bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Modeling of Distributed Inhomogeneities and Their Effect on Rolling Contact Fatigue Life
Authors: Zhou Qinghua , Jin Xiaoqing , Wang Zhanjiang , Wang Jiaxu , Keer Leon M. , Wang Qian
Published: July 2013

This research explores the influence of distributed non-overlapping inhomogeneities on the contact properties of a material. Considered here is the half-space Hertzian contact of a sphere with an inhomogeneous material. The numerical analysis is conducted utilizing a simplified model based on Eshelby’s Equivalent Inclusion Method (EIM) and the principle of superposition. The solutions take into account interactions between all inhomogeneities. Benchmark comparisons with the results obtained with the finite element method (FEM) demonstrate the accuracy and efficiency of the proposed solution methods. The emphasis is given to a parametric study of the effect of inhomogeneities in a Gaussian distribution on material properties. Both compliant and stiff inhomogeneities are modeled. Material inhomogeneities strongly affect rolling contact fatigue (RCF) of a material, and a modified RCF life model is suggested. Homogenization and extensive numerical simulations result in semi-empirical fatigue-life reduction parameters to characterize the influence of material inhomogeneities.
Influence of Micro Textures on the Tribological Contact and Tribological Behavior on the Example of a CVT
Authors: Drechsler Sandra , Albers Albert , Merkel Philipp
Published: July 2013

CVTs are complex tribological systems with high potential concerning increasing efficiency of powertrains. To improve the performance of CVTs it is necessary to deepen the knowledge concerning parameters influencing the system behavior.
Squeeze Film Flow Analysis Using Moving Particle Semi-Implicit Calculation
Authors: Hirooka Nobuyuki , Terrell Elon J.
Published: July 2013

We have presented an application of the modified Moving Particle Semi-implicit (MPS) method for squeeze film flows. In addition to calculating the flow field of a squeeze film using the full Navier-Stokes equations, this method has the advantage of being meshless, which gives it the capability of analyzing dynamic and/or highly transient squeeze films by discretizing the domain as a series of particles and numerically analyzing inter-particle interactions. Although past literature has indicated the MPS method in its original form to be unstable in terms of its calculation of pressure, a modified algorithm was implemented to provide agreement between the numerical results and the analytical solutions.
Lubricant Flow and Evaporation Model for Heat Assisted Magnetic Recording Systems Including Reactive End-Group Effects and Thin-Film Viscosity
Authors: Bechtel Joanna E. , Bogy David B.
Published: July 2013

The lubricant applied to the disk in a hard drive is a critical component for head-disk interface reliability. In Heat Assisted Magnetic Recording (HAMR), the heat supplied to the disk by the laser will add new thermal considerations to lubricant performance. Investigations into how the lubricant behaves at the small time and length scales seen in HAMR systems need to be conducted numerically. Published works on HAMR lubricant modeling have considered only the van der Waals contribution to disjoining pressure, commonly called the dispersive component, and do not consider the film thickness dependence of viscosity. However, lubricants with reactive end groups such as Fomblin Zdol are widely used, and such simple disjoining pressure and viscosity models do not capture certain lubricant behavior. We have developed a simulation tool that incorporates film thickness dependencies of viscosity and polar and dispersive disjoining pressure into a continuum lubrication model. We investigate the effect of initial thickness on lubricant flow and evaporation under HAMR write conditions considering both components of disjoining pressure and thin-film viscosity. Simulation results indicate the effect of including polar disjoining pressure depends on the initial lubricant thickness. The inclusion of viscosity thickness dependence does not affect simulation results under scanning laser conditions but will be important in reflow simulations.
Experimental Investigation of Transition in Lubrication Regime for Thin-Film Coated Surfaces
Authors: Lorenzo Martin C. , Ajayi O. O. , Torrel S. , Fenske G. R. , Erck R. A.
Published: July 2013

Friction and wear behavior of lubricated sliding contact is determined by the operating lubrication regime. A useful approach to determining the operating lubrication regime is the calculation of the λ ratio, which is defined as the ratio of lubricant fluid film thickness (h), and the composite surface roughness (ơ) of contacting surfaces (λ = h/ơ). Thin-film tribological coatings are increasingly being used for application in lubricated machine elements such as gears and bearings. It is usually assumed by design engineers that application of thin-film coatings has no effect on fluid-film lubrication. This paper presents our experimental investigation of the impact of several (5) commercially available coatings on lubrication regime during a unidirectional sliding contact. Using a ball-on-flat contact configuration and lubricated with PAO basestock oil, tests were conducted in which the λ ratio was varied as a function of time, for both uncoated and coated flat specimen. In test with uncoated flat, the various distinctive lubrication regime of hydrodynamic, mixed and boundary were observed as indicated by the measured friction coefficient (Stribeck Curve). In tests with some of the coatings, especially the carbon based DLCs, there was no obvious distinctive transition in lubrication regime. In other coatings (ex. TiCN), various lubrication regime were also observed; although the rate of transition from one regime to the other was different. The effects of coatings are attributed to their inherent mechanical and tribological properties as well as their impact on the run-in process.
Influence of Surface Topography on the Tribo-Characteristics of an Eccentric-Tappet Pair
Authors: Wang J. , Venner C. H. , Lubrecht A. A.
Published: July 2013

The cam-tappet pair is one of the most important components in an engine and determines the overall performance of the motor. Compared with modern car engines using rolling-sliding tappets for the transmission of the rapid up-down lifting motion of the cam to open and close the engine’s inlet and exhaust valves, the flat-tappets are often subject to fatigue failure. Upon stripping down a damaged motor, the tappets are invariably found to be heavily pitted. This study performs a theoretical simulation of the surface topography influence on the tribo-characteristics of an eccentric-tappet pair. The asperities on the flat-tappet surface generate fluctuations of the pressure, film thickness and temperature distributions. The pressure fluctuations result in alternative stresses in the metal. The periodical variations of pressure, minimum film thickness and thermal rise are investigated by changing the eccentricity and roughness wavelength. The results suggest an explanation for the rapid occurrence of cracks or even complete fracture in the cam and flat-tappet pair.
Surface Texturing for Energy Efficiency and Sustainability
Authors: Menezes Pradeep L. , Kishore  , Kailas Satish V. , Lovell Michael R.
Published: July 2013

Precise control of friction is very important for energy efficiency and sustainability in manufacturing processes. In the present investigation, various surface textures have been employed to vary the frictional conditions. More specifically, textures were varied from unidirectional to criss-cross to unidirectional by grinding the steel surfaces against emery papers for various numbers of cycles. Sliding experiments were conducted using an inclined pin-on-plate apparatus against the prepared steel surfaces under dry and lubricated conditions. In the experiments, it was observed that the coefficient of friction and transfer layer formation on the harder surfaces were controlled by the textures of the harder surfaces under both dry and lubricated conditions. The asperity angle of the harder surface plays a dominant role in controlling the friction and transfer layer at the sliding interface. Thus, by understanding appropriate roughness parameters, the friction and wear performance can be accurately controlled to enhance energy efficiency and the quality of the finished products in manufacturing process.
A Hybrid Mobility Solution Method for Dynamically Loaded Misaligned Journal Bearings
Authors: Boedo S.
Published: July 2013

This paper presents a hybrid mobility solution approach to the analysis of dynamically loaded misaligned journal bearings. Mobility data obtained for misaligned bearings (calculated from a finite element representation of the Reynolds equation) are compared with existing curve-fitted mobility maps representative of a perfectly aligned bearing. A relative error analysis of mobility magnitude and direction provides a set of misaligned journal bearing configurations (midplane eccentricity ratio and normalized misalignment angle) where existing curve-fitted mobility map components based on aligned bearings can be used to calculate the resulting journal motion. For bearing configurations where these mobility maps are not applicable, the numerical simulation process proceeds using a complete finite element solution of the Reynolds equation. A set of numerical examples representing misaligned main and connecting rod bearings in a four-stroke automotive engine illustrate the hybrid solution method. Substantial savings in computational time are obtained using the hybrid approach over the complete finite element solution method without loss of computational accuracy.
Analysis of ILI, ACVG and DCVG Indications in Conjunction With CIS: A Case Study
Authors: Matocha Garry , Burns James F. , Garrity Kevin C. , Eastman Alan
Published: July 2013

To support pipeline integrity initiatives, Spectra Energy (Spectra) undertook to verify the pipeline coating condition on certain pipeline assets by performing DCVG or ACVG surveys on Class 2 and Class 3 locations and in HCA’s. The process undertaken was to consider the alignment of coating anomaly indications with ILI anomaly indications and to compare the results of direct examinations to anomaly indications. The alignment and comparison of the data is based upon the analysis of DCVG, ACVG, CIS and ILI data. The results of the direct examinations at the sites in the affected segments were reviewed to evaluate the condition of the pipelines as it relates to specific severity of the identified coating anomalies.

This paper will discuss the results and findings of those studies.
Supporting Guidelines for Reviewing Reliability-Based Assessments of Onshore Non-Sour Natural Gas Transmission Pipelines
Authors: McCallum Marcus , Mora Rafael G. , Emmerson Graham , Senadheera Thushanthi , Francis Andrew
Published: July 2013

In Canada, a great deal of effort has been invested into the use of reliability-based techniques for the design and assessment of non-sour natural gas transmission pipelines. This led to the inclusion of Annex O in the Canadian onshore pipeline code CSA Z662 in 2007, which gives detailed descriptions of all of the key components of reliability-based approaches. However, the annex does not and is not intended to provide recipes for using the reliability-based techniques for particular fields of application such as evaluating the acceptability of changes to location class, service or increasing maximum operating pressure. Consequently, the onus is on the reliability/integrity engineer to tailor the approach to the particular field of application and the specifics of the pipeline. This means that even working in accordance with the code, the approach and optimizing techniques adopted by one engineer may be very different to that adopted by another. This presents a challenge for those reviewing reliability based plans, designs and alternatives for approval.

The National Energy Board (NEB) engaged Andrew Francis & Associates Ltd (AFAA) to assist them with constructing a set of supporting guidelines to assess the comprehensiveness and safety of reliability based submissions. Unlike customary design reviews, the guidelines are geared towards provoking a reviewer into asking delving questions rather than into going through a ‘box-checking’ questionnaire. Indeed, asking the case-specific and clarification questions is regarded as a crucial step towards determining the adequacy and effectiveness of the measures proposed in the content and conclusions of a particular filing. Simply questioning whether Annex O has been followed is not encouraged and, even when safety criteria appear to have been met (i.e. box-checking), a reviewer is prompted to challenge the reasonableness of assumptions and ask whether safety levels are providing the lowest practicable risk to the Canadian public. One line of inquiring might be: are sufficient data available; are the data reliable; are the data relevant to the case under consideration; or have the data been analyzed using a valid method applicable to the case. Other typical questions would be have the consequences been properly assessed and are the mitigative and preventative measures providing the lowest practicable risk compared to pressure reduction and pipe replacement.

The purpose of this paper is to present an overview of the assessment guidelines and the approach and key considerations for conducting efficient, consistent and fair reviews of reliability based assessments of hazardous material pipelines. In doing so, the paper also identifies some of the pitfalls that engineers conducting reliability based integrity assessments should seek to avoid.
Effects of Cold Temperature on Pressure Transmitter/Flexible Hose Gaugeline Assembly Mounted on a Pipeline Transporting Diluted Bitumen
Authors: Botros K. K. , Geerligs J. , Staszelis P.
Published: July 2013

Pressure transmitters (PT) are mounted on Diluted Bitumen (DilBiT) pipelines particularly in various locations around the pump stations. Conventional assembly of the PT includes short rigid tubing closely connected to the pipe. Due to fluid flow and equipment induced vibration of the main pipe, these tubing, being very short and close to the pipe, are vulnerable to break and hence becomes an integrity and reliability issue. For this reason, PT’s are often mounted at a longer distance away from the pipe (of the order of 2 meters) with the use of a flexible SS hose gaugeline to dampen vibration generated at the pipe/tubing connection. While this solves the problem of tube breaking, it creates an issue surrounding the effects of the long gaugeline on the dynamic response of the PT/gaugeline assembly to pressure variations, particularly in cold ambient temperature (e.g. −40°C). An experimental setup of a typical PT/flexible hose gaugeline assembly was placed in a cold chamber, and several tests were conducted on warm (10 to 20 °C) and cold temperatures (−40°C) to compare the difference in the dynamic response of the assembly. Several fluids filling the gaugeline were tested and compared. This paper present the test results and make a recommendation of the best fluid to use for the gaugeline to cope with −40°C ambient temperature. It was also found that no heat tracing would be required if this fluid is used.
Analysis and Numerical Simulation on Dynamic Response of Buried Pipeline Caused by Rock Fall Impaction
Authors: Jing Hongyuan , Deng Qinglu , Hao Jianbin , Han Bing , Li Liangliang
Published: July 2013

Theoretical analysis methods are discussed to estimate additional stresses of shallow buried oil and gas pipeline caused by rock fall impaction. The process of impaction is simulated using finite elements software, in the model a 1 m3 square shape falling hard rock impacts soil ground upright of pipe with a vertical velocity, and dynamic response of pipeline is analyzed. The impact force, soil additional stresses, pipe displacement and additional stresses in the impaction process are studied. The effect of pipeline buried depth and rock velocity to the impaction also discussed. Results show that the impaction process is very short and the duration is about 10−3∼10−2s. The maximum impact force has approximately direct ratio with the velocity of rock. The additional vertical stress in soil caused by impaction load has a stress concentration region near the surface of pipe, and its distribution has the similar pattern with that in static load, but has a faster attenuation from the impaction center to sidewall. The most dangerous pipe cross-section appears in the underside of impaction center, and the maximum additional equivalent stress appears in the top of the cross-section, and has an approximately direct ratio with the velocity of rock if other impaction conditions are confirmed. The buried depth of pipeline has major influence to impaction. Large thickness of soil cover has marked effect on improve the protection of pipeline. According the study, shallow buried pipeline has weak defense to rock fall. The additional internal force and stress of pipeline caused by impaction of rock fall can be approximately estimated using theoretical methods or numerical simulation.
Development of Industry Standard for Pipeline Security Pre-Warning Technology
Authors: Li Yunjie , Zheng Juan , Tan Dongjie , Liu Yanshuang , Chen Pengchao
Published: July 2013

This article describes the development of industry standard for pipeline security pre-warning (PSP) technology which is an achievement of China National Petroleum Corporation’s Eleventh Five-Year science and technology project. By comprehensive application of signal acquisition and identification technologies, the PSP system monitors the pipeline for real time and promptly warns and locates the damages caused by illegal excavation, drilling hole for oil-stealing, pipeline erosion and natural disaster. This technology applied and operated well on some long distance transport pipelines in China and was listed on the Recommendation Projects for Safe and Security by the State Administration of Work Safety in 2009.

To speed up the industrial application and promotion of the PSP technology, the Oil & Gas Storage and Transportation Standardization Committee (OGSTSC) of the Petroleum Industry organized the development of the standard from which transferred the research and development results. The standardization process has taken two years and gone through five major steps: first, determining the standard range; second, researching relative standards, laws and regulations; third, carrying out field tests; fourth, drafting the specifications, finally, revision and finalizing the standard. The development of PSP standard is a typical example for OGSTSC of transferring knowledge from R&D to industrial standard and finally to end users. The PSP standard development process was finished in 2010 and the industry standard SY/T 6827 Specification for Security & pre-warning System of Oil & gas Pipeline was published in the July of 2011.
Guidance for Field Segmentation and Welding of Induction Bends and Elbows
Authors: Bruce William A. , Amend Bill , Rapp Steve
Published: July 2013

The use of cold field bends is not practical for some pipeline construction applications, particularly for large diameter pipelines built with restricted work space. For many reasons, the use of segmented induction bends and long-radius elbows becomes a necessary part of normal construction practice.

This paper describes the results of the second phase of a recently-completed joint industry project pertaining to welding of field segmented induction bends and elbows for pipeline construction. In this phase, optimal methods for mapping, cutting, beveling, and transitioning induction bends and elbows were developed. Recommended practices for welding in the field and for a variety of related issues were also developed. The information was summarized and used to develop a generic specification for segmenting and welding of induction bends and elbows.
Further Development of Heat-Affected Zone Hardness Limits for In-Service Welding
Authors: Bruce William A. , Etheridge Bradley C.
Published: July 2013

Welding onto an in-service pipeline is frequently required to facilitate a repair (Figure 1) or to install a branch connection using the “hot tapping” technique (Figure 2).

Welds made in-service cool at an accelerated rate as the result of the ability of the flowing contents to remove heat from the pipe wall. These welds, therefore, are likely to have hard heat-affected zones (HAZs) and a subsequently increased susceptibility to hydrogen-assisted cracking.

During the evaluation of procedure qualification welds, HAZ hardness is often used as an indicator of the susceptibility to cracking. A widely used value below which it is generally agreed that hydrogen cracking is not expected to occur is 350 HV. Both the US standard API 1104 Appendix B[1] and the Canadian standard CSA Z662[2] indicate that procedures for in-service welding that produce HAZ hardness greater than 350 HV should be evaluated with regard to the risk of hydrogen cracking. A previous paper on this topic[3] is referenced in CSA Z662 as guidance for performing this evaluation. The present paper describes the further development of HAZ hardness acceptance criteria that can be used to evaluate welds during the qualification of procedures for welding onto in-service pipelines.[4] This further development involved taking the effect of material thickness (restraint level) into account and further validation.
A Method to Determine the Safe Time for High Waxy Crude Pipeline With Uncertainty
Authors: Xu Bo , Miao Qing , Lan Hao , Yan Feng , Liu Donglei
Published: July 2013

More than 80% crude oils produced in China has a high content of wax. Pipeline transportation for such high waxy Chinese crude has a serious safety risk due to its characteristics of high gel point (up to 30 degree) and high viscosity below the wax appearance temperature. In the case of pipeline shutdown the crude cools down. After a certain amount of time, depending on the crude oil properties, the crude oil temperature plot file, the hydraulic data as well as the pipeline construction and environmental related data, the required pressure to restart the pipeline might exceed the maximum allowable operation pressure (MAOP) which makes the restart of operation become very difficult or even impossible.

To mitigate the safety risk in case of the pipeline shutdown or to avoid congeal accident, determining the safe time after which the pipeline is still able to restart is necessary. However, the complexity of the presented problem lies in the uncertainty of the operation parameters and the environmental related data, such as the uncertainly of the flow rate and natural temperature.

A method is developed to predict the safe time based on the uncertainty of parameters. In the method, the field data is firstly collected, then processed and analyzed to obtain the static rules of these data. By doing so, the complexity of uncertainty is successfully handled. The method is then applied to two pipelines, the results show that the safety of the pipeline is ensured and the energy consumption is also significantly reduced.
Implementing Corporate Initiatives
Authors: Greaves Thomas H.
Published: July 2013

IT enabled corporate projects have failure rates that approach 68% (Standish CHAOS 2009 Report). This paper will chronicle the steps needed to increase your chances of successfully implementing a corporate initiative.

Examples will be provided based on the recent roll out of a revamped Management of Change (MOC) program that included simple processes and policies, appropriate training at the right time, and an IT tool that was well established prior to roll out.
Study on a Method Monitoring Oil and Gas Pipelines in Permafrost Regions
Authors: Ma Yunbin , Tan Dongjie , Song Ning , Chen Pengchao , Ma Tao
Published: July 2013

Based on conditions of oil and gas pipelines in permafrost regions, this paper demonstrates a method for monitoring pipeline stress and displacement as well as permafrost temperature field. To measure pipeline displacement, Total Station measuring technique which calculates displacement by measuring the change of pipeline sign post was adopted; and to monitor pipeline stress and temperature field of permafrost, Fiber Grating Sensing technique was used. This method has been applied to Pipeline No. A for a year, according to the test results, during the year, displacements of different degrees have been occurred to the pipeline; this pipeline was not influenced by frost heave in winter but was influenced by thaw collapse in summer. Due to this monitoring method for oil and gas pipelines in permafrost regions, the condition of permafrost and the change of pipeline under the impact of permafrost were successfully monitored; therefore, this method is effective and feasible.
ECA by Failure Assessment Diagram: Case Studies
Authors: Tyson W. R. , Xu S. , Ward I. , Duan D.-M. , Horsley D.
Published: July 2013

State-of-the-art Engineering Critical Assessment (ECA) employs the methodology of the Failure Assessment Diagram (FAD) for stress-based design. Current versions of FADs used in leading standards are reviewed and applied to girth weld flaws in pipelines. The intent of the work is to provide background information as a contribution to a proposed upgrade of the Canadian Standards Association standard Z662, “Oil and gas pipeline systems”.
Detection of Small Leaks in Liquid Pipelines Utilizing Distributed Temperature Sensing
Authors: Siebenaler Shane P. , Walter Gary R.
Published: July 2013

Leaks from hazardous liquid pipelines can have significant impacts on safety and the environment. The detection of such leaks in their infancy is important to the overall integrity management of pipelines. The traditional means of detecting leaks on this infrastructure typically involve visual inspection or computational monitoring. However, such methods are often inadequate for detecting and locating small discharges that can result in damage to the environment. One potential alternative technology is distributed temperature sensing (DTS).

The analytical work in this paper details near-field thermal effects surrounding the pipeline, seasonal and diurnal impacts on temperature as a function of buried depth, and the impact of transient temperature response from batch product operations. The analysis demonstrated that DTS employed on a buried transmission line would be immune from many of these effects and would not generate numerous false alarms due to these conditions.

Laboratory testing was conducted on both Brillouin and Raman-based DTS systems; a total of four different manufacturer’s products were utilized. The testing characterized any limitations of such systems as a function of wetted length. The testing demonstrated that such technology could accurately detect small temperature fluctuations over distances exceeding 12 km (7.5 mi) to a location with a resolution of one meter. In addition to sensitivity testing of the systems, the automated alarm systems were tested to ensure that the systems could detect leaks without generating numerous false alarms.
Geotechnical Management in OCP Pipeline
Authors: Salguero Gualberto Chiriboga
Published: July 2013

Landslides are one of the main threats in maintaining pipeline integrity and depend directly on natural geological and geotechnical conditions. External factors such as weather, rainfall, and others, can trigger land movements and displace the pipeline.

The Ecuadorian OCP (Heavy Crude Oil Pipeline) is a buried pipeline going in an East to West direction, crossing 485 kilometers of the Ecuadorian territory. It starts in the Amazon Region (approximately 300 meters above sea level), and then climbs the Andes Mountains (4060 meters above sea level in its tallest portion), to then descend to the shores of the Pacific Ocean. The OCP pipeline crosses many regions with varying climates, varying rainfall patterns, variable morphologies, diversity of soils, and areas affected by tectonic faults, among others.

In order to prevent pipeline failures, OCP Ecuador has instituted programs to perform preventive and corrective actions in order to handle the following geological concerns:

• Intervention of a specialized geotechnical team to identify and monitor critical points along the pipeline route. This team identifies unstable sites based on the observations of cracks, land movements, or other visual deformations of the pipeline route and its surroundings.

• Upkeep of the preventive program.

• Execution of third-level studies required to understand specific unstable zones in detail: nature of the subsoil, underground water level, geo-mechanic characteristics, stability factor, and stabilization works.

• Geotechnical instrumentation used: inclinometers to search the spread of movement, shifting direction, speed, (landslide location); strain gauges for preventive control of pipeline strain, alert levels, efficiency of stabilization works; and topographic surveys to monitor superficial movements.

• Data processing and mapping on GIS Software.

• Annual over-flights to detect massive landslides.

• Internal inspectors (online-ILI) providing a wide range of information: geometry measurements, curvature monitoring, pipeline displacement, etc. In addition, it allows detection of probable zones depicting soil movement.

The purpose of this technical paper is to present the methodology applied by OCP Ecuador to prevent failure of the pipeline along its route.
Intelligent Valve Placement Enhancements Incorporate Value Assessment and Broaden Protection to Consequence Areas
Authors: Li Yanping , Weir David A.
Published: July 2013

In previous International Pipeline Conference papers, Weir et al. (IPC 2006) and Weir, Li (IPC 2008) described an approach for determining the location of new remote controlled sectionalizing valves on an existing liquid pipeline system and for new pipeline development that considers a) valve placement to protect major water crossings (defined as 100 feet wide or greater), b) the volume out reduction potential of valve placement to areas of high consequence, and c) a set volume out threshold. High consequence areas include high and other populated areas, drinking water, environmentally sensitive areas, and commercially navigable waterways as defined by 49 CFR 195.450. These papers describe the use of an effectiveness calculation and effectiveness curve that is used to determine a valve location based on a calculated effectiveness score being above a set predetermined threshold.

Effectiveness is a measure of the volume out reduction achieved to one or more high consequence areas by the placement of a remote controlled sectionalizing valve. All other conditions being equal, the effectiveness score is higher for sections of pipeline contained within or having the ability to affect many high consequence areas versus sections of pipe with limited or no potential to affect such areas. As a result, the effectiveness scoring method does not work well for those pipe sections with the potential to impact small but significant high consequence areas or non-major water crossings (i.e. width less than 100 ft) or that do not impact a high consequence area.

Recent incidents and a heightened public awareness about pipelines and measures that are required to alleviate concerns of environmental impacts in the event of a pipeline rupture have necessitated a reevaluation and refinement of the Intelligent Valve Placement approach. This paper outlines enhancements that Enbridge Pipelines has made to its Intelligent Valve Placement approach. These enhancements include a) set valve spacing for high vapor pressure (HVP) pipelines, b) a new definition of major water crossing, c) tighter volume out thresholds, and d) application of a value assessment applied to the placement of valves for pipeline sections in areas that may or may not contain high consequence areas.
Study on Pipeline Integrity Management Performance Evaluation Techniques and its Application in China Pipeline Companies
Authors: Gu Yulei , Zheng Honglong , Yang Yufeng , Zhou Lijian , Zhang Huabing , Li Yi
Published: July 2013

Nowadays, more and more pipeline operators vigorously promote the implementation of integrity management programs (IMPs for short) in order to improve the integrity of their pipeline systems. But how can the operators measure the performance of their pipeline IMPs? In other words, how can the operators evaluate the efficiency and effectiveness of their programs so as to make continuous improvement? The regulations and standards of pipeline integrity management just gave some requirements and recommendations on performance measurement, but no specific methods were presented. Normally, the pipeline operators measured the performance of IMPs on the base of their management objectives and local regulations’ requirements.

The paper introduced the methodology and achievements of pipeline integrity management performance evaluation work conducted in PetroChina Pipeline Company. Considering the company’s specific integrity management goals and objectives, the metrics were established and applied to evaluate whether those goals had been achieved or not, and found out the shortage of the IMP for giving suggestions for improvement. Considering the input and output parameters of IMP, the performance measures system was set up. The input parameters included the input of workforce, facilities and other investments. The output parameters indicated the output of IMP, such as the accomplishment of the objectives, the quality of the work and the safety improvement through IMP. In order to clearly define the input and output parameters of IMP, the IMP was divided into nine parts, such as data management, high consequences areas identification, risk assessment, integrity assessment, corrosion prevention, defect repair, geo-hazards control, pipeline patrol, pipeline security. For each part, considering the management objectives, the “input-output” parameters metrics were set to measure the performance.

In order to see the performance of IMP from a macroscopic perspective, a simplified index system was built which mainly focused on the safety improvement such as the number of leakage, failures, accidents and economic loss. The grading performance evaluation system could conveniently meet the different focus of different levels managers.

In addition, in order to eliminate the influence of the different management difficulties to the performance of IMP, the paper built a set of adjustment factors to modify the investment parameters to make sure the evaluation results more objective and fair.

At last, the paper showed the application results of the IMP performance evaluation conducted in PetroChina Pipeline Company and its branches.
Featuring Pig Movement in Two-Phase Gas Pipelines
Authors: Bueno David E. G. P. , Figueiredo Aline Barbosa , Baptista Renan Martins , Rachid Felipe B. F. , Bodstein Gustavo C. R.
Published: July 2013

This paper presents a mechanical model, along with a numerical scheme for obtaining approximating solutions for the resulting initial-boundary-value problem, for describing the pig movement in transient two-phase gas pipelines. By taking advantage of the best features of the existing models presented in the literature so far, an idealized general purpose pig model is proposed, contemplating the possibility of representing, within a same context, different types of pigs or pig functions. Both mechanical and hydrodynamic friction forces at the interface of the pig and the pipe wall, as well as by-pass flow rates for the liquid and gaseous phases, are naturally incorporated in the modeling in a coherent mechanical context. The governing equations of the two-phase flow model are intentionally written in a general form, so that different existing models can be used within the framework presented herein. Following this same strategy, a detailed numerical scheme is presented in which the discretization of the flux terms are left open, so that different numerical strategies of first or higher orders can be accommodated without any additional difficulties.
Dynamic Behaviour of High Strength Pipeline Steel
Authors: Van den Abeele F. , Peirs J. , Verleysen P. , Oikonomides F. , Van Wittenberghe J.
Published: July 2013

The occurrence of a longitudinal crack propagating along a gas pipeline is a catastrophic event, which involves both economic losses and environmental damage. Hence, the fracture propagation control is essential to ensure pipeline integrity. The commonly used ductile fracture control strategy for the design of high pressure pipelines is the Battelle Two Curve Method. This approach stipulates that if there is a crack speed at a given pressure that exceeds the gas decompression velocity at the same pressure, propagation will occur.

However, for high strength pipeline steels, this method does not yield conservative predictions, as the absorbed impact energy during a Charpy test no longer reflects the actual burst behaviour of the pipe. Enhanced toughness measures, like Crack Tip Opening Angle and instrumented Battelle Drop Weight Tear test are being proposed as alternative options. These emerging toughness tests are complemented by numerical simulations of ductile crack propagation and arrest. Most of these models are based on the computation of void growth, and account for the local softening of the material due to void growth and subsequent coalescence.

The constitutive behaviour of the sound pipeline steel is often modelled as merely an elastoplastic law, measured under quasi-static conditions. However, both Charpy tests and Battelle tests are dynamic events, which require knowledge of the strain rate sensitivity of the pipeline material. In addition, very high strain rates can occur in the vicinity of a running crack in a high pressure gas pipeline. Hence, the constitutive model for the pipeline steel has to account for strain rate sensitivity.

In this paper, Split Hopkinson Tensile Bar (SHTB) experiments are reported on high strength pipeline steel. Notched tensile tests are performed at high strain rates, to assess the influence of both strain rate sensitivity and triaxiality on the response of the material. In addition, dynamic experiments are conducted at low temperatures (−70°C) to evaluate the ductility of pipeline steel under such severe conditions. The results allow discriminating between the effects of strain rate, triaxiality and temperature, and provide reliable experimental data to accurately model the constitutive behaviour of high strength pipeline steel.
Value and Cost Effectiveness of Conducting a Root Cause Analysis
Authors: Ferrari André-Michel , Jones Brad
Published: July 2013

The formal Root Cause Analysis (RCA) process consists of a structured approach to identifying the underlying factors that result in the unwanted outcomes of one or more typically negative past events (chronic or sporadic). The process helps to identify what systems or behaviors need to be modified to prevent recurrence of similar outcomes. The fundamental driver of the RCA is to eliminate the causes that lead to the unwanted event rather than addressing the symptoms of the event. This generally leads to multiple corrective actions rather than a single solution.

Based on various root causes analyses conducted by a department in Enbridge Pipelines since 2006, various benefits provided by RCA exercises are highlighted in this paper. The findings were mainly derived from completed RCAs as well as RCA team member surveys.

Firstly, the cost effectiveness of the RCA process was identified as a primary driver for this exercise. For example, one RCA involving a multidisciplinary team of 8 members, costing approximately $35,000, led to $1M in recommended solutions generating $16M in potential savings. In other words, each of the 350 hours spent on the RCA produced $8,571 in savings underlining the value creation to the company.

Secondly, the RCA process combined with the power of the team reflection led to the identification of new issues which were causing other revenue losses to the company. Because these issues were not part of the defined scope of the original RCA, their root causes were not be immediately assessed but nevertheless their impact could easily be quantified and forwarded to Management for review.

The third benefit highlighted by RCAs is more of an educational benefit to team members and subsequently the organization. Through cross functional examination of the issues and events, the team members became aware and educated on issues that would not have otherwise been apparent. Additionally, by working through the RCA methodology, the team members enhanced their problem solving abilities which benefit their everyday work.

In conclusion, other than identifying techniques to preclude unwanted outcomes and providing cost saving opportunities in a very cost effective manner, RCAs can be considered as an effective knowledge enhancement tool for an organization.
Comparison of In-Line Inspection Service Provider Magnetic Flux Leakage (MFL) Technology and Analytical Performance Based on Multiple Runs on Pipeline Segments
Authors: Desjardins Guy , Nickle Randy , Skibinsky Darren , Yip Joe
Published: July 2013

This paper presents the results of a comparison between three In-Line Inspection (ILI) vendor’s high resolution magnetic flux leakage (MFL) inspections. Between 2009 and 2011, Alliance Pipeline Ltd. (Alliance) commissioned the inspection of a number of pipeline segments, where each vendor inspected all segments. These inspections have enabled Alliance to conduct a round-robin comparison of the performance and capabilities of each of the vendor’s abilities to detect and size metal-loss anomalies.
Spill Impact Assessment: Crude Oil Pipeline ERCB License Number 3353-1
Authors: Gin Gordon E. , Davis John
Published: July 2013

Gibson Energy performed a liquid pipeline spill analysis on the approximately 1 kilometre long 168.3 mm Crude Oil pipeline near the Edmonton South Terminal. This pipeline crosses a sensitive tributary that drains into the North Saskatchewan River. The pipeline is currently not in operation, however is locked in with product. This spill analysis is unique in that the pipeline is under minimal pressure with no appreciable flow rate. As a result, the objective of this analysis was to illustrate the length of time required to perform drain down at various locations along the pipeline. The Spill Analysis consisted of modeling a potential liquid release scenario for overland flow modeling of a liquid release and reports both direct and indirect High Consequence Area (HCA) impacts. Additionally, data showing spill plume extents, final volumes and other GIS data was generated for map generation. This presentation will discuss the methods, data, parameters, and results of this analysis and the next steps in providing regulators sufficient information for a comprehensive contingency plan of the Edmonton terminal.
Protecting Mainline Valves From Ice Flows
Authors: Hansen John W.
Published: July 2013

In the spring of 2009, the Red River of North Dakota flooded six feet deep and ten miles wide in Pembina County. The flood was followed by arctic temperatures that froze the floodwaters 8-inches thick and also froze around the stems of seven isolation valves. These isolation valves were for pipelines carrying crude oil and natural gas liquid (NGL). The pipeline sizes varied from 36-inch to 18-inch diameters. The ice around the valves was subjected to wind forces of 50 mph putting the valves at risk. Also, when the second spring runoff came, the river current pulled ice down through the valley. This ice flow took out trees, power poles, and damaged a couple of isolation valves. The damage was minimal, but could have been worse. No leaks occurred.

This paper will explore the unique problems associated with protecting the valves and delve into keys and principles that led to an innovative solution. Technical issues will be discussed that will help future projects solve problems on how to protect equipment from ice flows. The underlying soils were known for their excessive settlements and low shear strength. The soil was predicted to settle 6-inches after adding eleven feet of fill for protective berms. The preliminary pipe stress calculations based on the predicted settlement of 6-inches put the allowable pipe stress near the limits of acceptability. The valve site was also located miles from the nearest road. The forces from the ice loads in a river can be enormous and engineering judgment had to be used to obtain a practical solution.
Extreme Testing: Assessing CPM Leak Detection Systems on a Northern Oil Pipeline
Authors: Vinh Paul , Zhang Lichun , Barlow Rick
Published: July 2013

Pipelines in remote and ecologically sensitive regions pose special challenges for pipeline integrity monitoring. These challenges include difficulties of access, reliability issues of communication and instrumentation that may impact the leak detection technology applied in these regions. The selection, application and continuous testing of an appropriate technology to detect possible leaks are important to pipeline integrity monitoring.

The paper reports theoretical assessment and extensive testing on an Enbridge subarctic liquid pipeline. It also reports the comprehensive cost-benefit analysis to guide the leak detection instrument design/configuration and the evaluation of the capabilities of alternative computational pipeline monitoring (CPM) technologies for leak detection.

The selected test pipeline is an 869 kilometer (540 mile), NPS 12 inch pipeline that transports sweet crude through environmentally sensitive areas. This pipeline currently uses a real-time transient model (RTTM) style CPM as the leak detection system (LDS). The pipeline LDS is tested annually by a number of industry-recognized methodologies. These include fluid withdrawal tests, simulated leak tests and an API-1130 instrument adjustment approach. This pipeline is also assessed by API-1149 for its theoretical CPM leak detection sensitivity.

A pilot project invited commercial CPM-style vendors to participate in an LDS test using data from fluid withdrawal and simulated leak tests. Five vendors responded and were included in the test suite. The paper describes the design and implementation of the test process. The results of the commercial systems are presented in aggregated form and the participating vendors remain anonymous. Performance assessment focuses on the LDS evaluation factors of sensitivity and accuracy. The paper concludes with a “lessons learned” review of issues associated with test design.
Material Development of X80 for Strain-Based Design Applications
Authors: Rivinius Christoph , Schwinn Volker , Liessem Andreas , Schröder Jens , Pant Martin
Published: July 2013

Due to the further increasing demand for natural gas, the construction of long-distance pipelines traversing through seismically active regions or arctic regions with ground movement caused by permafrost phenomena will become more and more necessary. To guarantee the safe operation of those pipelines, the pipe material has to fulfill strain-based design requirements in the coated condition. Hence in longitudinal direction low yield-to-tensile ratios, high uniform elongation values and a roundhouse shape of the stress-strain curve combined with sufficient strength values in transverse direction are essential.

The basis for appropriate pipe properties is an adequate design of the plate material. To achieve these objectives the microstructure has become a central element. Nevertheless, it has to be taken into account that the cold deformation during the pipe manufacturing process and the heat treatment of the pipe during the subsequent coating have a major influence on the final line pipe behavior.

The current paper describes recent development steps and approaches. The mechanical properties of the different concepts will be compared and the advantages and disadvantages will be highlighted.