bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk Assessment of Gas Transmission Pipelines in Mexico
Authors: Martinez Jose L. , Alcerreca Héctor G. , Rodríguez B. Enrique , Hernandez Jesus 
Published: October 2016

In recent years significant changes have taken place in the Mexican gas industry. Activities related to gas transmission, distribution and storage are no longer the exclusive privilege of PEMEX Gas & Petroquimica Basica (PGPB), a traditionally state-owned company. The first priority of PGPB is to ensure a safe, efficient and reliable pipeline network. Several projects have been established to guarantee a smooth transition from a monopoly to open market competition.
Among these projects is a pipeline risk assessment and management programme (RAMP), to provide feedback on all safety related conditions of PGPB’s pipeline facilities. This project is planned to have a permanent application within PGPB, although a risk acceptance criteria based upon experience gained through the different project stages has yet to be established. This paper provides an approach adopted to assessing risk in more than 13,000 kilometres of pipeline, regardless of the transported fluid. Risk management is considered to be the step following the risk factors evaluation. However, PGPB is aware of the importance of calculating realistic indexes, so that management policies may be defined according to a well known risk magnitude.
Technology Management Renewal at NOVA Gas Transmission
Authors: Cormier Randy C. , Dorling David V. 
Published: October 2016

NOVA Gas Transmission Ltd. (NGTL) is an industry leader in successfully applying new technology to meet business needs. The company has had a formal technology development program since 1983 and invests approximately $5.5 million annually towards developing and implementing beneficial new technology. Over the years, this leadership has provided tremendous value to NGTL’s customers, shareholders, employees and the communities in which it operates.
In 1994, as part of the company’s re-engineering initiative, a high-level scoping effort identified several opportunities to further enhance the business value derived through the application of technology. To realize these opportunities, NGTL launched an effort to renew its processes for managing technology. Through this renewal effort, NGTL: 1) developed guiding organizational principles for managing technology, 2) established Key Technology Areas of focus, 3) re-structured its technology development organization, 4) leveraged best-practice concepts to improve the process of developing and implementing technologies, and 5) made significant progress in marketing the value of technological innovation across the organization.
This paper will highlight NGTL’s technology management renewal effort including its historical context and rationale, the process used and the major outcomes.
Route Selection for Project Success: Addressing “Feeling/Perception” Issues
Authors: Mohitpour M. , Von Bassenheim G. , Braun Ardean 
Published: October 2016

Selecting a route for a pipeline right-of-way (ROW) generally consists of engineering (technical and economic), socioeconomic and biophysical components. To effectively select a route, simultaneous consideration must be given to all the components from the initiation of a project to the integration of all aspects of each throughout the route selection process. To successfully select a route which creates a win-win situation for all the stakeholders of a pipeline project, political/governmental issues, community and land owner views, public perceptions and other similar controlling factors (such as Safety, Health, Environment and Risk (SHER)) must be carefully analyzed and integrated into the process. It is the consideration of all these issues that will lead to a ROW which will provide a technically acceptable solution, which is at the same time the least expensive, economically viable and acceptable to the community it traverses.
This paper will provide an overview of route selection techniques (including new technologies) used and the process generally practiced by pipeline designers, highlighting controlling issues and optimization methods that need to be utilized in order to achieve a cost effective route selection. It provides details on significant “Feeling/Perception” issues that can either thwart or, by careful consideration of these issues, lead to a successful pipeline project. An example of such a route selection process will be provided on a project located in rough and mountainous terrain, that has significant regulatory/governmental, land, environmental, indigenous and geological issues.
Countdown to the Year 2000
Authors: Bachor Vernon W. 
Published: October 2016

The Year 2000 problem, also known as Y2K or the Millennium bug, is an enterprise-wide issue that potentially touches all aspects of businesses and our personal lives. This paper is designed to heighten awareness of this critical issue and promote businesses to act.
This paper provides a primer on year 2000 issues for process control, with some pipeline-specific thoughts. The paper presents the potential impacts from the rollover, describes where to look for problems, outlines the methodology a year 2000 project should follow, provides guidance for vendor relations, and, finally, notes the critical processes for a pipeline.
Pipeline Isolation Tool
Authors: Jones David R. , Cooman Andre , Dyck John , Flatekval Gerry , Gotowik Horst 
Published: October 2016

Maintenance procedures conducted on pipelines often require isolation of a section of the line. Valve replacement, tie ins, pipe replacement are a few examples of procedures which normally require the pipeline to be taken out of service and drained down, or solid material stops intrusively applied to the pipeline.
Pipeline isolation tools have been available and applied for many years; these tools required pressure differential or tethered control to activate and deactivate the isolating mechanism. While these tools were applied with success, there was no way to accurately monitor this early generation of tool for performance and determine with reliability whether the tool was properly set. These tools had the capability of performing one task, once the tool had completed its task, it was removed from the pipeline and readied for its next application.
A new isolation tool has been developed and proven for pipeline application and this paper will discuss the Multi-Set Isolation Tool (Iso-Tool), its unique features, development and application.
Use of Surface Pipeline Segments to Mitigate Slide Problems on the Fort Nelson Natural Gas Mainline
Authors: Cavers Drummond S. , McClarty Edward A. 
Published: October 2016

Skid mounted surface pipelines have been used to cross four major creek valleys on the Westcoast Energy 762 mm Fort Nelson mainline where very large deep-seated slides are progressively failing. The surface pipeline segments range up to 2.2 km long and were used to cross very large slides on the creek approach slopes, or in one case, down valley sliding of the valley floor, which had resulted in major operational problems for the originally buried pipelines. The surface pipeline segments were used for slides where there were no other options for a conventional buried pipeline. During the studies to support the design of the surface pipelines, comprehensive geotechnical investigations included drilling, installation of slope indicators, and electric piezocone penetrometer testing to monitor subsurface pore water pressures and to detect deep seated slide surfaces. Typical peak movement rates of the slides varied to a maximum of several meters per year. The unstable soils were predominantly medium to high plastic silty clay tills and high plastic glaciolacustrine clays with residual internal angles of friction of 7.5 to 8.5°.
The pipelines were placed on pressure treated timber skids on graded rights-of-ways (RoW) with comprehensive surface and subsurface water control. Aerial clear span crossings were used across the watercourses with geogrid reinforced abutments on the unstable soil. Geogrids were also used to add stability to structural fills and to reinforce an area of the RoW subject to encroachment from a rapidly moving earth flow up to 6 m deep. The general maintenance and operational guidelines are also discussed. Provincial and Federal regulatory concerns and their abatement are presented and discussed. Over the past five years of operation of the pipelines, one of the slopes moved 1.5 m in a twenty-four hour period and related total movements left a 5 m high head scarp on the RoW. Displacement of soil and areas of thrusting resulted in unsupported pipe spans of 35 m with negligible deleterious impact on the pipeline. This magnitude of movement would have almost certainly caused a failure of the original buried line. All of slopes have continued to move and would have caused a varying magnitude of operational problems had the pipelines still been buried.
Pipeline Exposure at River Crossings: Causes and Cures
Authors: Sawatsky Les F. , Bender Michael J. , Long Dejiang 
Published: October 2016

Erosion is a common problem at pipeline watercourse crossings. Watercourses are naturally vulnerable to erosion but the risk is particularly acute after sub-soil and armour materials have been disturbed by trenching and backfilling during pipeline construction.
The process of pipeline exposure at watercourse crossings can be grouped into these types. One common type of erosion phenomenon is episodic exposure resulting from general and local scour. This is associated with temporary river scour during flood events. It includes general scour involving temporary lowering or the entire river bed during high flows, as well as local scour which involves development of a scour hole during high flow events at a predictable location on the river bed. River engineers have adopted various design methods to ensure sufficient pipeline burial depth which minimizes pipeline exposure due to such periodic occurrences.
A second type of erosion phenomenon causing pipeline exposure is progressive river channel bed and bank erosion. This is not a function of a single event but occurs periodically, resulting in progressive removal of pipeline cover. Progressive erosion at pipeline crossings includes riverbed degradation, bank erosion and growth of gullies. River bed degradation (progressive river bed lowering) is a complex phenomenon associated with the stage of geomorphic development of the drainage basin. Its prediction is based on a sound understanding of sediment supply, river hydraulics and river outlet conditions. Bank erosion is a common occurrence and is readily observed. It may be a continuous or episodic occurrence and is often related to the river’s tendency to change its meander pattern, cross sectional shape or bed level. Growth of gullies is a very common cause of erosion at pipeline crossings and results from changes in land use, soil composition, and landscape drainage networks. Techniques for predicting progressive erosion are not well developed and widely understood. As a result, progressive erosion is a common cause of erosion and even pipeline exposure at pipeline crossings of rivers, streams, and gullies.
A third mechanism of pipeline exposure is river avulsion. This is often associated with a tortuously meandering channel, a steep braided channel with a wide flood plain or an immature channel on a delta.
Methods of avoiding or controlling erosion are based on a sound understanding of causal factors. Each river crossing location is unique and the local risks of pipeline exposure must address specific local conditions. Methods of estimating the risk of local and general scour, progressive erosion, and river avulsions are discussed. Methods of mitigating erosion at pipeline crossings include proper siting of pipeline crossings, deep burial, conventional armouring and a combination of bank toe protection and upper bank vegetation cover.
Application of the Quartz Crystal Microbalance to Corrosion Investigation
Authors: Sun Hejian , Donini John C. , Michaelian Kirk H. , Papavinasam Sankara , Revie R. Winston 
Published: October 2016

The quartz crystal microbalance (QCM) provides an extremely sensitive technique for detecting small changes in mass and viscosity on the quartz crystal surface. QCM can be used in oil, gas or water without the problems of high solution resistance.
In order to use QCM to model pipeline corrosion, an iron quartz crystal electrode was prepared using an electrodeposition method. The reproducibility, effectiveness and accuracy of the iron QCM were tested in salt solution. The adsorption of amines was studied to investigate their effects on the corrosion behaviour of the iron QCM.
Repairing Pipe Defects (Cracking, Arc Burns, Corrosion, Dents) Without Operational Outages Using the PETROSLEEVE Compression Sleeve Repair Technique
Authors: Smyth Robert J. 
Published: October 2016

Non-serviceable defects, such as cracking, dents, corrosion, or mill defects, are found in operating pipelines. Past methods to repair these defects have included removing the defect, welding a pressure containing sleeve, or, for corrosion, installing either a mechanically tightened or fibreglass reinforcing sleeve. These methods involved potential system shut downs, potential loss of throughput, and in some cases welding to the carrier pipe.
The PETROSLEEVE compression sleeve repair system consists of installing steel plate material that is shaped and sized to encircle the carrier pipe. The repair is completed while the carrier pipe continues to operate at the pipeline’s operational pressure.
Following installation, the pipe and sleeve act as one unit, expanding and contracting with pressure changes. Depending on the installation parameters, the repair sleeve can be installed so that compressive stresses are maintained in the pipe for all pressure operating ranges.
This repair method does not require any welding to the operating pipeline. It can be installed when the carrier pipe is at maximum operating pressure.
Mechanical Development of a NPS 36 Speed Controlled Pipeline Corrosion Measurement Tool
Authors: Evenson Robert S. , Jacobs Scott K. 
Published: October 2016

High pressure natural gas pipeline companies conducting in-line magnetic flux leakage (MFL) corrosion inspection operations had to significantly reduce gas throughput velocity to accommodate MFL corrosion tool inspection speeds.
A large bypass, variable speed NPS 36 MFL corrosion inspection tool has been developed and run successfully in several high pressure natural gas pipelines without noticeable impact on operational throughput Active speed control enables the tool to run at speeds significantly lower than line velocity commonly experienced in high pressure natural gas pipelines. Unique mechanical innovations include large diameter flow bypass, an efficient speed control mechanism, variable drag backing bars and an independent bypass override system. A floating backing bar system ensures uniform sensor/wall contact for optimum data collection. Magnetic self-levitation of the backing bar results in reduced load on suspension and wheels providing more reliability and longer life to these components. Operating in higher line velocities infers higher possible tool speeds. This potential required development and construction of a more durable tool capable of higher speeds than typical MFL corrosion inspection tools. In this paper, development, testing and field operation of this tool is described.
NPS 8 Geopig: Inertial Measurement and Mechanical Caliper Technology
Authors: Michailides Phil , Deis Todd 
Published: October 2016

The Geopig inspection tool provides pipeline operators with three-dimensional geographic and geometric information of their pipeline system. This paper reviews two of the primary technologies onboard the NPS 8 Geopig that are used to provide such information: the inertial measurement unit (IMU), which provides structural and geographical characteristics of the pipeline, and the mechanical caliper arms, which capture the internal diameter of the pipeline.
Recognizing the benefits of the tool and the data it can provide, Wascana Energy Inc. executed an inspection of a natural gas pipeline in Northern Alberta. The pipeline, which had buckled and sheared at a specific location, was inspected with the Geopig to further identify any other possible buckles, wrinkles or dents prior to re-commissioning. This paper reviews the inspection project undertaken, the data compiled by the Geopig, and the steps taken in the development of a predictive finite element model of the pipeline.
The Role of Pressure and Pressure Fluctuations in the Growth of Stress Corrosion Cracks in Line Pipe Steels
Authors: Wilmott Martyn J. , Sutherby Robert L. 
Published: October 2016

Stress corrosion cracking of pipeline steels involves the interaction of a susceptible material with a corrosive environment under appropriate loading conditions. The stress exerted on pipeline steel is a combination of the internal operating or hoop stress, cyclic stresses due to pressure fluctuations within the pipe, residual stresses developed during pipe manufacture and pipeline construction, as well as other sources of stress such as stress concentrators like corrosion defects and geotechnical stresses.
As the internal pressure of an operating pipeline is never static the fluctuations in pressure result in cyclic loading of the pipeline material.
Whilst there are many stresses acting on a pipeline the predominant stress is the hoop stress created as a result of the internal operating pressure. In this paper experiments are described which are aimed at determining the effect of pipeline hoop stress on the growth of stress corrosion cracks under neutral pH conditions.
The propagation of stress corrosion cracks in pipeline steels at near neutral pH was studied under realistic environmental conditions. The impact of hoop stress on the growth of shallow surface cracks in an X60 pipeline steel was investigated at 40%, 70% and 100% of the specified minimum yield strength of the material. Crack growth rate is shown to be independent of the applied stress in the range studied for these shallow cracks. Cyclic stresses appear to be more important for crack propagation under neutral pH SCC conditions.
In light of the results obtained in this test program an attempt was made to characterize the pressure changes occurring on an operating gas pipeline. A computer program was developed to enable characterization of the pressure fluctuations for operating gas pipelines. The results of characterization of pressure histories from a number of operating pipelines are presented.
Prediction of Maximum Time for Delayed Cracking in a Simulated Girth Weld Repair
Authors: Malik Lalit , Pussegoda Lakshman N. , Graville Brian A. , Glover Alan G. 
Published: October 2016

In a previous publication, the use of a simple two dimensional finite difference model to predict hydrogen distribution in a simulated part wall pipeline girth weld repair was demonstrated. The validity of the model prediction was assessed using slow bend tests where the deflection to failure was an indirect indicator of the local bulk hydrogen concentration at the critical site for delayed cracking. In the present investigation, the same hydrogen diffusion model has been used to predict the maximum time for delayed cracking in a simulated girth weld repair for two ambient temperatures, (20° and −10°C). These predictions are compared with the delayed cracking times in “constant deflection” tests performed at the selected ambient temperatures.
The results obtained showed that there was some scatter in the relationship between the experimentally applied deflections and the delay time to crack initiation. The delay time predicted by the model for the local hydrogen concentration to reach its maximum value at the crack initiation site, however, was a function of the ambient temperature and these agreed reasonably well with the maximum delay times to cracking observed in the experiments.
An Instrumented Field Corrosion Test Loop
Authors: Demoz Alebachew , Michaelian Kirk H. , Donini John , Papavinasam Sankara , Revie R. Winston 
Published: October 2016

A multi-purpose instrumented loop in line with an oil producing well is described. The loop has several ports for coupons which were replaced periodically. Some of the coupons were used for electrochemical monitoring in addition to weight loss and visual inspection.
Weight loss, pit rate and all the electrochemical methods used gave corrosion rates that were dependent on the positions of the coupons inside the loop. The corrosion rate of the coupons increased from top to bottom. This order reflected the media and flow to which the coupons were exposed in a multi-phase producing well.
The Use of Reliability Based Limit State Methods in Uprating High Pressure Pipelines
Authors: Francis Andrew , Espiner Richard , Edwards Alan , Senior Gary 
Published: October 2016

There is an increasing demand for operators of transmission pipelines to maximise the throughput of their pipeline systems. This can be achieved relatively easily with new pipelines, by using limit state design, new materials, novel fabrication techniques etc., Operators are also looking to maximise the throughput of existing transmission pipelines. Obviously, they are not able to make use of new materials etc., but limit state design concepts can be applied to show that a pipeline can be safely uprated to a higher design pressure.
The limit state of an engineering structure or component is defined as the mathematical relationship between the parameters associated with a particular failure mode at the onset of failure. To assess the impact on pipeline integrity and safety, a limit state approach incorporating probabilistic analysis has been developed. The approach addresses all credible failure modes and takes account of uncertainties in the relevant parameters for each mode.
The probabilistic approach takes the limit state approach a step further by describing the parameters as statistical distributions rather than single values. This allows failure probabilities to be computed which are a more meaningful measure of safety and allow areas of over conservatism (or under conservatism) to be identified. It is important to note that the approach is only as good as the limit states used and the data used to construct the distributions. Clearly uncertainties in both of these can exist and the absolute values of the computed probabilities must be viewed with caution. However, the strength of the approach lies in the relative values of the computed probabilities and previous ‘safe’ operation. If a system has a significant operational history with few or no failures and it can be shown that there is little change in the theoretical failure probability associated with a change in operating conditions, it can be inferred that few or no failures will occur in practice.
The paper describes the above approach in detail and outlines a study carried out to determine the effect on pipeline integrity of uprating three pipelines from a current maximum operating pressure of 70 bar to an uprated pressure of 85 bar, exceeding the current design criteria. By application of the limit state approach incorporating probabilistic analysis, it is shown that there would be an insignificant change in failure probability as a result of uprating to 85 bar, and hence that the integrity of the pipelines is unimpaired by uprating.