bluuebunny/crossref_metadata_2025 huggingface dataset:
Algorithm Study for Metal Magnetic Memory Signal Processing
Authors: Feng Zhanjun , Wang Weibin , Dong Hongjun , Lin Song , Wang Dianxue , Wu Kai
Published: July 2013

Currently, Metal Magnetic Memory (MMM) non-destructive testing has been applied on trenchless inspection for buried pipeline. However, the problem of signal pattern recognition still exists. This paper introduces two signal processing methods to enhance the inspection accuracy of MMM: the signal segmented fluctuation and the signal segmented dissimilarity. Both of the two methods are designed for Signal singularity detection (SSD) of MMM signal. It is well known that the MMM signal of the stress concentrated area (SCA) is more fluctuant and dissimilar in contrast to those of non SCA, which is the basis of deriving the two algorithms. The two methods have the advantage in the detection of the metallic work piece which is non defective in looks but fatigued as well as may be helpful to detect the singularity of the signals such as negative pressure wave, ultrasonic wave etc. Experimental result with real data demonstrates the effectiveness of the proposed algorithms. Moreover, the MMM SSD software implementation is considered.
Trends on Integrity Management Programs (IMP) and Management Systems (MS) Audit and Incident Findings
Authors: Mora Rafael G. , Paviglianiti Joe , Slocomb Richard , Bourassa Mota Anne-Marie , Zaidi Mohsin
Published: July 2013

Over the past 12 years, as directed by federal and provincial regulations, Canadian pipeline companies have been formally developing and implementing Integrity Management Programs (IMPs). Since 1999, IMPs have been a requirement in the Canadian consensus industry standard CSA Z662. Furthermore, since the release of CSA Z662 Annex N in 2005, both the BC OGC and the Alberta Energy Resources Conservation Board (ERCB) (Canadian provincial regulators) have made CSA Z662 Annex N mandatory for their regulated companies. Annex N incorporates key management system (MS) elements such as a company’s policy and commitment, responsibilities, competency, planning, management of change, review and evaluation.

This paper presents the findings of IMP audits conducted by the NEB and BC OGC regulators during the period of 2001–2011. This paper also includes the findings of NEB’s analysis of pipeline incidents that occurred between 2005 and 2009 and how these incident findings correlate to the audit findings.

This paper is structured as follows:

• Integrity management regulatory frameworks

• IMP and MS elements and their interconnection

• Audit findings from the NEB and the BC OGC

• Incident findings from the NEB

• Analysis of the audit findings and their correlation to incidents

• Trends on IMP and MS audit and incident findings

The paper provides a general understanding of the findings and their trends on pipeline integrity management and on incidents in terms of IMP/MS elements as described in Table 1. The results from this study may help stakeholders to determine strategies to increase the adequacy, implementation and effectiveness of pipeline integrity management. This paper does not include any company-specific information nor results and conclusions from any particular audit report or incident.
Lateral-Axial Pipe/Soil Interaction Events: Numerical Modelling Trends and Technical Issues
Authors: Pike Kenton , Kenny Shawn
Published: July 2013

In predicting the geotechnical constraint against pipeline movement, it is imperative to properly account for frictional behavior at the pipe-soil interface, especially in the axial direction. The translation angle of the pipeline varies in reality; hence the effects of this variance must be captured in relation to the interaction forces in the lateral, axial and vertical directions. This study focuses on lateral-axial pipeline movement in cohesive soil material. The main finding of the present study is that the incorporation of a shear stress limit in the definition of tangential shear behavior has a considerable effect on the axial pipeline reaction forces. Without the shear stress limit, the axial forces are effectively doubled in comparison to a limit equal to half of the undrained shear strength. There is less of an effect on lateral interaction.
Development of Modern High Strength Heavy Plates for Linepipe Applications
Authors: Meuser Heike , Gerdemann Florian , Grimpe Fabian , Stallybrass Charles
Published: July 2013

High strength linepipe steels have to fulfil increasing property demands in modern pipeline applications. The transport of large gas volumes at high pressures from remote areas to the market is achieved in the most economical way by large diameter pipelines. For the last 30 years, high strength heavy plates for pipes and pipe bends were developed and produced at Salzgitter Mannesmann Grobblech. These products were steadily improved for example in terms of toughness and fracture behaviour at low temperatures. This is a strong focus of materials development around the world.

Modern high-strength heavy plates used in the production of UOE pipes are generally produced by thermomechanical rolling followed by accelerated cooling (TMCP). The combination of high strength and high toughness of these steels is a result of the bainitic microstructure realised by TMCP and are strongly influenced by the rolling and cooling conditions. This paper gives an overview of the development of high strength plates for line pipe application at Salzgitter Mannesmann Grobblech. From comparably thin-walled X80 plates with no or medium DWTT requirements to recent requirements for approx. 28 mm thick X80 plates with requirements of 75/85% shear area fraction at −30°C and more than 250 J Charpy energy at −40°C the development work and the result of the last five years are described and presented.

Classical light-optical characterisation of the microstructure of these steels is at its limits because the size of the observed features is too small to allow reliable quantitative results. Therefore Salzgitter Mannesmann Grobblech and Salzgitter Mannesmann Forschung (SZMF) developed alternative methods with the aim of a quantification of microstructure features and a correlation of those with the mechanical properties and processing conditions.

In several investigations, the information is related to the mechanical properties of the plate material. It was found that a variation of the processing conditions has a direct influence on parameters that are accessible through the EBSD method and correlates with mechanical properties. The detailed correlations vary depending on steel grade and TMCP strategy. The results have to be carefully interpreted and help understanding the connection between processing and properties. Consequently this can be used as valuable input for the definition of the processing window for heavy plate production with optimized properties.
Research on Leak Test for Long Distance Gas Pipline
Authors: Yan Feng , Miao Qing , Xue Xiangdong , Wang Yubin , Li Daquan , Zhang Jingnan
Published: July 2013

The main purpose of pre-service leak test is to prove the tightness of the pipeline system. It plays an important role to guarantee the safety operating of pipeline. However, the duration of leak test is different in different countries. If the duration of tightness test is longer, the tightness level can be sufficiently detected, which is benefit for pipeline safe operating, but the cost and the time of project must be extended; if the duration of tightness test is shorter, the defect of pipeline can not be fully exposed, which may be left hidden trouble for pipeline safe operating. Meanwhile, the tightness test may be influenced by many factors, for example the test medium, pipeline capacity, pressure, ambient temperature variation, leak detection methods, and so on. Therefore, it is unreasonable to leak test with same duration for different kinds of gas pipeline, which regulated in some standards, for example CSA Z662-11, BS EN1594:2000, ISO 13623:2008, GB 50251-2003, and so on. At the same time, those standards all regulated that the duration of tightness test should be properly extended while the pipeline capacity and ambient temperature variation obviously affect the accuracy of leak test, but the definite value is not regulated. In addition, they also regulated that the pressure increases or decreases during leak test shall be acceptable provided that it can be demonstrated through calculations that the pressure change is caused by ambient temperature variations, but there is no explicit calculation method. Now, the specified duration of leak test in different standards are all based on the engineering experience. Because there is no rational theory way, it makes the identification and modification of the duration for different kinds of pipeline become blind.

Based on the theory of fluid mechanics, material mechanics, elastic mechanics, a mathematical model about the duration of leak test for long distance gas pipeline is developed for the first time. The influences of the test medium, pipeline capacity, pressure, ambient temperature variation and other factors which may impact the duration of leak test are synthetically considered in the model. The experimental verification shows that the result calculated by the model is accurate. It can provide reliable theoretical guidance for determining reasonable leak test duration for long distance gas pipeline.
Long-Term Evaluation of the Bonding Strength of Composite Repairs
Authors: Farrag Khalid , Stutenberg Kevin
Published: July 2013

The long-term performance of composite repair systems depends on their structural integrity and interaction with the carrier pipe. The adhesives used in the composites are critical components that not only bond the repair to the pipe, but also bond the individual layers of the repair to one another. The durability of the inter-laminate adhesive bond is required to ensure adequate load transfer between the pipe and the composite layers over the predicted lifetime of the repair.

A testing program was performed to evaluate the shear strength of the adhesives used in composite repairs. The testing program evaluated the performance of seven commercially-available composite repair systems and it consisted of short-term and long-term shear tests on the adhesives and cathodic disbondment tests on the repair systems. The long-term shear tests were performed for 10,000 hours on samples submerged in a water solution with pH value of 9 and at various loading levels at temperatures of 70°F, 105°F and 140°F.

The results of the long-term tests at elevated temperatures were extrapolated to predict the shear strengths at longer durations. The 20-year shear strengths of the composites were estimated using: (a) direct extrapolation of the best-fit curves and (b) the application of the rate process procedure. The results demonstrated the significant effect of temperature on the bond strength of the composites and provided a comparative analysis to evaluate the long-term shear strength and cathodic disbondment of the composite repair systems.
Analyzing the Crash Between Gauging Pig and the Elbows of U-Shaped Pipeline
Authors: Li Daquan , Zhang Peng , Ai Muyang , Zheng Jianguo , Yan Feng , Wang Yubin
Published: July 2013

Gauge pigging runs are performed to detect restrictions, dents and other deformations within pipelines. After a gauge tool is run, the gauge plate is examined to see if there are any impressions or damage on the plate which would indicate deformation or restrictions within the pipeline. It is important to note however, that in the process of the gauge pig traveling through the pipeline, collisions can occurs at locations where no deformations are present. Such locations can include pipeline elbows. Therefore, precautions in both the pig design as well as in the pipeline operation should be taken to prevent this from happening. For example, a U-shaped pipeline is often designed, with a series of 90° elbows, for pipeline river crossings. When a gauge pig passes through such elbows, the plate may incur damage if the pig velocity is too high or the pig’s design is inadequate. This can lead to erroneous judgment calls with regard to the presence of deformations within the pipeline. This paper describes the analysis performed on the motion of a gauge pig as it passes through the elbows of a U-shaped pipeline segment. And the geometric properties of elbow and caliper pig have been analyzed too.

It is concluded that if the velocity of the pig exceeds a specific threshold value, the centrifugal force of the pig as it travels through the elbow becomes large enough such that the supporting disks will yield and allow plate damage to occur. If the front support plates of the pig are deformed enough, the plate will collide with the outside arc of the elbow. A variety of factors, described in this paper, determine this critical pig velocity threshold value. Additionally, it is concluded that the plate can be damaged at the inside arc of the bend if specific geometric relationships exist between the gauge plate, pig and the bend itself.

Based on these conclusions, required modifications to both pig designs, as well as to pipeline velocity can be determined in order to avoid damaging gauge plates at pipeline elbows.
A Real-Time AC/DC Measurement Technique for Assessment of AC Corrosion of Buried Pipelines
Authors: Su Cindy X. , Xu Luyao , Cheng Frank Y.
Published: July 2013

In this work, a real-time AC/DC signal data acquisition (DAQ) technique was developed, which is capable of separating the DC and AC potential components from the recorded total potential, providing mechanistic information about the steel corrosion in the presence of AC interference. It was found that the corrosion of the steel is enhanced by the applied AC current density from 0 to 400 A/m2. With the further increase to 600 A/m2 and 800 A/m2, the corrosion rate of the steel decreases, which is attributed to passivation of the steel at sufficiently high AC current densities, and a compact film is formed on the steel surface. Moreover, the derived mathematic relationships between AC potential and AC current density provides a potential alternative to determine AC current density on pipelines based on measurements of AC potential in the field.
Blunt Crack Initiation and its Transition to Sharp Cracks in Pipeline Steel in Near-Neutral pH Solution
Authors: Fang B. , Eadie R. L. , Elboujdaini M.
Published: July 2013

This paper reviews our research into pipeline stress corrosion cracking (SCC) in near-neutral pH (NNpH) environment to help understand the mechanisms on pit-to-crack transition and early growth to contribute to pipeline integrity management so that the risk of failure can be avoid or reduced.

Pitted specimens by using two different techniques (passivation/immersion and electrochemical methods) were cyclically loaded in NNpH environment sparged with 5% CO2 / balance N2 gas mixture at high stress ratios (minimum stress/maximum stress), low strain rates and low frequencies which are close to the operational pipelines in the field. Blunt cracks initiation was seen first and associated with the pit geometry, and most of the blunt cracks were observed to have initiated from the corrosion pits that had the pit depth to surface width aspect ratios greater than 0.5. The blunt crack growth was engendered by anodic dissolution, which was facilitated by stress. So it was called as stress facilitated dissolution crack growth. These blunt cracks had considerably large crack tip width to crack mouth width aspect ratios, and the majority were below 0.5 to 0.6 mm deep, and considered dormant. Once cracks surpassed the critical value, around 0.5 to 0.6 mm, the cracks would be reactivated and the crack tip width to crack mouth width ratios became significantly smaller. Meanwhile, more hydrogen would be trapped in the plastic zones. Thus, hydrogen would play an important role in the crack propagation. So in this stage, cracks tended to become sharp and the mechanism was referred to hydrogen facilitated cracking. The observations from the field can be interpreted very well by using the proposed models. It was proposed that two different mechanisms are responsible for the early-stage crack growth and sharp cracks be removed to reduce the risk of failure in pipelines.
Methodology for Vintage Pipelines Assessment
Authors: Phelippon Mélissandre , Hertz-Clemens Stéphane , Notarianni Philippe
Published: July 2013

During inspection and maintenance operations, pipeline operators may encounter pipes showing incomplete records. However, data such as pipe tensile properties and toughness are essential to perform a realistic pipeline fitness for service analysis.

These situations most often occur with older pipelines, in a period where line pipe quality control and quality assessment were not as stringent as today. In order to avoid a cut and a replacement of the pipe, introducing transit interruption and high expenses for the operator, a methodology for determining mechanical properties has been developed.

The methodology described in this paper relies on data obtained from many tests performed on this specific type of line. The study and analysis of these database information led to working out correlations between parameters measured on field, and missing recorded mechanical properties.

The first data that can be obtained quite easily is the chemical composition of steel, which can be analyzed in a laboratory from samples directly removed from parent material of the line pipe.

Using the result of the previous analyses, the following correlations have been determined from the database information, and have been compared to correlations given in international standards (API 579, BS7910,…):

- Charpy V energy measured at 0°C versus Charpy U energy pleasured at 20°C,

- Charpy V energy versus sulfur content,

- Fracture toughness versus Charpy V energy,

- Fracture toughness versus sulfur content.

A practical experiment of these results have been performed, as chemical composition analysis from samples were made on 5 removed test pieces issued from line pipes. These tests aimed at comparing the results given by correlations with the mechanical properties of the line pipes, and validating the feasibility of this methodology on the field.

At the same time, database information was also used to check the theoretical behavior of parent metal regarding to the design temperature, by using a relation between steel toughness value, and its transition temperature at 28 J, issued from toughness transition curves.
Southern Lights Connectors Hydraulic Surge Alleviators
Authors: Furzer Jeremy , Wengreniuk Greg
Published: July 2013

Enbridge Pipelines Inc. (Enbridge) is a leader in the field of Integrity Management (IM). Enbridge’s primary concern is to ensure the safety of people, equipment, and the environment by building integrity management into company’s standards, procedures and facilities. One example of Enbridge’s commitment to IM includes the attention given to transient modeling within piping systems and the implementation of transient over pressure protection systems such as the Hydraulic Surge Alleviators (HSAs) used at the Edmonton Terminal.
Data Smoothing for Leak Detection
Authors: Gao Jianping , Lewis Chris , Rizwan Tania
Published: July 2013

Noise is prevalent in all pipeline instrumentation and measurement system data and is perhaps one of the biggest environmental factors, which determines if a system will operate reliably in practice. Noise present in data can be random or repetitive, occurring continuous or in isolated bursts and can have a multitude of sources. At Enbridge, the leak detectability of Computational Pipeline Modeling (CPM) based leak detection (LD) systems is notably affected by the presence of noise in the pipeline data. Data smoothing of noisy pipeline data is a non-trivial process; these techniques are used not only to eliminate “noise” from the operating data, but also to extract real trends and patterns within the data, and to maintain important characteristics of the signal itself, particularly during transient time periods. Finding an effective data smoothing methodology has, therefore, become an important and challenging task for the Leak Detection team at Enbridge.

This paper presents an innovative approach on data smoothing with the aim of improving data quality and detectability of the CPM based LD systems using the Wavelet analysis method which is incorporated in the MATLAB toolbox. Wavelet-based algorithms have proved to be quite an effective tool for the analysis, synthesis, denoising, and compression of signals and provide more precise information about signal data than other signal analysis techniques, such as Fourier Transform. In this paper the Wavelet analysis technique has been reviewed and is shown to be effective in manipulation and smoothing of pipeline data, both during the transient and steady state conditions. Based on the algorithm and utilities developed, extensive tests have been performed and comparison studies have been made to validate the methodology using simulated leak test data, fluid withdrawal test data, and API 1130/1149 calculations etc. The test results indicate that data smoothing technique employed has a substantial effect on the data quality which in turn has significantly improved the detectability of Enbridges current leak detection system.
Application of Nano-Material Based Hybrid Pour-Point Depressant for Long-Distance Waxy Crude Pipeline
Authors: Zhang Dongmin , Zhang Lixin , Huo Lianfeng , Zhi Shujie , Ouyang Xin , Xu Bo , Xiong Hui , Jiang Baoliang , Li Jianting , Wang Shuai
Published: July 2013

A new type of nano-material based hybrid pour-point depressant with significant efficiency has been developed and successfully used in industrial application. For Daqing crude oil, a typical high waxy Chinese crude, with 80–100g/t new pour-point depressant and 58–65°C thermal treatment temperature, the wax appearance temperature of the Daqing crude oil can be decreased by 3–4°C. The viscosity/pour-point reduction, shearing resistance, and fluidity at low temperature of the modified crude with new type of pour-point depressant is much better than the effect of using traditional ethylene-vinyl acetate (hereinafter referred as “EVA”). Therefore the safe shutdown time for a pipeline is dramatically increased which not only enhances the safety of the pipeline operation but also significantly saves the energy consumption of the pipeline company. Besides, the reheating temperature can only be greatly reduced to 35°C. The relationship between the crystal structure of the nano-material based pour-point depressant and the type of the waxy crude, together with its influence on the crystal form/wax appearance temperature of the waxy crude by using X ray diffraction (hereinafter referred as “XRD”) and Polarizing microscope (hereinafter referred as “POM”)are studied.
Research on Leak Monitoring Technology for Product Oil Pipeline
Authors: Yu Dongliang , Xu Bin , Wang Likun , Tan Dongjie , Wang Hongchao , Xiong Ming , Yang Xiliang
Published: July 2013

As an important tool for the long-distance transportation of product oil, pipeline construction has being developed rapidly in recent years in the world. In the long-term running, leak will occur occasionally and seriously endanger the operation safety of the pipeline system, which may be caused by internal & external factors including pipe aging, mechanical damage, chemical corrosion, and natural disaster, etc. In order to timely find out and accurately locate the leakage, and reduce the economic loss and the accident risk, it is necessary to research into leak monitoring techniques and apply them in field. Compared with crude oil pipeline, due to multi-batch transportation, multi-distribution operation and frequent regulation, leak monitoring for product oil pipeline is much more difficult. Once leak occurs, the oil loss at the leakage point induces an oil pressure drop, causing negative pressure wave as well as acoustic wave. Through analyzing negative pressure wave signals and acoustic wave signals acquired by sensors, it can find out and locate the leakage. For interference signals like background noises in the product oil pipeline, wavelet packet decomposition technology is used to denoise the acquired negative pressure wave signals and acoustic wave signals, and extract the feature signals. Meanwhile, the signal velocity in product oil is calculated dynamically to improve the location accuracy. Field Tests indicate that the technology combining negative pressure wave and acoustic wave is accurate and reliable, and has good performance.
Influence of Alloying Elements on the Toughness in the HAZ of DSAW-Welded Large-Diameter Linepipes
Authors: Stallybrass Charles , Dmitrieva Olga , Liessem Andreas , Schröder Jens
Published: July 2013

There is a strong interest worldwide to transport large gas volumes from remote areas and hostile environments to the market. Pipe producers are therefore faced with increasingly demanding requirements both with regard to the toughness of the base material and the heat-affected zone. The toughness of the base material depends primarily on the steel composition and the TM processing conditions. Impressive levels of toughness in the base material were achieved by extensive alloy and process development over the past decades. These were realised by balancing the steel composition and processing parameters to give an optimum microstructure with a low grain size and homogeneous distribution of phases. During double submerged arc welding (DSAW) in the production of large-diameter linepipes, the heat-affected zone (HAZ) undergoes severe changes in the microstructure that include grain coarsening by about one order of magnitude and phase transformation during cooling and intercritical reheating. These have a negative impact on the toughness close to the fusion line. The higher austenite grain size close to the fusion line leads to a coarser structure after the phase transformation with larger carbon-rich M/A-phase particles than are typically observed in the base material in the as-rolled condition. This causes a drop of the toughness close to the fusion line compared to the base material.

Classically, the carbon equivalent is an empirical measure for the weldability of steels and is known to correlate with the maximum hardness. However, its purpose is not to reflect the effect of individual alloying elements on the HAZ-toughness. The present paper addresses the relationship between base material composition and the HAZ-toughness of linepipe steels. An experimental investigation was carried out at EUROPIPE GmbH in cooperation with Salzgitter Mannesmann Forschung GmbH in which the chemical composition of laboratory heats was varied systematically. These heats were thermomechanically rolled to a wall thickness of 30 mm and subsequently used for submerged arc welding trials. The processing parameters during rolling and welding were held constant in the trials in order to ensure that the effect of the alloying elements could be isolated. The fusion line toughness was tested at −30°C and the microstructure was investigated by high-resolution scanning electron microscopy. This was complemented by microstructure investigations in the HAZ of large-diameter pipe material between the X65 and X80 strength levels. It was found that the influence of alloying elements on the HAZ-toughness is only reflected to some degree by the commonly used carbon equivalents, especially at similar strength levels. The results of the investigation were used for optimisation of the HAZ-toughness in production.
Monitoring Strain in Flexible Pipelines Through Acoustic Resonance
Authors: Freitas Miguel , Jimenez Marcelo Roberto , von der Weid Jean Pierre
Published: July 2013

Inspecting the integrity of flexible pipelines in offshore installations requires the use of non invasive techniques, as the removal of the external sheath to allow inspection of the axial load carrying wires will increase the chance of structure degradation. Determining the strain in axial wires provides a significant indication of wire breakage and whether or not the structure has been compromised. This paper investigates the feasibility of employing a new technique based on acoustic resonance to monitor the mechanical stress in these wires. Results from experiments with flexible pipelines show that it is possible to obtain the wire’s resonance signals through the outer sheath in some circumstances. The technique, called Electromagnetic Acoustic Resonance (EMAR), produces ultrasonic waves on the wire using electromagnetic transducers (EMAT) and is able to estimate the mechanical stress by measuring the frequency of the acoustic resonances for different polarizations of the shear waves. Variations in coupling quality such as lift-off or even the unknown wire separation will not directly affect the estimated stress values. Laboratory experiments with the armor wires have shown that stress estimation is possible within a range of uncertainty of 18.8 MPa. Measurements on flexible pipelines through the external sheath, composed of 5 mm of polymer layer, two Kevlar layers and an adhesive tape, were made. Higher lift-offs, up to about 9–10 mm, are still possible depending on particular pipeline’s construction.
Identification of Coincident Features in Pipelines Using ILI Data
Authors: Dawson Jane , Weller Rodger , Rao Girish
Published: July 2013

Many pipelines are vulnerable to multiple threats and damage types such as internal and/or external corrosion, axial and/or circumferential cracking, laminations, gouging, dents, ovalities and wrinkles. These different types of damage may occur in isolation or can occur coincidental at the same location in the pipeline. Whilst two or more of these feature types may be coincident in the pipeline, the different feature types often require detection by different ILI technologies which are quite often run at different times and even by different ILI vendors.

It is important to identify where different types of features are coincident:

• Discrimination and sizing of certain feature types can be adversely affected and hence uncertainties may be higher at these locations.

• Evaluation of feature severity should account for the types of feature present and any interaction between features.

• To aid the excavation and repair planning processes.

It can be difficult and time consuming to identify the exact location where multiple features may be coincident with each other because this requires accurate alignment, accounting for positional tolerances, matching and overlay of data from ILI runs of different technologies and often from several years apart.

This paper describes an approach to identify where coincidental features occur within a pipeline by:

• Combining and overlaying multiple ILI technologies and data sets in a common interface.

• Allowing different proximity tolerances to be used to account for positional accuracy in the determination of coincident feature groups.

• Enabling the identification of the ILI reported features (e.g., cracks, internal and external corrosion, dents, mill faults including laminations, gouges etc.) that could be coincident and therefore may interact.

Case studies are used to illustrate the approach and to evaluate the results obtained.
Enhancing Pipeline Project Management With Improved Rock Excavation Forecasting
Authors: Keaton Jeffrey R. , Parks Theodore H. , Boudra Luther H. , Walker Lee D.
Published: July 2013

Accurate rock-excavation forecasting is one of the geotechnical risk factors that challenge successful management of cross-country pipeline projects. Rock excavation requirements commonly are estimated by pipeline construction personnel with local experience. Construction bid and contract documents typically call for excavation of “ditch” rock to be paid per lineal foot, whereas “area” or right-of-way grading (ROWG) rock is paid per cubic yard. Rock excavation forecasting tends to be used for economic feasibility more than for selecting contractors or preparing contracts. Recent pipeline projects in Pennsylvania and New Jersey used geotechnical estimates of rock excavation to update detailed cost and schedule projections after construction was underway because ROWG rock excavation exceeded the expected volume. Geotechnical estimates of rock excavation were based on a rapid desktop study followed by field observations and measurements. The desktop study used available digital data manipulated with geographic information management software (GIS). Topographic data (digital elevation models) at 10-m resolution and the pipeline centerline in 10-m-long segments were used to plot alignment elevation profile and ground slope, as well as to calculate slope aspect and apparent ground slope across the ROW perpendicular to centerline. The centerline was plotted in Google Earth Pro for a virtual geologic field reconnaissance to identify areas where rock was likely or unlikely to be encountered within ditch depth. Digital geology was used to assess bedrock type along the alignment and digital soil survey data were classified to identify soil units with shallow cemented zones or bedrock. These complementary data types were combined into an overall rock excavation index factor (0 = uncemented soil; 1 = cemented soil; 2 = weathered rock near ditch bottom; or 3 = nearby rock outcrop, weathered rock near top of ditch, or unweathered rock at any ditch depth). GIS polygons of “rock factors” were converted to a grid so that values could be extracted at points along the pipeline centerline. Ground-condition variability was considered subjectively for each rock factor by assigning length-based and area-based percentages where rock was considered likely to be encountered for both “average” and “maximum” rock conditions. Rock factor areas were used to select locations for 115 or 230-ft-(35 or 70-m-) long seismic refraction surveys. Seismic velocities > 4,000 to 4,500 ft/s (1,220 to 1,370 m/s) were considered blast rock in trench excavations. Locations where the 4,000-ft/s contour was shallower than ditch depth were used to refine subjective ground variability estimates. Additional construction records of actual blasting details are needed to further improve the rock excavation model. Unique aspects of geology may require model parameters to be modified for other settings.
“Show-Stopper” — Effectively Managing Project Social Risks: Improved Approaches to Aboriginal Engagement and Consultation
Authors: Mathewson Andrew
Published: July 2013

A number of proposed pipelines in western and northern Canada have highlighted critical path social risks associated with effectively engaging and consulting with impacted Aboriginal rightsholders along pipeline rights-of-way. Opening up new markets for Canada’s oil sands, shale and off-shore gas resources will require an expansion of the pipeline system in northern British Columbia, Alberta and the Northwest Territories. While navigating the regulatory approval process can be a formidable hurdle, a far greater challenge is how proponents manage the process of building relationships and consulting with affected Aboriginal communities. Failing to earn Aboriginal support for proposed projects can be a “show-stopper”.

Exploration of new basins in Canada, driven by increased demand for energy in Asia, may compete with other land uses and constitutionally-protected rights and practices of indigenous peoples. Public, media and environmental response to new pipelines is often lead by the reaction of impacted communities. The task of identifying the social risks to a project, understanding the engagement process, fulfilling the regulatory consultation requirements of different jurisdictions, balancing impacts with benefits, managing issues and resolving disputes, communicating with the public and media effectively all require improved skills and approaches.

The paper surveys the stakeholder engagement experience and differences in approaches for recently proposed major arctic gas and western oil pipeline projects, as well as pipelines to service Liquefied Natural Gas export facilities on the Pacific north coast, providing practical insights with possibly international application. Utilizing decision and risk analysis and scenario planning methodologies, applied to development of an Aboriginal engagement and consultation strategy, the paper examines how multi-billion dollar investments in new pipelines can be better secured by integrating stakeholder engagement into a project’s risk management design. With greater precision and improved approaches proponents can effectively manage social risks, reduce stakeholder conflict and associate project uncertainties.
Acoustic Leak Detection Technology Assessment
Authors: Garcia-Hernandez Augusto , Siebenaler Shane
Published: July 2013

Leak detection systems are a vital part of a pipeline integrity management program. For liquid hydrocarbon pipelines, these leak detection systems can take the form of measuring conditions inside the pipeline (internal detection) or by use of hardware installed outside of the pipe (external detection). One internally-based technology is acoustic leak detection, sometimes known as rarefaction-wave monitoring. This technology is based on detecting transient pressure waves that are generated when a sudden leak occurs. Acoustic pressure waves travel in the pipeline at the speed of sound of the fluid that is being transported and can be detected by dynamic pressure sensors. Various filters and algorithms can be used to identify this disturbance and distinguish it from other pressure events on the pipeline. This architecture can even be used for noise and for signal pattern recognition to allow for automatic alarming of potential leak events. Each manufacturer of such technology applies unique algorithms or processing methods to capture and analyze the pressure signals that are used to later predict leaks and their locations.

This paper presents a comprehensive review of the technical basis and methodology employed by acoustic leak detection systems in order to further understand their capabilities and limitations. This work included a vast amount of hydraulic modeling aimed at understanding the physics of wave propagation caused by leak events. Diverse parameters, such as initial pressure wave amplitude, signal attenuation, flow and pressure dependence, speed of sound effects, and sensor locations were evaluated. This modeling was conducted for a variety of simulated fluids. A proportional relationship between leak rate and the initial pressure disturbance caused by a leak was obtained. This linear trend can be used in combination with an attenuation model to calculate sensor location limitations. The work determined that the uncertainty in the speed of sound for a pipeline fluid segment significantly impacts the error bands of leak location. The modeling was used to generate correlations for signal attenuation over distance as a function of pipeline conditions.
Experiences in Establishing Trustworthy Digital Repositories Within a Large Multi-National Pipeline Company
Authors: Weir David A. , Murray Stephen , Bhawnani Pankaj , Rosenberg Douglas
Published: July 2013

Traditionally business areas within an organization individually manage data essential for their operation. This data may be incorporated into specialized software applications, MS Excel or MS Access etc., e-mail filing, and hardcopy documents. These applications and data stores support the local business area decision-making and add to its knowledge. There have been problems with this approach. Data, knowledge and decisions are only captured locally within the business area and in many cases this information is not easily identifiable or available for enterprise-wide sharing. Furthermore, individuals within the business areas often keep “shadow files” of data and information. The state of accuracy, completeness, and timeliness of the data contained within these files is often questionable. Information created and managed at a local business level can be lost when a staff member leaves his or her role. This is especially significant given ongoing changes in today’s workforce.

Data must be properly managed and maintained to retain its value within the organization.

The development and execution of “single version of the truth” or master data management requires a partnership between the business areas, records management, legal, and the information technology groups of an organization. Master data management is expected to yield significant gains in staff effectiveness, efficiency, and productivity.

In 2011, Enbridge Pipelines applied the principles of master data management and trusted data digital repositories to a widely used, geographically dispersed small database (less than 10,000 records) that had noted data shortcomings such as incomplete or incorrect data, multiple shadow files, and inconsistent usage throughout the organization of the application that stewards the data.

This paper provides an overview of best practices in developing an authoritative single source of data and Enbridge experience in applying these practices to a real-world example. Challenges of the approach used by Enbridge and lessons learned will be examined and discussed.
Synthesis, Performance Evaluation and Field Application of Polymer-Type Natural Gas Drag Reduction Agent
Authors: Xu Haihong , Gao Yanqing , Li Guoping , Zhang Zhiheng , Chang Weichun
Published: July 2013

Natural gas is gaining popularity in the world as a high quality, clean burning alternative to oil and coal. The Mechanism of Drag Reduction in the natural gas pipelines is to control the radial pulsation of gas adjacent to pipeline wall effectively. The way to lower the pulsation intension of the gas in the thin layer along the wall is to use gas drag reduction agents, whose polar end absorbs fixedly to the surface and whose non-polar long chain suspends in natural gas so as to have a function of restraining the gas’ radial pulsation. The drag reduction agent molecule absorbed to the protruding is mainly to weaken the gas pulsation producing by virtue of roughness degree. The drag reduction agent molecule absorbed to and collected in the dents also has the function of lowering the equivalent roughness degree of the wall surface. A polymer-type natural gas drag reduction agent with polarity as well as nonpolarity long chain was studied. We synthesized polymers that contain long chain fatty acid (F) or long chain ester (E) as soft chain, and alkoxy residues or acylations as polar group, then studied the effects of this polymer-type gas drag reduction agent on the pipe wall, natural gas quality, station processes and equipments as well as post-processing. A test loop with control software was developed for evaluating natural gas drag reduction agents. An on-line injected system for natural gas reduction agent was established. The product was applied on natural gas pipelines in China. In No.1 oil production plant of Changqing oilfield, the drag reducing efficiency is 19.5%, and the flow increase rate is 12.4%. In pipeline from Lanzhou to Yinchuan, the drag reducing efficiency is all above 10%, and the flow increase rate is all above 5%.
Novel High Performance Elastomers: New, Recyclable Materials for Oil and Gas From In-Line Inspection to Pipe Coating
Authors: Magerstädt Michael , Schmidt Holger , Blitz Gunther , Dopieralla Ralf , Schellbach Frank
Published: July 2013

Starting out from the need for polyurethanes with higher abrasion and tear resistance for pipeline inspection, an entire class of new high performance elastomers were developed. Within a few years materials were synthesized which did not only extend the mechanical properties of polyurethane elastomers, but also led to the development of completely new products. Applications range from intelligent plastic solutions combining elastomers and electronics via highly abrasion resistant pipe coatings to a new process for recycling and reuse of crosslinked polyurethanes.

Fundamental to these successful developments is the “building-block” chemistry of polyurethanes. A very high number of permutations of the up to 7 components used in the synthesis of a polyurethane elastomer is possible. By choosing the right combinations and the right reaction conditions, specific material properties can be designed.

Materials exhibiting the following material properties, hitherto not found in polyurethanes, were developed:

• An operating temperature range from −50 to +135°C.

• Chemical resistance to highly acidic and alkaline media, e.g., pure ammonia.

• Significantly higher abrasion and tear resistance than standard polyurethanes.

• Exactly adjustable visco-elastic damping (rebound resilience).

• Adhesion to steel higher than reported with any other polyurethane elastomer.

• A novel polyurethane elastomer with more than 90% share of recycled material reaching mechanical properties in the same range as virgin material.

This presentation will detail the materials and their properties and give application examples from pipeline cleaning, pipe protection, and pipe coating to mechanical protection devices made from recycled polyurethane elastomer.
Comparison and Analysis of Pipeline Failure Statistics
Authors: Cunha Sérgio B.
Published: July 2013

Failure statistics for onshore pipelines transporting oil, refined products and natural gas from the USA, Canada and Europe are compared. Failure data from Brazilian pipelines are presented and included in the comparison. Failure rates for internal and external corrosion, human action and natural forces are analyzed and the expected failure rate for each failure mechanism is indicated. The effects of relevant construction and environmental factors on the failure rates are studied and mean trends are obtained. Furthermore, the sizes of the holes observed in each type of failure are also compared. Finally, the probability of ignition after a failure in gas and liquid pipelines is evaluated. This study may serve as basis for the estimation of failure frequency, hole size and probability of ignition for hazard liquids and gas pipelines.
Developing Guidelines for On-Stream Mechanical Cleaning of a Complex Pipeline Network
Authors: Al-Muslim Husain Mohammed , Al-Otaibi Nader A. , Alshammari Mashaan
Published: July 2013

On-stream pipeline cleaning is essential to pipeline operations in terms of maintaining both pipeline efficiency, as well as integrity. Running effective brush cleaning pigs through pipelines will remove accumulated solid debris as well as smoothen the pipe wall. This will reduce pipeline pressure as well as increase product flow. A pig with sealing discs will push out accumulated condensates in gas pipelines and will prevent internal corrosion. The concept is simple, but the implementation is challenging for a complex pipeline network such as the one covered in this paper. The network consists of different types of services both upstream and downstream including oil, gas, and refined products. The pipeline sizes range from 3″ to 56″. The age of pipes vary from 50 years old to new installations and accordingly, their conditions and cleanliness vary. Although pigging is largely based on experience and it is more of an art than a defined science, the complexity of the network needed a systematic approach to develop meaningful and useful guidelines. The approach included conducting gap analysis of current pigging practices in the company, interviews with the senior Operators and subject matter experts, and reviewing the latest literature including manufacturer brochures. The developed guidelines include selection criteria, design, material, as well as measurement effectiveness. The objective of the paper is to present the approach taken to develop the guidelines, as well as to give an overview of the guidelines themselves.