermore, recent failures in Canada have demonstrated that the existing guidance can be non-conservative when a shallow dent is combined with fatigue loading or other undetected damage.
The United Kingdom Onshore Pipeline Operators Association (UKOPA) is developing a strategy for the management of dents to provide guidance to operators based on published best practice. The aim of the work is to ensure that dents now identified but not sized by MFL inspection tools are appropriately inspected, investigated, assessed and repaired.
UKOPA’s methodology allows shallow dents to be screened and assessed without the requirement for numerous feature investigations. This management strategy is:
Stage 1: Use previously published UKOPA guidance on the prioritization of dents. This involves following a series of flow charts, leading the operator from dent discovery, through decisions affecting assessment and possible repair.
Stage 2: This Stage provides a series of criteria to indicate whether a weld is likely to be of sufficient toughness to withstand shallow denting, then gives a method to carry out an engineering assessment of a dent based on finite element analysis.
This paper presents the background and justification of ‘Stage 2’, and updates ‘Stage 1’. It includes a review of recent published work covering dents on welds, including analytical studies, finite element analyses, testing and failures. The results of this work by UKOPA will form an input to the planned updates to the Pipeline Defect Assessment Manual (PDAM).
The paper then applies the updated guidance to operational dent assessment problems provided by UKOPA members. Finally, an example of a dent assessment under the previous and updated guidance, including a finite element analysis, is given to illustrate how a shallow dent on a weld of unknown toughness may be re-categorized as not requiring repair.
Maintenance of Gas Pipeline Automatic Block Valves
Authors: da Cruz Thales B. , de Novaes Márcia G. , Leite João Paulo de B. 
Published: December 2014

The concept of gas pipelines sectionalized by block valves in Brazil has focused on safety rather than operability, and so all such valves are automatically controlled. However, operational history has indicated that undesired actuation of automatically controlled blocking valves is among the major risks of supply failure. Thus, a statistical study was carried out to identify the chief causes for undesired closures and opportunities for improvements. One of the most important causes is the lack of standardization of equipment and procedures within the pipeline network. The lack of standardization usually results in higher costs and complexity of operation and maintenance.
With the purpose of overcoming such drawbacks, it was required to establish a program for process optimization, in order to obtain well-adjusted maintenance and operational procedures throughout the life cycle of the equipment and facilities. A maintenance strategy for the automatic block valves is an important point to achieve the objectives defined in this program, such as an increase in operational reliability, minimizing the risks of gas-supply failure and the reduction of operational costs.
Although the project is still in progress, it is already possible to observe some positive outcomes related to operational reliability, showing a significant reduction in the number of operational occurrences of automatic block valves in 2013.
Inspection and Prioritization Methods for Small Diameter Auxiliary Piping
Authors: Pecush Adam , McTavish Mark , Ellestad Brian 
Published: December 2014

To serve the pumping and storage needs of its customers; Enbridge operates more than 25 terminals and 150 pump stations across North America. In each of these facilities, small diameter (NPS 6 and smaller) piping is used in auxiliary systems including instrumentation, measurement, and product re-injection. Traditionally, in the design of facilities, this small piping has received less attention than large diameter process lines and, during construction, has typically been field run based on standard installation details. This, in conjunction with 65 years of changing design and construction philosophies, as well as asset acquisitions, has resulted in a wide variety of installation configurations across the Enbridge liquids system.
The Small Diameter Piping Program in the Facilities Integrity group centrally manages the integrity of all small diameter auxiliary piping across the Enbridge liquids system. Historically, the management and remediation of small diameter systems has been based on addressing specific installation types identified through incident investigations. While generally effective at minimizing re-occurrence, this approach has been limited in its ability to proactively identify installations that should be addressed.
In support of our goal of zero incidents, Enbridge has developed a proactive methodology for the inspection and prioritization of small diameter auxiliary piping. Installation types are evaluated on their susceptibility to specific damage mechanisms.
An inspection and prioritization model was developed through the combination of internal lessons learned and prioritization methodologies outlined in industry publications, specifically those from the overseas oil and gas industry. This model, sets a standardized process to assign a likelihood of failure (LOF) score to individual small diameter installations of specific types and/or functions.
Presently, likelihood of failure scores are used to identify installations requiring remediation, and to most effectively prioritize system-wide remediation activities. Over time, these scores will also be used to demonstrate an overall reduction in the likelihood of failure for small diameter piping in the Enbridge liquids pipeline system.
Experiments and Finite Element Model Results on the Deformation Response of an X80 Weld Zone
Authors: Puydt Q. , Kulakov M. , Poole W. J. , Collins L. E. , Kenny S. 
Published: December 2014

The modification of microstructure and mechanical properties of steels after a welding process has received considerable attention in the literature. In the case of welding HSLA steels for pipeline applications, the filler metal employed usually is overmatched (i.e. higher strength) compared to base metal to avoid fracture in this zone of the weld. For this reason, considerable work has emphasized microstructure evolution in the heat affected zone and the associated modification of mechanical properties in this region. In this study, the combined effect of microstructure/property distribution and the geometry of the weld are examined to understand where localization, necking and fracture occurs under tensile loading of a laboratory weld.
To achieve that, a series of tests were conducted on two different types of X80 submerged arc welds: Single and tandem wire welds. The tensile samples were machined transverse to the weld on plates 16 mm thick. Samples were tested where the geometry of the weld was preserved (i.e. the weld cap is left intact) and where the cap was removed in order to remove its effect. The local plastic strain during testing was determined using the Digital Image Correlation technique (DIC).
For the single wire weld, the influence of the cap geometry seems to be of second order, as the fracture location is the same with or without caps. But for the tandem wire welding, the fracture location is very different depending on the geometry: In the case where caps are kept, the fracture occurs outside the HAZ, in the base metal suggesting the important interplay between local mechanical properties and the weld geometry.
A Finite Element Model (FEM) was developed to gain insight into the geometrical effects on the local strain field distribution. The experimental strain distribution is compared to the FEM results to rationalize the effect of geometry. The model results are then used to discuss the position of fracture for the different samples, which correspond well to the experimental results.
How Safe Failure Pressure Ratios are Related to %SMYS
Authors: Kariyawasam Shahani , Huang Terry 
Published: December 2014

Majority of the pipeline operators manage corrosion using inline inspection (ILI). ILIs enable operators to choose which anomalies should be excavated and, on the flip side, which anomalies are safe to remain on the pipe. If the remaining anomalies grow to a critical size before the next ILI cycle there will be in-service failure. This is avoided by forecasting the growth of the measured defects appropriately and assessing them for future integrity.
When an ILI is performed on a pipeline the ILI vendor reports the anomaly sizes, burst pressures and the Failure Pressure Ratios for each anomaly. Failure Pressure Ratio (FPR) for an anomaly is defined as the burst pressure divided by the Maximum allowable operation pressure (MAOP). In order to avoid ruptures, operators will excavate anomalies that have a limiting value of FPR. These limiting values are also referred to as response criteria, excavation criteria, safe failure pressure ratios, or safety factors. As the FPR depends heavily on the operating stress (or %SMYS) the limiting FPR value, below which we respond, should also depend on %SMYS. However, currently there is inconsistency in the use of response criteria in the industry. Some utilize the same response criteria for all pipe irrespective of %SMYS. This study shows that using the same limiting FPR does not provide the same level of safety for different %SMYS scenarios. It shows that the size of remaining anomalies in the lower %SMYS pipe would be significantly larger than in higher %SMYS pipe, leading to lower reliability in pipelines that have lower %SMYS. For gas pipelines, these lower %SMYS pipelines are often in higher location class pipelines with higher consequences of failure.
In other words, even though the FPR value is the same for two anomalies in two different %SMYS pipes, the two anomalies would have very different probabilities of failure, where one anomaly could be safe while the other is not.
This paper examines the ranges of FPR and the safe response criteria as a function of %SMYS. It examines the remaining anomaly sizes in different %SMYS pipe as allowed by current standards. The effect of the uncertainties on the response criteria due to measurement errors, material and geometric properties and model errors are also examined. It examines the response criteria in different jurisdictions. The effect of using different assessment equations, such as Modified B31G or RSTRENG, on the response criteria is also discussed. In order to obtain consistent safety, the consideration of %SMYS and consequences in defining a response criterion is discussed.
Many sets of ILI data, which have pipe in different %SMYS, have been assessed in order to examine practical ranges of FPR with %SMYS. The practical implications of different response criteria are studied and discussed.
A Semi-Quantitative Risk Assessment to Support Oil Pipeline Risk-Based Design
Authors: Mitchell James , Jasper Steve , Mihell Jim 
Published: December 2014

During the regulatory phase of the Enbridge Northern Gateway Project (Northern Gateway), the Joint Review Panel (JRP) requested information on “how the risk factors resulting from the geotechnical and geographic aspects of the pipeline will be taken into account” and to demonstrate “the integration of risk factors with the environmental and socio-economic consequences from potential hydrocarbon releases”. Furthermore, the JRP required Northern Gateway to identify where a risk-based approach to design would be used to address geotechnical and seismic hazards, valve locations for spill consequence reduction and risk reduction in consequence areas”. [1]
To meet this requirement a semi-quantitative risk assessment (SQRA) was undertaken. Risk was defined as a function of probability and consequence, where the probability (expressed as a frequency) of loss of pipe integrity was quantitatively determined and the consequence of failure was qualitatively determined. The frequency of failure was a probabilistic combination of the calculated probability of failure from reliability methods, historical frequencies and assessed geo-hazard failure frequency rates. Consequence scoring was based on intersection of theoretical spills with “consequence areas” for environmental or socio-economic effects Frequency and consequence were then combined to provide risk scoring and ranking.
Failure frequencies were developed using reliability methods where appropriate. The use of reliability methods addresses the primary challenge associated with quantifying risk for new pipelines as industry failure statistics are not directly applicable to modern pipeline designs, materials, and operating practices. In the pipeline industry, reliability models exist for the most significant threats, including third-party damage, internal corrosion and external corrosion. In addition, geotechnical threats can be characterized in terms of expected magnitude and associated frequency of occurrence, thereby enabling pipeline reliability to be established for each geo-hazard.
Consequence scoring was based on modeling full bore rupture spill scenarios and determining whether these spills would potentially intersect identified “consequence areas”.
Over the course of the application and hearing process two SQRA’s were undertaken. Following the filing of the first SQRA, additional measures were included in the pipeline design to reduce the frequency of failure and to reduce potential consequences. This resulted in the calculated overall risk being reduced by a factor of 84%, primarily due to increases in wall thickness resulting in a reduction in the likelihood of 3rd party damage and in a reduction of consequence by an increased number of valves.