bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomass Combustion and Its Utilization to the Distributed Power Generation
Authors: Aoki Hideyuki , Matsushita Yohsuke , Yamamoto Tsuyoshi , Miura Takatoshi
Published: March 2009

A wood chip combustion behavior in a turntable type moving bed combustor is numerically analyzed in order to understand the fundamental combustion behavior in the combustor. An experiment is also carried out to compare the experimental data with numerical results and estimate the performance of the numerical analysis. Wood is used as building materials in most countries, and wooden house is the most popular in Japan. In some countries such as Japan, the period of durability of wooden house is for several decades because of high humidity and warm weather. A great amount of wooden waste is disposed and buried every year. From a viewpoint of effective use of energy, these kind of wooden wastes should be converted to valuable source of energy by efficient combustion operation. It is however difficult to operate the wooden waste conversion system because this waste includes other material such as plastics, plaster board, stone and soil. These kinds of intermingled material cannot be separated easily from wooden waste. In this study, we develop the turntable type moving bed combustor which effectively discharges the intermingled material from the combustor. We also develop the numerical model for the analysis of the combustor. The turbulent gas flow in the combustor is described by k-ε two-equation model and a momentum exchange between gas and moving bed of wood chip is considered. A solid phase is assumed to be a Newtonian fluid. Gas and solid phase temperature are calculated with considering convective and radiative heat transfers. Devolatilization reaction of wood is calculated by a first order chemical reaction model. Chemical reactions of gas and solid surface are also calculated with considering both chemical and gas film diffusion rates. Governing equations above-mentioned are simultaneously solved by control volume method. The geometry of the combustor is 470 mm in diameter and 1,500 mm in height. The combustion air is introduced tangentially from side wall. Wood chip is fed by screw feeder from side wall. Wood chip feed rate is 50 kg/hr, initial temperature of wood chip is 293 K and air ratio is 1.2. Numerical results are fairly in good agreement with experimental data. High temperature and low oxygen gas which contains unburned CO near centerline region of the combustor is observed in both experimental and numerical results. The mixing promotion of this fuel containing gas and oxygen rich gas near sidewall region is a problem of the development of efficient energy conversion system. This combustor would be one of the heat sources for a steam-driven electric power plant utilizing wooden waste as the source of fuel in local area.
Control of Spray Flame Characteristics Using High Shear in a Double Concentric Swirl Burner
Authors: Mehresh P. , Habibzadeh B. , Gupta A. K.
Published: March 2009

The effect of high shear on the spray flame characteristic has been examined. The shear has been provided with the help of swirl angles in inner and outer swirlers (65° in inner swirler and 30° in outer swirler). Laser diagnostic tools like Particle Image Velocimetry (PIV) and Phase Doppler Particle Analyzer (PDPA) are used to obtain an exhaustive set of data related to droplet size, velocity, number density, vorticity in the flow and strain rate in the axial direction. A double concentric swirl burner and a commercially available air-assist nozzle have been used in this study. The burner allowed independent control of swirl and combustion airflow in the inner and outer annulus of the burner. Results have been obtained for a swirl combination of 65° in inner swirler and 30° in outer swirler (mentioned as 65°/30° in the rest of paper) and are compared with the swirl combination 50°/30°, data taken earlier by the authors (1). The distribution of air is also varied as it was done previously. The results provide a thorough understanding of the effect of giving high shear to the combustion air on the droplet size and distribution, which in turn controls the flame characteristic and stability (1).
Wolf Creek Feedwater Heater Repair
Authors: Schafer Bruce W. , Wahlmeier Stan
Published: March 2009

Since 1990, an increasing number of the 304 SST feedwater heater tubes in the number 1 and 2 feedwater heaters (six heaters total) at the Wolf Creek Nuclear Power Plant have experienced failure due to fretting wear within the drain cooler region. Tube damage was due to thin end plate design resulting in tube wear at the end plate and support plate locations. Despite performing extensive eddy current inspections and preventative plugging on the heaters, the damage mechanism is powerful enough that tube leaks were continuing to occur while at power, resulting in the forced shutdown of a string of heaters for plugging. As an option to feedwater heater replacement, a method of reducing the tube-to-end plate gap, by expanding the tube into very close contact with the end plate, and sleeving tubes with wear indications was evaluated. Based on an evaluation of outage schedule time and cost, it was decided that the option of repairing the feedwater heaters, rather than replacing them, would be pursued. During Wolf Creek’s September 2000 refueling outage, Framatome ANP performed feedwater heater tube plug removal, tube expansions at the end plate, and sleeving. All work on-site was performed within the outage scheduling constraints.
Petroleum Coke as a Supplementary Fuel for Cyclone Boilers: Characteristics and Test Results
Authors: Tillman David A.
Published: March 2009

Petroleum coke is periodically tested and used as a supplementary fuel for cyclone boilers. Its high heat content and low cost make it an attractive fuel for power generation. In cyclone boiler firing, it also has environmental advantages. While it is high in sulfur content, it can be used to reduce NOx emissions along with such trace metal emissions as mercury and arsenic. Successful firing of petroleum coke in cyclone boilers, however, requires considerable attention to fuel properties of the coal and the opportunity fuel including fuel structure and reactivity, and ash chemistries. This paper reviews selected properties of petroleum coke including traditional analyses plus structural characterization using 13Carbon Nuclear Magnetic Resonance (NMR), drop tube reactor (DTR) characterization for kinetics and volatility evaluation, and thermogravimetric analysis (TGA) for char oxidation kinetics. The paper then summarizes results of petroleum coke firing at the Paradise Fossil Plant of TVA, and Bailly Generating Station of Northern Indiana Public Service Company (NIPSCO). Results presented include impacts of cofiring on boiler efficiency, NOx emissions, and the fate of selected trace metals including arsenic, mercury, nickel, and vanadium. It documents the overall benefits and issues associated with cofiring petroleum coke with coal in cyclone boilers as a significant opportunity fuel.
Low Solids Coal Water Slurry Cofiring for NOx Trim
Authors: Battista Joseph J. , Hughes Evan E.
Published: March 2009

Over the past decade, members of the Upgraded Coal Interest Group and EPRI, the Department of Energy, the Energy and Environmental Research Corporation (GE-EER), Washington Energy Processing (WEP), Penn State University and the previous owners and operators of Seward Station located in western Pennsylvania, conducted a series of formulation and combustion tests using coal waste fines as a low solids coal water slurry cofiring fuel for electric power generation. The fine coal was recovered from coal fines impoundments and fresh coal cleaning plant fines that were cleaned, thickened and then cofired with pulverized coal in utility scale boilers. This paper explains the need for a program to eliminate these impoundments and describes the results of some of the tests conducted on the technology that demonstrate the effectiveness of trimming NOx emissions by the use of slurry cofiring. This method of trimming NOx emission has been shown to have the capability of reducing NOx emissions by 20% to 35% below the levels achieved by some low NOx burners and selective non-catalytic reduction systems (SNCRs).
Geosynthetic Clay Liners (GCLs)
Authors: Herlin Bruno , von Maubeuge Kent
Published: March 2009

Geosynthetic Clay Liner’s (GCLs) are an established sealing product in the geoenvironmental industry. They are used in landfill applications as caps and base liners, secondary containment for fuel storage facilities, as well as within various other containment structures such as dams, canals, rivers, and lakes. Rolled out like a carpet to provide a durable impermeable liner, Geosynthetic Clay Liners consist of a layer of high swelling sodium bentonite sandwiched between two geotextiles. Manufactured around the world in different techniques, the Canadian manufactured GCL, is mechanically bonded by needlepunching from one nonwoven geotextile through the bentonite to the other nonwoven or woven geotextile. The low hydraulic conductivity of the GCLs are used mainly as a replacement to thick, difficult to build compacted clay liners to provide a barrier to liquids and gases, offering both a technical and economical advantage. GCLs, with an average thickness of 7mm, offer a volume advantage over Compacted Clay Liners. They are more capable of withstanding freeze-thaw and wet-dry cycles; offer substantial construction cost savings in reduced on-site QC/QA and a quicker installation. Furthermore, GCLs offer equivalent or lower rates of release of fluids and chemicals than Compacted Clay Liners (CCLs). Bentonite is a clay mineral with expansive characteristics and low permeability, where montmorillonite is the chief mineral. Montmorillonite, swells when contacted with water approximately 900% by volume or 700% by weight. When hydrated under confinement, the bentonite swells to form a low permeability clay liner, the equivalent hydraulic protection of several feet of compacted clay. A relatively new engineering material for some, geosynthetic clay liners have been used extensively over the past two decades, and are finding increasing use in every sector of the environmental industry. This paper will review the technical properties of these materials, their documentation at the research level, their integrity as a sealing barrier and recent field applications in the pipeline industry. Further, because these materials are factory produced, their properties are predictable, assisting the engineer to design with a high confidence level. Technical properties and economical benefits are sure to further increase GCL installations around the world to protect our environment and more importantly our groundwater.
A System-Wide Pipeline Automation Project: Application Colonial Pipeline System
Authors: Simmons Steven , Watson Roger
Published: March 2009

This paper will discuss the objectives, challenges, and methods of implementing a system-wide pipeline automation project at Colonial Pipeline, focusing on the pilot project and early years. Currently the company is in the midst of a five-year project to automate and remotely operate delivery facilities, tank farms, and origination stations along over 5000 miles of existing pipeline. The end result will bring control of over 200 facilities into to the Central Control Center. Technically, the project goal is to install state of the art infrastructure to enhance safety and reliability, standardize to a common platform across the system, and integrate into an existing SCADA Control System. From the business perspective, the project goal is to meet or exceed typical industry guidelines for project management metrics, reach a unitized cost basis and provide a foundation for consistent and repeatable operations across the entire pipeline system. The Common Project Process (a cross-functional integrated project team strategy) and an engineering alliance are being used to define and execute the project phases. Colonial’s Engineering team recast itself in 1999 on the basis of establishing core competencies, leveraging internal talent and knowledge, and establishing an effective outsourcing strategy. This automation project is one of the first large-scale efforts to put this new model to task. In 2000, Colonial Pipeline and Mangan, Inc. formed an engineering alliance to capitalize on the strengths of both teams. Colonial’s pipeline engineering and operations knowledge have been equitably matched with Mangan’s project management, engineering and integration skills. The result is an energetic and committed technical project team, as well as a win-win opportunity for both sides. This alliance provides a valuable model for engineering team outsourcing and contracting. Except for original construction projects, it is rare for a pipeline company to take on a system-wide infrastructure upgrade opportunity of this scope. Success of the pilot project depended on integrating the field automation with SCADA system capabilities and developing both control center and human resources plans. The field hardware, the technical focus of this paper, is a small piece of the entire project objective; however it represents the foundation of the entire business model. Selecting and committing to a common controls platform was an engineering objective. The hardware had to provide a certain level of assurance that the standard model would be available both at the start and the end of the project, in addition to supporting legacy systems for future challenges. In summary, this automation project represents more than engineering and integration. It’s a combination of the talent, hardware, and vision which will accomplish the goal of the core business product — safe and efficient delivery of consumer fuels.
Pipeline Trenching in Permafrost: A Review
Authors: Blanchet Denis , Lenstra Nick , Skalski John , Zhou Joe , Smith Bruce
Published: March 2009

BP America Inc., Enbridge Pipelines Inc., and TransCanada PipeLines Limited recently sponsored a comprehensive technical review of the use of wheel and chain trenchers for excavating pipeline ditches for large diameter, long distance oil and gas pipelines in permafrost. The purpose of the review was to identify techniques that could be implemented to improve the productivity of trenchers in permafrost and reduce pipeline construction costs. This paper summarizes the key findings of the study. The study included an analysis of data obtained from previous field trials and construction case histories in permafrost, including the results from proprietary trials that have never been published. The study found that the primary subsurface conditions affecting the productivity of both wheel and chain trenchers in permafrost soil are: 1) the concentration and lithology of cobbles and boulders; 2) the presence and strength of bedrock within the depth of trenching; and 3) the tensile strength of the permafrost soil. With current technology, neither wheel nor chain trenchers can achieve satisfactory rates of production if more than 5 to 10 percent cobbles or boulders are present, or if hard bedrock exists within the depth of trenching. The study evaluated a number of techniques for improving the productivity of both wheel and chain trenchers in permafrost soil which may or may not contain hard inclusions. These methods included pre-blasting along the ditchline using either conventional blasting techniques or shaped charges. In addition, a wide variety of multi-pass trenching techniques were evaluated as part of the study.
The Effects of Heat Input and Gas Flow Rate on Weld Integrity for Sleeve Repair Welding of In-Service Gas Pipelines
Authors: Kim Woo-Sik , Kim Young-Pyo , Oh Kyu Hwan
Published: March 2009

The experimental and numerical study has been conducted on the sleeve-repair welding of API 5L X65 pipeline. In order to simulate the in-service condition, the internal pressure of 45kgf/cm2 was applied using a nitrogen gas. SMAW and GTAW were applied to weld the sleeve. The macrostructure and hardness of repair welds have been examined. The finite element analysis of the multi-pass sleeve-fillet welding has been conducted to validate the experiment and investigate the effects of in-service welding conditions. The effect of gas flow rate on the hydrogen cracking was investigated. The effect of internal pressure on residual stresses and plastic strain was investigated. The allowable heat input was predicted considering the maximum temperature of inner surface of pipe and cooling rate at CGHAZ from the simulation of 1-pass sleeve-fillet welding.
The Use of Simulators to Comply With Legislated Pipeline Controller Proficiency Testing
Authors: Wike Andrew , Hall Randall A. , Miller Rex , Hays Rebecca L.
Published: March 2009

In the United States, recent legislation has dictated that by October 2002, all personnel that perform tasks that can affect the safety and integrity of pipeline operations (“covered tasks”) must have demonstrated that they are “qualified” to perform those tasks. Around the world, governments are considering passing equivalent legislation to require control room staff (and other operations personnel) to demonstrate their proficiency. The U.S. Department of Transportation has instituted the “Operator Qualification” rule in 49CFR Part 192 Subpart N (natural gas), and Part 195 Subpart G (hazardous liquids). After October 27th 2002, it will be unlawful for anyone performing a covered task not to have demonstrated proficiency in that task, unless they are under the direct supervision of a “qualified” person. While the rule applies to anyone performing a covered task, this paper concentrates simply on pipeline controllers. One specific focus of the law is the demonstration that staff are qualified to perform covered tasks under both normal and abnormal conditions. For control room staff, abnormal conditions occur only rarely, and the likelihood that any one individual is in the control room when a pipeline incident occurs is slim, at best. Simulation is uniquely situated to help train and qualify control room staff. Not only can pipeline controllers, as part of their training, be repeatedly exposed to abnormal conditions in a safe environment, but structured testing involving simulated abnormal conditions can also demonstrate qualification to react appropriately. This paper summarizes key points of the U.S. legislation, and introduces pipeline controller training simulators in outline. The experiences of three operating companies in their use of simulators to comply with legislated proficiency testing are recounted.
Effective Time Method for the Determination of Interface Diffusion of H2S Slugs in Natural Gas Pipeline Systems
Authors: Sennhauser Daniel J. , Botros Kamal K. , Van Egmond T.
Published: March 2009

The primary objective of the work described in this paper is to examine the fate of H2S contaminated natural gas slugs as they travel through a gas pipeline network. The important phenomenon that affects the spread of the H2S slug as it travels downstream of a pipe is the diffusion with the sweet gas at the front and back interface of the slug. It was determined that the diffusivity constant (D) used in the calculation of the interface spread varies along the pipeline, which prohibits the use of a closed form solution of the Fick’s law equation. An effective time parameter has been introduced to account for the variation in the diffusivity in a “marching in time” scheme of solution. The model has been utilized to demonstrate the effects of pipe diameter, mean flow velocity and pipe internal roughness on the contamination spread. A test loop has also been constructed to validate the diffusion coefficient in gaseous flows. Excellent agreement was obtained between the measured vs. predicted results. The mean error in predicting the interface spread was approximately 6.2%.
Buried SAGD Flow Lines
Authors: Thomas Lance N. , Marsden Rick A.
Published: March 2009

EnCana Resources is enjoying economic success at their Steam Assisted Gravity Drainage (SAGD) research facility at Senlac, Saskatchewan. This has been achieved largely due to the successful application of new and innovative ideas and technologies. During the summer of 2001, PanCanadian Energy (now EnCana Resources) made use of a novel buried piping technology at the Senlac Thermal Project to solve the problem of connecting distant well pairs to the processing plant. The four-kilometer pipeline system accommodated a thermal growth of approximately 12 meters over its entire length using buried expansion loops and “Z” bends. The pipeline was installed at an estimated 30% cost savings over conventional above ground methods. This paper summarizes the successful installation of this unique piping technology at Senlac and its applicability to future commercial SAGD projects in the context of the heavy oil reserves in Alberta.
A Time Series Approach for Pipe Network Simulation
Authors: Costa Andre´ L. H. , de Medeiros Jose´ L. , Arau´jo Ofe´lia Q. F.
Published: March 2009

We applied time series predicting tools for the simulation of the temporal behavior of large pipeline networks submitted to timely changing inputs. The inputs may consist of a set of specified flow rates at client or supply nodes, while the outputs are another set of nodal pressures and internal flow rates. According to the topology, size, age and history of the network, the continuous generation of phenomenological dynamic simulations may be impossible, imprecise or numerically expensive, demanding thus alternative approaches. Our methodology is particularly oriented to this kind of demand. From recorded network past data covering relevant history of inputs and selected outputs, ARX-MIMO predictors are built with identification methods and launched for continuous estimation of the network outputs one time step ahead. Results are precise enough for engineering, training and monitoring applications.
A Preliminary Strain-Based Design Criterion for Pipeline Girth Welds
Authors: Wang Yong-Yi , Rudland David , Denys Rudi , Horsley David
Published: March 2009

The strain capacity of girth welds containing surface-breaking welding defects is examined through numerical analysis and experimental verification under a PRCI (Pipeline Research Council International) funded project. Some important insights on the various factors affecting the girth weld strain capacity are generated. The defect size is identified as one of the most important factors in determining strain capacity of a girth weld. Other factors, such as the strain hardening rate of the pipe and weld metals, weld strength mismatch, fracture toughness, and weld cap height, can play a significant role if the defect size is within certain limits. It is discovered that the girth weld response to the remotely applied strain may be characterized by a three-region diagram. For a given set of defect size and weld strength mismatch conditions, the crack driving force may be bounded, unbounded, or gradually changing, with respect to the remotely applied strain. A set of parametric equations is developed that allow the computation of allowable strains with the input of defect depth, defect length, CTOD toughness, and weld strength mismatch. The comparison of the developed strain criteria with full-scale bend tests and tensile-loaded CWPs (curved wide plates) shows the criteria are almost always conservative if lower bound CTOD toughness for a given set of welds is used. However, the criteria can significantly underpredict strain capacity of girth welds with short defects. Although defect length correction factors were added to the strain criteria based on the comparison of axisymmetric finite element (FE) results and full-scale bend test results, a more thorough investigation of the effects of defect length on strain capacity is needed. Future investigation that incorporates the finite length defects is expected to greatly reduce the underprediction. The influence of other factors, such as strain hardening rate, should be further quantified.
Target Reliability Levels for Onshore Gas Pipelines
Authors: Zimmerman Tom , Nessim Maher , McLamb Martin , Rothwell Brian , Zhou Joe , Glover Alan
Published: March 2009

Establishing target reliability levels that have wide industry and regulatory acceptance is necessary in order to proceed with the implementation of reliability-based design techniques for pipelines. The target reliability levels described in this paper are based on life safety considerations and are applicable to natural gas pipelines. They were calibrated to a series of pipeline designs based on ASME B31.8, using design parameters and operating practices intended to be representative of North American pipelines. The targets define an upper bound to the total failure rate due to failure events involving significant leaks (excluding pinholes) and ruptures. This paper summarizes the results of the analyses undertaken to establish the target reliability levels, provides the target reliability curves developed and presents an approximate analysis of their economic implications.
Pipeline Construction in Extremely Sensitive Environmental Areas
Authors: Renno´ Gomes Marcelo Rosa , de Albuquerque Vasconcelos Elinaldo , de Carvalho Dias Correia Luiz
Published: March 2009

As a result of increased energy demand in recent years, PETROBRAS has experienced a continuous growth in the number of pipeline construction projects. To rise to this challenge, it was necessary to construct pipelines in extremely sensitive environmental areas, as well as areas with severe constraints for construction. As a result, alternative construction methods had to be evaluated and implemented. The purpose of this paper is to present PETROBRAS’ design and construction methods in three different regions of Brazil: Pantanal, the Amazon rain forest, and the Aparados mountains. Construction practices are described along with the environmental and engineering criteria that were considered. Each of the three regions have special characteristics that required different construction methods: Pantanal — Located in the western part of Brazil, this region of 140,000 km2 is primarily swampland. The Brazil-Bolivia Gas Pipeline crossed nearly 70 km of this region using the push method. Amazon Rain Forest — This region covers an area of approximately 3.3 million km2 and has unique environmental importance to the world. PETROBRAS owns the Urucu Oil and Gas Field in this region. Over the past years almost 600 km of pipelines have been built in this area. Construction logistics, which had to take into account the hydrologic phases of rivers, was the key to successful projects. Aparados Mountains — Located in the south part of Brazil, this region is characterized by the presence of canyons. Horizontal and vertical tunneling were used to cross an escarpment while avoiding disturbance to unstable slopes. Special methods were implemented in these regions to allow successful installation of the pipeline while maintaining the highest possible level of environmental protection.
Probabilistic Modeling of Corroded Pipeline Structures
Authors: Brennan D. P. , Akpan U. O. , Orisamolu I. R. , Glover A. , Konuk I.
Published: March 2009

Corrosion is one of the most important damage mechanisms for in-service pipelines, and a significant portion of the maintenance budget is directed toward corrosion-related problems. A major challenge associated with the assessment of the impact of corrosion on the integrity of pipeline structures involves quantification of the amount and severity of corrosion damage present in the structure. Corrosion defects are typically characterized by spatially random distributions and variabilities in size, shape, and morphological characteristics throughout the exposed part of the structure. For pipeline corrosion, such spatial randomness and variability are best modeled using a nonhomogeneous random field approach. A review of some existing random field modeling strategies and their potential for modeling in-service pipeline corrosion data (including their limitations) is presented. A practical random field modeling strategy is developed, which is suitable for in-service pipeline corrosion modeling and circumvents the limitations of existing models. The application of the strategy is demonstrated via example problems, wherein the model is applied to actual pipeline corrosion data. A preliminary application of the corrosion model is also undertaken to assess the residual strength of a pipeline subjected to corrosion damage.
Approach to Assessment of Corrosion Growth in Pipelines
Authors: Gu Bill , Kania Richard , Sharma Sandeep , Gao Ming
Published: March 2009

Two key components of corrosion growth assessment in pipelines are accurate determination of corrosion growth rate and application of corrosion growth to future integrity of a pipeline. PII has developed a corrosion growth assessment tool, Run Comparison (RunCom) software that allows accurate determination of corrosion growth. RunCom compares the raw signals of the same defect present in two inspection runs to report the real active corrosion defects and their growth with less error. Since variations in corrosion growth along the pipeline can be significant, a single value of average or maximum corrosion growth rate does not represent the corrosion condition of the pipeline and could result in a conservative or non-conservative conclusion for future integrity. PII introduces a Decision Tree Analysis method to categorize the corroded regions along the pipeline and calculate the mean corrosion growth rates in these specific areas. Relationships between corrosion growth rate and defect geometry are also identified. The influence of soil, drainage, and topography on corrosion rates is examined to determine representative corrosion growth rates along the pipeline. A systematic approach incorporating statistical analysis with mechanistic understanding of corrosion for preliminary corrosion assessment of pipeline systems is discussed.
A Framework for Safety-Constrained Integrity Management for Gas Pipelines Using Defined Risk Acceptance Criteria
Authors: Fenyvesi Louis L. , Keeter James , Colquhoun Iain
Published: March 2009

Risk assessment has been used historically in pipeline integrity to provide relative risk rankings based on a mixture of qualitative and quantitative inputs. With the improvement of assessment and data collection techniques and technologies, and the corresponding improvement in hazard and consequence modeling that these techniques have made possible, pipeline operators are now able to calculate risk on an entirely quantitative basis. This improvement allows operators to manage pipeline integrity-related risk within a framework that allows levels of risk reduction to be related to integrity costs using comparable terms and to measure the acceptability of residual levels of risk against responsible and defensible risk acceptance criteria. The framework outlined in this paper, coupled with quantified risk models, allows pipeline operators the ability to identify areas that may require risk reduction, identify preferred risk-reduction methods, provide justification for the project, and monitor residual levels of risk. The introduction of defined risk acceptance criteria also provides operators with a tool to move beyond relative risk prioritization towards the ability to discriminate between pipe operating at acceptable integrity levels and pipe requiring risk mitigation.
Permeable Coatings and CP Compatibility
Authors: Jack Tom , King Fraser , Cheng Yufeng , Worthingham Robert
Published: March 2009

Protective coatings applied to the external surface of line pipe are designed to protect the underlying steel from corrosion over the life of the installation. These coatings are usually used in combination with cathodic protection (CP) to ensure that the steel exposed by coating damage or defects remains protected. The ultimate success of this approach very much depends on the nature, performance and failure mode of the coating. Disbondment of a high impedance coating such as a polyolefin tape can block CP while allowing water access to the underlying steel. Corrosion and near neutral pH SCC can result. In contrast, pinholes or impact damage on coatings such as fusion bonded epoxy allow both CP and water to penetrate to the pipe surface. Coatings that become permeable in service such as asphalt enamels similarly allow protection of the pipe despite a general loss of barrier properties. Because no corrosion or environmentally assisted cracking occurs where adequate CP potentials are sustained, these coatings can be regarded as being “CP compatible”.
The Role of a Geographic Information System (GIS) in the Sustainability of Export Pipeline Projects
Authors: Wild Patricia C. , Barringer Jennifer , Lukens William
Published: March 2009

Sustainable development in the energy industry is rapidly expanding beyond the conceptual stage. Policies addressing the three principles of Sustainable Development (economic growth, environmental protection, and social progress) are being established and strategies to execute these policies are being developed and implemented in the field. Export pipeline projects provide a wide variety of applications for the three elements of sustainable development. Properly designed, installed and operated pipeline systems enable the energy industry to deliver hydrocarbon products to the market place in a way that delivers economic rewards while preserving the integrity of the environment and surrounding communities and their ways of life. Conoco is developing a strong corporate culture around sustainable development; and, pipeline systems play a vital role in delivering the triple bottom line results for our stakeholders. This paper will present some of the key focal points used by Conoco Inc. in pipeline project development. It proposes GIS technology to make pipeline projects a contributor to sustainable growth success.
High Resolution Satellite Imagery or Ortho-Photography? A Wealth of Experience From Pipeline Integrity Mapping and Oil/Gas Asset Management
Authors: Adam Steve
Published: March 2009

Since January 2000, 1m resolution satellite imagery has been commercially available from the Ikonos satellite. Recently, the Quickbird satellite also became operational acquiring images with running 70cm resolution. We commonly assume that new technologies, such as Ikonos and Quickbird, will displace traditional methods. This may be the case in the far distant future, but at the present time (and for many years to come) there is plenty of room for both high resolution satellite imagery and traditional aerial photography. In fact, air photo use is steadily increasing as spatial information systems gain popularity in industry and government.
Girth Welding of X100 Pipeline Steels
Authors: Hudson Mark G. , Blackman Stephen A. , Hammond John , Dorling David V.
Published: March 2009

Girth welding trials involving pipes of minimum proof strength 690 MPa (X100) from several linepipe manufacturers have been conducted. Welding consumable selections for the trials were based on background data generated at Cranfield University coupled with potential weld metal mechanical property requirements thought necessary for the implementation of X100 pipeline steels. Mechanised pulsed gas metal arc welding (PGMAW) and semi-automatic/ manual welding procedures were used to generate mechanical property data of mainline girth welds, tie-ins and repairs using equipment and procedures as close to current field practice as possible. The trials showed no detrimental weldability issues for the X100 steels examined. Testing comprised tensile, toughness (CVN and CTOD), hardness, side bend and nick break data generation, using pipeline welding specifications where possible.
Designing Gas Turbine Packages for Reduced Installation Time
Authors: Kendig Bryan K. , Pido Ernest J.
Published: March 2009

Gas turbine users increasingly seek to install equipment in remote and harsh operating environments. Experience has shown that the cost of performing work in such an environment can be an order of magnitude greater than the cost of similar work performed in the manufacturer’s workshop. For this reason, gas turbine users have requested manufacturers to create package designs that minimize installation time. This paper describes changes made to aero-derivative gas turbine package design over the past seven years that achieve reduced installation time. Package changes have been permitted by advances in component technology affecting air inlet, exhaust, and control systems. Advances have also been made in piping, cable and baseplate designs. Component and package changes are described via a comparison of today’s standard aero-derivative gas turbine package to the standard package provided five to seven years ago. The comparison is made for a pipeline compressor application.
A Satellite-Based Mechanical Damage Management Solution
Authors: O’Neil Gregg , Besserer Michael , Moore Daron , Fanyvesi Louis
Published: March 2009

Numerous industry studies have characterized mechanical damage to be the pipeline industry’s largest single hazard. A proactive approach to preventing incidents due to mechanical damage is desirable. A process combining high-resolution satellite imagery with geomatic technologies such as GIS and image analyses is in the process of being demonstrated to be able to detect, georeference and characterize potentially injurious encroaching activities that may cause mechanical damage. The intrinsic advantages of a satellite imagery-enabled process include the high revisit frequencies (in comparison to typically used aerial patrol frequencies), the wider swath width of monitoring and the analysis -friendly digital nature of the imagery. The successful implementation of such a process will contribute to averting incidents in the many cases where One-call (Call before you dig) systems are not notified. In addition, as a by-product of the process, this service could assist in continuously surveying the right-of-way. Working with leading North American pipeline operators, via+ is developing and bringing to market commercial delivery models of this process. The elements of the process and the technologies current and anticipated capabilities are presented. Sample results of the process implementation are also presented.
Modeling of Pipeline Repair Sleeves
Authors: Lazor Robert , Carroll L. Blair , Bloom Michael E. , Booth Robert F.
Published: March 2009

Full encirclement repair sleeves with fillet-welded ends are used as a permanent repair on pipelines to reinforce areas with defects such as cracks or corrosion which may penetrate the pipe wall subsequent to the installation of the repair. CSA standards require that these sleeves be tapped to relieve the stress field surrounding the defect unless an engineering assessment indicates that the defect will not extend beyond the ends of the sleeve during future operation of the pipeline. This paper describes an engineering assessment recently completed to establish the relative performance of a sleeved pipe with and without a pressurized annulus. Finite element analysis (FEA) was used to relate changes in stresses in the weld region to internal pressure fluctuations. The FEA included an estimate of the effects of circumferential fillet weld shrinkage on local stiffness due to residual stress fields. Relationships between stress and internal pressure were used to convert the line pressure history to local weld stress fluctuations. This stress history was then used to assess the potential for fatigue crack propagation of possible circumferentially-oriented weld flaws using a fatigue crack growth algorithm. The results showed that the highest stresses were developed in the weld toe and root regions. The operating conditions of the line, as well as the pipe and sleeve dimensions, were considered when making recommendations concerning sleeve tapping.
Contractor Performance Assurance System
Authors: Erb Jeff
Published: March 2009

Maintaining competitiveness in today’s marketplace can be challenging to say the least. Assuring product/service quality, peak performance, and cost effectiveness are the basics for business success. As a result more and more corporations are seriously looking at the concept of rightsizing/downsizing their organizations to reflect business needs. This in most cases translates into contracting out of services. By the very nature of the pipeline industry, contractors are essential especially as it relates to construction. A wide number of pipeline companies are expanding the use of contractors in many areas such as engineering, production, and maintenance. Through this ever-increasing use of contractors a very real challenge is presented to employers wanting to assure quality, contractor control, and top performance. Effective contractor management is critical to the overall success of pipeline companies around the globe. The purpose of this presentation is to discuss one such strategy and the benefits associated with it.
Risk Assessment Studies of Gasketed and Non-Gasketed Bolted Pipe Joints
Authors: Abid Muhammad , Nash David H.
Published: March 2009

Over many years much effort has been made to develop design codes for pressure vessels, pipe-work, flanges and so on to design a system of high structural integrity. In-spite of the efforts the reliability of the system can be adversely affected for many reasons. Poor construction practices, incorrect selection of components such as gasket, improper quality of bolts and surface treatment, incorrect tooling, wrong application, underestimated joint size due to incorrect loading consideration, incorrect use of code, lack of thought to plant use, or a change of use during the life of a plant may make a joint unsuitable. The list is not exhaustive and not all the possible causes of failure may become apparent during commissioning. Failure of a pipe joint means the achievement of a leak rate below a certain maximum limit or the gross failure of the pipeline in which structural integrity is lost. So the high reliability of a system can be obtained if the right joint is selected for an application and factors that affect the reliability should be considered carefully. A very limited work has been done for the risk assessment of bolted pipe joints. At first, the most comprehensive work is done by Det Norske Veritas (DNV) regarding risk assessment of pipe joints. In addition, Webjorn and Thompson have also performed comparative reliability studies for these joints. Both DNV and Webjorn concluded that compact flange joints show better functional safety than conventional gasketed flange joints. Thomson concluded that both the joints are of high integrity and perform well in excellent service under appropriate installation and maintenance conditions. All above studies have been performed based on information and observations. Present author has performed detailed failure mode and effects analysis (FMEA) in the light of above-mentioned studies, idustrial surveys, analysis, experimental work and subsequent observations. The aim of the study was to increase the reliability knowledge about the gasketed and non-gasketed flanged pipe joints and thereby to increase the basis for finding the optimal pipe connection based on general observation and experimental studies performed.
Extruded Outlet Headers for Pipeline Service
Authors: Lankston Robert J.
Published: March 2009

Extruded outlet headers are furnished as special fittings to the various fittings specifications. These specifications provide the controls for materials and manufacturing necessary to produce the fittings. Some of these specifications are complete while others refer to ASTM (or CSA) standards for part of the control. The piping codes provide the rules for design of the outlets. Most of the codes have a special section covering the reinforcing rules for extruded outlets. These rules require control of dimensions and radii, and require that the reinforcing be integral with the body of the fitting and cover the complete circumference. The outlet radii must be produced by forming, rather than by machining of grinding. For qualified fittings, the amount of reinforcing required can be reduced for outlet diameters smaller than the run. Some of the piping codes require integral reinforcing for the more critical applications. The piping codes also provide Stress Intensification Factors (SIF’s) to be used for piping fatigue analyses. Although the codes give SIF’s for many types of outlets, they do not provide guidance for properly reinforced outlets made per the rules for extruded outlets. Taylor Forge (TF) has run tests over the years demonstrating that properly reinforced extruded outlets, will not only pass burst tests as required by fittings specifications, they also have SIF’s approaching those listed for tees. (B31.3 recently increased the SIF’s for tees with smaller crotch radii, and TF tests indicate that properly reinforced extruded outlets are better than indicated by the new rules for tees.) Reasons to consider extruded outlet headers for pipeline service are: • Versatility of size, spacing, number of outlets, etc.; • Low stress concentrations, fatigue resistant construction; • Radiographable butt weld connections; • Design and analysis rules are code qualified; • Field work is minimized.
How Do Defect Assessment Methods Influence the Choice and Construction of In-Line Inspection Tools
Authors: Reber Konrad , Beller Michael , Uzelac Neb I.
Published: March 2009

The paper describes which aspects of tool accuracy are important for the choice of ILI tools and design of new ones. It is discussed what constitutes an inspection run comparison. What kind of work is carried out, especially if several ILI vendors are involved? What kind of integrity statement can be deduced and how is this influenced by tool accuracy? Finally, the paper will discuss how some aspects of fracture mechanics affect the design of crack detection pigs. What are the minimum requirements for an ILI tool to allow for reasonable defect assessment? In addition, relation between companies performing In-Line Inspection (ILI) and those providing defect assessment is discussed. To what degree should an inspection company also deal with issues of pipeline integrity?
On the Coupling Between In-Line and Cross-Flow VIV Response
Authors: So̸reide Martin
Published: March 2009

As offshore installations are moving into deeper water, engineers have to face new challenges in design of structures. Risers and free-span pipelines, subjected to heavy wave loads and large current velocities, are important components of these installations. Vortex induced vibrations (VIV) is a well known subject for most offshore engineers. VIV can cause large stresses and fatigue damage of slender marine structures. Hence, large safety factors are applied to the fatigue limit state design criterion (FLS), due to uncertainties regarding VIV. The present paper describes the preliminary investigation into the coupling between in-line and cross-flow VIV response. Most experimental data so far has been concentrated on predicting the cross-flow response. However, in-line displacements can make a valuable contribution. In fact, it has been proved that in-line responses may decrease the cross-flow response significantly when allowing the pipe to oscillate in both directions. The paper is based on a master of science thesis at the Norwegian University of Science and Technology (NTNU).
An Approach to Corrosion Mitigation for Wet Gas Pipelines
Authors: Bich Nguyen N.
Published: March 2009

Relationship between flow regimes and corrosion mechanisms in pipelines is discussed. Flow regime affects how the water is delivered to the internal surface of the pipeline and the protective nature of the corrosion products / liquid hydrocarbon barrier film. Differences in corrosion mechanisms between CO2, CO2 + low H2S, and CO2 and high H2S are also presented. Mitigation measures should be designed to match expected flow regimes and corrosion mechanisms during all phases of production including start up, steady state, shut-in, acid stimulation, etc. Different corrosion monitoring methods are compared. Verification of pressure containing capability by inspection is also key to a pipeline corrosion management program.