bluuebunny/crossref_metadata_2025 huggingface dataset:
Geothecnical Thematic Maps of PETROBRAS Pipeway
Authors: de Oliveira Wilson Jose´ , Rodrigues Moreira Lino Francisco , Portugal Valente Julio Cezar , Vieira Andre´ Calixto , Dourado A´ureo Furtado , Viitaniemi Tauno
Published: December 2008

The Geothecnical Thematic Mapping (GTM) was created inside of The Standard for Management of the Pipeline Structural Integrity (2002) and intends to predict geothecnical risk areas. These maps were made along five thousand kilometers of pipeways. The GTM has as its purpose of classify the pipeways and adjacent areas (400 meters) according to the area’s susceptibility to geological-geothecnic accidents. From this classification, inspection frequency was established in each portion of the strip. When this work is done, it will be possible to increase the knowledge of the geothecnical problems that exist throughout pipelines, allowing to ration out the utilization of the resources applied to field inspections. This work generated these products: - Features and geothecnical risk maps through photo interpretation techniques; - Potencial Geothecnical Risk Map acquired through GIS technology. These maps are incorporated to the GIS TRANSPETRO system, in such a way that allows its utilization by all the professionals involved. The GTM was obtained from the integration of two distinguished methodologies: indirect observation, through the utilization of photo interpretation techniques and the fusion of GIS processing. The photo interpretation of aerial susceptibility to geothecnical hazard, according to its intensity which is classified as high, medium and low susceptibility. The features and classifications of the risk identified during photointerpretation were digitalized and geo-referenced, making possible the check of the models adopted in the geoprocessing. All the generated data statistics were analyzed, in a way to point out areas where there was evidence of high risk of geothecnical occurrence. These analyses allowed the elaboration of a risk index. This index was calculated to portions of 5 Km of the pipeway, allowing its ranking in terms of high, medium and low susceptibility to geothecnic. In the end of the project, the company may have a good definition of all pipeways and of all the portions that represent a major probability of problems and where to allocate money for prevention.
Defective Pipeline Fatigue-Life Prediction Using Failure Assessment Diagram Technique
Authors: Luo Jinheng , Zhao Xinwei , Xiong Qingren , Huo Chunyong
Published: December 2008

The life prediction, whose results can be used to define the inspection, repair or replacement cycle of in-service pipeline, is a main component of safety assessment of gas and oil pipeline. At present, failure Assessment Diagram (FAD) technique has been widely used in quantitative engineering safety evaluation system of pipeline that contains crack-like flaws. In past work, the authors developed a very useful model to predict the fatigue life of defective pipeline and established a computer calculating method. Based on FAD technique, toughness ratio and load ratio are calculated repeatedly with every crack increment in the model. With the self-developed full-scale test system, the full-scale pipe fatigue test was collected to verify the applicability of this method.
Alloying Concept for High-Strength Seamless Heavy-Wall Line Pipe Suitable for Sour Service Applications
Authors: Biermann K. , Kaucke C. , Probst-Hein M. , Koschlig B.
Published: December 2008

Offshore oil and gas production worldwide is conducted in increasingly deep waters, leading to more and more stringent demands on line pipes. Higher grades and heavier wall thicknesses in combination with deep temperature toughness properties, good weldability and suitability for sour service applications are among the characteristics called for. It is necessary that pipe manufacturers develop materials to meet these at times conflicting requirements. An alloying concept based on steel with very low carbon content is presented. This type of material provides excellent toughness properties at deep temperatures in line pipe with a wall thickness of up to 70 mm, produced by hot rolling followed by QT heat treatment. Pipes from industrial production of identical chemical composition and heat treatment achieved grades X65 to X80, depending on wall thickness. The properties of the steel used in pipes are presented. The resistance of the pipe material to the influence of sour gas was assessed by standard tests. To demonstrate weldability, test welds were performed and examined.
Experiences With a Complex Leak Detection System in an Offshore Basin
Authors: Scortegagna de Medeiros Nathan , Quinn Joe
Published: December 2008

Silvertech have implemented a large, complex leak detection system for an offshore basin with some 80 pipeline sectors in a number of multiple input-multiple output configurations with varying pipeline operational scenarios. This paper addresses two key issues. First a systematic approach to the determination of the risk and consequencees of a pipeline leak and hence the performance criteria and economic justification for a leak detection system is outlined. The challenges associated with the Campos Basin leak detection system implementation are then described, including operational issues and the continuing verification of the performance of the leak detection system. Leak detection systems are often specified as a requirement without a sound basis of leak risk and consequence analysis and quantification of the risk reduction that will be afforded by any leak detection system and the system performance required to ensure the risk reduction is achieved and maintained. Silvertech have adopted a methodology that provides a systematic, sound approach to the quantification of pipeline leak risk, the commercial and environmental consequences and the risk reduction required to provide acceptable risk and consequence. The implicit trade-off between impact on production and leak consequence reduction is also considered. Finally the lessons learnt from the analysis and system implementation experience are used to derive the key issues that apply to the implementation of leak detection in large, complex pipeline configurations. The particular challenges of applying leak detection to existing installations are also highlighted.
Tensile Strain Limits of Buried Defects in Pipeline Girth Welds
Authors: Wang Yong-Yi , Cheng Wentao , Horsley David
Published: December 2008

Buried defects, such as lack-of-sidewall fusion defects, are some of the most commonly occurring defects in mechanized girth welds. Although some of the existing ECA (Engineering Critical Assessment) procedures permit the assessment of the significance of buried defects, their application is limited to the nominally elastic applied stress range. The assessment of buried defects is more complex than that of surface-breaking defects. There is much more experimental data on the behavior of surface-breaking defects than buried defects. One simplistic approach is to treat buried defects as surface-breaking defects under a generally accepted assumption that buried defects are less detrimental than surface-breaking defects of the same size. This paper focuses on the behavior of girth welds containing buried defects subjected to high longitudinal strains. The high longitudinal strains in onshore pipelines may be caused by soil movement such as seismic activity, slope instability, frost heave, mine subsidence, etc. For offshore pipelines, the highest longitudinal strains typically occur during pipe laying operations. The paper describes a strain design methodology based on a crack driving force method that has been previously applied to obtain tensile strain limits of surface-breaking defects. The focus of this paper is the application of the crack driving force methodology to examine the factors affecting the strain limits of girth welds containing buried defects. By using crack driving force relations in conjunction with a constraint-sensitive fracture mechanics approach, tensile strain limits are derived as a function of material grade, defect size, toughness, and pipe wall thickness. The paper concludes with the comparison of strain limits between buried and surface-breaking defects.
Application of Constraint-Sensitive Fracture Mechanics to the Assessment of Girth Weld Integrity
Authors: Wang Yong-Yi , Liu Ming , Horsley David
Published: December 2008

It has been known since the 1960’s that the crack-tip fields of specimens containing sharp cracks depend on the mode of loading. Experimental evidence has shown that cracked specimens loaded in bending have lower toughness than the same material loaded in tension. This phenomenon has been attributed to the “constraint effect” on fracture. Modern constraint-sensitive fracture mechanics has brought about fundamental theoretical understandings on the constraint effects. The constraint-sensitive fracture mechanics has moved from academic circles to practical application, as evident by a number of recently published fitness-for-service (FFS) assessment procedures that incorporates the constraint effects. This paper reviews the developments in constraint-sensitive fracture mechanics with the focus on its potential applications to the assessment of pipeline girth weld integrity. The review covers (1) constraint theories and experimental evidences, (2) constraint models for brittle and ductile fracture, and (3) limitations of current constraint models. The paper closes with thoughts on the applications of the constraint models and theories to ductile fracture processes, which are the most relevant to modern linepipes and their welds.
Petrobras Transporte S.A. – Transpetro Solution for the Minimization of External Corrosion of Thermal Insulated Pipelines for Underground Heated Oil Transportation in Brazil
Authors: Costa Pinto Mucio Eduardo Amarante , Abe Rodnei Massamiti , Passos Douglas de Oliveira
Published: December 2008

Underground heated oil transportation within the processes of Petrobras/Transpetro is a critical issue because of the need to maintain the temperature of the oil in the pipeline network from the point of origin to destination with as little heat loss as possible. Insulated pipelines using polyurethane rigid foams as insulation have been used for many years for this transportation process. However, instrumentation inspections have shown a severe external corrosion process in some insulated pipelines after a number of years in operation. Due to the extent of the insulated pipeline network in Brazil, this kind of problem was possible to identify only after some leakage emergencies. After a deeper investigation in the field it was verified that the pipe protection and insulation system was not adequate for avoiding the corrosion process. In order to prevent and avoid any greater damage to the environment and mainly to the communities living around these underground pipeline zones, a quick review of the entire methodology was necessary. The focus of this article is to describe the identification of this corrosion problem by field experiences and the solution found by adapting the EN 253 norm for pre-insulated bonded pipe systems for underground hot water networks.
An Evaluation of Cathodic Protection Design Calculations on a Long Pipeline
Authors: Haas Peter , Carlson Lorne
Published: December 2008

Cathodic protection survey data from a major gas transmission pipeline is reviewed to determine the accuracy of the original design calculations. The calculations used to predict cathodic protection requirements are discussed to show the advantages and limitations of different methods. The analysis shows that the design calculations can predict overall trends, but significant variations can exist locally due to variations in the pipeline and its environment. Observed coating conductance values and recommendations for improved methods are given to aid in the design of future pipeline cathodic protection systems.
Correlation Between Microstructure and Hardness of the Weld HAZ in Grade 100 Microalloyed Steel
Authors: Poorhaydari K. , Patchett B. M. , Ivey D. G.
Published: December 2008

The weld thermal cycle results in significant changes in microstructure and, consequently, mechanical properties of the weld heat affected zone (HAZ). In this paper, hardness variations across the HAZ and for different welding heat inputs (0.5–2.5 kJ/mm), obtained in a Grade 100 microalloyed steell, are explained based on the microstructural observations. Micro- and nano-hardness examination provided hardness profiles across the HAZ and nano-distribution of hardness in each HAZ sub-region, respectively. Optical microscopy and transmission electron microscopy (TEM) were used for evaluation of grain size, phase structure and precipitate type, shape and distribution. Both carbon replicas and thin foils (prepared by focused ion beam technique) were used for TEM. The fine-grained HAZ for all heat inputs was primarily composed of polygonal ferrite, with some regions of twinned martensite in the higher heat input (1.5 and 2.5 kJ/mm) samples. Twinned martensite regions were also identified in the coarse-grained HAZ of the 0.5 kJ/mm sample. Grain size changes were the major cause for the variation of hardness in the fine-grained HAZ; however, large packets of bainitic ferrite and martensite in the coarse-grained HAZ, with small ferrite/martensite laths, were responsible for the relative hardening in the coarse-grained HAZ.
Relationship Between Defect Shape Resolution Accuracy and Calculated Remaining Strength of Corroded Pipelines
Authors: Grant Ritchard , Chauhan Vinod , Sloterdijk Wytze
Published: December 2008

Reliable predictions of the remaining strength of corroded pipelines are dependent on the assumptions made during the defect assessments, and the availability of an accurate description of the defect shape that is detected by in-line inspection (ILI) tools. If only the maximum defect dimensions are recorded and subsequently used in a defect assessment then a low remaining strength is likely to be predicted for the corroded pipeline. However, if the defect profile had been more accurately mapped then improved predictions of the remaining strength can be determined from the subsequent defect assessment. This improved assessment could be enough to justify safe operation of the corroded pipeline rather than to undertake expensive repairs. For these reasons, PRCI has sponsored Advantica to investigate aspects of both ILI data accuracy and assessment methodology to determine the benefits gained in the remaining strength predictions. This has been undertaken using a combination of in-house specialist computer software and finite element modelling. Work has been undertaken to determine the benefits of an improvement in the measurement accuracy of the three characteristic flaw dimensions (depth, length and width) when determining the remaining strength of a pipeline, and to determine the effect that changes to the defect interaction criterion, used in the assessment, has on remaining strength predictions. Case studies using example ILI data from two pipeline operators are used to determine how measurement accuracy affects remaining strength predictions. Using deterministic assessment methods, such as RSTRENG, it is concluded that sizing accuracy for the defect depth and length are most critical in predicting remaining strength predictions. The defect width is used only to determine interaction of closely spaced defect clusters. In addition, it is concluded that the interaction criterion generally used in industry is overly conservative and could be relaxed.
Development of a Risk Ranking Tool Based on Quantitative Methods
Authors: Hicks Ray , Ward Clive
Published: December 2008

US pipeline integrity management regulations require operators to rank the risks caused by their operations. Many operators use qualitative methods for this risk ranking process. Such methods have several benefits including simplicity and flexibility. Unfortunately, they rely heavily on engineering judgment and produce results that are very specific to the pipeline system(s) being ranked. This makes it extremely difficult to relate the outputs from different systems or companies within an organization. This paper describes the development and application of a risk ranking approach that requires less judgment and provides the user with an estimate of the true risk of operating the pipeline. Quantitative methods, based on an understanding of structural mechanics, are applied to seven of the nine threat categories listed in ASME B31.8S in order to determine the pipeline’s reliability. An assessment of risk to life is achieved by combining the output from structural mechanics models with a quantitative consequence of failure model. The software operates on a GIS platform, making it easier to demonstrate compliance with the integrity data management requirements that are now part of the relevant federal codes. Results produced from the quantitative approach have been compared to those generated by qualitative methods, in a case study. This illustrates some important differences between the two and show that a more rigorous, quantitative approach can provide the operator with significant benefits including the ability to generate meaningful results with less data. In particular, quantitative methods have the potential to allow operators to move towards a more performance-based approach to their ongoing integrity management processes.
Improvements and Modifications to Electromagnetic Pipeline Surveys
Authors: Hunter Jim , McGregor Shawn , McDonnell Shamus , Krissa Len
Published: December 2008

This paper outlines the development and manufacture of a new pipeline evaluation tool with the capability for multipurpose applications on various types of pipeline systems. Developed with financial assistance from the National Research Council, the new survey system provides pipeline companies access to a cost-effective in-direct integrity assessment process to assist with ensuring safe and reliable operation of their facilities. The technological options available to pipeline integrity assessment are extremely costly and/or considerably outdated. Until recently, external evaluation instrumentation had not been significantly modified since its inception in the mid-1980’s. Although there are inline inspection (ILI) tools or “smart pigs” available to assess the overall integrity of a pipeline, they are extremely expensive. The use of internal inspection tools is also restricted to only those pipelines of uniform diameter and which are modified to accommodate launching and receiving traps. The data from ILI logs does not include depth of cover or coating condition assessment, which are also critical in maintaining the integrity of a pipeline. The majority of small diameter pipelines, such as those in gathering systems, are typically not compatible with the internal inspection technique. The incentive for improving and modifying electromagnetic pipeline coating assessment equipment was based upon: • Customer demand for new pipeline maintenance technologies; • Aging infrastructure; • Increased regulation; • Higher facility throughput and less down time requirements. The new generation of instrumentation is still based upon electromagnetic theory while incorporating the latest in computer and digital technology. In comparison to its predecessors, the package is more accurate, efficient, dependable and robust for a variety of harsh field conditions. The equipment has the ability to reliably collect and evaluate substantial amounts of data in real-time through environmentally sensitive areas such as water crossings and regions of wildlife. Compatibility with industry standards was considered in the development of the associated software used for processing and managing the significant quantity of information collected. The software also offers compatibility with GPS (Global Positioning System) and sonar technologies. Geodetic co-ordinates and, if applicable, water depths are obtained simultaneously with all the associated pipeline survey data, providing permanent reference should future remedial action be required. With the collected data set, it is now possible to effectively monitor erosion effects and shifts in pipeline position through three-dimensional modeling of the pipeline corridor and water crossing.
Robotic Inspection System for Unpiggable Pipelines
Authors: Torbin Robert , Leary William , Vradis George
Published: December 2008

Much of the existing natural gas infrastructure was designed and built without pigging as an operational consideration. There are many physical obstacles in pipelines that make the passage of SMART pigs impossible. The most intractable obstacles include: • Elbows with tight bend radius. • Back to back combinations of elbows. • Partially ported values. • Reductions/expansions greater than two pipe sizes. The use of pigs is totally dependent on the availability of pressure to “push” the pig through the pipeline. Unfortunately, the operation of many utility owned transmission pipelines is at a pressure too low to support the operation of a conventional pig. Although most interstate pipelines are many miles long, many high consequence areas along transmission pipelines are usually extremely short. Many of these pipeline segments are only one to two miles in length with no installed local traps. With the advances in robotics and sensor technology, the Office of Pipeline Safety has recently endorsed the concept that all oil and gas transmission pipelines should be capable of 100 percent inspection. The cost to replace just unpiggable valves and sharp bends has been estimated at over $1.5 billion (gas only). Therefore, the ability to inspect unpiggable pipelines presents a formidable technical and financial challenge. The inspection of unpiggable pipelines requires the marriage of a highly agile robotic platform with NDE sensor technology operating as an autonomous system. Foster-Miller and PII are developing a robot that is essentially a battery powered, train-like platform. Both front and rear tractors propel the train in either the downstream or upstream direction. Like a train, the platform includes additional “cars” to carry the required payloads. The cars are used for various purposes including the NDE sensor module(s), the power supply, and data acquisition/storage components. The onboard distributed intelligence gives the platform the capability of an engineer steering the train through the complex pipe geometry. The robot is designed with a slender aspect ratio and the ability to change shape as required by the physical obstacle presenting itself. The MFL sensor module must also morph itself through the physical obstacles, and thus, will require some level of segmentation. The system requires a very simple launch and retrieval station that is significantly less expensive to deploy.
Field Trial of Coating Systems for Arctic Pipelines
Authors: Worthingham Robert , Cetiner Matt , Kothari Meera
Published: December 2008

A pipeline to bring arctic gas to southern markets requires an appropriate coating system able to withstand the rigors of northern construction and operations. A multi-layer system of fusion bond epoxy overcoated with polyethylene was selected for the mainline coating of a construction project in Northern Alberta, Canada to test out proposed arctic construction materials and practices. Coating of the girth weld area is critical to the overall coating performance. A multi-layer liquid coating system and an epoxy primer based hot melt shrink sleeve system were tested and used for coating the welds. Preliminary full-scale application trials at −48C were performed to validate the proposed field application procedures. Results of the trials and field experience will be reported.
Evaluation of Hydrogen Cracking Susceptibility in X120 Girth Welds
Authors: Macia M. L. , Fairchild D. P. , Koo J. Y. , Bangaru N. V.
Published: December 2008

To reduce the cost of long distance gas transmission, high strength pipeline steels are being developed. Implementation of high strength pipeline materials requires the avoidance of hydrogen cracking during field girth welding. A study of hydrogen cracking in X120 girth welds has been conducted. Cracking resistance of both the weld metal and heat affected zone (HAZ) were investigated. The laboratory tests included the controlled thermal severity (CTS) test, the WIC test and the Y-groove test. In addition, multi-pass plate welds and full pipe welds were completed and examined for the presence of hydrogen cracks. The suitability of each test method for predicting cracking in X120 girth welds is determined. The morphology of hydrogen cracks in X120 girth welds is described, and the conditions necessary to prevent hydrogen cracking are identified. Following the laboratory studies, construction of X120 pipelines without cracking was demonstrated through a 1.6 km field trial.
SCC Integrity Management Case Study: Kinder Morgan Natural Gas Pipeline of America
Authors: Davis J. D. , Marr J. E. , Venance D.
Published: December 2008

Natural Gas Pipeline Company of America (NGPL), a subsidiary of Kinder Morgan, Inc., has been monitoring their pipeline system for the presence and severity of stress corrosion cracking (SCC) for more than thirty years. With the identification of near neutral pH SCC (also called low pH SCC) on this system, over the past five years NGPL has implemented a comprehensive SCC integrity management plan (IMP). Through their SCC IMP, NGPL has been finding and eliminating near critical near neutral pH SCC and other defects from their system, while using data from the program to obtain a better understanding of the relationship of SCC to existing pipe and environmental conditions. NGPL transports commercial quality natural gas to the Chicago area through a multi-line system that originates in various North American supply regions. The system right-of-way encompasses most of the American mid-west and crosses many physiographic areas. The pipelines have varying grades, diameters, and wall thicknesses, and were constructed at different times. Overall there are approximately 10,000 miles (16,000 kilometers) of pipeline that fall within the current NGPL SCC IMP. The primary purpose of this paper is to relate some of our experience with SCC on our system and describe the some of the innovative technical aspects of the existing in-house SCC IMP. This paper outlines some historical examples of the NGPL methodology for detecting near neutral pH SCC in pipeline steels using two or more separate pipeline investigation techniques. The basic steps of SCC direct assessment (DA) are described, as well as the process of integrating the predictive SCC model with in-line inspection (ILI) low level analysis signatures to determine the extent and severity of near neutral pH SCC on the NGPL pipeline system.
The Fracture Arrest Behaviour of 914 mm Diameter X100 Grade Steel Pipelines
Authors: Andrews Robert M. , Millwood Neil A. , Batte A. David , Lowesmith Barbara J.
Published: December 2008

The drive to reduce the installed cost of high-capacity long-distance pipelines has focused attention on increasing the strength of the pipe material, in order to reduce the tonnage of material purchased, transportation and welding costs. In parallel with developments in plate rolling and pipe fabrication, the properties and performance of prototype pipe materials and construction welds have already been extensively evaluated. While these studies have provided considerable confidence in the performance of X100 pipe, a major remaining issue in the introduction of such steels has been an understanding of the resistance to propagating fractures. The scarcity of relevant fracture propagation data and concerns about the measurement and specification of toughness in high strength steel pipes have led to doubts that the existing methods for control of ductile fracture can be extrapolated to X100 strength levels. In order to provide experimental data on which to base fracture control approaches, a Joint Industry Project has been undertaken using conditions representative of potential applications. Results are presented from two full-scale fracture propagation tests on 914mm pre-production grade X100 pipes pressurised using natural gas. The full-scale results are compared with small-scale test specimen data and also with results from other full-scale tests on high strength steel pipes. This provides a valuable insight into the fracture response of these materials. Information has also been obtained concerning the predictive capability of current gas decompression models. These results provide a contribution to the development of fracture control plans in pipelines using X100 steel linepipe.
Research on Operation Optimization of Multi-Product Pipeline
Authors: Liang Yongtu , Gong Jing , Kang Zhengling , Yang Fafu
Published: December 2008

It is a difficult task for pipeline operators to operate a long-distance complicated multi-product pipeline optimally, safely and efficiently. The off-line optimization simulation software for multi-product pipeline can assist to solve the problem rapidly and efficiently. Considering the operating characteristics of a complex multi-product pipeline with a variety of equipment configurations and demands for products along the pipeline, etc, the mathematical model for optimizing operations of multi-product pipeline was established, following the optimization theory, which is solved via the Dynamic Programming. In the model, the peak-to-valley ratio of electricity price is also taken into account. Almost all the governments make the policy of peak-to-valley electricity price to encourage users to consume more electricity during the valley load of electrical network. In China, the peak-to-valley ratio of electricity price is 3:1 generally, so the pipeline companies can obtain great profits via reasonable transportation plan. Based on the study, the “STROBER” software has been developed, which can support users to schedule and verify the off-take plans and control plans of the inlet pressure of pressure-reducing station, to propose the optimal pump configuration and to provide the optimization operation cost results. Input data and calculated results can be presented in kinds of forms users are accustomed to. The simulation software has been successfully applied to “LanZhou-ChengDu-ChongQing” multi-product pipeline, the most complicated one in China so far, including 13 off-take stations, 2 pressure-reducing stations and 4 pumping stations. The software simulates the operations on LanZhou-ChengDu-ChongQing multi-product pipeline, and provides the off-take plans and control project of pressures in the pipeline system, thus contributing to operators’ routine work. The feedback from the field indicates that it’s reliable for prediction and instruction.
Geotechnical Data Management System of TRANSPETRO Pipe Routes: GeoRisco
Authors: Seixas da Rocha Renato , Maia da Costa A´lvaro , Amaral Cla´udio dos Santos , Lodi da Cruz Ana Lu´cia , Soares Anderson Oliveira , Poiate Ju´nior Edgard , Rabaco Lis Maria Leoni , Lins Alexandre Farias , Rodrigues Moreira Lino Francisco , Soares Jose´ Pereira
Published: December 2008

The integrity management of an extensive pipeline mesh requests the acquisition, transmission, storage, analysis and control of a great amount of data. Guarantee the quality of the data in each one of those stages is of extreme importance in the execution of an effective decision process. Among several fields or disciplines that are related to the structural integrity of on-shore pipelines, the Geotechnics is receiving the right importance. More and more a buried pipeline has been considered as a geotechnical work, once the interaction of the foundation soil with the pipes has been demonstrating to be an important phenomenon to be monitored, with the objective of maintaining acceptable levels of strain and stress in the pipe. Therefore, the whole process of reading the geotechnical instrumentation installed in the piperoute domain has a great impact on the management of the pipeline integrity. As examples of that instrumentation we have: inclinometers, piezometers, strain-gages, etc. This work presents the information system and the methodology that were implanted by TRANSPETRO in the data management of its geotechnical instrumentation and that was named GeoRisco System. The GeoRisco System almost embraces all the stages of the monitoring process where geotechnical instrumentation exists. The monitoring process begins with the standardization of the readings supply. For this purpose, a program was created to generate XML files that facilitate the transmission and sharing of data on the Web. To store the readings of the field instrumentation it was implemented a database that centralizes these data and can be accessed in all the units of the Company. In order to facilitate for the technicians the analysis of these data, a computer program was created, where several types of graphs and spreadsheets were implemented for each instrument type. Finally, a program was developed to alert for critical changes in the measured variables that were selected to control the pipelines safety.
An Integrated Integrity Management Approach to Uprating High Pressure Gas Transmission Pipelines and Above Ground Installations
Authors: Jandu Charanjit , Cousens Paul , Wheat Steve , Bramley Neil
Published: December 2008

Advantica have recently developed an uprating methodology that provides the operator with a logical and auditable justification of safe operation at the increased pressure that can be presented to the regulator for approval. The overall approach can be described by seven distinct phases: • Feasibility study; • Data acquisition, field surveys and assembly; • Stress analysis; • Code compliance checks; • Fitness-for-purpose assessments including Risk & ALARP assessment; • Detail design; • Safety justification submission. The purpose of this paper is to briefly describe the above approach detailing the relevant aspects of each phase. Particular emphasis is given to the fitness-for-purpose phase which provides the major contribution to the overall safety justification. A case study is also provided within the paper detailing the application of the approach.
Structural Design Capacity of X120 Linepipe
Authors: Minnaar Karel , Duffy Brian W. , Olso Erlend , Papka Scott D. , Zhang Michael M.
Published: December 2008

A new high strength steel linepipe with a specified minimum yield strength of 120 ksi (X120) has recently been introduced to industry. The newly developed linepipe meets all mechanical property targets of an X120 grade material as verified through an extensive small and large-scale experimental program. Design equations have been developed and verified with full scale testing that allow pipeline designs that take full economic advantage of the higher strength of X120. This paper focuses on the development and verification of capacity equations for bending loads, external pressure (collapse) loads, combined bending and external pressure loads, and internal pressure (burst) loads. The corresponding response of the pipe was investigated with finite element analysis (FEA). Analytical equations that predict the burst, bending, and collapse capacities were then established based on parametric studies performed using FEA models. To gain confidence in the models, full size pipe tests were conducted and the results compared to FEA. The testing demonstrated that the FEA models accurately predict the behavior of the X120 pipe. Modifications to the existing equations were made when necessary to ensure the capacity equations correctly capture the pipe response for higher D/t ratios and for the higher strength X120 material. Material sensitivity studies show that the new equations accurately predict the X120 behavior over the range of load conditions evaluated.
A Single Specimen CTOA Test Method for Evaluating the Crack Tip Opening Angle in Gas Pipeline Steels
Authors: Hashemi Sayyed H. , Howard Ian C. , Yates John R. , Andrews Robert M. , Edwards Alan M.
Published: December 2008

Failure information from recent full-scale burst experiments on modern TMCP gas pipeline steels having a yield strength level of 690MPa and higher has shown that the CTOA fracture criterion can be effectively used to predict the arrest/propagation behaviour of the pipe against possible axial ductile fractures. The use of CTOA as an alternative or an addition to the Charpy V-notch and DWTT fracture energy in pipelines is currently under review. A significant difficulty currently limiting the more extensive use of CTOA in pipeline assessment is its practical evaluation either in the real structure or in a laboratory scale test. Different combinations of experimental and finite element analyses have been proposed for the measurement of the CTOA of a material. Although most of these models are able to predict the CTOA effectively, their implementation requires extensive calibration processes using the test load-deflection data. The authors have recently developed a novel test technique for direct measurement of the steady state CTOA using a modified double cantilever beam geometry. The technique uses optical imaging to register the uniform deformation of a fine square grid scored on the sides of the specimen. The slope of the deformed gridlines near the crack tip is measured during crack growth from captured images. Its value is a representative of the material CTOA. This paper presents recent results from the implementation of the technique to determine the steady state CTOA (steady state in this work refers to regions of ductile crack growth where CTOA values are constant and independent of crack length) of API X80 and X100 grade gas pipeline steels. In each case the approach was able to produce large amounts of highly consistent CTOA data from both sides of the test sample even from a single specimen. This extensive data set allowed an evaluation of the variance of the stable CTOA as the crack grew through the microstructure. The test method generated a steady CTOA value of 11.1° for X80 and 8.5° for X100 steels tested, respectively.
Pipelining of Viscous Waxy Crude With the Pour-Point-Depressant Beneficiation: Successful Experience in the Lu-Ning Pipeline
Authors: Qian Jianhua , Zhang Jinjun , Wang Kezhong , Qiu Dongping
Published: December 2008

The Lu-Ning Pipeline in the eastern China, 655.37 km long and 720 mm O.D., transports viscous Shengli waxy crude with a wax content of ca 15.24%(wt), a density of 922 kg/m3 at 20°C , a gel point of 24°C, and a viscosity of 3210 mPa·s at 25°C. It was designed as a hot oil pipeline. In the mid 1990’s, with decreasing of the crude throughput, the fuel consumption for pipelining per ton of crude increased dramatically. For reducing fuel consumption, the technology of pour-point-depressant (PPD) beneficiation was adopted. Great success was achieved. With a PPD dosage of 50 ppm and a beneficiating temperature of 60°C at the initial pumping station, the gel point of the crude was reduced by 16°C, and the viscosity at 25°C was reduced by 87%. As a result, the crude temperature at the inlet of the intermediate heating stations was lowered from 34°C to 27±1 °C. This resulted in annual 17200 tons of fuel oil saving. Thanks to improvement of the crude flow properties, running heating stations were reduced from twelve before using the PPD to only one (the initial station) in summer, seven in winter, and two to five in spring and autumn depending on ground temperature. This was the pipeline with the longest distance, the largest diameter, the largest throughput and the most running pumping stations in China that ever used the PPD-beneficiation technology. We believe that experiences gained from this pipeline and other pipelines operated by the SINOPEC Pipeline Transport and Storage Company will be helpful to safe and economical operation of hot waxy crude pipelines.
An Experimental Investigation of Oil-Water Flow Patterns in Horizontal Pipes
Authors: Yao Hai-Yuan , Gong Jing
Published: December 2008

In this paper, an experimental research on the oil-water liquid-liquid two-phase flow patterns and their transitions in horizontal pipes are carried out. According to online oil-water flow structures and the analysis of pressure drop signals., different flow patterns are defined and distinguished. A new classification for oil-water flow patterns is proposed. The flow pattern maps are obtained from the experimental data, and the factors affecting the transition mechanism of different flow regimes are discussed. In addition, some semi-theoretical criteria for the transition between different flow patterns are proposed. Especially, an accurate model is developed to predict the critical conditions for phase inversion. Comparisons of the proposed criteria with other experimental data show reasonable agreements.
Enhancement of Efficiency and Environmental Friendliness of Driving Gas Turbines by Integrating of Existing Turbomachine and High Temperature Ceramic Overstructure
Authors: Soudarev A. V. , Souryaninov A. A. , Tikhoplav V. Yu. , Kozlov S. I.
Published: December 2008

Gas turbine engines have been widely applied to pipeline systems to drive pumping equipment (gas compressors, oil pumps, etc) and electric generators. Thus, there are over 4000 units involved into the gas industry operation in Russia. Nearly 90% of machines of around 60 models are running as gas pumping units. E.g. eight types of gas turbine engines of power ranging 1 500 to 4 300 KW are operated at the electric stations to supply electric power for gas pipeline’s own needs (ONS). The bulk (over 30%) of the standard units were designed during the 60s of the past century and, therefore, their efficiency is rather low (23–28%) with the running time mounting to 60 000–80 000 hours. A good number of the existing units do not meet the international norms in terms of admissible toxic emissions (NOx, CO, etc). At the same time, the state of the basic hardware (casing, rotors, bearings, combustors, heat exchangers, etc) is, in fact, not bad, i.e. all these devices and systems could operate for, at least, 100 thousand hours more. This is an industrially well matured and thoroughly mastered, reparable and relatively inexpensive equipment. Therefore, it is of a real practical interest to implement an upgrade of the “old” machines which would allow provision of both using the existing hardware under standard operating conditions and their efficiency increasing (by 6–10% abs) and the NOx emissions reduction (up to 12.5–37.5 ppm) and CO emissions (up to 50 ppm). The like upgrade could be put into effect on the basis of integration of the existing turbomachines of gas pumping units or ONS and the ceramic overstructure — a high pressure unit. The Research–Engineering “Ceramic Heat Engines” Center (NIZ KTD) jointly with the JSC “Proletarsky Works” (St. Petersburg) has developed an ONS gas turbine drive on the base of the 1.5 MW gas turbine engine with a high temperature ceramic overstructure made as a high pressure turbocompressor with a lox-toxic combustor installed between its compressor and turbine. As a result of such modification, a pilot GTE was produced with the initial gas temperature of 1050°C instead of 827°C but of the same power and with the efficiency of 28% instead of 22%, the NOx emissions being 12.5 ppm instead of 50 ppm. The main design modifications of the base-line engine first and foremost were linked with the standard compressor (4 last stages are envisaged to be removed) and the combustor. The independent high pressure unit, at the same time, must be designed and manufactured anew. Given an effective small-size ceramic airheater is applied, you can increase its initial gas temperature (up to 1350°C with the GTE efficiency increased up to 42–47%.
State-of-the-Art Review on Existing Repair Techniques for Damaged Pipelines
Authors: Diaz Vale´rie , Zarea Mure`s
Published: December 2008

In 2000, the EPRG Workshop on Fitness for Purpose identified a need for a state-of-the-art review on repair techniques for pipelines, focused on the limitations of existing repair techniques, in order to allow the EPRG Design Committee to assess the potential need for further work. The review consisted of four steps: • Definition of a functional specification and of the criteria to meet this specification. • Literature review on existing repair techniques. • Analysis of limitations of existing repair techniques. • Recommendations for future developments. This paper is based on the EPRG report [3] which ended the review. It summarizes the findings of the detailed review of ten repair techniques which were analyzed using the format of the technical specification sheet that was agreed by the Committee.
Probabilistic Assessment of Pipeline Resistance to Third Party Damage: Use of Surveys to Generate Necessary Input Data
Authors: Wolvert Geoffray , Zarea Mure`s , Rousseau Didier , Andrieux Ce´cile
Published: December 2008

A complete risk assessment procedure for pipelines relies, among other things, on the evaluation of failure probabilities. Incident reviews in western countries have identified third party damage as the main cause of failures with leaks. While some approaches already exist in order to evaluate the failure probability of transmission pipelines subject to third party damage, the issues of feeding the models with appropriate statistical data is a key factor for the success of the evaluation. We present here briefly the outline of the tool developed by Gaz de France R&D Davison to evaluate failure probabilities in the event of third party damage. Then we discuss the issue of available data, and particularly the most critical one, i.e. the population of ground working machinery, a majority of which are excavators. In order to assess as well as possible the exposure of pipelines to the threat of interference with excavators, we conducted a large scale survey in rural, semi-urban and urban areas in Western Europe in order to determine important parameter distributions of the excavators population: mass, digging depth, tool types and dimensions, soil type, type of ground works, etc. Random variables are used to describe these parameters and their influence on the failure probability is illustrated in a series of illustrative case studies. The importance of access to reliable information about the loads to which a pipeline is exposed is clearly shown in this paper, particularly due to the fact that the dispersion is a lot larger for the parameters linked with third parties working around the pipeline than for parameters of the pipeline: geometry and material properties.
Analytical Modeling of Bolted Flange Joints With Full Face Gaskets
Authors: Galai Hichem , Bouzid Abdel-Hakim
Published: December 2008

Following the low leakage performance of flat face flanges, neither Appendix 2 nor Appendix Y of the ASME code which describes the design rules of flanges, are reliable to assess load changes when full face gaskets are used. The prediction of the tightness of these connections relies very much on the level of precision of the gasket contact stress during operation. However, determining this stress is complex, due to the many geometric and material parameters involved. This paper analyses the behaviour of bolted joints with full face gaskets. It presents an analytical approach to evaluate the operating flange rotation, gasket load and contact stress that may be used for leak prediction. The method is based on the gasket-bolt-flange elastic interaction, including flange rotational flexibility. The proposed model is supported by comparison with numerical FEA of different size flanges.