bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metallugical Design and Performance of ERW Linepipe With High-Quality Weld Seam Suitable for Extra-Low-Temperature Services
Authors: Toyoda Shunsuke , Goto Sota , Okabe Takatoshi , Kimura Hideto , Igi Satoshi , Matsui Yutaka , Yabumoto Satoru , Sato Akio , Suzuki Masahito , Inoue Tomohiro 
Published: July 2013

To clarify the effect of inclusions on the Charpy impact properties, the 2 mm V-notched Charpy properties of X60 – X80-grades steel were numerically simulated using the finite element method code ABAQUS. The yield strength and the tensile strength of the steel were 562 MPa and 644 MPa, respectively. The striker’s velocity and the temperature dependency of the stress-strain curve were taken into account. To estimate the effect of nonmetallic inclusions, a 200 μm long virtual inclusion with a 1 μm edge radius was situated at the maximum point of the stress triaxiality. Four types of micro crack initiation were determined: (a) ductile void generation in the matrix, (b) cleavage crack generation in the matrix, (c) void generation by inclusion fracture and (d) void generation by matrix-inclusion interface debonding. Without inclusions, a ductile micro void was generated when the striker stroke was 3.3 mm, independent of the temperature. With inclusions, an inclusion fracture occurred when the striker stroke was 0.6 mm at room temperature. The striker stroke decreased as the temperature decreased.
Based on the above numerical estimation results, electric resistance welded (ERW) Linepipe with high-quality weld seam MightySeam® has been developed. Controlling the morphology and distribution of oxides generated during the welding process by means of temperature and deformation distribution control is the key factor for improving the low-temperature toughness. The Charpy transition temperature of the developed ERW pipe was much lower than −45°C. Based on the low-temperature hydrostatic burst test with a notched weld seam at −20 °C, the MightySeam® weld provides a fracture performance that is the same as UOE Double Submerged Arc Welded pipe. The pipe has been used in actual, highly demanding, severe environments.
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.
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.