bluuebunny/crossref_metadata_2025 huggingface dataset:
A Risk Based Approach to Optimize Inspection and Maintenance Resources
Authors: Pang David , Fales Raymond P. , Guedes Bruno
Published: October 2008

Pipelines have been used to transport oil and gas for more than a century. The first wooden gathering line for oil, about 9 miles in length, was built in 1865. The first Crude oil trunk line, named Tidewater, was built in 1879. Since then pipelines have played a very important role in the transportation of oil and gas. Now there are some 460,000 miles of oil and gas transmission pipelines in US, with about 300,000 miles of gas pipelines and about 160,000 miles of liquid pipelines. Pipelines have connected most of our families together to form an energy transporting network. With the increasing network of pipelines around our society and the increasing construction activity near pipelines, pipeline accidents due to third party damage has become a serious concern for pipeline industry and regulatory bodies. On January 17, 2006, the Pipeline and Hazardous Materials Safety Administration (PHMSA) issued an advisory bulletin raising the concern that “excavation damage continues to be one of the three leading causes of pipeline damage. PHMSA has seen an increase in pipeline operators damaging their own pipeline facility”. PHMSA requested the pipeline operators to reinforce the need for safe excavation practices and recommended that pipeline operators integrate the Operator Qualification regulations into their marking, trenching, and backfilling operations to prevent excavation damage mishaps. This paper will first analyze the pipeline damage data from the past 30 years. The data is divided into three categories: natural gas distribution incident data, natural gas transmission incident data, and hazardous liquid accident data. The analysis, with statistical data from 1968 up to today, indicates that the third party damage, corrosion, and defects in design/construction have being the top three causes on both the frequency of accidents and the values of property damages. This paper will focus on the analysis of the causes of “Outside Force Damage” and “Corrosion”. Through the data analysis the proportion of the risks from these two causes will be presented. The results will provide recommendations for different loss control plans based on the risks from the two causes in different stages of the service life of pipelines.
A Comprehensive Approach to Corrosion Management Based on Structural Reliability Methods
Authors: Stephens Mark , Nessim Maher
Published: October 2008

Quantitative analysis approaches based on structural reliability methods are gaining wider acceptance as a basis for assessing pipeline integrity and these methods are ideally suited to managing metal loss corrosion damage as identified through in-line inspection. The essence of this approach is to combine deterministic failure prediction models with in-line inspection data, the physical and operational characteristics of the pipeline, corrosion growth rate projections, and the uncertainties inherent in this information, to estimate the probability of corrosion failure as a function of time. The probability estimates so obtained provide the basis for informed decisions on which defects to repair, when to repair them and when to re-inspect. While much has been written in recent years on these types of analyses, the authors are not aware of any published methods that address all of the factors that can significantly influence the probability estimates obtained from such an analysis. Of particular importance in this context are the uncertainties associated with the reported defect data, the uncertainties associated with the models used to predict failure from this defect data, and the approach used to discriminate between failure by leak and failure by burst. The correct discrimination of failure mode is important because tolerable failure probabilities should depend on the mode of failure, with lower limits being required for burst failures because the consequences of failure are typically orders of magnitude more severe than for leaks. This paper provides an overview of a probabilistic approach to corrosion defect management that addresses the key sources of uncertainty and discriminates between failure modes. This approach can be used to assess corrosion integrity based on in-line inspection data, schedule defect repairs and provide guidance in establishing re-inspection intervals.
Airborne DIAL (Differential Absorption Lidar) for Broad Area Hazardous Liquid Leak Detection
Authors: Stearns Steven V. , Gigliotti Trevis J. , Murdock Darryl G.
Published: October 2008

Over the summer of 2005 ITT Space Systems Division successfully detected, measured, and imaged a range of different hazardous liquids from an airborne platform during a series of field tests in Texas and New York. Under contract from the United States Department of Transportation Pipeline and Hazardous Materials Safety Administration (DOT/PHMSA), ITT examined the ability of its Airborne Natural Gas Emission Lidar (ANGEL) Service’s system to detect, measure, and image a wide range of different hydrocarbons from a remote sensing airborne platform. The objectives of the DOT/PHMSA contract were to: 1) develop an understanding of hazardous liquid pipeline leaks, 2) demonstrate that ITT’s DIAL (differential absorption lidar) technology can detect and measure hazardous liquid emissions over a broad area and in real world conditions, and 3) use this information to design a “next generation” airborne sensor system optimized for the detection of both natural gas and hazardous liquid emissions. Hazardous liquids examined in this study included propane, gas condensates, crude oil, and refined hydrocarbons like gasoline, aviation gas, diesel fuel, Jet A, and kerosene. As part of this study, ITT, in cooperation with El Paso Production and Texas A&M–Corpus Christi, completed two separate sets of overflights of a hazardous liquid storage facility. During each set of overflights, data was collected with the storage facility’s vapor recovery unit (VRU) operating and again after the VRU was turned off. In addition, hatches on each of the tanks were opened to create further emission sources. Additional aerial collections of gasoline vapors, propane, and natural gas were also completed. Data from each of the overflights was processed and the results analyzed. The ITT ANGEL Service technology was shown to be capable of rapidly detecting, measuring, and imaging a wide range of different hydrocarbons while flying at an altitude of 1,000 feet and speeds of up to 150 mph. An overview of the results from these flight tests and a discussion of the DOT/PHMSA Hazardous-Liquid Airborne Lidar Observation Study findings will be discussed.
Liquefied Natural Gas Pipeline Suspension Bridge Design
Authors: Queen David J. , Felber Andreas , Scarborough Clark , Taylor Peter
Published: October 2008

A new Liquefied Natural Gas (LNG) plant, in Equatorial Guinea, Africa required a pipeline corridor with supplementary utilities from the processing plant at about 55 m (180’) above sea level, down to the marine loading facility. The use of conventional structures and foundations on the unstable slope had substantial associated costs and risk. Various options were considered and the suspension bridge solution, avoiding the geotechnically unstable slope by providing tower foundations above the slope on stable ground and in the ocean, was selected. Buckland & Taylor Ltd. developed the final design of a 350 m (1148’) main span inclined deck, suspension bridge to carry the pipeline corridor across the unstable geotechnical slope. The configuration of the bridge was dictated by the site conditions and the allowable movements of the pipelines. The superstructure consists of steel towers approximately 60 m (197’) tall with two main cables, each composed of three 89 mm (3 1/2”) strands, supporting a 12 m (39.4’) wide truss deck system. The deck of the bridge is fully grated for safety and ease of installation of the pipes and utilities once the main bridge structure was complete. With the pipes in position, the walkway provides continuous access to the pipelines and utilities for future maintenance, as well as provides a fixed pedestrian route from the plant to the loading facility. The details of all of the components were developed to address the demanding schedule, available fabrication facilities, shipping restrictions to the remote location, flexibility in the erection sequence and ease of construction. Repetitive structural components were detailed to simplify fabrication, facilitate transportation to the site and improve the schedule during construction. The aggressive project schedule dictated that field investigations were still being undertaken while final design was being completed. Buckland & Taylor Ltd. made design changes to suit field conditions or methods of construction with minimal impact on fabrication and construction. The design process considered various methods of erecting the bridge to simplify details and improve the construction schedule. The design of the suspension bridge was initiated in August 2004, with the conceptual design complete in a month and the detailed design issued for construction in January 2005. The main foundation construction and structural steel fabrication proceeded immediately with priorities set to meet the construction schedule. With the progress of design, fabrication and construction, Buckland & Taylor Ltd. anticipates that pipes will be installed on the bridge 20 months after the start of design.
Optimizing Energy in ORBEL II Oil Pipeline
Authors: Paulini Reinaldo Machado , Pires Luis Fernando Gonc¸alves
Published: October 2008

Energy is the major operating expense in a pipeline company. There is considerable incentive to optimize energy utilization to reduce losses as much as possible. This article presents a study of the process and economic effects of substituting traditional pressure control valves by medium voltage frequency variable drives in the ORBEL II oil pipeline. Three drive configurations were chosen and their implementation costs were investigated. Pipeline flow simulation software was used to study the process effects of the drive configuration applications and to calculate the amount of energy spent using control valves and using velocity variable control systems. The differences in energy savings were quantified in financial terms using energy supply contract data and operational data. Finally, an investment analysis was carried out in respect of the energy savings and an estimation of overall implantation costs of the drives.
A Tiered Approach to Girth Weld Defect Acceptance Criteria for Stress-Based Design of Pipelines
Authors: Wang Yong-Yi , Liu Ming , Horsley David , Bauman Gery
Published: October 2008

Alternative girth weld defect acceptance criteria implemented in major international codes and standards vary significantly. The requirements for welding procedure qualification and the allowable defect size are often very different among the codes and standards. The assessment procedures in some of the codes and standards are more adaptive to modern micro-alloyed TMCP steels, while others are much less so as they are empirical correlations of test data available at the time of the standards creation. A major effort funded jointly by the US Department of Transportation and PRCI has produced a comprehensive update to the girth weld defect acceptance criteria. The newly proposed procedures have two options. Option 1 is given in an easy-to-use graphical format. The determination of allowable flaw size is extremely simple. Option 2 provides more flexibility and generally allows larger flaws than Option 1, at the expense of more complex computations. Option 1 also has higher fracture toughness requirements than Option 2, as it is built on the concept of plastic collapse. In comparison to some existing codes and standards, the new procedures (1) provide more consistent level of conservatism, (2) include both plastic collapse and fracture criteria, and (3) give necessary considerations to the most frequently occurring defects in modern pipeline constructions. This paper provides an overview of the technical basis of the new procedures and validation against experimental test data.
Study on Ultrasonic Guided Waves in Fluid-Filled Pipes Surrounded by Water
Authors: Jin Shijiu , Sun Liying , Liu Guichun , Li Yibo , Zhang Hong
Published: October 2008

A new non-destructive pipe inspection method, ultrasonic guided wave method as well as the comparison between ultrasonics and guided waves is introduced. An investigation of the guided ultrasonic waves traveling along pipes with fluid loading on the inside and outside of the pipe is described. The effect of inner and outer media has been researched by considering a steel pipe with air and water inside and outside the experimental pipe. Site experiment was carried out on a heating pipe in the resident area of Bohai Oil Company, China. A typical cylindrical guided wave, longitudinal guided wave was used to examine pipes with artificial defects and its propagation characteristics along the pipe were studied. Good agreement has been obtained between the experiments and predictions for pipes with different loading on the pipe.
Guidelines for Assessing Corrosion Associated With Welds
Authors: Leis B. N. , Clark E. B. , Zhu X.-K. , Galliher R. D.
Published: October 2008

Factors that create important property and stress-field differences between welds and base metal have been reviewed as have a variety of seam and girth weld field failures and laboratory tests to define considerations that must be address in adapting corrosion assessment criteria for the pipe body to weld seams. Thereafter, guidelines for the use of such criteria in applications to weld seams were developed in terms of metrics that include mechanical and fracture properties, the pipeline’s loadings and service conditions, and the nature of the corrosion. A flowchart was developed to implement these metrics. The guidelines were validated by comparison of their predicted outcome against results for full-scale tests, laboratory tests, and in-service failures involving corrosion on weld seams, for both girth welds and longitudinal seams. For some applications, the one-size-fits-all approach adopted in formulating these guidelines can lead to conservative results.
Impact of Technology on Pipeline Assessment/Rehabilitation Projects
Authors: Tomar Munendra S. , Fingerhut Martin
Published: October 2008

Pipeline assessment/rehabilitation projects are an expensive, but essential component of pipeline operations. The advent of newer, faster and more advanced technologies has provided the project managers with viable options for reducing the expenditure associated without compromising, and sometimes, enhancing the quality of assessment. But, in-order-to derive the maximum benefit from the technology, a fresh, holistic approach, rather than a segmented, metric-based approach is required. The following paper aims at highlighting the impact of choosing the right technology using scenario-based project management, and the need for a fresh outlook on project management for an efficient utilization of technology.
Deterministic Assessment of Minor Mechanical Damage on Pipelines
Authors: Rosenfeld M. J. , Beckett Alan , Neogi Bhaskar , Baskurt U. J. , Johnson Elden
Published: October 2008

In-line inspection (ILI) of the Trans Alaska Pipeline System (TAPS) using high resolution metal loss and caliper tools indicated 77 locations with suspected minor mechanical damage features (MDFs). The tools used are able to detect the presence of a suspected feature, and measure indented dimensions, but are insufficient to detect the presence of cracks or gouges needed to reliably assess feature severity based solely on the ILI data. Excavations of 42 sites deemed most severe provided important field data characterizing residual deformation dimensions, revealed the occurrence of generally surficial gouges or cracks, and allowed a reliable field assessment of defect severity. Upon completion of the excavations, 35 possible MDF locations remained unexcavated. An engineering evaluation was undertaken to assess whether or not the remaining MDFs pose a threat that is significant enough to warrant excavation. Multiple assessment methods were utilized including deterministic, probabilistic, and risk assessment methods. A deterministic mechanics model was developed to estimate the safe operating life of the pipeline at each of the remaining uninvestigated locations considering the characteristics of previously observed damage, the perceived severity of uninvestigated damage, material properties of the pipe, and the fatigue environment resulting from expected modes of pipeline operation. The results strongly suggested that 33 of 35 damage features were extremely minor, with remaining life well in excess of the remaining project life cycle. None of these features were judged to threaten the immediate integrity of the line, and are unlikely to do so in the foreseeable operating life of the facility. The results also were found to support the outcome of the operator’s risk-based evaluation process.
A New Approach to Risk Based Pipeline Integrity Management
Authors: Palmer-Jones Roland , Turner Susannah , Hopkins Phil
Published: October 2008

The use of risk based integrity management systems for pipelines is increasing in popularity, and now changes in legislation in the USA require operators to use risk assessment in high consequence areas. The methodologies used range from point scoring qualitative schemes to detailed quantified systems requiring structural reliability analysis, release modelling and post incident behavioural modelling. In the UK a risk based approach to pipeline integrity management has been included in legislation since 1996, and is widely used. Experience with implementing systems and applying them to onshore and offshore pipeline systems has led to the following conclusions: • Point scoring systems cannot replace expert knowledge. • Point scoring systems always need to be modified to suit a particular system and need updating as parameters change. • Detailed automated systems generate a huge number of sections and range of risks. this can be confusing and cannot easily be accounted for in inspection planning. • A clear link between risks and inspection or monitoring is needed. • Simplicity and flexibility are critical. This paper describes a radical new approach to using risk assessment for pipeline integrity management. This new approach focuses on identifying whether hazards are time dependant (e.g. corrosion) or random (e.g. third party damage), and then either estimating a time to failure or a probability of occurrence. These estimates can be based on experience, history, or specific detailed studies. The effect of inspection and monitoring is also considered. This methodology allows the user to manage the risks associated with their pipeline in a way that is flexible, rational, consistent, and can be readily understood by others. It also allows the reasons for decisions regarding inspections to be recorded, and new users to quickly learn the key safety issues for the pipeline.
Finite Element Analyses of Circumferential Cracks in Thin-Walled Cylinders: T-Stress Solutions
Authors: Lewis Timothy , Wang Xin , Bell Robert
Published: October 2008

The elastic T-stress is a parameter used to define the level of constraint at a crack tip. It is important to provide T-stress solutions for practical geometries in order to apply the constraint-based fracture mechanics methodology. In the present paper, T-stress solutions are provided for circumferential through-wall cracks in thin-walled cylinders. Cylinders with a circumferential through-wall crack were analyzed using the finite element method. Three cylinder geometries were considered; defined by the pipe radius (R) to wall thickness (t) ratios: R/t = 5, 10, and 20. The T-stress was obtained at eight crack lengths (θ/π = 0.0625, 0.1250, 0.1875, 0.2500, 0.3125, 0.3750, 0.4375, and 0.5000) for remote tension and remote bending loads. These results are suitable for constraint-based fracture analysis for cylinders with circumferential cracks.
Modeling the Interactions of Hydrogen, Stress and Dissolution in Near-Neutral pH Stress Corrosion Cracking of Pipelines
Authors: Cheng Frank Y.
Published: October 2008

A thermodynamic model was developed to determine the interactions of hydrogen, stress and anodic dissolution at the crack-tip during near-neutral pH stress corrosion cracking in pipelines. By analyzing the free-energy of the steel in the presence and absence of hydrogen and stress, it is demonstrated that a synergism of hydrogen and stress promotes the cracking of the steel. The enhanced hydrogen concentration in the stressed steel significantly accelerates the crack growth. The quantitative prediction of the crack growth rate in near-neutral pH environment is based on the determination of the effect of hydrogen on the anodic dissolution rate in the absence of stress, the effect of stress on the anodic dissolution rate in the absence of hydrogen, the synergistic effect of hydrogen and stress on the anodic dissolution rate at the crack-tip and the effect of the variation of hydrogen concentration on the anodic dissolution rate.
Application of Ground Movement and Automated Route Planning Technologies for Pipeline Planning and Management: The PIPEMON Project
Authors: Riedmann Michael , Sims Richard A. , Rogg Caroline , Schleider Oliver
Published: October 2008

Innovative technologies provide the key to making pipeline operations more efficient. Thanks to recent progress in satellite-based remote sensing and image processing, it is now possible to design pipeline monitoring systems with remote sensors and context-oriented image processing software, as has been demonstrated in particular by the three-year ESA funded market development activity “PIPEMON – Geo-information services for pipeline operators: ground motion monitoring and route planning”. Business partners involved in the Project are currently undertaking pre-commercial trials with market players and potential customers, to better introduce and demonstrate Earth Observation (EO) data and services to the pipeline industry.
Analysis of the Transient Cooldown of Sub-Sea Pipelines
Authors: Barrera Escobedo J. Jhordann , Nieckele Angela O. , Azevedo Luis Fernando A.
Published: October 2008

A precise analysis of the transient cooldown of subsea pipelines is crucial for offshore flow assurance, to avoid, for example, hydrate formation or wax deposition. Flow assurance in transportation lines, where column separation can occur due to large temperature drop coupled with large pressure drop, must also be addressed. Usually, pipeline thermal insulation is designed for steady state conditions. However, during shutdowns, the temperature drop experienced by the stagnant fluid is more pronounced, eventually reaching some critical temperature level, that can lead to flow line blockage and flow re-start problems. Thus, the determination of the temperature and pressure distributions along the pipeline under transient conditions is important to maintain the line operating safely. To determine the transient heat transfer in pipelines, the fluid flow conservation equations coupled with the heat conduction equation applied to the pipeline wall were numerically solved. The heat loss from the pipeline was determined by solving the transient heat conduction equation for the pipewall layers, utilizing a simple one-dimensional model in the radial direction. The coupled system was solved numerically employing the finite difference method. Transient analyses were performed for two scenarios. In the first one, the cooldown process of oil in a subsea pipeline was evaluated, with the effect of variable thermal properties on the temperature profile being investigated. The dependence of the temperature on the thermal conductivity and specific heat capacity was analyzed. In the second scenario, gas flows inside the pipeline, and the effect of temperature variation on a stagnant fluid is presented. Tests for different values of thermal diffusivity corresponding to new and old thermal insulations were performed.
Compressor Station Availability: Managing Its Effects on Gas Pipeline Operation
Authors: dos Santos Sidney Pereira , Bittencourt Maria Ange´lica S. , Vasconcellos Luiz Diogo
Published: October 2008

As competitive market for gas transmission becomes more and more dynamic and we face an increase of regulatory agencies influence, the pressure on cutting down cost of service without affecting reliability and safety is a consequence. Notwithstanding this trend, transportation companies must act in a way that guarantees a fair return on investment and optimizes assets and operation costs. Contractual obligations play an important role since most of the contractual capacity is on a firm basis and subject to liabilities related to capacity shortage or interruption. Compressor stations availability study play a fundamental role in providing information that will support decision making in terms of defining a criterion for installing stand-by units. This paper presents two methods adopted for the Bolivia-Brazil Gas Pipeline Project: (1) Monte Carlo Simulation and (2) Scheduled and Unscheduled Maintenance. A technical end economic feasibility study is also presented to support the decision of installing stand-by units.
Evaluation of Composite Sleeves for Reinforcement of Dented Pipelines
Authors: Perrut Valber Azevedo , Meniconi Luiz Cla´udio M. , de Souza Filho Byron Gonc¸alves
Published: October 2008

Composite sleeve repair systems, now of widespread use in the market, were originally developed for the reinforcement of corroded pipelines. Transpetro, the Brazilian pipeline operator, asked Petrobras/CENPES to address the behavior of those sleeves when applied to dented pipelines. A short verification experiment was envisaged, in which both the dent filling material and the sleeve material were varied. Artificial dents with depths of 19% OD were imposed to 22 in. OD, 0.5 in. thick, API 5L X60 tubular specimens. Concrete and polymeric materials were tested for dent filling, whereas glass and carbon fiber composites, in two different thicknesses, were tried as the sleeve structural material. The main purpose of the repair sleeve in this case is to provide a repair procedure installed at low temperature and capable of reducing the stress range at the hot spot in the dent. The goal is to improve the fatigue resistance of the repaired pipeline. Low cycle fatigue tests were performed, both using non-repaired specimens (to serve as the basis for comparison) and the specimens repaired using the different schemes proposed. The tests were fully instrumented to analyze deformations in each specimen. After the fatigue tests, each specimen was pressurized until collapse, in order to quantify their ultimate strength. This paper reports the main results of the tests and the deformation analysis of each repaired specimen, aimed to define parameters which will serve to the design of future cases.
A Statistical Predictive Model to Prioritize Site Selection for Stress Corrosion Cracking Direct Assessment
Authors: Merle Anthony , Ehlers P. F.
Published: October 2008

Pipeline stress-corrosion cracking (SCC) is an ongoing integrity concern for pipeline operators. A number of different strategies are currently employed to locate and mitigate SCC. Ultrasonic in-line inspection tools have proven capable of locating SCC, but reliability of these tools in gas pipelines remains in question. Rotating hydrotest programs are effectively employed by some companies but may not provide useful information as to the location of SCC along the pipeline. NACE Standard RP0204-2004 (SCC Direct Assessment Methodology) outlines factors to consider and methodologies to employ to predict where SCC is likely to occur, but even this document acknowledges that there are no well-established methods for predicting the presence of SCC with a high degree of certainty. Predictive modelling attempts to date have focused on establishing quantitative relationships between environmental factors and SCC formation and growth; these models have achieved varying degrees of success. A statistical approach to SCC predictive modelling has been developed. In contrast to previous models that attempted to determine direct correlations between environmental parameters and SCC, the new model statistically analyzed data from dig sites where SCC was and was not found. Regression techniques were used to create a multi-variable logistic regression model. The model was applied to the entire pipeline and verification digs were performed. The dig results indicated that the model was able to predict locations of SCC along the pipeline.
Commissioning a Real-Time Leak Detection System on a Large Scale Crude Oil Pipeline During Start Up
Authors: Mabe Joanna , Murphy Keefe , Williams Gareth , Welsh Andrew
Published: October 2008

This paper describes the process of incremental pipeline filling and the phased commissioning of a real-time leak detection system for the 1768 km long BTC crude oil pipeline. Due to stringent environmental requirements, it is essential for the leak detection system to work from the moment that crude oil is introduced into the pipeline. Without any prior operational data and with the pipeline partially filled, it is challenging for the leak detection system to monitor the integrity of the pipeline throughout the whole filling process. The application of the pig tracking software to track the oil front as the crude displaces nitrogen is also discussed.
Design of a Transparent Multiphase Flow Facility for Non-Invasive Optical Investigations
Authors: Coronado-Diaz Haydee , Hugo Ronald J.
Published: October 2008

A multiphase flow facility was designed to handle flow in three phases: water, air and oil. Two pumps, one for water and one for mineral oil are placed at the end of a separation tank, two branches of 2 in. pipe coming out from each pump run at the very top of the bench; water and oil are mixed 6 feet before the air injection. A tube with four entries of 1/2 in each was built for the injection of air. Ten feet of cast acrylic pipe is placed in front of the injection of air to visualize the pattern. An optical countoring allows a more accurate view of the inside of the tube. This optical countoring was specially designed for the acrylic filled with water. Separation is done by segregation. This facility was created specifically to study bubble flow and reproduce the behavior of the coalescence and breakup of bubbles and droplets of oil. The analysis over the bubble flow is made by using an optical sensing method (non-intrusive method). The facility can be used to study other flow regimes of two and three phases. The observations of flow of water and air are presented in this paper.
Stability Design Criteria for Above-Ground Unrestrained Pipeline Anchors and Line-Stops, Considering Frictional Forces Caused by Thermal Expansion and Weight of Pipeline
Authors: Farrokhzad M. A.
Published: October 2008

Pipeline anchors and line stops are essential elements for design and construction of a pipeline system. Anchors limit and isolate the thermal growth of the pipeline and control as well as guide it in favorable directions. Steel piles are often used to serve as anchors. Designing of anchors should include a combination of reactions between pipe to shoe-anchor, shoe-anchor to steel pile and steel pile to soil as well as stability consideration of soil at the location where anchor is applied. Many factors have to be considered in the engineering design of pipeline anchors and line stops, including loads, displacements and maximum allowable forces. Industrial-wise, expansion growth and frictional forces for above-ground pipelines have to account for the basic design conditions as well as bending and possible elastic instability of the pipe and its anchors due to the longitudinal compressive forces. Stress calculation formulas for anchors tend to consider the ambient to design temperature as the design criteria for thermal loads, however due to the complexity of reactions between static-dynamic frictional forces and thermal expansion forces, anchors may be subjected to higher loading in lower temperature than design temperature. This effect can be crucial to the stability of anchors during commissioning. This paper considers and establishes the stability design criteria due to temperature for anchors and associated components subjected to thermal and frictional forces.
Fiber Optic Sensors for Monitoring Pipe Bending Due to Ground Movement
Authors: Cauchi Sam , Cherpillod Thierry , Morison Don , McClarty Ed
Published: October 2008

This paper describes an installation of fiber optic sensors designed to measure pipe bending due to ground movement at three sites on a 16” gas transmission line. The sour gas pipeline had failed in December, 2004 from excessive forces related to ground movement. As temporary mitigation the pipeline was daylighted to reduce the soil traction forces but a comprehensive monitoring program had to be developed before placing the pipeline back into conventional service. During the time when the section of pipeline was daylighted, three linear and three coiled fiber optic sensors were installed at each of three sites selected as part of a system designed to measure bending strains in the 0.01–1.0% range. The two types of sensors were placed in pairs approximately at the 12, 4, and 8 o’clock positions. Conventional vibrating wire (VW) strain gauges were also installed at the fiber optic sensor locations for comparison purposes. Slope inclinometers were installed at each of the instrumentation sites to correlate ground movement to pipe bending. Following pipeline re-coating, and back-filling, visits to the site were made at approximately monthly intervals to gather data at conveniently placed break-out boxes. The complete fiber optic sensor system functionality is described and results are presented that show how the raw strain data are transformed into bending using software that also serves as a secure database.
In-Line In-Situ Direct Measurement of Absolute Biaxial Stress in Pipelines
Authors: Russell David A. , Buttle David J. , McCarthy John C.
Published: October 2008

This paper reports on recent work on the in-situ determination of absolute levels of biaxial stress in ferromagnetic pipeline materials. The response of pipe-wall materials to an applied alternating magnetic field is measured, and knowledge of the variation of magnetic properties of the material used to determine stress values. A wide variety of means are in use to detect, characterize and measure an equally wide range of defects in pipelines. These may arise from pre-existing conditions, errors in construction, effects of corrosion, accidental damage or other causes. Caliper tools, mapping tools, MFL, EMAT and ultrasonic tools are all used to detect conditions that may result in unacceptable stress in a pipeline. The ultimate aim, for all of these detection techniques, is to prove that the inspected pipeline’s fitness for purpose is maintained; and where this is not demonstrated, to provide accurate and reliable information on which to base a rehabilitation program. Recently attention has been raised by a number of groups working on the development of techniques intended to utilize the dependence of the magnetic response of ferrous materials to applied stress in order to directly measure stress. Most of these techniques have been based on the Barkhausen effect. This paper discusses the use of an alternative technique based on other magnetic properties that have been shown to allow derivation of a quantifiable relation between the level of stress present in material and the magnetic response. This technique, named MAPS by its developers, ESR Technology, has been employed with considerable success out-with the pipeline industry. Recent work has concentrated on applications in dynamic situations, in particular in pig-mounted inspection systems. A series of tests are described with dynamic measurements made inside pipes, covering measurement of applied (bending) stresses and artificially simulated defects. Measurements are described at velocities up to 4 m/s in prototype systems at 24” diameter with stand-offs of 2mm and up. Magneto-dynamic effects from the motion of the sensors past the metal of the pipe-wall have been characterized and variations in signal due to the velocity and instrument stand-off are described. It is considered that this work forms the basis for a pipeline inspection technique using these instruments.
A Mobile Sensor System to Detect Water Hold-Up Locations and Internal Corrosion in Pipelines
Authors: Sridhar Narasi , Tormoen Garth , Sabata Ashok , Brossia C. Sean
Published: October 2008

This paper presents an evaluation of the thin film corrosion sensors that could be used in combination with a mobile, wireless platform to detect internal corrosion along a pipeline. The iron-copper, thin film interdigitated sensor was found to be appropriate for detecting the presence of corrosive conditions within the pipe. The sensor reading using DC resistance measurement method reflected the corrosivity of a number of electrolytes and was able to determine the corrosion rate of iron in these environments. The sensor readings were reproducible. The sensor was able to distinguish between bulk aqueous solution and condensed moisture film. The sensor response was relatively rapid (within 60 s), thus permitting it to be used as a transient, retrievable sensor. The sensor life in the presence of acid gases, CO2 and H2S, was relatively short (less than a week). The sensor readings were only slightly dependent on sensor geometry.
The Influence of Magnetization on Corrosion in Pipeline Steels
Authors: Jackson Joshua E. , Lasseigne-Jackson Angelique N. , Sanchez Francisco J. , Olson David L. , Mishra Brajendra
Published: October 2008

Laboratory measurements have shown a strong increase on the hydrogen content in steel after electrochemical hydrogen charging with a two Tesla applied magnetic field and a serious increase in hydrogen-induced cracking and pitting. Cold work combining with the effect of applied magnetic field creates a material more crack sensitive to increased hydrogen content. A derivation based on the use of the Helmholtz Free Energy is applied to examine the thermodynamic effect of magnetization on hydrogen content. The effect of magnetization on the electronic spin configurations, magnetostriction (directional strain induced in steel from an applied magnetic field), and interstitial solute-induced strain are considered. A possible kinetic model for enhanced hydrogen ion pickup and corrosion based on surface effects associated with the Gouy-Chapman Layer and the Helmholtz Double Layer is examined. Disturbance of these layers acts to enhance hydrogen transport to the surface. The high applied and remanent magnetic fields and large cathodic protection currents returning in the pipe simultaneously may disturb these surface layers, resulting in enhancement of both cathodic and anodic reactions.
Development of a 3D Ultrasonic Inspection Device for Pipeline Girth Welds
Authors: Sato Hiroshi , Hamajima Takayuki , Katayama Masahiro , Kanamaru Yasuhisa
Published: October 2008

Quality requirements for girth welded joints in gas pipelines necessitate adequate penetration to the inner surface and no harmful defects. Toho Gas has completed development of the world’s first inspection system applying the ultrasonic synthetic aperture method for welds in steel pipes used to carry gas (external diameter 200mm, pipe wall thickness 5.8mm). In recent years, ultrasonic phased-array technology and ultrasonic TOFD methods etc. have attracted attention. However, the ultrasonic synthetic aperture method is an imaging technology that is superior to these, as it can synthesize several thousands of wave form data at high speed, its image clarity is the best in the world. The four features of the system are (1) the ability to provide an image of the interior of a weld, (2) the ability to quantity incomplete root bead penetration, (3) automatic high speed collection of data, and (4) data base management capability. The ultrasonic synthetic aperture method simplifies defect judgments because it does not require that operators possess special qualifications and training. It can produce three-dimensional high picture quality data. It can be handled easily at work sites because it is portable. This report describes the ultrasonic inspection system development process and the results of trial inspections.
Pipe Systems With Enhanced Operational Reliability Manufactured by ChTPZ Group CJSC for Field Pipelines
Authors: Medvedev A. P.
Published: October 2008

About 200,000 km of internal field pipelines are being operated in the Russian Federation in ten oil companies. The reasons and factors for pipeline breakdown are as follows: • Lack of pipeline cleaning; • Low pipeline workload; • Ineffective program for inhibitor protection and corrosion monitoring; • Utilisation of washing and other process water into field pipelines; • Use of non-treated water in the RPM (reservoir pressure maintenance); • Low corrosion resistance and crack resistance of steels. The regulatory documentation (GOSTs) for oil and gas pipelines has become obsolete and does not take into account the enhancement of corrosion activity of oil field media fixed in recent years. Both internal field and pressure oil pipelines at oil fields are amenable to internal corrosion—pipes fail, as a rule, due to pit corrosion, less frequently due to groove (“rill”) corrosion. ChTPZ Group CJSC ranks the second in the Russian Federation by the volume of manufacture of pipes and welded connecting elements of oil tubular goods. Jointly with research centre specialists, in the course of a number of years it has been carrying out the development of oil and gas pipelines having an enhanced corrosion resistance and cold endurance. Pipes and connecting elements manufactured according new technologies have been operating without accidents since 1996 at a number of West Siberian and other deposits.
Simulation on Solar Hydrogen Generation With PEM Cells and Solar Modules
Authors: Kawashima Yousuke , Kawanami Osamu , Honda Itsurou
Published: October 2008

A simulation of solar hydrogen generation with solar modules and PEM cells in consideration of the solar module temperature for one year was carried out using our measured weather data. The optimal combination of the number of PEM sheets and solar modules was determined and hydrogen conversion efficiency was estimated. Solar module temperature was predicted from the measured data of global solar radiation, ambient temperature, and wind velocity. The current-voltage (I-V) curves of a solar module in arbitrary states were calculated from the (I-V) curves in the reference states using conversion equations (JIS C8913).
Hydrogen Production Using Autothermal Reforming of Biodiesel and Other Hydrocarbons for Fuel Cell Applications
Authors: Colucci Jose´ A.
Published: October 2008

The department of Chemical Engineering of the University of Puerto Rico (UPRM) in collaboration with Argonne National Laboratory (ANL) works in the development of a reforming catalyst characterization program. The purpose of this research is to study the viability of using new catalysts to convert Biodiesel, Glycerin and Methanol to a hydrogen rich product gas and compare their production potential, identify the conditions for the accumulation of coke and determine the influence of reactor temperature and water to carbon and oxygen to carbon ratios. A Basket Stirred Tank Reactor (BSTR), Plug Flow Reactor (PFR), Gas Chromatography Mass Spectrophotometer (GCMS) and Gas Chromatography Thermal Conductivity Detector (GCTCD), and Pt and Rh-based catalysts synthesized at ANL were used. During the preliminary ATR experiments, methanol, glycerol and biodiesel showed an increase in H2 production with decreasing O2/C ratio and increases in the reactor temperature. Additionally, Scanning Electron Microscopy (SEM) and EDAX analysis has been performed in some of the catalysts samples. All biodiesel and glycerol experiments performed had shown coke formation. Future research will include, experiments with bio-ethanol and methane as fuel using a Ni-based catalyst synthesized at ANL.
Experimental Study of Underfloor Air Supply System With Air Solar Collector and Shape-Stabilized PCM
Authors: Xiao Wei , Zhang Yinping , Zhang Qunli , Lin Kunping , Di Hongfa
Published: October 2008

In this paper, a new kind of solar energy heating system with shape-stabilized PCM is put forward. It can absorb the solar energy in the daytime and release the heat at night in winter. The solar radiation energy was gained by air solar collector, and the heated air was sent to the underfloor space of the room with ducts at daytime. Then the thermal energy was stored in the shape-stabilized PCM plates. The shape-stabilized PCM can keep the shape stabilized when PCM undergoes a phase change because it is microencapsulated by the supporting material. At night the heat energy stored in the PCM could be released into the room by the ductless air supply. The thermal performance of a room using such system was experimentally studied. The experiments show that the thermal comfort degree of solar buildings can be improved when applying shape-stabilized PCM suitably. The conventional space heating energy consumption in winter can be greatly saved. Besides, the experimental results provide the data for further modeling and simulation research of such kind of system.
Radiative Transfer Within a Cylindrical Cavity With Diffusely/Specularly Reflecting Inner Walls Containing an Array of Tubular Absorbers
Authors: Melchior Tom , Steinfeld Aldo
Published: October 2008

Monte Carlo radiative transfer analysis is applied to a cylindrical cavity-receiver containing an array of high-temperature tubular absorbers directly exposed to concentrated solar power entering through a spectrally selective window. The cavity walls are assumed either diffusely or specularly reflective. The relative dimensions, the number of tubes, and their position are optimized for maximum energy transfer efficiency or maximum absorber temperature. A single-tube absorber operating at 2000 K performs best when located at 60% relative distance to the cavity’s aperture. Higher absorber temperatures are attained for a specularly reflective cavity that serves as internal infrared mirror, but at the expense of lower energy transfer efficiencies. In contrast, diffuse reflecting cavity walls promote a more uniform temperature distribution around the tubular absorber. Decreasing the window-to-cavity areas ratio further results in an increase of the absorber temperature, which peaks for an optimum absorber-to-cavity radii ratio. This optimum ratio shifts to lower values for multiple-tube absorbers. However, the average absorber temperature is not significantly affected by using multiple-tube absorbers of constant total cross sectional area.