bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Taper Angle on Plastic Collapse of Pipe Joint With Different Wall Thickness and Strength
Authors: Baek Jong-hyun , Kim Young-pyo , Kim Woo-sik 
Published: July 2013

The plastic collapse behavior of the pipelines with the different wall thickness and different strength was evaluated by using the finite element analyses. Joint designs of the API X65-API X80, API X42-API X65 and API X42-API X80 were employed to investigate the plastic collapse under tensile, internal pressure or bending load.
The wall thickness ratios of the pipe joint combinations with an outer diameter of 762 mm (30 inch) were 1.22, 1.54 and 1.89. End face of the pie joint with the different wall thickness was machined with a taper angle between 4° ∼ 45° along the longitudinal direction of the lower strength and thicker pipe.
A parametric study was shown that the tensile strength and moment of the pipe joint with the wall thickness ratio less than 1.5 were not influenced by the wall thickness ratio and taper angle; however those of the pipe joint with the wall thickness ratio more than 1.5 considerably decreased at the low taper angle. The failure pressure of the pipe joint with the different wall thickness was not influenced by the wall thickness ratio and taper angle.
Application of Laser Profilometry for Fitness-for-Service Assessment on Pressure Vessel External Corrosion
Authors: Nelson Grant , Bradley Ian , Fingerhut Martin , Yu Deli 
Published: July 2013

In order to safely extend the life of damaged in-service components, Fitness-For-Service (FFS) assessments are used to evaluate structural integrity. These FFS assessments largely depend upon the quality of the inspection data. Compared to traditional inspection methods such as pit gauge or ultrasonic techniques, laser profilometry provides faster results with higher resolution and accuracy. Improved inspection data enables more precise FFS assessments and leads to fewer unnecessary repairs and non-conservative assessments.
This paper examines how laser profilometry measurements were taken of several corrosion areas on the exterior shell of a pressure vessel in order to complete a FFS assessment equivalent to an API 579 Level 2 assessment. The results of the FFS assessment show how laser profilometry data may be used in a detailed structural integrity analysis to consider a vessel safe for continued use. A discussion of how laser profilometry data could also be used for an API 579 Level 3 assessment, using finite element analysis, in areas not acceptable for Level 1, or 2 assessments is included.
Non-Standard HIC and SSC Testing Under More Severe Test Conditions
Authors: Schmidt Tanja , Haase Thomas , Bosch Christoph 
Published: July 2013

The challenging environment appearing in recent and moreover future deep offshore explorations promoted the development of linepipe steel grades with reliable sour service resistance. Severe sour conditions such as the combination of elevated production temperature, increasing pipeline pressures and high stress loads initiated by modern laying methods or introduced during service are leading to increasing corrosion demands. Steel pipelines used for the transport of media containing wet Hydrogen Sulphide (H2S) are faced with the danger of the cracking phenomena HIC (Hydrogen Induced Cracking) and SSC (Sulphide Stress Cracking). To prove resistance to HIC and SSC, test specimens are typically tested according standardised test methods. The exposure of test specimens in a sour test solution to a H2S pressure of 1 bar for 96 h, as described in NACE TM0284 is used to prove HIC resistance. Commonly four-point bend testing as described in EFC publication no. 16 is performed for SSC resistance testing with the appliance of a specific load, typically 80% of the actual yield strength.
Within this work HIC testing at test conditions representing higher H2S partial pressures (up to 5 bar) and longer test durations (up to 6 months) have been performed on seamless quenched and tempered line pipe steel of grade X65 and X70 produced by VALLOUREC & MANNESMANN TUBES by plug and continuous mandrel mill process. Beside material in as delivered condition also pre-strained material was tested. SSC four-point bend testing has been performed on specimens which were strained up to 10% of plastic strain in longitudinal direction.
Quantitative HAZOP Risk Analysis for Oil Tanks Using the Fuzzy Set Theory
Authors: Cao Tao , Zhang Huabing , Zheng Honglong , Yang Yufeng , Wang Xin 
Published: July 2013

Oil storage tanks are identified as the major hazard installations because of the hazard of huge fire & explosion. Evaluating the risk and controlling the danger is the advancement of accident prevention and the compulsory requirement of laws. HAZOP (Hazard and Operability Analysis), is a simple but intensive, systematic, qualitative risk analytical method, is an important technique for the identification of hidden hazards in operation of tank facility. It can only qualitatively account for potential risks, but cannot quantify their possibility and severity. Thus, research involving HAZOP quantitative analysis has become an area of focus. Due to uncertainty of deviation probability in the traditional HAZOP analysis, this paper discusses a new approach of HAZOP quantitative analysis, combining HAZOP with fuzzy set theory to calculate the possibilities of deviation and consequence quantitatively. The evaluation process and technique route of risk analysis is also brought forward in this paper.
Based on the traditional HAZOP analysis, the typical outputs of a HAZOP analysis can be achieved, including identification of possible deviation states, identification of the possible causes for deviations and probable worst case consequence. Next, according to fuzzy evaluation of some HAZOP experts on deviation by means of their knowledge, the triangular fuzzy-number is introduced in this paper to conduct quantitative calculation. Based on the fuzzy set theory, combining Delphi method and judging matrix method, the linguistic values are transformed into triangular fuzzy numbers. The probability of deviation is evaluated by fuzzy cut and raking method of fuzzy numbers. Finally, the probability of consequence caused by deviation is evaluated.
A complete quantitative risk analysis example for oil tank is conducted, the probabilities of deviations and incident consequence are computed, the quantitative risk is determined and reasonable mitigations of the storage tanks are given. It is shown that the proposed approach is advanced and practicable to make a quantitative assessment on the risk of existing deviation, which is helpful for risk managers to bring forward the suggested measure and regulate the hidden hazards.
Reliability Scorecards for Operating Pipelines
Authors: Jones Brad , Ferrari André-Michel 
Published: July 2013

Scorecards are generally used to track operational performance in various fields of work and direct the management team toward correcting the observed deviations. Generally, a Scorecard is made up of specific metrics which have been carefully identified against defined operating objectives. In this paper, the Scorecard examined uses a reliability growth indicator in combination with other traditional factors to measure speed of progress to a target level. As a leading liquid pipeline operator, Enbridge Pipelines Inc. (hereafter “Enbridge”) holds established and comprehensive management systems governing all aspects of its operations. In essence the Reliability Scorecard adds enhanced capabilities to the existing systems.
In September 2010, using current throughput performance and failure historical data, the Reliability Team in Enbridge developed a quarterly Reliability Scorecard for its pipeline network. Metrics for each pipeline consisted of utilization, adherence to shipping schedules and a unique reliability growth indicator of the overall line as well as the top ten failure modes. This enabled not only the tracking of performance levels but also the direction and speed of improvement or decline in those metrics. The analysis was conducted using the Crow-AMSAA Analytical Process. Using the throughput impact (e.g. barrels not shipped), level of reliability performance and magnitude of reliability improvement for each failure mode on all pipelines, it became easy to select targets for improvement. Unacceptable deviations were those having more than a 10% share of throughput volume impact per failure mode combined with a Crow AMSAA growth factor (Beta) of 1.2 or greater.
The advent of this Reliability Scorecard has improved the organizational focus on areas with greatest impact on pipeline performance and revenue generation. Having a solid indication of the issues affecting each pipeline system, the Reliability Team was able to target its efforts accordingly. For example, for a specific high impact failure mode, a formal Root Cause Analysis would be conducted to identify the causes and implement a corrective action plan. Additionally, systematic lack of improvement for one failure mode over multiple quarters would be shared with relevant teams as awareness of specific threats to performance in their area.
In essence, if well-defined and accepted, an effective Scorecard can be a powerful driver for improvement in an organization. It can assist in channeling the efforts of individuals, departments or the overall organization in addressing real threats to performance specific fields. Management can also use this tool to justify where appropriate resources need to be allocated. Finally, as demonstrated in this case, in addition to traditional operational targets, an improvement or regression factor can also be used to measure the progress or decline of specific scorecard metrics.
DEH Cable System Preventive Protection With Distributed Temperature and Strain Sensors
Authors: Ravet Fabien , Børnes Atle , Borda Carlos , Tjåland Even , Hilde Halfdan , Niklès Marc 
Published: July 2013

Hydrate and wax formation in subsea flowlines is a major cause of production impairment. Among various approaches used to minimize the risk, Direct Electrical Heating (DEH) is being applied. DEH is based on passing a current through the pipe wall to mitigate heat losses from the fluid to the surroundings during events which require flow assurance measures. The Piggyback Cable, a high voltage cable attached to the DEH pipeline, is during operation exposed to thermal and mechanical loads which may be critical for the integrity of the DEH system. The overall safety requirement is that any potential Piggyback Cable fault is detected and disconnected from the power source before damage is caused to the pipeline.
Conventional cable fault detection methods based on current measurements give adequate protection for the main part of the pipeline. However, for the far end of the Piggyback Cable complementary fault detection is required. A method based on fiber break monitoring has been qualified for this purpose. The new method is implemented in the North Sea on two DEH pipelines operated by Statoil, 43 and 21 km long respectively. The protection is facilitated by standard single-mode fibers integrated into the DEH cables.
Although not basis for the design the integrated fibers open up possibilities for temperature and strain sensing using stimulated Brillouin scattering. Sensing has been performed on a 43 km DEH pipeline using the DITEST AIM (Distributed Temperature and Strain Asset Integrity Monitoring). Analysis of the sensing results reveal that distributed fiber optic sensing is capable of pin-pointing thermal events and strain induced loads for an object of this length.
Upheaval Buckling of Small Diameter Pipelines Induced by Strong Ground Shaking
Authors: Horikawa Hiroyuki , Tsunasawa Yoji , Shinkai Hajime , Suzuki Nobuhisa 
Published: July 2013

Upheaval buckling of small diameter gas pipeline occurred due to strong seismic excitation during the 2007 Niigata-ken Chuetsu-Oki earthquake whose diameters were 4″ and smaller. This paper deals with investigation of the upheaval buckling of gas pipes conducted by Ministry of Economy, Trade and Industry of Japan to establish seismic design guidelines to mitigate upheaval buckling.
Sand box and field tests were conducted using small diameter pipes to simulate the upheaval buckling behaviors and construct a simple finite element model. The results clarified that the tensile properties of pipe material and pipe-soil interaction were the most effective parameters to explain the buckling behaviors.
Interaction curve of pipes can be found in the relationship between compression and bending moment in the combined loading tests. The deformation behaviors of the buried pipe tests followed the interaction curve and local buckling of buried pipes occurred in lower bending moment than that of pipes not buried.
Human Factor Modelling in the Pipeline Industry
Authors: Urra Susan , Green Jessica 
Published: July 2013

Most pipeline leaks and ruptures can be attributed to some degree to human factors. Therefore, identifying, measuring and improving areas of potential human factor issues can greatly decrease the risk of pipeline failure.
‘Human factors’ refers to the study of various aspects of human characteristics and job experience, job and task design, tools and equipment design, and work environment which can affect pipeline operations and overall system performance.
Enbridge Pipelines has developed a risk assessment model that assesses the risk of human factors along the company’s nationwide liquid pipeline system. The Human Factors Risk Assessment Model generates a risk score for each aspect of the pipeline as well as an overall risk score which highlights the business areas of highest concern.
The implementation of the model included the execution of a pilot study to calibrate the model. To perform the pilot, data was collected from the control center, field and office locations through different methodologies such as survey, interview and databases available.
The results from the control room operation surveys indicate that the main areas of human error potential in the control room can be mitigated by decreasing the number of manual calculations the operators have to complete and ensuring operators aren’t taking on extra work that should be completed by other areas. These workload improvements would decrease the chance of an operator having to complete two or more control operations at the same time. Lastly, controlling the amount of phone activities that interfere with monitoring and control operations also gives an opportunity to reduce the potential for human error in the control room.
Improvements that can be made in the office to reduce human error potential include the development of a human factors standard and improving the critical procedure observation and management of change systems.
Measuring, acknowledging and mitigating human factor risks at Enbridge will yield a decrease in the risk of pipeline failure across the entire liquid pipeline system.
Development of a Novel Electromagnetic Quantitative Residual Stress Sensor for Characterization of Steel Pipeline Mechanical Damage
Authors: Lasseigne Angelique N. , Koenig Kamalu M. , Jackson Joshua E. 
Published: July 2013

Nondestructive residual stress mapping of damage in pipeline steel has been demonstrated as a new approach for pipeline integrity management. The handheld system for rapid characterization pipelines has been used on dents and wrinkles, two of the most common forms of mechanical deformation. The ability to compare residual stresses with design stresses will allow for a much more accurate criteria for use in fitness-for-service and improved modeling of pipeline stresses. As the capabilities of in-line inspection technologies continue to improve, operators are often faced with thousands of indications that require examination. Accurate assessment of residual stresses will provide a more effective method of combatting the most common form of pipeline failures, mechanical damage.
The residual stresses associated with the mechanical damage forms the basis for the nucleation and growth of cracks at areas with the highest residual stresses. Quantitative, real-time knowledge of the through-thickness residual stress levels associated with the mechanical damage will enable enhanced Risk-Based Inspection and drastically improve pipeline integrity. The development of a non-destructive, quantified residual stress measurement system to evaluate the damage severity on pipeline steels through the structural coatings (without any removal) will enable improved integrity assessment and reduce the number of unnecessary removal and replacement activities. The development of a real-time, through-thickness residual stress sensor to assess steel pipeline mechanical damage is presented in this paper.
Implications of Reduced Heating of Heavy Crude Pipeline on Pump Lubrication Systems
Authors: Lopez Byron G. 
Published: July 2013

OCP Ecuador S.A. was designed for transporting heavy crude oil from the Ecuadorian Amazonian forest to the Pacific Ocean, crossing the Andes (highest point @ 4060 masl). OCP have four pumping stations PS1, PS2, PS3, PS4 located across the first 182km.
Main pumps were designed with an inherent product circulation from pressure connection via orifice to mechanical seal (API Plan 11) for lubricating and cooling. In order to achieve required viscosity, crude oil from the main line must be heated. Low sulfur crude oil (LSCO) is burned for this purpose.
In order to optimize fuel consumption, some efforts were conducted since 2006. The first aim was to increase feed rate of lubricating oil, in order to extend the viscosity within seals up to 700cP. This modification resulted in considerable heat exchange depletion, representing about 50% of costs reduction related to reduce heating of crude oil in the main line.
Since 2009, there were some adverse scenarios, which forced the company to seek more and better ways to optimize the fuel oil consumption. These scenarios were:
• The continued decline in the quality of crude oil delivered by the shippers quality from shippers. Reduced quality was seen as a threat to the integrity of mechanical seals.
• Unavailability of LSCO in the country,
• The under-utilization of transport capacity due to low volumes of oil (30% of its capacity).
Facing this situation, OCP decided to analyze the technical and economic feasibility of operating without heating oil, in an intermediate pump station (PS3: KP 148 @ 1800 masl). This pump station, at the time of the study, was operated heating crude oil.
The greatest difficulty in achieving the goal of reducing heating oil was the maximum viscosity that mechanical seals could withstand, without affecting its integrity. To mitigate this threat, an API plan 32 was designed and implemented in PS3.
Simultaneously, the organization was evaluating the possibility of installing a similar system in PS4, where climatic conditions are more adverse than PS3. Based on thermal models and after risk evaluation and cost benefit analysis, OCP decided to run operations accepting the risk of potential damage to the seals in PS4.
At the moment, OCP Ecuador S.A. is operated without heating crude oil and API plan 32 was placed on standby, reducing considerably the operating costs.
This paper is intended to share the learned lessons, some actions taken; obstacles faced up as well as achieved results in this cost reduction effort.
Geohazard Mapping and Identification Along Pipeline Right-of-Ways Using Space-Borne Synthetic Aperture Radar
Authors: Henschel Michael D. , Robert Gillian , Deschamps Benjamin , Gailing Richard W. 
Published: July 2013

Many energy pipelines traverse hilly and mountainous terrains that are prone to landslides and other geohazards. The mapping, identification, and monitoring of geohazards along pipeline right-of-ways are essential in effectively managing the risks they may pose to pipeline integrity and human safety. One approach to monitoring potential geohazards is to use space-borne synthetic aperture radar (SAR). SAR is an effective and proven technology used to monitor ground surface change over vast areas and can be used in a cost-efficient manner, especially in areas that are remote or challenging.
This paper focuses on aspects of a novel three-fold approach for monitoring geohazards using satellite radar imagery. This is accomplished by combining interferometric SAR (InSAR), automated amplitude change detection, and polarimetric change detection. The resulting analyses are to be merged into a new geohazard index map that will provide a simplified overview of the change influence for given pipeline segments over an extensive area. It is anticipated that the geohazard index map would be used to support operator decision-making in proactively mitigating the potential adverse effects identified.
A brief introduction to the methodologies employed and a discussion of the validation that is currently underway as a joint project between MDA Geospatial Services and Southern California Gas Company is provided by this paper.
Research and Development of Heavy Wall X80 Transmission Pipeline Steel With High Deformation Characteristics for Polar Environments at Shougang Steel
Authors: Zha Chunhe , Jiang Zhonghang , Wang Wenjun , Li Jiading , Li Shaopo , Ding Wenhua , Stalheim Douglas , Bai Xuejun 
Published: July 2013

Oil and gas transmission pipeline steels with high deformation capability are required for environments (earthquake zones, permafrost zones, forest heave, deep sea applications, etc.) where large strata movement may occur. When large strata movement occurs the pipeline is exposed to large plastic deformations that can result in failure. Transmission pipelines that must operate in these environmental conditions utilize a strain based design strategy to protect the pipeline from failure. This strain based design strategy for these transmission pipeline environments requires that the steel design used for pipe production must not only have the capability to withstand the high internal operating pressure but must also have good deformation resistance characteristics.
Shougang Steel has conducted research into the metallurgical design required for heavy wall X80 transmission pipeline steel with high deformation and good low temperature mechanical property characteristics. This research coupled with the production capability of the Shougang Steel’s Qinhuangdao China (Shouqin) 4.3 m heavy wide plate mill has resulted in the successful production of a cost effective low C-Nb X80 alloy design with good deformation and low temperature toughness capabilities suitable for applications such as the natural gas TCPL/ExxonMobil proposed Alaskan Pipeline Project. This paper will discuss Shougang Steel’s research and development of heavy wall X80 pipeline steel. Key process parameter and equipment capabilities of the Shouqin 4.3 m wide heavy plate mill along with heavy wall X80 production results will be discussed.