bluuebunny/crossref_metadata_2025 huggingface dataset:
Management of Pre-Regulation Pipe
Authors: Zamarin Chad J. , Hereth Mark L.
Published: July 2013

This paper establishes a broad approach including a process to verify and where necessary achieve integrity of pre-regulation pipelines based on fitness for service (FFS) analysis. FFS is an accepted set of processes to demonstrate the mechanical integrity of in-service equipment, including pipelines. FFS analysis is specifically designed and has been demonstrated to support decisions on future disposition of equipment. The analysis for pre-regulation pipe rigorously focuses on material and construction threats, the primary threats to pre-regulation pipelines. All other threats to these pipelines are otherwise addressed through B31.8S and CSA Z662. The FFS analysis for pre-regulation pipe includes consideration of material properties, testing history, and operating history and provides guidance for achieving integrity where the FFS deems either insufficient data or actual pipeline characteristics warrant action. The methods currently used in FFS evaluations have been applied in the petroleum refining, petrochemical, nuclear, paper and steam electric power industries as well as the pipeline industry since the 1980s. One of the first acknowledged threat specific applications was actually in the pipeline industry with the development of B31G, a method for calculating the remaining strength of pipelines in areas with metal loss, first published in 1984. In the late 1990’s, subject matter experts across a number of these industries created a compendium of methods to address a breadth of flaw types. The document was first published in 2000, as American Petroleum Institute (API) Recommended Practice (RP) 579. It was updated in 2007 through a joint effort between API and the American Society of Mechanical Engineers (ASME) and published as API RP 579-1/ASME FFS 1. Implementing the FFS process will require time to evaluate pipelines in a prioritized manner, manage customer service impacts and implement necessary actions. The paper addresses how to start applying the process and extend it over time. The FFS process prioritizes the right place to start as pipelines within high consequence areas (HCAs) that have incomplete strength test records. The testing, repair, remediation or replacement of these pipelines within HCAs will be accomplished over a defined time frame, and during that period findings will be continually evaluated to derive lessons learned for future work. In parallel, consistent with NTSB’s goal of making systems capable of accommodating in-line inspection tools and advancing research, industry and in-line inspection (ILI) providers will work to commercialize ILI technology that can more rigorously demonstrate FFS, from the standpoint of construction and material threats, for pre-regulation pipe. Innovative ILI technologies will be incorporated into the FFS protocol on a risk-prioritized basis.
Crack-Like Defects in Pipelines: The Relevance of Pipeline-Specific Methods and Standards
Authors: Cosham Andrew , Hopkins Phil , Leis Brian
Published: July 2013

Oil and gas transmission pipelines have a good safety record; however, like any engineering structure, pipelines do occasionally fail. The main causes of pipeline failures in North America and Europe are defects, such as damage due to external interference, corrosion defects, or material defects. Consequently, the pipeline industry developed its own ‘pipeline-specific’ methods for assessing the significance of these defects. These pipeline-specific methods have their origins in fracture mechanics, but the complexity of the underlying failure mechanisms was addressed through empiricism. Over the intervening years, more accurate ‘pipeline-specific’ methods have been developed that better model the underlying failure mechanisms. The toughness of line pipe steels is typically characterised in terms of the Charpy V-notch impact energy. This is a qualitative measure of toughness. The pipeline-specific methods use empirical correlations between Charpy V-notch impact energy and fracture toughness.

In parallel to the development of the pipeline-specific methods, fracture mechanics has been generalised in standards such as BSI 7910: 2005 and API 579-1/ASME FFS-1, using the ‘failure assessment diagram’ (FAD). The pipeline-specific methods and the methods in these general (‘generic’) standards have common roots.

The pipeline industry has used its pipeline-specific methods for 50 years, as there was little need to use the generic methods. This was because most of the defects detected in pipelines were corrosion or damage (e.g. dents), where pipeline-specific methods were well-researched and validated.

The increasing sophistication of in-line inspection methods (‘intelligent pigs’) in the pipeline industry mean that cracks in pipelines are now easily detected. Additionally, recent failures caused by crack-like defects (e.g. the San Bruno failure in the USA in 2010), mean that the industry needs guidance on how to assess these crack-like defects. There is little or no guidance on pipeline-specific methods for crack-like defects. Therefore, the industry has adopted the generic methods, without any evaluation of their relevance or accuracy.

The similarities and differences between the generic and pipeline-specific methods for crack-like defects in pipelines are illustrated in this paper through comparison with published full-scale test data for pipes containing notches and cracks. The significance of correlations between Charpy V-notch impact energy and fracture toughness is highlighted.

In conclusion, a commentary is given on how and when to take advantage of either approach. The critical gaps in the existing methods are also identified.
Ruptures in Gas Pipelines, Liquid Pipelines and Dense Phase Carbon Dioxide Pipelines
Authors: Cosham Andrew , Jones David G. , Armstrong Keith , Allason Daniel , Barnett Julian
Published: July 2013

Ruptures in gas and liquid pipelines are different. A rupture in a gas pipeline is typically long and wide. A rupture in a liquid pipeline is typically short and narrow, i.e. a slit or ‘fish-mouth’ opening.

The decompression of liquid (or dense) phase carbon dioxide (CO2) immediately after a rupture is characterised by a rapid decompression through the liquid phase, and then a long plateau. At the same initial conditions (pressure and temperature), the initial speed of sound in dense phase CO2 is greater than that of natural gas and less than half that of water. Consequently, the initial decompression is more rapid than that of natural gas, but less rapid than that of water.

A question then arises … Does a rupture in a liquid (or dense) phase CO2 pipeline behave like a rupture in a liquid pipeline or a gas pipeline? It may exhibit behaviour somewhere in-between the two. A ‘short’ defect that would rupture at the initial pressure might result in a short, narrow rupture (as in a liquid pipeline). A ‘long’ defect that would rupture at the (lower) saturation pressure might result in a long, wide rupture (as in a gas pipeline). This is important, because a rupture must be long and wide if it is to have the potential to transform into a running fracture.

Three full-scale fracture propagation tests (albeit shorter tests than a typical full-scale test) published in the 1980s demonstrate that it is possible to initiate a running ductile fracture in a CO2 pipeline. However, these tests were on relatively small diameter, thin-wall line pipe with a (relatively) low toughness. The results are not applicable to large diameter, thick-wall line pipe with a high toughness.

Therefore, in advance of its full-scale fracture propagation test using a dense phase CO2-rich mixture and 914×25.4 mm, Grade L450 line pipe, National Grid has conducted three ‘West Jefferson Tests’. The tests were designed to investigate if it was indeed possible to create a long, wide rupture in modern, high toughness line pipe steels using a dense phase CO2-rich mixture. Two tests were conducted with 100 mol.% CO2, and one with a CO2-rich binary mixture.

Two of the ‘West Jefferson Tests’ resulted in short ruptures, similar to ruptures in liquid pipelines. One test resulted in a long, wide rupture, similar to a rupture in a gas pipeline. The three tests and the results are described. The reasons for the different behaviour observed in each test are explained. It is concluded that a long, wide rupture can be created in large diameter, thick-wall line pipe with a high toughness if the saturation pressure is high enough and the initial defect is long.
Quality Program for Natural Gas Pipeline Operation and Maintenance
Authors: Ferreira Fernando A. Carriço , Leite João Paulo de Barros , Novaes Márcia G. de , Silva Marcos José Moraes da , Tomaz Luciane
Published: July 2013

The 670-km gas pipeline crossing the Amazon Forest to connect the production field in Urucu to Manaus, the main city of Brazil’s North region, presents many challenges for operation and maintenance. The difficulties of accessing remote areas in the forest, seasonal flooding and lack of infrastructure result in complex and expensive logistics. Many intermediate installations of the pipeline can only be accessed by helicopter. This highly complex operational scenario has been chosen as the prototype for a broader management program which aims to eliminate risks of failures that can impact natural gas delivery.

The main principle behind this program is focus on the critical equipment and prioritization of better maintenance for that equipment. The program combines concepts of asset management, reliability centered maintenance (RCM), and Lean Six Sigma. A well-designed asset management program, supported by remote monitoring of instrumentation, allows better control and management of the critical equipment, meaning faster maintenance response and less transport of spare parts. RCM provides a suitable mechanism to define the critical equipment and Lean Six Sigma simplifies both operational and maintenance processes by reducing the activities that do not add value while working to prevent risks of failures of critical equipment.

An interactive computational system has been developed to disseminate and facilitate the use the Six Sigma quality tools. In addition, the program coordinators have already been trained in the Six Sigma Green Belt module and the technical staff will be trained in the Yellow Belt module. As a result of the initial stages of implementing the program, the number of execution standards for operation and maintenance has been reduced from 35 to 8, with an increase in productivity. For the next stages of the program, further productivity improvements are expected, along with more efficient control of critical processing and transport equipment, to minimize or promptly mitigate the effects of failures that can prevent delivery of natural gas.
Continuous Real-Time Pipeline Deformation, 3D Positioning and Ground Movement Monitoring Along the Sakhalin-Khabarovsk-Vladivostok Pipeline
Authors: Borda Carlos , Niklès Marc , Rochat Etienne , Grechanov Alexander , Naumov Alexander , Velikodnev Valeriy
Published: July 2013

Operating in remote regions, Russian pipelines not only are subjected to harsh environmental conditions, but also in some of their sections to seismic activity. In order to secure these assets’ integrity, monitoring is mandatory.

Due to the long distances to be monitored and to the linear nature of these pipelines, distributed fiber optic sensing is the only solution to provide remote monitoring operation with accurate localization of events. In some cases, it can even take advantage of the telecommunication fibers laid along the pipelines to minimize installation cost.

A complete and commercially available solution based on the DITEST Asset Integrity Monitoring (AIM) system combines strain and temperature measurement over 100’s kilometers at meter spatial resolution with dedicated fiber optic cables specifically developed for strain, temperature and ground movement measurement to provide continuous information on any abnormal pipeline behavior, including leak, intrusion, excessive tube deformation and seismic activity.

This scalable monitoring solution was adopted to monitor the most critical areas of the Sakhalin-Khabarovsk-Vladivostok pipeline route, which crosses 32 Active Tectonic Faults (ATF) zones. A combination of pipeline deformation monitoring, ground movement detection and leak detection is used to monitor these critical pipeline regions. The early knowledge of abnormal events allows the pipeline owner/operator to take preventive mitigation measures in response to these critical geohazards.
How the Uncertainties of ILI Data Affect Pipeline Crack Assessment
Authors: Jäger Christoph , Willems Herbert , Barbian Alfred , Uzelac Neb
Published: July 2013

Crack inspection of pipelines using liquid-coupled ultrasonic technology has established itself as an accepted ILI (in-line inspection) technology that is routinely applied by many operators. The inspection is based on the pulse-echo technique using 45° shear waves which provide very good detection sensitivity. While length sizing of cracks is reasonably precise, the accuracy of (amplitude-based) depth sizing is limited to some extent. Apart from the crack size, the methods applied for crack assessment have to take into account the geometry of the actual pipe, the relevant material properties and the loading conditions.

The work presented is based on the FAD method (Failure Assessment Diagram) being the most common technique for assessment of crack-like defects in pipes. It is shown how the assessment results depend on the quantities determined by ILI (e.g. crack size, wall thickness) and their associated measurement uncertainties. Using a deterministic approach the sensitivity with regard to the different parameters can be compared quantitatively. Probabilistic crack assessment based on the combination of the FAD method with Monte Carlo simulations is well suited for taking into account the statistical distribution of the measuring tolerances. It allows, for example, the calculation of statistical properties such as the probability of failure as will be demonstrated for realistic defect situations.
A Practical Approach to Pipeline System Materials Verification
Authors: Lutz Andrew R. , Bubenik Thomas A.
Published: July 2013

The Pipeline and Hazardous Material Safety Administration (PHSMA) has increased emphasis on records that are “traceable, verifiable, and complete.” Organizing records into a document structure that is traceable, verifiable, and complete can be a daunting task.

Through work with operators, Det Norske Veritas (U.S.A.) Inc. (DNV) identified a methodology to efficiently search and organize material property data and records into a structure that is fit for regulatory audit. The methodology consists of four steps:

(1) Search/Organize Documentation.

(2) Digitally Capture Paper Documents.

(3) Determine Document Precedence.

(4) Create a Reference-able Listing.

The first step reviews all files and records and identifies records that are pertinent to properties verification. The search is conducted at an operator’s office(s) by a team of personnel familiar with pipeline construction and maintenance documentation.

Once records have been identified, they are digitally captured (scanned) making them easy to reference. This requires a set of metadata and unique name for each document. The metadata consists of project number, document type (maintenance form, drawing, etc…), pipeline name, and information location.

Document precedence is used to identify documents most likely to contain correct material information. Document precedence is determined with operator employees that can identify document(s) that have been historically given high reliability.

Finally, a listing tabulates material properties along with the unique document name(s) for the specific records. The listing contains pipe (by segment or joint), fittings (valves, prefabricated elbows, etc…), and other components that may affect Maximum (Allowable) Operating Pressures. Typically the listing uses linear pipeline stationing as the main reference.

Implementation of the methodology yields a listing of material properties specifically linked to a digital document database — i.e., a records system that is “traceable, verifiable, and complete.” In addition to material properties, this methodology has also been applied to risk-related information (e.g. cathodic protection, crossings, coating information, etc…). The listing can then be used to identify any information gaps and potentially prioritize them based on reliability.
Predicting Pipeline Performance in Geohazard Areas Using ILI Mapping Techniques
Authors: Lockey Aaron , Young Andy
Published: July 2013

Pipelines that cross mountainous areas are susceptible to ground movement loading from landslides. In-line inspection using inertial mapping tools provides an excellent method of evaluating the current pipeline integrity. A single inspection only gives an indication of the pipeline integrity at a single point in time. Multiple inspections over a period of time can be used to estimate positional change and the nature of the loading process. An essential element of pipeline integrity management in geohazard areas is the ability to determine future performance so that intervention methods are correctly designed and scheduled and resources are efficiently administered. This requires the reliable prediction of the future development of pipeline integrity based on trends in the mapping data from multiple inspections.

The approach developed by the authors to predict the future integrity of pipelines affected by ground movements is set out in this paper. It involves inertial mapping data from multiple inspections and calculates future strains in the pipeline using finite element analysis. Unlike methods based on interpreting inspection data alone, the finite element model includes the effects of soil-pipe interaction and axial pipeline stress together with the operational loads to provide a more complete assessment of pipeline integrity. The method is illustrated through the use of a case study.
Critical Components Method for Inventory Optimization
Authors: Prescott Jonathan W. , Ferguson James , Blackwell Chris
Published: July 2013

Undetected time-dependent hazards that lead to first time failures of oil and gas pipeline installations result in unplanned maintenance of the facility. The operator is usually unprepared for this type of failure which can result in significant downtime because long lead time components that are needed for the repair will be unavailable. The cost of downtime is, therefore, largely dependent on the lead time to procure these components. Analyzing pipeline facilities for critical components can reduce the likelihood of an extended downtime.

Inventory levels for any system are determined by first deciding which components to inventory, and secondly, determining the quantity to inventory. Solutions to problems of this nature (inventory optimization) can be achieved by rigorous analysis of probability and statistics. The disadvantage of this approach is that it relies on the accurate determination of input parameters for its solution.

This simplified methodology outlines a method to inventory components for primary process piping components (static equipment) in pipeline installations without the need for rigorous mathematical analysis. The simplified methodology entails the following tasks: identifying the critical flow path for the system using drawings; creating a bill of materials for the system from drawings or during a field visit; specifying a threshold permissible lead time for components in service; applying a repair methodology created from CSA Z662 to determine the quantity of components needed; and cross referencing the bill of materials with a database of long lead time components which are known from performing an availability study.

This analysis provides a solution for pipeline operators wanting to limit downtime due to failure of critical components on static equipment.
Time-Dependent Corrosion Growth Modeling Using Multiple ILI Data
Authors: Zhang S. , Zhou W. , Al-Amin M. , Kariyawasam S. , Wang H.
Published: July 2013

This paper describes a non-homogeneous gamma process-based model to characterize the growth of the depth of corrosion defect on oil and gas pipelines. All the parameters in the growth model are assumed to be uncertain; the probabilistic characteristics of these parameters are evaluated using the hierarchical Bayesian methodology by incorporating the defect information reported by the multiple in-line inspections (ILIs) as well as the prior knowledge about these parameters. The bias and random measurement error associated with the ILI tools as well as the correlation between the measurement errors associated with different ILI tools are taken into account in the analysis. The application of the model is illustrated using an example involving real ILI data on a pipeline that is currently in service. The results suggest that the model in general can predict the growth of corrosion defects reasonably well. The proposed model can be used to facilitate the development and application of reliability-based pipeline corrosion management.
Root Cause Analysis of Dent With Crack: A Case Study
Authors: Arumugam Udayasankar , Gao Ming , Krishnamurthy Ravi , Wang Rick , Kania Richard
Published: July 2013

A combined caliper and tri-axial MFL in-line inspection (ILI) reported a bottom side 2.7%OD dent associated with 76% metal loss. The reported dent depth is well below the 6% limit while strain analysis of this ILI dent profile showed a maximum equivalent strain of 17.4%, which exceeds the 6% strain limit for gas pipeline. Due to the high dent strain level, the raw signals of metal loss were revisited, which indicated this associated metal loss appears to be a crack rather than corrosion. In-field investigation revealed that this dent is indeed associated with branched cracks both at internal and external pipe surface but no leak was detected.

The primary objective of this case study is to determine the cause for cracking in the dent. As part of this study, detailed investigation was performed including LaserScan based strain analysis, lab pressure-cycle testing and fracture surface examination. An attempt was made to quantify the plastic strain damage of this dent and its susceptibility to cracking using the existing plastic damage models, namely, ductile failure damage indicator (DFDI), strain limit damage (SLD) and minimum elongation limit criterion. The investigation showed that the internal cracks were formed at the time of indentation while the external cracks formed by spring-back (elastic rebounding) due to the removal of rock constraint. Full size fatigue testing of this cracked dent showed leak failure modes rather than rupture. In this paper, the approach, results and the findings are summarized and discussed.
An Approach to Sinkhole Prevention on Post Pipeline Construction at Trenchless Road Crossings
Authors: Wong Everett , Sasaki Greg , Harrison James
Published: July 2013

Sinkholes manifest unpredictably at road crossings long after the completion of pipeline installation. In recent pipeline projects, Alberta Clipper Expansion and Line 4 Extension, over 1200 km of NPS 36 oil pipeline was constructed across Alberta, Saskatchewan, and Manitoba. Over 600 road crossings were executed across these provinces utilizing standard industry crossing techniques and under a wide variety of soil conditions. Several months after construction, sinkholes appeared on roads at locations along the centerline of the newly constructed pipeline. It is hypothesized that bores which were observed to have been over-reamed, re-reamed, or had pipe pulled back, may have contributed in development of unconsolidated soil or “voids” in comparison to adjacent native subsurface soil, which then manifested into sinkholes. In other cases, the evolution of voids may have been attributed to pre-existing soil conditions. Since sinkholes pose safety concerns to the public as well as the integrity of the pipeline mitigation, control measures were taken to assess and remediate other locations prior to sinkhole manifestation.

An approach to prevent sinkhole manifestation is identifying high-risk crossings, scanning for voids, and void remediation. Identification of high-risk sinkhole manifestation at crossings involved desktop evaluation which was based on: observations noted inspectors’ reports, geotechnical conditions, depth of crossings, the elevation difference between the entry and exit holes, and crossing method. Once prioritized, selected road crossings were scanned for voids using a technology called Ground-Penetrating Radar (GPR), which is the focus of this paper. Ground-penetrating radar employs a system of radio waves at various frequencies directed at the subsoil. The changing velocities between consolidated and unconsolidated soil provides different views of the subsurface. Factors such as pipeline depth, soil type, and interference, played a factor in the ability to accurately scan for voids. For remediation, the injection of polyurethane foam was used. This paper describes the approach, process, accuracy factors, and findings of Ground-penetrating radar used on pipeline projects.
Incorporating Environmental Considerations Into Pipeline Integrity Management Programs
Authors: Taylor Patricia , Wielki Jeff , Shea Troina
Published: July 2013

Canada’s extensive pipeline grid can be traced back to the 1950s when major crude oil and natural gas finds in western Canada led to the construction of large pipeline systems [1]. Some of the currently operating pipelines in Canada have been operating for over 60 years. With the objective of ensuring that pipelines are suitable for continued reliable, safe and environmentally responsible service, the National Energy Board (NEB) issued the Onshore Pipeline Regulations (OPR) in 1999 (OPR-99) mandating pipeline companies to develop and implement Integrity Management Programs (IMPs).

The OPR-99 allows pipeline companies to tailor the content of the IMPs to particular circumstances. From a life cycle perspective, the majority of pipeline IMPs involve inspection and testing, data management and interpretation, risk assessment, integrity or engineering assessment and pipeline repairs. Despite the evident benefits of implementing IMPs, conducting pipeline repairs can also trigger environmental concerns and permitting requirements. Developing effective Environmental Protection Plans (EPPs) and obtaining federal and provincial environmental permitting in sensitive areas can be time consuming and costly. If these factors and costs are not incorporated to the planning process they can create subsequent delays and financial burdens. Additionally, implementing environmental management practices throughout the life cycle of IMPs will aid pipeline companies in managing environmental issues systematically and effectively while enhancing environmental stewardship and corporate social responsibility. Including environmental setting considerations, identifying regulatory requirements and conducting stakeholder engagement during the earliest stages and throughout the IMP is essential to ensure the sustainability of the Program. This paper describes an integrated management system which incorporates environmental considerations throughout the overall IMP and a strategic approach to information management.
Enhanced Use of ILI Data to Improve Integrity Decisions
Authors: Taylor Collin , Zhu Renkang Rain
Published: July 2013

With the current generation of in-line inspection (ILI) tools capable of recording terabytes of data per inspection and obtaining millimeter resolution on features, integrity sciences are becoming awash in a sea of data. However, without proper alignment and relationships, all this data can be at best noise and at worst lead to erroneous assumptions regarding the integrity of a pipeline system. This paper will explore the benefits of a statistical alignment method utilizing joint characteristics, such as length, long seam orientation (LSO), wall thickness (WT) and girth weld (GW) counts to ensure precision data alignment between ILI inspections. By leveraging the “fingerprint” like morphology of a pipeline system many improvements to data and records systems become possible including but not limited to:

• Random ILI Tool performance errors can be detected and compensated for.

• Repair history and other records become rapidly searchable.

• New statistically accurate descriptions are created by leveraging the sensitivities of various ILI technologies.

One area of material data improvement focused on within this paper relates to long seam type detection through ILI tools. Due to the differing threat susceptibility of various weld types, it is accordingly important to identify the long seam weld types for integrity management purposes. Construction records of older vintage lines do not always contain information down to the joint level; therefore, ILI tools may be leveraged to increase the accuracy of construction records down to this level. In this paper, the possibility of ILI tools, such as magnet flux leakage tools, ultrasonic crack tools, and ultrasonic metal loss tools, to distinguish different types of longitudinal seam welds is also discussed.
Providing Safety: Using Probabilistic or Deterministic Methods
Authors: Kariyawasam Shahani , Huyse Luc
Published: July 2013

The primary objective of a good engineering design or maintenance process is to provide safety with optimized resources. Most parameters and models used in engineering have uncertainty — some more so than others. Probabilistic assessments strive to account for these uncertainties explicitly while the deterministic methods account for uncertainties implicitly by using conservative inputs and safety factors. Deterministic methods are preferred by many due to their simplicity. However if inputs and safety factors are not defined prudently with explicit consideration for uncertainties and consequences they can lead to unsafe or unduly conservative solutions.

The main objective in using reliability based methodologies is to provide consistent safety by explicitly accounting for uncertainties in a probabilistically quantified manner. Reliability methods also allow the articulation of the level of safety. This level of consistency in safety cannot be achieved in a deterministic analysis using safety factors because uncertainties are not accounted for explicitly and consequently the uncertainties lead to variable solutions. However safety factors can be calibrated using reliability methods so that more consistent safety levels can be assured when using deterministic methods.

There is a relationship between the reliability level and the deterministic safety factors. This relationship between reliability levels and deterministic safety factors is examined both from a mathematical and practical perspective. Consequently it is shown that reliability based methods can be used to calibrate deterministic methods to improve the consistency of the safety level with due consideration to underlying uncertainties and consequences. This kind of calibration is used in other industries such as structural design and nuclear facilities. Providing more consistent safety enables optimization of maintenance activities which enables the safest system to be provided with available resources.

Currently the pipeline industry uses deterministic methods with conservative inputs that are not based on risk or safety principles. Consequently there is a large variation in the inputs and safety factors used in the industry. Some examples of these are safety factors used in response to inline inspection that vary from the reciprocal of the design factor to 1.1 for all location classes.

This paper shows that the maximum safety factor achievable for a given design is defined by the original design factor and the ratio between flow stress and yield strength. It also shows the inadequacy of using safety factors that are not risk based. The paper focuses on the importance of using a sound risk based rationale for appropriate safety factors in deterministic methods.

A glossary of terms is provided at the end of the introduction.
AHP Method: Application in Pipeline Projects in Brazil
Authors: Librais Valter , Lourenço Sergio Ricardo , Vasconcelos Claudemir Duca
Published: July 2013

This article considers that the most cost-effective way to transport products of fossil fuels, liquids or gases, is by a pipeline system which provides high operational reliability, lower power consumption and less environmental impact consequently. It becomes more and more necessary implementing new pipeline projects in Brazil. In the early seventies, discussions have started regarding the pressure for reduction of costs and pursuit of sustainable development, linked to the Triple Bottom Line, which uses economic, environmental and social dimensions. So far, the decisions in several sectors of the oil industry have been taken based on just one criteria, usually economical. This study proposes the establishment of a multicriteria analysis to be used in future pipeline deployments in Brazil, aiming to support the decision makers by supplying them quantifiable and unquantifiable criteria. For the development of this analysis, it will be used the Analytic Hierarchy Process (AHP) in which the various relevant criteria are represented through relative weigh. A project of a new pipeline will be used as a case study to demonstrate the application of the proposed model. The organizations can use the result of the analysis as an input to decision-making on future ductwork ventures in Brazil, especially in terms of environmental and social dimensions.
Quantitative Risk Assessment for Projects Schedules
Authors: Hassanien Sherif S. , Skow Jason B.
Published: July 2013

Despite vigilant efforts in project scheduling and planning by engineers and project managers, recent market research reported a marked decrease in project success rates. The market research tracked projects across a broad range of industries and concluded the primary failure causes to be a lack of sufficient detail in the project planning stage, poor or no risk analysis, scope creep and poor communication. This paper focuses on a strategy to minimize the first cause. Specifically, how to obtain sufficient schedule and resource estimates to better predict time allocation and expected costs with a focus on capital pipeline projects. To this end, a quantitative risk assessment (QRA) methodology is applied to project schedules allowing the uncertainty of key task durations and/or costs to be fully accounted for in the schedule. Projects managers will be able to quantify the uncertainty in their projects and support decision makers with a more accurate prediction of the likelihood of being on time and on budget. This paper introduces a systematic approach for both aleatory and epistemic uncertainty quantification. In addition, the expected benefits of adopting QRA for projects schedules are discussed through a hypothetical simple project schedule from the pipeline industry.
Effects of Detector Dynamics on Magnetic Flux Leakage Signals From Dents and Gouges
Authors: Clapham Lynann , Babbar Vijay
Published: July 2013

The current study was designed to model the dynamic effects of detector ride and magnet liftoff on Magnetic Flux Leakage (MFL) signals from dents as well as gouges that have significant denting. The MFL tools have long been used for the detection and sizing of corrosion defects. This is comparatively straightforward for a number of reasons, one of which is that the MFL detector assembly can ride relatively smoothly along the inner pipe wall surface. This is not the case when significant denting is present, since the dent presents a perturbation in the pipe wall that can cause liftoff of the detector or magnet system. Since the tool travels at relatively high speeds down the pipe, the dent itself can cause the detector to lose contact with the trailing half of the dent. In addition, the magnet pole piece may experience partial liftoff as it traverses the dent, thus causing a change in the local flux density.

In this study results from ‘static’ measurements are compared with a dynamic case in which detector liftoff is simulated through modeling and experiment. Results are discussed regarding the severity of MFL signal loss at the trailing edge of the defect as a result of detector liftoff.

The effect of partial liftoff of the magnet as it passes over the dent is also examined. Magnet liftoff is found to increase the local magnetic flux near the liftoff region, causing the MFL signal from the dent wall to increase rather than decrease in the vicinity of magnet liftoff region.
A Study of Deformation Behavior of Double Jointing Girth Welds
Authors: Yokota Tomoyuki , Murakami Yoshiaki , Sakimoto Takahiro , Satoshi Igi , Endo Shigeru
Published: July 2013

Demand for double jointing technology is increasing to improve pipeline construction productivity. Submerged arc welding (SAW) utilized for double jointing is likely to cause a much wider heat affected zone (HAZ) than those of typical field welding by gas metal arc welding (GMAW), and it should be taken into account for strain-based design of high strength line-pipes. However, guidelines for SAW welds properties to ensure strain capacity of high strength line-pipes such as X80 have not been established yet.

In this study, a submerged arc weld joint was produced using tensile strength (TS) over-matching welding consumable. API standard type transverse weld tension test was conducted to measure local elongation at weld metal, HAZ, and base material. Elongation at weld metal increases prior to base material, but soon after that elongation at the HAZ softening region and base material adjacent to the HAZ catch up with the elongation in the weld metal, and finally, deformation concentrates at the HAZ softening region before final fracture.

Deformation behavior of the joint was analyzed to verify applicability to double jointing girth welds for strain-based design. From finite element (FE) analysis of notched wide plate test which characterizes tensile strain capacity of a pipeline, it is suggested that ductile crack would not initiate before base material start necking in this particular TS over-matching weld joint in which the defect size is 1mm of notch depth and 25mm of notch length. Thus, the weld joint would be applicable for double jointing girth welds based on strain-based design.
Optimization of Valve Placement in Liquids Pipeline Systems
Authors: Rout Cameron T.
Published: July 2013

Many considerations go into the design of liquid pipelines relative to the placement of valves. Proper consideration of this issue must address not only minimization of capital costs, but the minimization of potential environmental and safety consequences. Critical to minimizing operating risks is the impact of valve placement on the potential outflow during a loss of containment event. In order to optimize the placement of valves in a pipeline, the effectiveness of each of many potential valve placement combinations must be measured by properties of the potential spill behaviour (i.e., average spill volume, peak spill volume, and HCA impacts). Factors affecting spill volume are topography, product properties, detection periods, valve closure timelines, and pump shut-down behaviour. This paper presents a solution to the challenge of optimizing valve placement in both interconnected and isolated systems through iterative generation of valve placement scenarios and hydraulic modeling. Various considerations that designers and operators should address are presented, along with results that are calibrated against real-world incidents.
New Specialty Resins for High Performance Fusion Bonded Epoxy Coatings
Authors: Miller Tim , Aguirre Fabio , Hudack Ray
Published: July 2013

In the last decade, the evolution in the exploration and transportation of oil and gas as well as efforts to delay the effect of corrosion on strategic and valuable assets like pipelines, have triggered the development of new Fusion Bonded Epoxy (FBE) anticorrosion coatings. A major component in a FBE formulation are solid epoxy resins, which when properly formulated enable the FBE coating to reach higher performance requirements to cope with the ever more challenging conditions in the field. This paper describes how solid epoxy resins (SER) can help high glass transition temperature FBE coatings to protect pipelines operating at high service temperatures from corrosion. A second area of innovation is a solid epoxy resin that helps FBE to cure at lower application temperatures than standard FBE coatings while maintaining the similar corrosion performance. Damage tolerance is the third area of innovation. Dow Coating Materials has developed an epoxy/copolymer resin system which helps the FBE formulator overcome the brittleness of FBE Abrasion Resistance Overcoat (ARO) at subzero temperatures.
J-Resistance Results From Multi-Specimen and Single-Specimen Surface Notched SEN(T) Geometry
Authors: Pussegoda Lakshman N. , Tiku Sanjay , Park Dong-Y. , Tyson William R. , Gianetto Jim
Published: July 2013

In a collaborative program, J-R results were compared from multi-specimen and single-specimen procedures for toughness testing with single-edge notched tensile loaded SEN(T) specimens. Grade 483 MPa (X70) grade pipeline steel was used to prepare surface notched axially loaded specimens. Test procedures followed the multi-specimen method and a single-specimen recommended practice recently developed at the CANMET Materials Technology Laboratory (recently name-changed to CanmetMATERIALS) in a program jointly funded by PERD, PRCI, and DOT. The multi-specimen method adopted side grooves with the objective of comparison with results from the single–specimen method. The specimen geometry was B × B for both test procedures. The target ao/W was about 0.5.

The multi-specimen testing was performed at BMT Fleet Technology. The single-specimen testing was performed at the CANMET laboratory, formerly located in Ottawa.

The paper describes experimental and analysis details, and compares results from the two techniques, using J expressions developed at CANMET. The results showed similar J-resistance curves at small crack extensions for both techniques, and higher J-resistance values at larger crack extensions for the multi-specimen method. The results are discussed in terms of initial crack length and the analysis methods adopted for the two techniques. Validity criteria according to ASTM E1820 were applied and the results are presented.
Advanced Insights on Composite Repairs
Authors: Alexander Chris , Souza Jim
Published: July 2013

In response to inquiries from pipeline operators regarding the long-term performance of composite materials, manufacturers have performed additional tests to evaluate the performance of their composite repair systems. Insights were gained through these additional tests that demonstrated the long-term worthiness of the composite system. Of particular importance were two types of tests. The first involved the application of strain gages between layers of the composite repair system that was used to reinforce a corroded pipe test sample. As the sample was pressurized the strain gages permitted a comparison between the measured values and design stresses per the ASME PCC-2 design code. The second series of tests involved pressure cycling a 75% corroded sample to failure. In addition to the inter-layer strain measurements, the pressure cycling provides an important insight regarding the long-term performance of the composite repair.

This paper addresses how the ASME PCC-2 Code, along with additional well-designed tests, can be used to design a composite repair system to ensure that it adequately reinforces a given defect. As composite materials are being used to repair pipeline anomalies beyond the corrosion-only defects, it is essential that pipeline operators utilize a systematic approach for ensuring the long-term performance of composite repair systems.
Considerations for Implementation of Safety Instrumented Systems (SIS) for Pipeline Control Systems
Authors: Sahraei Alireza
Published: July 2013

Safety instrumented systems are now well recognized and utilized by various operational companies in oil and gas majorly in integrated plants such as refineries, upgraders and petrochemical plants based on the both reliability and availability of these systems to prevent and mitigate any risk associated with any high consequence initiating event. The SIS requirements are well developed and globally accepted within IEC61511 and ISA84.01 standards in which the safety lifecycle requirements have to be met. The initial implementation of SIS in each plant has always been a challenging program because it needs tremendous effort to develop processes and procedures to meet any single clause of the lifecycle. At the same time, following the engineering best practices is another key factor of success for this implementation.

However, in pipeline operations industry, there are additional aspects regarding risk management, design, operations and maintenance of the SIS, which have to be considered in addition to all code requirements and considerations on the integrated plants such as refineries, as mentioned above. These special considerations should not be underestimated and have to be dealt with as special requirements for the industry. These aspects raise sets of technical challenges for any implementation initiative and other planning or execution challenges which are directly related to the safety lifecycle.
Standardization and Delegation of Pipeline Sizing Calculations
Authors: Garwood Dan
Published: July 2013

For all pipeline projects, a method must be chosen to select the pipe diameter. These methods range in complexity from someone’s “gut feel” to transient multi-phase optimization studies. Regardless of the project’s complexity or scope, pipeline sizing calculations require some common decisions. The pipeline designer must decide what fluid flow rates or ranges of fluid flow rates to use in the design. The designer must also determine what criteria to use to select the pipe size (usually fluid velocity, pressure loss, and/or pressure loss gradients).

More complex and rigorous analyses of pipeline projects have some significant advantages. On some projects they may save money by avoiding over-sizing that can occur due to conservative assumptions that are often used in less rigorous analyses. More rigorous analyses typically have the advantage of being run by a very experienced engineer, who is likely to understand the fundamental principles of the calculations better than a less experienced engineer who might run a less rigorous analysis.

There are also disadvantages to the more rigorous design approaches. The software required is often expensive, and training required may also have a significant cost in time and money. The pool of users capable of performing such studies may also be very limited. Complex, rigorous design studies also require more extensive assumptions, which may lead to wider variations in results from one engineer to another. The increased complexity of the analysis makes it more difficult to convey the assumptions to management—limiting the transparency of the design process.

This paper describes a standardized approach to the pipeline sizing process. This approach allows the pipeline designer to delegate portions of the design work to personnel who are not experienced hydraulics engineers. For more complex projects, the standardization is limited to recommended pipe sizing criteria based on velocity, pressure loss, and pressure gradient. For less complex projects, two spreadsheet-based tools have been developed to further standardize the process and allow delegation of design tasks to those not familiar with more complex pipeline design tools.