bluuebunny/crossref_metadata_2025 huggingface dataset:
End Boundary Effects on Local Buckling Response of High Strength Linepipe
Authors: Fatemi Ali , Kenny Shawn , Taheri Farid , Duan Da-Ming , Zhou Joe
Published: April 2011

In this paper, the significance of the length to diameter ratio (L/D) on the local buckling response was evaluated using continuum finite element modelling procedures. A numerical model was developed, using the finite-element simulator ABAQUS/Standard, to predict the local buckling and post-buckling response of high strength pipelines subject to combined state of loading. The numerical procedures were calibrated using test data from large-scale experiments examining the local buckling of high strength linepipe. The numerical model’s response was consistent with the measured experimental response for predicting the local buckling behavior well into the post-yield range. A parametric study was conducted to examine the significance of the linepipe L/D ratio with respect to the yield stress to ultimate stress ratio (Y/T) and hoop yield stress to longitudinal yield stress ratio or anisotropy factor (R). As the models with high L/D ratio exhibit global Euler-type response, a numerical algorithm was developed to calculate the local section moment response for the FE analysis. The analysis conducted provides insight on the significance of end effects on the local buckling response. There are questions on the approach taken by current industry practice with respect to establishing compressive strain limits for local buckling when using shorter linepipe segment lengths. The results from this study suggest end effects require assessment and potential mitigation.
Weld Metal Toughness: Sources of Variation
Authors: Quintana Marie A. , Babu S. S. , Major Jeff , Dallam Craig , James Matthew
Published: April 2011

Many material properties are statistical in nature. If one measures the same property of the same material repeatedly, ideally the result is a normally distributed “bell” curve about a mean value. This ideal case does not necessarily hold true for all mechanical properties of interest in steel weld metals. Tensile strength measurements tend to exhibit normal behavior for a given weld metal chemical composition deposited using a reasonable consistent welding procedure, Figure 1a. However, toughness measurements are not nearly as well-behaved or predictable. In a tensile test, assuming a defect free weld, the strength measurement is based on the bulk response of the material throughout the gage length. In a Charpy V-notch (CVN) impact test, again assuming a defect free weld, the toughness measurements are controlled largely by the very local response of the material at the point of highest stress where fracture initiates just below the notch. This paper presents a detailed assessment of a C-Mn weld metal and explains how CVN toughness can vary from less than 20 ft-lbf to over 200 ft-lbf in the same weld, often with test specimens located adjacent to one another in the test weld, Figure 1b. The much localized microstructure features that give rise to this degree of variation are a combined result of chemical composition, welding procedure, pass sequence, and individual welder technique. The evidence suggests that retained austenite in coarse grained regions of the as-deposited weld metal transform to martensite at the CVN test temperature, effectively creating local brittle zones in the weld metal. This example provides basis for examination of a broader range of microstructural discontinuities in steel weld metals and their potential influence on toughness measurement.
Evaluation of Compressive Strain Limit of X80 Saw Pipes With Girth Welding by FE Analysis
Authors: Shitamoto Hidenori , Hamada Masahiko , Okaguchi Shuji , Takahashi Nobuaki , Takeuchi Izumi , Matsuhiro Yoshiyuki , Fujita Shusuke
Published: April 2011

The expansion of supply capacity of natural gas to market is expected from the concern of environmental conservation by less CO2 emission. Transportation cost has been focused for natural gas to be competitive in the market. High-pressure gas pipelines have constructed by large diameter and high strength line pipes to improve transportation efficiency of gas transmission pipelines. High strength line pipes have been developed to cope with high-pressure operation. Strength in circumferential direction on line pipe is the prime target to hold high pressure safely. In terms of pipe size, pipe diameter has been increased to lead larger D/t. Both of higher strength and larger D/t result in less favorable to deformability of pipeline. To apply strain based design to pipeline, the evaluation of strain capacity, which is related to deformability of line pipe, is required supposing the pipeline encounters large scale ground movement such as earthquake or landslide. It is not simple to find the criteria to prevent leak or rupture of pipeline in such events, as not only pipe property but also interaction between pipe and soil are needed to consider. Gas transmission pipelines are constructed by joint girth welding. The strain capacity of pipeline with girth weld has to be investigated for strain based design. Full scale bending test of joint welded pipe was conducted and FEA model to assess strain capacity of pipeline with girth weld is developed.
Investigate Performance of Current In-Line Inspection Technologies for Dents and Dent Associated With Metal Loss Damage Detection
Authors: Gao Ming , Krishnamurthy Ravi
Published: April 2011

Integrity management of dent and dent associated with metal loss requires knowledge of in-line inspection (ILI) technologies, government regulations and industry codes, prescriptive requirements, and most importantly assessment models to estimate severity of the mechanical damage. The assessment models have greatly relied on the assumed capabilities of current ILI technologies to detect, discriminate and size the mechanical damage. Therefore, an investigation of the current ILI technologies and validation of their capabilities are practically important. In this paper, the current status of ILI technologies for dent and dent with metal loss is reviewed. Validation data provided by ILI inspection vendors and pipeline operators are analyzed in terms of probability of detection (POD), probability of identification (POI), probability of false call (POFC), and sizing accuracy using binomial probability distribution and confidence interval methods. Linear regression analysis is also performed to determine sizing error bands. High resolution pull test data validated with LaserScan 3-D mapping technology is used to demonstrate a better evaluation of ILI performance with minimized in-ditch measurement errors and the effect of change in dent geometry and dimension due to re-bounding and re-rounding. Issues associated with field measurement and improvement are discussed.
Applicability of Existing Fracture Initiation Models to High-Strength Steel Line Pipe
Authors: Shim Do-Jun , Wilkowski Gery , Brust Frederick , Horsley David , Toch Max
Published: April 2011

The original fracture criteria developed by Maxey/Kiefner for axial through-wall and surface-cracked pipes have worked well for many industries for a large variety of low strength and low toughness materials. However, newer line-pipe steels have some unusual characteristics that differ from these older materials. One example is a single test that has demonstrated that X100 line-pipe with an axial through-wall-crack can fail at pressures about 30 percent lower than predicted with commonly used analysis methods for older steels. Thus, it is essential to review the currently available models and investigate the applicability of these models to newer high-strength line pipe materials. In this paper, the available models for predicting the failure behavior of axial-cracked pipes (through-wall-cracked and external surface-cracked pipes) were reviewed. The applicability of these models to high-strength steel pipes was investigated by analyzing limited full-scale pipe fracture initiation test results and the shortcomings were identified. For both through-wall and surface cracks, the major shortcomings were related to the characterization of the material toughness, which generally leads to non-conservative predictions in the J-T analyses. The findings in this paper may be limited to the test data that was consider for this study. The requisite characteristics of a potential model were also identified.
Pressure and Bending Tests on Fibreglass Augmented Steel Technology Pipes
Authors: Ozkan Istemi F. , Salama Mamdouh M. , Chen Qishi
Published: April 2011

The demand for the transportation of natural gas over long distances requires larger diameter pipes operating at higher pressure levels. A new technology, Fibre Augmented Steel Technology Pipe (FAST-Pipe™), emerges as one of the more cost-effective options to achieve this goal. As part of the qualification program of this new technology, a total of 15 tests were conducted on FAST-Pipe™ specimens fabricated from 12.75-inch outer diameter, 0.25-inch wall thickness, ERW, X60 steel liners hoop-wound with 0.2- and 0.35-inch thick dry fibreglass. This paper presents the results of several tests, including burst pressure testing of eight specimens to assess the effects of external environment (frozen and frozen/thawed), load duration (0 to 1,200 hours) and the wrap thickness (0.20 to 0.35 inch) on the burst capacity of the FAST-Pipe™. Variations of these parameters resulted in burst capacities ranging from 5,550 to 7,360 psi as compared to the unwrapped pipes whose burst capacities were in the range of 3,400 to 3,650 psi. It was observed during the cold burst tests that failure did not occur at the frozen or frozen/thawed section; instead, failure occurred in the transition zone between the frozen or frozen/thawed section and the dry (unfrozen) region. This paper also presents the results of two specimens that were subjected to constant internal pressure and imposed curvatures until buckle formation (pressure-bend tests) to assess the effects of wrap thickness (0.35- to 0.20-inch) on the bend capacity of the FAST-Pipe™ and to develop data from which to validate the analytical predictions. As expected, the overall curvature and moment capacities were higher for the 0.35-inch thick wrap than that for the 0.20-inch wrap.
Pipeline Integrity Evaluation of Oil Pipelines Using Free-Swimming Acoustic Technology
Authors: Ariaratnam Samuel T. , Chandrasekaran Muthu
Published: April 2011

Significant financial and environmental consequences often result from line leakage of oil product pipelines. Product can escape into the surrounding soil as even the smallest leak can lead to rupture of the pipeline. From a health perspective, water supplies may be tainted by oil migrating into aquifers. A joint academic-industry research initiative funded by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) has lead to the development and refinement of a free-swimming tool called SmartBall®, which is capable of detecting leaks as small as 0.03 gpm in oil product pipelines. The tool swims through the pipeline being assessed and produces results at significantly reduced cost to the end user compared to current leak detection methods. GPS synchronized GIS-based above ground loggers capture low frequency acoustic signatures and digitally log the passage of the tool through a pipeline. This paper presents the development, laboratory and field validation testing of the SmartBall for oil pipeline integrity.
Flooding Simulation of Hilly Pipeline Commissioning Process
Authors: Zhang Nan , Gong Jing , Zhu Baoli , Zheng Lin
Published: April 2011

The “pipeline flooding process”, refer to filling the empty pipe with water or oil when basic facilities’ construction of a pipeline has been completed, is very important for pipeline commissioning. The pipeline flooding process becomes more complicated for the long-slope pipe segments of a hilly pipeline because of air entrapped in fluid. The accumulated air in the fluid which is called air pocket can cause significant damage on pump equipments. The existence of air pocket can also provide difficulties for tracking the fluid front and the interface between oil and water because of the effect of air pocket on the velocity profile of fluid. To avoid such difficulties, the only method is to efficiently discharge the accumulated air. Consequently, the location and the volume of air pocket need to be accurately predicted. In this study, a comprehensive two-fluid model was developed for this prediction using the fundamentals of mass balance and momentum transfer in multiphase flow. By taking into account the effect of air pocket, the location and velocity of flooding front, the pressure at each point in the flooding segment can also be calculated. Therefore, the prediction accuracy of this model can be estimated by comparison with the recorded pressure distribution of SCADA. The model was applied for a specific pipeline in China. In comparison with the SCADA data, an adequate prediction from this model was provided.
Improvement of In-Line Process Control in High Frequency Welded Steel Pipe Mill Using Advance Tube Tracking System
Authors: Babakri Khalid Ali
Published: April 2011

This study is based on practical experience of improving in-line process control in High Frequency Induction Welded steel pipe mill through the use of a unique advance tube tracking system. The system was designed and implemented in Saudi Steel Pipe Co in early 2009. The new tracking system goes beyond identifying the tube, coil, and heat number. It has the advantage of allowing the quality control inspectors to enter the hold tubes numbers in the system and restrict those hold tubes from processing in the next stages. This has led to significant improvement in segregation process and eliminating the hold pipes from reaching the final stage or the customer site. The tracking system is also linked to the Continues Electronic Process Control (CEPC) where all the welding and annealing parameters such as welding power, line speed, and annealing temperature are recorded and automatically linked to each produced coil. Furthermore, all in-process inspection reports are entered directly on the system which has resulted in reduction of manual work and availability of huge database for analysis. Engineers, managers, and even third party inspectors have the chance of viewing all inspection reports through the system. They can even check the history of each pipe, when and how many times it was tested and/or held at each station. The full history of each pipe can be obtained using only the find option in the tracking system. A significant improvement was also noticed in reducing manual work in preparation of release documents since all information is available in the system and can be checked and reviewed in a real time basis.
Application of Reliability Based Design and Assessment to Maintenance and Protection Decisions for Natural Gas Pipelines
Authors: Nessim Maher , Yue Howard , Zhou Joe
Published: April 2011

This paper describes a detailed assessment that was carried out to investigate the practical implications of using the Reliability Based Design and Assessment (RBDA) methodology, as described in Annex O of CSA Z662, as a basis for evaluating existing pipelines and making decisions on maintenance planning and damage prevention strategies. Two key pipeline failure threats are addressed, namely corrosion and equipment impact. The assessment was based on a number of test cases covering a wide range of diameters, grades, pressures, location classes and corrosion severities. The reliability levels associated with these cases were calculated as a function of time and compared to the reliability targets. Cases that did not meet the targets were re-analyzed with increasingly enhanced maintenance measures until the targets were met. Maintenance actions considered included higher maintenance frequencies and more stringent repair criteria for corrosion, and enhancements to such parameters as right-of-way patrol frequency and condition, public awareness programs and dig notification response for equipment impact. The results demonstrate that the reliability targets can be met through the implementation of reasonable and practical maintenance measures for the cases considered. The impact of using RBDA on the expected failure rates is discussed. In addition, the diameter and class ranges of pipelines requiring enhanced maintenance over the current norm are identified.
Application of Reliability Based Design and Assessment to Seismic Evaluations
Authors: Nessim Maher , Yoosef-Ghodsi Nader , Honegger Doug , Zhou Joe , Wang Shanshan
Published: April 2011

The application of reliability based design and assessment (RBDA) as a basis for seismic evaluations of natural gas pipelines is explored through analysis of a number of representative pipeline examples. To accomplish this, a simplified approach was developed to generate a representative probability distribution of permanent ground deformations due to soil liquefaction. An idealized pipeline alignment through a liquefiable layer under a river was defined, and a number of cases representing NPS12 and NPS36 pipelines in classes 1, 2 and 3 were analyzed using a finite element model. The probability of exceeding the strain limits for pipe body and girth weld were calculated and compared to the reliability targets. The results were used to identify diameter and class combinations that can meet the reliability targets, and to make preliminary conclusions regarding the viability of using RBDA for seismic evaluations.
Capturing Carbon Dioxide: The Feasibility of Re-Using Existing Pipeline Infrastructure to Transport Anthropogenic CO2
Authors: Seevam Patricia , Race Julia , Downie Martin , Barnett Julian , Cooper Russell
Published: April 2011

Climate change has been attributed to green house gases, with carbon dioxide (CO2) being the main contributor. Sixty to seventy percent of carbon dioxide emissions originate from fossil fuel power plants. Power companies in the UK, along with oil and gas field operators, are proposing to capture this anthropogenic CO2 and either store it in depleted reservoirs or saline aquifers (carbon capture and storage, CCS), or use it for ‘Enhanced Oil Recovery’ (EOR) in depleting oil and gas fields. This would involve extensive onshore and offshore pipeline systems. The decline of oil and gas production of reservoirs beyond economic feasibility will require the decommissioning onshore and offshore facilities post-production. This creates a possible opportunity for using existing pipeline infrastructure. Conversions of pipelines from natural gas service to CO2 service for EOR have been done in the United States. However, the differing sources of CO2 and the differing requirements for EOR and CCS play a significant part in allowing the re-use of existing infrastructure. The effect of compositions, the phase of transportation, the original pipeline specifications, and also the pipeline route require major studies prior to allowing re-use. This paper will first review the requirements for specifying the purity of the CO2 for CCS and to highlight the implications that the presence of impurities and the current water specifications for pipelines has on the phase diagram and the associated physical properties of the CO2 stream. A ‘best’ and ‘worst’ case impurity specification will be identified. Then an analysis on the impact and subsequent validation, of equations of state based on available experimental data on the phase modelling of anthropogenic CO2 is presented. A case study involving an existing 300km gas pipeline in the National Transmission System (NTS) in the UK is then modelled, to demonstrate the feasibility of using this pipeline to transport anthropogenic CO2. The various issues involved for the selected ‘best’ and ‘worst’ case specification are also covered. This is then followed by an investigation of the options for transport in the ‘gas’ phase and ‘supercritical’ phases, and also identifying the limitations on re-using pipeline infrastructure for CCS.
Evaluating Mechanical Properties of Hybrid Laser Arc Girth Welds
Authors: Pussegoda L. N. , Begg D. , Holdstock R. , Jodoin A. , Light K. , Rondeau D. , Hansen E.
Published: April 2011

This paper presents the challenges and results associated with mechanical testing of overmatched X80 and X100 pipeline steel girth welds that were produced by Hybrid Laser Arc Welding (HLAW). The weld profile produced by this process is characterized as having a broad weld cap and a narrow leg, which traverses the through thickness direction. The development and testing of the HLAW process was conducted on NPS36 pipes of 10.4 mm and 14.3 mm thickness, respectively. The welds were deposited in the 5G welding position with all parameters and laser visual inspection data being collected for each weld pass. Subsequent sample extraction and testing of the hybrid laser arc welds were achieved by standard test practices for girth welds and modifications of these practices, where the latter was required to facilitate testing of the narrow HLAW geometry. Charpy results indicate that the fracture transition temperature, with the notch in either the weld metal or the heat-affected zone (HAZ), is higher at the 3 and 9 o’clock positions when compared to 9 and 12 o’clock positions. The likelihood of crack deviation influencing the results due to the non-conventional weld geometry needs to be examined in a further study. For crack tip opening displacement (CTOD) testing, shorter fatigue crack lengths were employed to reduce the possibility of fatigue crack deviation. The results show that this method does not influence the validity of the test outcomes.
Guidelines to Conducting Threat Susceptibility and Identification Assessments of Pipelines Prior to Reactivation
Authors: Bunch Chad , Cameron Glenn , Mora Rafael G.
Published: April 2011

This paper provides guidelines to identify all threats and assess a pipeline’s susceptibility to those threats in order to select appropriate and effective mitigation, monitoring, and prevention measures prior to reactivating pipelines. The intent of this paper is to provide pipeline operators, consultants and regulatory agencies with a generic threat assessment approach that has to be customized to the pipeline-specific characteristics and conditions, and the regulatory requirements of its own jurisdiction. A literature review and authors’ experiences across the pipeline industry have identified the need for a generic, yet complete approach that guides pipeline integrity engineers in the methodologies that adequately and effectively assess threats prior to reactivation and that can be validated in a timely manner during the operations. Pipeline operators may be called on to reactivate pipelines that are facing challenges such as aging, changes in operational conditions, lack of maintenance and inconsistent integrity practices while facing constraints from increasing population density, higher pressure and flow throughput requirements of a competitive marketplace, and regulatory requirements insisting on higher levels of safety and protection of the environment. This paper was structured with the following components to assist the reader in conducting threat assessments: • Current regulations and recognized industry standards with respect to reactivating pipelines; • Definition of and differentiation between hazard and threat; • Hazard identification analysis for the known and potential situations, events and conditions; and • Threat susceptibility and identification analysis process for the known categories derived from the hazard identification process. A case study is described as an example of applying the guidelines to conduct threat susceptibility and identification assessments of a pipeline prior to its reactivation. The results from the threat susceptibility and identification assessment process can help operators, consultants and regulators in determining effective inspection, mitigation, prevention and monitoring measures.
Understanding Strain Performance Considerations in Composite Repair of Dents and SCC
Authors: Leewis Keith , Laughlin Shawn
Published: April 2011

This paper reviews the key strain principles behind the technical design regarding the effect of a repair and reinforcement of steel pipelines with composite sleeves and composite wraps. Data is presented for the repair of large strains–dents, and the repair of small localized strains–SCC cracks.
Development of the SENT Test for Strain-Based Design of Welded Pipelines
Authors: Tang Huang , Macia Mario , Minnaar Karel , Gioielli Paulo , Kibey Sandeep , Fairchild Doug
Published: April 2011

Strain-based design (SBD) pipelines are being considered to develop hydrocarbon resources in severe environments. As part of a research program to develop a SBD methodology, work was conducted to develop a suitable fracture mechanics test that can be used as part of a strain capacity prediction technique. The single edge notched tensile (SENT) specimen geometry has been chosen due to the similarity in crack-tip constraint conditions with that of defects in pipeline girth welds. This paper describes a single-specimen compliance method suitable for measuring ductile fracture resistance in terms of crack tip opening displacement resistance (CTOD-R) curves. The development work included investigation of the following items: specimen geometry, crack geometry and orientation (including crack depth effects), direct measurement of CTOD. The results demonstrate that toughness measurements obtained using a B = W configuration (B = specimen thickness, W = specimen width) with side grooves are similar to those using a B = 2W configuration without side grooves; however, specimens with side grooves and B = W geometry facilitates even crack growth. Studies of crack depth have shown that ductile fracture resistance decreases with increasing ratio of the initial crack depth to specimen width, a0/W. Studies of notch location and orientation (outer diameter (OD) and inner diameter (ID) surface notches and through-thickness notches) have shown an effect of this variable on the CTOD-R curves. This has been partly attributed to crack progression (tearing direction) with respect to weld geometry and this effect is consistent with damage modeling predictions. However the experimentally observed difference of CTOD-R curves between ID and OD notches is believed to be primarily due to the material variability through the pipe thickness.
Pipeline Infrastructure Growth Challenges
Authors: Mayberry Alan K.
Published: April 2011

The rapid and unprecedented recent pipeline construction boom to satisfy energy demand has successfully delivered needed energy supplies to growing markets. In the United States, inspectors from the Pipeline and Hazardous Materials Safety Administration (PHMSA) significantly increased their inspection focus to cover many projects over the last four years. The results of many inspections were the subject of a PHMSA public meeting in April 2009, along with at least one Advisory Bulletin. This paper describes key issues PHMSA has witnessed, addressed, and taken action. The paper will also provide guidance on where industry should focus quality improvement initiatives.
Analytical Methodology for Evaluating Stress and Strain of Pipeline Exposed in Flood
Authors: Wang Xiaolin , Shuai Jian , Guo Xiaomin
Published: April 2011

River-crossing pipeline is threatened by flood which could induce pipeline being eroded and exposed, moreover, floating in a large scale. Under the combined effects of dynamic wave, buoyancy, gravity and resistance of bank soil, pipeline presents spatial deformation. A mechanical analysis model is built according to loadings on pipeline and deformation of pipeline. Taking into account nonlinear soil-pipe interaction, axial force, nonlinear material property of pipeline steel and spacial deformation of pipeline, an analytical methodology for evaluating pipeline deformation and stress distribution is developed. Compatibility equation of pipeline physical elongation and geometrical elongation is derived, by which pipeline stress and strain are calculated with iterative method. Based on proposed methodology, a computer program is developed and a series of cases of pipeline in flood are analyzed with it. Compared with finite element analysis, results of proposed methodology are well accepted. Finally, safety assessment method for pipeline in flood is proposed based on limit state theory and the safety of pipeline exposed in mountain torrent are evaluated.
Improvements to Rich Gas Decompression Predictions for Offshore Pipelines
Authors: Starling Kenneth E. , Wilkowski G. M.
Published: April 2011

This paper describes how rich gas decompression predictions have been performed for use in the Battelle-Two-Curve ductile fracture model for application to offshore pipelines. The decompression behavior of rich gases in offshore pipelines is more complicated than for onshore pipelines for two major reasons, (1) the operating pressures typically are greater offshore than onshore, and (2) the effects of higher molecular weight components in rich gases are not well described by earlier methods. Although for lean gases the AGA8 method is very accurate for single phase gas and the GASDECOM method is reasonably accurate for gases which enter the two phase region, neither of these existing methods is sufficiently accurate for two phase conditions for gases containing more than about one mole percent hexanes and heavier hydrocarbons at pressures greater than about 15 MPa. This paper discusses the requirements for a method to achieve sufficiently accurate high pressure rich gas decompression predictions for use in the Battelle-Two-Curve ductile fracture model and provides examples of the use of an interim method which has suggested the path to an ultimate solution.
The Development of the Strategy and Plan for the Decommissioning and Abandonment of 36″ Offshore Oil Export Pipelines
Authors: Matthews Richard J. , Ga´lvez Reyes Marco Antonio
Published: April 2011

Execution of projects for the decommissioning and abandonment of platforms, facilities and pipelines have long been considered by oil and gas Operators as an issue and a significant financial burden best deferred for the future. However with increasing environmental awareness and legislation, decommissioning & abandonment projects can be effectively carried out today, by considering the options and adopting an environmentally acceptable and pragmatic solution whilst also avoiding the risk of more stringent future legislation. This paper is focused on the strategy and operational planning aspects of the decommissioning and abandonment of two 36″ offshore oil export and one 30″ ballast pipelines from a marine terminal to offshore PLEMs for PEMEX in Mexico. These pipelines were shutdown and isolated in 1990 pending decommissioning and since then suffered from a very poor failure record. As a result of these failures, the pipelines have been under the scrutiny of the Mexican Environmental Authority (PROFEPA), in order to monitor and manage the ongoing environmental risk. The paper reviews the applicable international standards and legislation with respect to pipeline decommissioning and includes a review of the decommissioning and abandonment options & considerations in this case.
Hardisty Contract Tankage Project: Design of a System for Long-Term Storage, Heating and Transporting Heavy Crude Oil in Cold Climates
Authors: Bagan Jamie , Larson Susan , Orieux Gilles , Thieson Dean , Wengreniuk Greg
Published: April 2011

In response to strong customer demand, Enbridge Midstream Inc. (Enbridge) expanded its’ crude oil contract terminal facilities which included a new terminal near Hardisty, Alberta. Commissioned in 2009, the new Hardisty Contract Tankage (HCT) terminal provides services to accumulate medium- and long-term liquid crude volumes on a fee-for-service basis. Stantec Consulting Ltd. (Stantec) was selected to perform the conceptual and detailed design based on their terminal experience and working relationship with Enbridge. Given the inherent intermittent operation of this facility it was deemed critical to design integrity management into the facility. The conceptual and detailed design project team included members from Enbridge’s Integrity Management team to enhance the design.
Yield Strength of Line Pipe: Analysis of Forming Operations and Flattened Straps
Authors: Walsh William J. , Preston David
Published: April 2011

The effects of line pipe forming processes (Spiral, UOE, JCE, 3 Roll Bending, ERW) on steel yield strength are investigated by material modeling and mechanical testing. A model is developed for predicting the performance of a flattened transverse-body-tensile sample as typically performed by pipe mills for yield strength determination. Consideration is given to the Bauschinger effect, and hardening behavior to examine the resulting residual stress patterns through the wall thickness and the effect on measured yield strength. The pipe forming processes are modeled as pure bending and analyses are performed to determine how well this assumption simulates the actual operations. Tensile and compression testing is performed to establish the Bauschinger effect in both the tension and compression initial loading directions. The tensile data is incorporated into the material model. The model illustrates the progressive evolution of the residual stress pattern throughout the sequence of forming operations and specimen preparation. In addition, the residual curvature remaining in flattened tensile samples is analyzed and correlated with mechanical tests. The apparent modulus caused by curvature is shown to cause significant variation in the reported yield strength of linepipe.
Environmental Considerations for Pipeline Abandonment: A Case Study From Abandonment of a Southern Alberta Pipeline
Authors: Swanson Jessica M. , Kunicky Tom , Poohkay Pete
Published: April 2011

Since the 1920s, over 400,000 km of petroleum pipelines have been installed in Alberta. Pipeline abandonment is an increasingly relevant issue as the pipeline network ages. The full or partial abandonment of pipeline systems is necessitated by factors such as wind or water erosion issues, pipeline integrity issues, changes in source supply and customer demand, urban development encroachment and regulatory requirements. Pipeline abandonment-in-place is generally the preferred option based on the technical condition and environmental sustainability of the pipeline, however, in some cases pipeline removal or partial removal cannot be avoided. In all cases, the planning process for abandonment includes technical evaluation, risk assessment, environmental assessment, landowner consultation and/or evaluation of future land use. Abandonment plans must also include environmental protection measures to be implemented during the removal of any pipeline segment and consideration of the post-abandonment implications of any pipeline left in place. These measures include topsoil conservation, erosion/sediment control and reclamation. This paper discusses environmental protection measures for pipeline abandonment, using issues faced during abandonment of one of the oldest natural gas pipelines in Alberta as a case study. Challenges faced during this project included gathering of appropriate historical information including leak history and maintenance records, removal of all aboveground facilities, accommodations for future land use plans including road development and measures taken to minimize the risk of the abandoned pipeline becoming a water conduit. In addition, the paper will discuss the extensive planning and construction effort required to undertake pipeline abandonment at several fish-bearing watercourse crossings, where pipeline exposures during high water events necessitated pipeline removal. A primary objective in the planning and the removal of the abandoned pipeline was minimal disturbance of the land.
Experimental Studies of Small Air Bubble Motion in Turbulent Pipe Flow
Authors: Zhukovskaya Olesya , Hugo Ronald J.
Published: April 2011

The main objective of this research is to collect statistical information concerning momentum phase coupling between the continuous phase and a single air bubble in turbulent flow in a horizontal pipe, and to develop data that can be used for the verification of numerical modeling efforts. In comparison with vertical pipe bubble flow, horizontal bubble flow has received less attention, especially from the experimental side. Thus, an experimental investigation of bubble behaviour in a horizontal square pipe was performed. Tracking of a single bubble released in water flow in a 56.8 mm × 56.8 mm square pipe was performed to provide a basis for characterizing the behaviour of the single bubble in turbulent pipe flow. A Shack Hartman Wavefront Sensor and a High Speed Video Camera were used to collect images at various points downstream from the bubble injection point, providing information on bubble size, velocity, and spatial location as a function of Reynolds number. Velocity profile information of the continuous phase was collected using Particle Image Velocimetry (PIV) in order to perform a complete characterization of the flow. The data collected using PIV coupled with the analysis of the three-dimensional trajectory of a single bubble provides information about parameters such as a gas slippage velocity with the fluid phase and bubble distribution as a function of both Reynolds number and mean velocity profile.
Analysis of the Mechanical and Electrical Performance of Conformal Load-Bearing Antenna Structure
Authors: Dai Fuhong , Du Shanyi
Published: April 2011

A Conformal Load-bearing Antenna Structure (CLAS) of the honeycomb sandwich structures embedded with the micro-strip antenna is designed. The mechanical and electrical performances of the CLAS are analyzed with the use of finite element method. The electrical performance of CLAS including loss and gain are calculated. The structural deformation is predicted using finite element method. The results of three-point bending test are compared with those of finite element method. A good agreement is showed. The variations of structural-load-carrying capacity for different honeycomb thickness are evaluated by the finite element method. The influence of honeycomb thickness on the electrical performance of CLAS is analyzed. Finally, the integrated relation curves including mechanical and electrical performance are obtained.
Chemomechanical Transduction in Hybrid Bio-Derived Conducting Polymer Actuator
Authors: Sundaresan Vishnu Baba , Zhang Hao
Published: April 2011

Biological ion transport has inspired recent developments in smart materials. The work by Leo and co-workers, Bailey and co-workers has demonstrated the feasibility to design engineered systems using biological ion transporters. The biological and bio-inspired systems utilize ion transport across a barrier membrane for energy conversion. Among smart materials, ionic-active materials demonstrate electromechanical coupling using ion transport across the thickness of the polymer. Inspired by the resemblance between ionic interaction in a conducting polymer and biological membranes, this paper presents a novel actuation mechanism that uses ion transport through a biological membrane to produce shape changes in a conducting polymer actuator. This paper presents the basic architecture, the physics of transduction and analysis of extensional and bending actuation in the hybrid bio-polymer actuator. An extensional actuator of size 1 cm × 1 cm × 1 μm is theoretically found to generate 135 mPa of blocked stress. A bimorph bending actuator of dimensions 10 mm × 1 mm × 2 μm is theoretically found to produce a free-displacement of 0.5 mm using biochemical gradients.
Experimental Test Results for a Fiber Bragg Grating-Based Flow Sensor
Authors: Pannekeet Robbert , Rodriguez-Erdmenger Rodrigo , Ruggiero Eric J. , Simpson Alexander , Wolfe Christopher
Published: April 2011

A fiber optic-based mass flow sensor has been developed that uses fiber Bragg gratings to deduce flow velocity. Flow velocity, local temperature, pressure measurements (that all can be extracted using fiber Bragg gratings) and geometric information can be combined to determine mass flow. A range of concepts have been investigated and compared using the same “design of experiment” for each sensor. The most promising concept has been further developed into a prototype. The working prototype successfully demonstrated a thermally insensitive sensor design that has the capability to track flow velocities. The sensor design is incorporated directly with a structural beam element to magnify the strain effect while simultaneously compensating for thermally-induced wavelength shifts in the sensor response. Further testing has been performed using three flexible beams at different angular positions showing that flow angles can be measured similar to the approach used for 3-hole pneumatic probes. As a final test, the sensor has been tested in a shock tube demonstrating superior performance compared to steady pneumatic measurements which rely on tubing to reach the measurement location.
Active Control of Geometrically Nonlinear Transient Response of Smart Laminated Composite Plate Integrated With AFC Actuator and PVDF Sensor
Authors: Kerur Shravankumar B. , Ghosh Anup
Published: April 2011

A coupled electromechanical finite element formulation for active control of geometrically nonlinear transient response of laminated composite plate is studied. First order shear deformation theory and Von Karman type nonlinear strain displacements are used. The plate is discritised using eight noded quadratic isoparametric elements with five mechanical degrees of freedom and one electrical degree of freedom per node. Newton-Raphson iterative method in association with Newmark time integration method is used to solve the nonlinear finite element equilibrium equation. Negative velocity feedback control algorithm is used to control the dynamic response of the smart laminated composite plate. Active fiber composite (AFC) layer poled in fiber direction acting as distributed actuator and PVDF layer poled in thickness direction acting as sensor are considered. Present study involves two types of actuator sensor arrangements. Case I: the substrate is sandwiched between AFC actuator and PVDF sensor. Case II: AFC actuator and PVDF sensor are collocated on top of the substrate. The effect of piezoelectric fiber orientation in actuator layer on vibration control for both cross ply and angle ply laminates are examined.
A Phase Field Model of Photo-Induced Trans-Cis-Trans Bending of Liquid Crystal Elastomer Films
Authors: Wang Hongbo , Oates William S.
Published: April 2011

A new class of glassy liquid crystal elastomers are studied to understand their light-coupled deformation characteristics. In particular, the photomechanics of azobenzene liquid crystal elastomers is modeled using a nonlinear continuum mechanics approach coupled with time-dependent liquid crystal domain structure evolution to understand light polarization effects on deformation. Light propagation and absorption within the elastomer is modeled using Maxwell’s electro-magnetic equations. By consideration of electric energy due to light absorption, light-induced electrical stresses are introduced which provide the driving force for mechanical deformation via coupling with the azobenzene liquid crystals. A liquid crystal director (i.e., orientation of the liquid crystal molecule) is used to describe liquid crystal evolution and elastomer deformation. This aspect of the model is extended to include 3D effects to accommodate trans-cis-trans photoisomerization. This is coupled to plane stress, nonlinear mechanics to demonstrate key field-coupled mechanics relations governing this class of smart materials. The results show that the model successfully predicts large, bi-directional bending of the polymer film by controlling the polarization of light. The results are consistent with recent experimental data given in the literature.
An Experimental Performance Evaluation of DC Power Generation and Power Loss in Full-Bridge Rectifier of Cantilever Type of Piezoelectric Vibration Energy Harvester
Authors: Adachi Kazuhiko , Tanaka Tohru
Published: April 2011

Rotating machinery is widely used in the industrial plant. In order to ensure safety operation of the rotating machinery, vibration condition monitoring of the machinery can play a crucial role. Authors have proposed a cantilever type of vibration energy harvester for vibration condition monitoring applications of rotating machinery. Proposed energy harvester consisted of Macro-Fiber Composite (MFC). In this study, not only the DC power generation performance but also power loss in full-wave bridge rectifier of the proposed vibration energy harvester is experimentally evaluated. The maximum DC output power through 287.6(kΩ) resistor which includes instruments internal resistances obtained 109.5(μW) when subjected to vibration source input magnitude of 0.71(mm/s rms) at the resonant frequency of the harvester. The impedance matching between MFC actuators and the electrical resistive load was also effective for maximizing the DC power transfer of the vibration energy harvester. The power loss in full-wave bridge rectifier reached 13.7(μW) at the resonant frequency.
Encapsulated Interface Bilayers for Durable Biomolecular Materials
Authors: Sarles Stephen A. , Leo Donald J.
Published: April 2011

This paper introduces the concept of hydrogel encapsulated interface bilayers as a novel approach for creating durable encapsulated biomolecular materials. The regulated attachment method (RAM) is used to form encapsulated interface bilayers from lipid-encased aqueous volumes contained in a deformable supporting substrate. Physically-encapsulated interface bilayers exhibit increased durability and portability over droplet interface bilayedrs and RAM enables the in situ bilayer formation without the need to dispense and arrange individual droplets. The results presented in this paper demonstrate that poly(ethylene glycol) dimethacrylate monomers (PEG-DMA, Mw = 1000), a photopolymerizable hydrogel monomer, and Irgacure 2959 photoinitiator can be incorporated into the aqueous phase in order to form hydrogel encapsulated interface bilayers. Following bilayer formation, exposure to an ultraviolet (UV) light initiates photopolymerization of the polymer on both sides of the bilayer, creating interface bilayers between solid aqueous phases. Electrical recordings of bilayer formation in the liquid state confirm that interface bilayers formed from photopolymerizable aqueous solutions have both high electrical resistances > 1GΩ necessary for observing transmembrane protein gating and survive the UV curing procedure required to polymerize the hydrogel. Photopolymerization for 60 seconds using a 1W hand held UV spot cure light produced water-swollen solids on both sides of the membrane. Hydrogel encapsulated interface bilayers last for hours to days and retain the fluidity necessary for delivering alamethicin proteins to the interface.