Academic literature on the topic 'Leakage assessment methodology'
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Journal articles on the topic "Leakage assessment methodology"
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Schneider, Tobias, and Amir Moradi. "Leakage assessment methodology." Journal of Cryptographic Engineering 6, no. 2 (February 12, 2016): 85–99. http://dx.doi.org/10.1007/s13389-016-0120-y.
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Pietrucha-Urbanik, Katarzyna, Barbara Tchórzewska-Cieślak, and Mohamed Eid. "Water Network-Failure Data Assessment." Energies 13, no. 11 (June 10, 2020): 2990. http://dx.doi.org/10.3390/en13112990.
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The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association’s Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the “mean time between failures.” The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations.
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Wang, Xiaojia, Xianli Liu, Zhaoyang Jin, Jiewen Zhu, and Baosheng Jin. "Theoretical Methodology of a High-Flux Coal-Direct Chemical Looping Combustion System." Processes 6, no. 12 (December 4, 2018): 251. http://dx.doi.org/10.3390/pr6120251.
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This study, as an extension of our previous experimental tests, presented a mechanism analysis of air reactor (AR) coupling in a high-flux coal-direct chemical looping combustion (CDCLC) system and provided a theoretical methodology to the system optimal design with favorable operation stability and low gas leakages. Firstly, it exhibited the dipleg flow diagrams of the CDCLC system and concluded the feasible gas–solid flow states for solid circulation and gas leakage control. On this basis, the semi-theoretical formulas of gas leakages were proposed to predict the optimal regions of the pressure gradients of the AR. Meanwhile, an empirical formula of critical sealing was also developed to identify the advent of circulation collapse so as to ensure the operation stability of the whole system. Furthermore, the theoretical methodology was applied in the condition design of the cold system. The favorable gas–solid flow behaviors together with the good control of gas leakages demonstrated the feasibility of the theoretical methodology. Finally, the theoretical methodology was adopted to carry out a capability assessment of the high-flux CDCLC system under a hot state in terms of the restraint of gas leakages and the stability of solid circulation.
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Campbell, Enrique, Amilkar Illaya-Ayza, Joaquín Izquierdo, Rafael Pérez-García, and Idel Montalvo. "Social-network-based water supply network sectorization methodology using monte carlo simulation to predict economical and operational benefits." Acta Universitaria 26 (March 3, 2017): 44–53. http://dx.doi.org/10.15174/au.2016.1060.
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Water Supply Network (WSN) sectorization is a broadly known technique aimed at enhancing water supply management. In general, existing methodologies for sectorization of WSNs are limited to assessment of the impact of its implementation over reduction of background leakage, underestimating increased capacity to detect new leakage events and undermining appropriate investment substantiation. In this work, we raise this issue and put in place a methodology to optimize sectors' design. To this end, we carry out a novel combination of the Short Run Economic Leakage Level concept (SRELL- corresponding to leakage level that can occur in a WSN in a certain period of time and whose reparation would be more costly than the benefits that can be obtained). With a non-deterministic optimization method based on Genetic Algorithms (GAs) in combination with Monte Carlo simulation. As an example of application, methodology is implemented over a 246 km pipe-long WSN, reporting 72 397 $/year as net profit.
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Pérez, R., S. de las Heras, J. Aguilar, J. Pascual, A. Peralta, and E. Landeros. "District management areas characterisation in water network based on clustering." Water Supply 9, no. 5 (December 1, 2009): 591–600. http://dx.doi.org/10.2166/ws.2009.633.
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The division of a network in different sectors is a usual practice in Water Companies. It improves the management of the network in different senses. Sectors have more homogenous characteristics and need specific cares and treatments that is not the same all through the network. Specifically for leakage detection and assessment it is interesting to know the performance of the sector before any leakage detection strategy is applied. In this paper a characterisation methodology for the sectors is presented. This methodology is based on the knowledge provided by the company but has been analysed using clustering techniques. The main objective of the classification was to give a scope of the different types of sectors present in the network. A decision table based on the relevant descriptors was built. This allowed choosing three interesting pilot sectors for the leakage detection methodology study.
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Rogozin, E. A., D. G. Silka, and O. A. Gulyaev. "METHODOLOGY FOR ASSESSING THE SECURITY OF INFORMATION PASSED THROUGH THE TECHNICAL CHANNELS OF A SPECIAL-PURPOSE INFORMATISATION OBJECT." Herald of Dagestan State Technical University. Technical Sciences 46, no. 4 (January 2, 2020): 123–33. http://dx.doi.org/10.21822/2073-6185-2019-46-4-123-133.
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Objectives. In order to determine the security of a special-purpose informatisation object, it is necessary to calculate the effectiveness indicators of information security (IS) measures aimed at preventing unauthorised access (UA) threats associated with information leakage through technical (acoustic) channels. In order to determine the actual channels of information leakage, it is necessary to develop a list of actions to neutralise potential threats, including the development of an information protection system for a special-purpose informatisation object.Method. A security assessment of the special-purpose informatisation object is carried out using expert documentary and instrumental methods.Results. The results of evaluating the indicators of protection against information leakage through the air (acoustic) channel are presented and aspects of improving special measures for protecting information at the special-purpose informatisation object are identified.Conclusion. Due to its relevance, the direction of this study requires further development of organisational and technical measures to implement the requirements of regulatory documents on the protection of information in special-purpose informatisation objects.
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Kozlov, A., and N. Noga. "About Some Risks Associated with Subjective Factors, and the Methodology for their Assessment." Review of Business and Economics Studies 9, no. 3 (November 22, 2021): 94–102. http://dx.doi.org/10.26794/2308-944x-2021-9-3-94-102.
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The authors propose a methodology for assessing the risk associated with subjective factors that may affect the achievement of the final goals of business projects, including ensuring information security. Such factors may include the level of salary, the level of professionalism, and others. At the same time, we propose carrying out the risk assessment by using the fuzzy logic method, which allows us to determine the dependence of the risk on various parameters under conditions of their uncertainty. According to the authors, the proposed methodology will help avoid some incorrect management decisions in the formation of author (working) teams, which could lead to negative consequences in the further implementation of the business project. These negative consequences can be expressed in delaying the implementation period, increasing the project’s cost, or even losing business due to critical information and personnel leakage. Also, this method allows you to increase the effectiveness of personnel policy in the organisation or the company. We noted that this method is applicable not only for individual enterprises but also for corporations and associations with complex network structures.
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Xiao, Ting, Brian McPherson, Richard Esser, Wei Jia, Zhenxue Dai, Shaoping Chu, Feng Pan, and Hari Viswanathan. "Chemical Impacts of Potential CO2 and Brine Leakage on Groundwater Quality with Quantitative Risk Assessment: A Case Study of the Farnsworth Unit." Energies 13, no. 24 (December 14, 2020): 6574. http://dx.doi.org/10.3390/en13246574.
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Potential leakage of reservoir fluids is considered a key risk factor for geologic CO2 sequestration (GCS), with concerns of their chemical impacts on the quality of overlying underground sources of drinking water (USDWs). Effective risk assessment provides useful information to guide GCS activities for protecting USDWs. In this study, we present a quantified risk assessment case study of an active commercial-scale CO2-enhanced oil recovery (CO2-EOR) and sequestration field, the Farnsworth Unit (FWU). Specific objectives of this study include: (1) to quantify potential risks of CO2 and brine leakage to the overlying USDW quality with response surface methodology (RSM); and (2) to identify water chemistry indicators for early detection criteria. Results suggest that trace metals (e.g., arsenic and selenium) are less likely to become a risk due to their adsorption onto clay minerals; no-impact thresholds based on site monitoring data could be a preferable reference for early groundwater quality evaluation; and pH is suggested as an indicator for early detection of a leakage. This study may provide quantitative insight for monitoring strategies on GCS sites to enhance the safety of long-term CO2 sequestration.
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McKenzie, R., and C. Seago. "Assessment of real losses in potable water distribution systems: some recent developments." Water Supply 5, no. 1 (March 1, 2005): 33–40. http://dx.doi.org/10.2166/ws.2005.0005.
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Considerable progress has been made over the past 10 years in the assessment and benchmarking of real losses in potable water distribution systems. Most of the advances have been based on the burst and background estimate (BABE) methodology, which was first developed in the mid-1990s by the UK water industry and has since been widely accepted and used in many parts of the world. Since the original BABE methodology was developed, several other key concepts have been added to the evergrowing list of water demand management tools. In particular, the infrastructure leakage index (ILI) and unavoidable annual real losses (UARL) introduced by A. Lambert, and the fixed area variable area discharge (FAVAD) theory by J. May, are now recognised as key “tools of the trade” in any water demand management assessment. One of the first main developments where the above-mentioned concepts were applied in practice to benchmark leakage was in South Africa, where the local Water Research Commission supported the production of the BENCHLEAK Model. This was basically the first comprehensive model to assess real losses in potable water distribution systems using the UARL and ILI concepts. The model was developed by one of the authors together with A. Lambert, and was soon followed by similar developments in Australia (BENCHLOSS) and New Zealand (BENCHLOSSNZ). Both models incorporated additions and enhancements to the original South African model, and were tailored to suit the local conditions in line with the clients' requirements. Similar developments took place in parallel by various leakage specialists, most notably in Brazil, Malaysia and Cyprus, to mention just a few of the similar initiatives. Each time a new model was developed, certain improvements were made and the “science” of leakage management and benchmarking was enhanced. Through the use of the different models and from discussions with various researchers from around the world, it has become clear that there is a genuine need for such models, and they are being readily accepted by clients in most areas. The discussions have also raised many questions concerning the derivation of the terms used to calculate the UARL and the ILI, and, to address these concerns a specialist group was created through the IWA to investigate the various issues. This paper will highlight the progress that has been made to date with regard to the key issues that have been raised by the task-team members, and recommendations based on the feedback that has been received from around the world. The paper will also present some of the results that have been obtained from different parts of the world to highlight both the progress and the problems associated with the assessment of real losses. The paper will conclude with a short description of several new models that have been developed and are in use, which demonstrate the latest improvements to an ongoing process to assess and benchmark real losses in water distribution systems.
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Andryianava, T. A., and S. B. Salomatin. "DLP: REDUCED RISK OF LEAKAGE OF CONFIDENTIAL INFORMATION OF THE BANK." «System analysis and applied information science», no. 3 (November 2, 2017): 76–82. http://dx.doi.org/10.21122/2309-4923-2017-3-76-82.
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Research application of DLP-system for protection of confidential information, a methodology for adapting the DLP-system to the specific activities of the organization, comparative analysis of the results of standard and adapted DLP-systems in the Bank. Developed: a technique for analyzing information security events, algorithm for responding to identified events, methodology and procedures for adapting the standard DLP-system to the specifics of the Bank’s activities. The methodology for adapting a standard DLP-system to the specifics of the Bank’s work consists of the following activities: identification of critical corporate information categories, audit of information systems, description of current risks and their assessment, introduction of rules for Bank’s critical information and setting up a DLP system in accordance with the specifics of the Bank’s work. Modernization of the configuration of a standard DLP-system includes the following procedures: selection of confidential information of the Bank based on membership criteria, setting up detection, creating perimeters and developing an algorithm for responding to identified information security events in the Bank. The algorithm is designed to improve the efficiency of the response of information security officers in cases of incident detection and describes the stages of the subsequent actions. The results of the research prove that using an adapted DLP-system significantly reduces the number of false positives, increasing the accuracy of detecting confidential information and reducing the risk of leakage of critical information outside the corporate network. The application of the adapted DLP-system in the Bank allowed to increase the speed of response of information security specialists to the information security events detected by the DLP-system adapted to the Bank, and also allowed the DLP-system to transition from the copy mode to the blocking mode of illegitimate transfer of information.
Dissertations / Theses on the topic "Leakage assessment methodology"
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Sharma, Neha. "Development of CFD Methodology to Quantify Particle-transmission Percentage of Personal Protective Equipment." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1523635154570205.
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Максюта, Дмитрий Игоревич. "Комбинированный метод аэродинамической оптимизации ступени осевой турбины." Thesis, НТУ "ХПИ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/21648.
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Диссертация на соискание ученой степени кандидата технических наук по специальности 05.05.16 – турбомашины и турбоустановки. – Национальный технический университет "Харьковский политехнический институт", Харьков, 2016. Диссертация посвящена разработке комбинированного метода аэродинамической оптимизации ступени осевой турбины, который основываясь на поочередном решении одномерной и трехмерной задач, позволяет значительно повысить эффективность всей ступени при этом учитывая как характер течения рабочего тела в решетках, так и влияние на него протечек. На основании современной тенденций к использованию методов вычислительной аэродинамики (CFD) при оптимизации проточных частей осевых турбин и при этом задействуя как можно большее количество управляющих параметров в оптимизационном процессе, предложен комбинированный метод оптимизации. Предложенный метод использует одномерную и трехмерную оптимизацию, что позволяет существенно повышать аэродинамическую эффективность ступеней, при этом значительно экономя время, необходимое для проведения расчетов. С помощью предложенного метода оптимизации и методики расчета протечек в осерадиальном уплотнении выполнена оптимизация 3-й ступени ЦВД турбины К-540-23,5. Результаты проведенных расчетов показали, что повышение эффективности ступени на этапе одномерной оптимизации происходит за счет выбора на среднем радиусе оптимальных α1, β2, значений степени реактивности ρ и относительного шага решетки t/b. Повышение эффективности ступени на этапе трехмерной оптимизации происходит за счет: выбора оптимального значения входного геометрического угла β1г рабочего профиля, обеспечившего улучшение обтекания профиля; устранения локальных диффузорных участков в межлопаточном канале; нахождения оптимальных законов закрутки, обеспечивающих равномерное натекание потока по всей высоте рабочих лопаток. Суммарно абсолютный КПД новой ступени увеличился более чем на 1 %.Thesis for degree of Candidate of Sciences in Technique for speciality 05.05.16 – turbomachinery and turbine-installations. – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2016. This thesis deals with the development of the combined method of aerodynamic optimization of the axial turbine stage, based on the iterative usage of one-dimensional and three-dimensional theories, thereby can significantly improve the efficiency of the entire stage taking into account the nature of the flow around turbine profiles and the impact of leakage on it. Based on current trends of using computational fluid dynamic methods (CFD) while optimizing of the flow path of the axial turbines, with engaging the largest pos-sible number of control parameters in the optimization process, the combined optimization method is provided. Developed method uses one-dimensional and three-dimensional optimization theories and can noticeably improve aerodynamic efficiency of whole turbine stage, thus significantly saving the time required for the simulations. A three-step comprehensive comparison of the results of simulations with the experimental data confirmed the accuracy of CFD usage while developing the optimization method. To calculate amount of leakage in the radial clearance during one-dimensional optimization phase more accurate, the methodology of flow rate determining in axial-radial seals depending on geometrical, operational characteristics and considering rotor against stator displacement was developed using a series of CFD simulations. Advanced CFD study was conducted to compare the axial-radial seal with the straight-flow one and to identify the new more effective designs of seal. It was shown that creation of artificial roughness on the shaft of the straight-flow seal could reduce the leakage by 45 % compared to the axial-radial seal. Utilizing the developed optimization method and the methodology of leakage calculation in the axial-radial seal, the optimization of the 3rd stage of the high pressure turbine K-540-23,5 was made. As a result of the optimization a new stage with an absolute efficiency increase more than 1 % compared to the original design was obtained.
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Максюта, Дмитро Ігорович. "Комбінований метод аеродинамічної оптимізації ступеня осьової турбіни." Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/21646.
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Дисертація присвячена розробці комбінованого методу аеродінамічної оптимізації ступеня осьової турбіни, який ґрунтуючись на почерговому вирішенні одновимірної та тривимірної задач, дозволяє значно підвищити ефективність всього ступеня враховуючи як характер течії робочого тіла в решітках, так і вплив на неї витоки. На підставі сучасної тенденцій до використання методів чисельної аеродинаміки (CFD) при оптимізації проточних частин осьових турбін і при цьому задіяючи якомога більшу кількість управляючих параметрів в оптимізаційному процесі, запропонований комбінований метод оптимізації. Запропонований метод використовує одновимірну та тривимірну оптимізації, що дозволяє істотно підвищувати аеродинамічну ефективність ступенів, при цьому значно заощаджуючи час, необхідний для проведення розрахунків. При розробці методу оптимізації достовірність застосування методів CFD підтверджена шляхом триетапного порівняння результатів розрахунків з результатами експериментальних досліджень. Для отримання більш точних даних кількості витоки робочого тіла в радіальний зазор при проведенні етапу одновимірної оптимізації, розроблена методика для визначення коефіцієнта витрати вісерадіального ущільнення в залежності від його геометричних і режимних характеристик, а також з урахуванням зсуву ротора відносно статора від теплового розширення. Дана методика розроблялася шляхом проведення серії CFD розрахунків. Додатково проведено CFD дослідження для порівняння вісерадіальних ущільнень з прямоточними та виявлення нових ефективних конструкцій ущільнень, яке показало, що шляхом створення штучної шорсткості на валу прямоточного ущільнення можна зменшити витрату через нього на 45 % в порівнянні з вісерадіальними ущільненнями. За допомогою запропонованого методу оптимізації та методики розрахунку витоки в вісерадіальному ущільненні виконана оптимізація 3-го ступеня ЦВТ турбіни К-540-23,5. Результати проведених розрахунків показали, що абсолютний ККД нового ступеня збільшився більш ніж на 1 %.Thesis for degree of Candidate of Sciences in Technique for speciality 05.05.16 – turbomachinery and turbine-installations. – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2016. This thesis deals with the development of the combined method of aerodynamic optimization of the axial turbine stage, based on the iterative usage of one-dimensional and three-dimensional theories, thereby can significantly improve the efficiency of the entire stage taking into account the nature of the flow around turbine profiles and the impact of leakage on it. Based on current trends of using computational fluid dynamic methods (CFD) while optimizing of the flow path of the axial turbines, with engaging the largest pos-sible number of control parameters in the optimization process, the combined optimization method is provided. Developed method uses one-dimensional and three-dimensional optimization theories and can noticeably improve aerodynamic efficiency of whole turbine stage, thus significantly saving the time required for the simulations. A three-step comprehensive comparison of the results of simulations with the experimental data confirmed the accuracy of CFD usage while developing the optimization method. To calculate amount of leakage in the radial clearance during one-dimensional optimization phase more accurate, the methodology of flow rate determining in axial-radial seals depending on geometrical, operational characteristics and considering rotor against stator displacement was developed using a series of CFD simulations. Advanced CFD study was conducted to compare the axial-radial seal with the straight-flow one and to identify the new more effective designs of seal. It was shown that creation of artificial roughness on the shaft of the straight-flow seal could reduce the leakage by 45 % compared to the axial-radial seal. Utilizing the developed optimization method and the methodology of leakage calculation in the axial-radial seal, the optimization of the 3rd stage of the high pressure turbine K-540-23,5 was made. As a result of the optimization a new stage with an absolute efficiency increase more than 1 % compared to the original design was obtained.
Book chapters on the topic "Leakage assessment methodology"
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Schneider, Tobias, and Amir Moradi. "Leakage Assessment Methodology." In Lecture Notes in Computer Science, 495–513. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-48324-4_25.
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Lepikhin, Anatoly, Victor Leschenko, and Nikolay Makhutov. "Defects Assessment in Subsea Pipelines by Risk Criteria." In Issues on Risk Analysis for Critical Infrastructure Protection [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.94851.
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Subsea inter-field pipelines are an important element of offshore oil and gas infrastructure. Leakage or fracture of these pipelines is associated with the risk of large economic and environmental losses. One of the main sources of pipeline fracture is pipe defects. The presented section discusses the methodological aspects of assessing the hazard of defects of subsea inter-field pipelines by risk criteria of accidents. A conceptual approach of defects hazard assessing by risk criteria has been formulated, based on analysis the requirement of modern standards. The risk is defined as the probability of negative consequences, the scale of which is determined by the hazard class of pipeline accidents. The probability and scale of accidents are linked by a risk matrix. A method for a three-level assessment of the suitability of a pipeline for operation after in-line inspection has been developed. The method allows assessing the hazard of the most typical defects in subsea pipelines, such as metal loss, metal delamination, cracks and crack-like defects. The allowable defect sizes are determined for the given risk criteria using partial safety factors. The novelty of the methodology lies in the substantiation of safety factors according to risk criteria corresponding to a given class of damage and loss. A scheme for making decisions on the admissibility of defects by risk criteria has been developed. An example of hazard assessment of defects in subsea pipelines is presented.
Conference papers on the topic "Leakage assessment methodology"
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Lei, Wan, Lihui Wang, Weijun Shan, Kun Jiang, and Qing Li. "A Frequency-Based Leakage Assessment Methodology for Side-Channel Evaluations." In 2017 13th International Conference on Computational Intelligence and Security (CIS). IEEE, 2017. http://dx.doi.org/10.1109/cis.2017.00137.
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Ford, Eric, Hans Petter Lohne, Katherine Beltrán-Jiménez, and Laurent Delabroy. "Methodology to Use the Cement Bond Quality Classification Matrix as Input for Leakage Rates Assessment." In IADC/SPE International Drilling Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/208685-ms.
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Abstract Verification of the quality of the cement barrier behind casing is often performed through acoustic or ultrasonic cement logs that probe the presence of cement and its bonding to the casing. In risk-based approaches to permanent well abandonment design, the probable conditions of the existing barriers in the well should be reflected in terms of reliability, or conversely, the risk of leakage through the barrier over time. Connecting the log response to a predictive model of leakage potential behind casings remains a key challenge for the industry. We build on ultrasonic cement logs acquired in two sandwich joints recently retrieved from a North Sea production well as part of the permanent abandonment operation. The joints consist of 30 years old annulus cement sandwiched between production and intermediate casing joints that have been subjected to a comprehensive test regimen involving pressure and seepage testing. Combined with the log response, these measurements offer an unprecedented opportunity to compare log response and physical measurements of leakage potential. We have developed a methodology for converting a log response to a likely, local microannulus size that in turn reflects the seepage potential of the annular barrier. Physical testing of the two sandwich joints used as basis for the study revealed significant local variations in seepage potential ranging from effective microannuli of tens of microns down to a very low permeable region with practically impermeable features over the timescale of measurement. Our methodology is based on a Monte Carlo approach for propagating uncertainty from log interpretation to annular seepage potential. We discretize the log response azimuthally and axially into volume elements of locally constant permeability and compare numerical log realizations to the physical measurements. We find generally good qualitative agreement with the cement log and demonstrate conceptually the possibility of utilizing a cement log response for a quantitative assessment of the barrier quality. Improved interpretation of barrier quality is a key step toward new rig-less abandonment operations and more efficient risk-based abandonment design. Our study represents a first conceptual study that attempts to connect physical measurements of the cement quality behind production casing to its log response. More efforts are required to fully utilize the information contained in cement logs for quantitative comparison of different P&A designs.
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Brown, Warren. "Development and Use of the Risk-Based Joint Integrity (RBJI) Assessment Methodology." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45896.
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The ability to determine, using a uniform approach, which joints in a unit, plant or company represent the highest level of risk of leakage is extremely useful. Similarly to Risk-Based Inspection (RBI), Risk Based Joint Integrity (RBJI) allows the identification and allocation of resources to the joints that pose the greatest risk of failure. This ensures that the appropriate level of effort is placed in the most appropriate locations. This paper outlines a quantitative methodology for assessing the probability of failure for any given pressure boundary bolted joint. It allows rapid calculation across a range of joints without resorting to the typical qualitative, reactive, experienced-based methods commonly employed to assess risk of joint leakage (i.e.: waiting for the joint to leak in order for it to be labelled a bad actor). This methodology has been successfully employed in a number of applications over the past three years, such as justification of heat exchanger replacement (demonstrating the expected improvement in joint integrity) and assessment of residual risk associated with historic joint assembly practices. Future applications include assessment of risk and definition of acceptable residual risk during the project design phase in order to eliminate problematic joints prior to fabrication and using the methodology to reduce the time associated with leak-testing of piping systems during maintenance turn-around activities.
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Kayll, D., M. Defo, T. Moore, and M. Lacasse. "A Methodology for Assessment of Building Assembly Air Leakage Moisture Response, Condensation Risk, and Expected Durability When Subjected to Projected Future Climate Loads." In XV International Conference on Durability of Building Materials and Components. CIMNE, 2020. http://dx.doi.org/10.23967/dbmc.2020.183.
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Gorash, Yevgen, Alan Bickley, and Francisco Gozalo. "Application of the CEL Approach to Consider FSI for the Assessment of Leak Tightness for Elastomeric Seals." In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84792.
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Swellable elastomeric seal is a type of specifically engineered packer that swell upon contact with wellbore fluids. Assessment of leakage tightness is a fundamental aspect in the design of swellable packers, since they should guarantee a reliable sealing under extreme pressures of the downhole fluids. Numerical capability of the leakage pressure prediction would facilitate improvement in the packer design methodology. Previous work was focused on investigation of the non-parametric optimisation capability seeking for an optimal external shape with a goal to maximise the grip of a packer with a borehole. The verification of an optimised design was done with a dynamic FE-simulation of packer’s failure by extrusion under an excessive pressure. The downside of that verification analysis was that Abaqus/Explicit solver couldn’t implement a realistic adaptive pressure application due to changing packer disposition and contact conditions. This simulation challenge is addressed in this paper by application of the Coupled Eulerian-Lagrangian (CEL) approach in Abaqus/Explicit, which provides the ability to simulate a class of problems where the fluid-structure interaction is important.
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Adams, Timothy M., and Scott Quiggle. "Application of Earthquake Experience Data as Part of the Seismic Verification of Modified Main Steam Isolation Valve Leakage Pathway Piping." In ASME/JSME 2004 Pressure Vessels and Piping Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/pvp2004-2916.
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The Monticello Nuclear Generating Plant made modifications to the turbine island in 1998 to achieve a 5% power uprate. The radiological analysis conducted for power uprate took credit for deposition and holdup of radioactive iodine in the steam lines downstream of the Main Steam Isolation Valves (MSIV’s) and in the main condenser. The original design basis of certain main steam system piping, equipment, and components that comprise the MSIV Leakage Pathway was not in accordance with Seismic Category I requirements. As part of the original program seismic verification walkdowns were performed to demonstrate the main steam system piping, equipment, and components were seismically rugged. The walkdowns were done using the methodology suggested to seismically evaluate this pathway in the Boiling Water Reactor Owners’ Group report, entitled “BWROG Report of Increasing MSIV Leakage Rate Limits and Elimination of Leakage Control Systems”. In 2001, Monticello made significant changes to improve the performance of the plants hydrogen recombiner process. The hydrogen recombiners are part of the off gas system a portion of which was in the original MSIV Leakage Pathway. These modifications significantly redefined MSIV Leakage Pathway and required an updated assessment of the seismic ruggedness of piping and associated equipment in the MSIV Leakage Pathway. This paper describes the approach and methodology used to update and expand the seismic evaluations and seismic verification walkdowns. It also summarizes the results of these walkdowns and the steps necessary to demonstrate the seismic adequacy of the piping and equipment.
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Ramachandran, Madhumitha, Jon Keegan, and Zahed Siddique. "Degradation Assessment of Reciprocating Seal Using Support Vector Regression." In ASME 2019 14th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/msec2019-2820.
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Abstract Reciprocating seal located directly on the rod/piston of a reciprocating equipment is used for preventing leakage and reducing wear between two parts that are in relative motion. Degradation assessment of reciprocating seal is extremely important in the manufacturing industry to avoid fatal breakdown of reciprocating equipment and machines. In this paper, we have proposed a data-driven prognostics approach using friction force to predict the degradation of reciprocating seal using Support Vector Regression. Statistical time domain features are extracted from friction force signal to reduce the complexity of raw data. Principal Component Analysis is used to fuse the relevant features and remove the redundant features from the process. Based on the selected features, a Support Vector Regression model is then built and trained for the prediction of seal degradation. A Grid search method is used to tune the hyperparameters in the SVR model. Run-to-failure data collected from an experimental test set-up is used to validate the proposed methodology. The study findings indicate that a small set of relevant features which can represent the pattern related to degradation is sufficient to have a high prediction accuracy. The seal tested for this study comes from oil and gas industry, but the proposed method can be implemented in any industry with reciprocating equipment and machines.
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Patil, Parimal Arjun, Asyraf M. Hamimi, M. Azuan B. Abu Bakar, Debasis Priyadarshan Das, Pankaj Kumar Tiwari, Prasanna Chidambaram, and M. Azran B A Jalil. "Determining Long-Term Fate of a CO2 Sequestration Project Utilizing Rigorous Well Integrity Risk Assessment Strategy." In Offshore Technology Conference Asia. OTC, 2022. http://dx.doi.org/10.4043/31463-ms.
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Abstract Depleted hydrocarbon reservoirs are considered inherently safe for carbon sequestration, but high well density penetrating the CO2 storage reservoir could compromise the containment performance in a carbon, capture & sequestration (CCS) project. Based on the available well data, it is crucial to understand the age of the well, materials used for wellbore construction, cement quality, barriers performance, and well integrity. A risk management methodology can be incorporated to evaluate primary and secondary barriers in existing plugged and abandoned (P&A) and development wells to ensure long-term fate of CO2 sequestration project. Existing P&A wells and development wells in a depleted field were drilled 3–5 decades ago. The wellbore construction utilized non-corrosive resistant materials. Health of all wells that ever penetrated the CO2 storage reservoir need to be analyzed from long term perspective of storing CO2. Throughout the lifespan of wells, subsurface barriers should maintain hydraulic isolation to prevent leakage happening from subsurface to environment of reservoir fluids and injected CO2. Deterioration of strength of wellbore construction material due to corrosion, induced by downhole pressure and temperature conditions, should be considered. This study investigated 3 exploration and 21 development wells. Risk register was developed for each well describing causes and CO2 leakage risks, impacts and consequences. Metrics were defined for parameters such as well age, well head materials, wellhead functional test and leak test, sustained casing pressures for risk determination. Wells were risk rated individually based on the assessment. Wells with low risk can be utilized for well conversion. While for high-risk wells, an opportunity risk matrix was developed to mitigate risks in all the wells. This study evaluates the well integrity and CO2 leakage risk along the wells that penetrated the CO2 storage reservoir. The improved rigorous risk assessment exercise evaluates well barrier failure causes and impacts along with estimating the risk number per well. The well risk assessment score calculated was between 9.24 and 13.35 for 21 development wells. Out of these 21 wells, 4 wells with risk score <10 can be utilized for wells conversion. Specific barrier restoration process by additional scope of work such as lower completion removal including packer milling, intermediate casing removal, or installation of downhole permanent barriers with remedial cement is discussed for designing the well abandonment process to minimize leak potential of high-risk wells for ensuring long-term containment security. Improved rigorous well integrity risk assessment for CO2 storage field is decisive for any CCS project economics that utilizes barrier identification process and remedial actions.
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Patil, Parimal Arjun, Asyraf M. Hamimi, M. Azuan B. Abu Bakar, Debasis Priyadarshan Das, Pankaj Kumar Tiwari, Prasanna Chidambaram, and M. Azran B. A. Jalil. "Scrutinizing Wells Integrity for Determining Long-Term Fate of a CO2 Sequestration Project: An Improved and Rigorous Risk Assessment Strategy." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-22348-ms.
Full textAbstract:
Abstract Depleted hydrocarbon reservoirs are considered inherently safe for carbon sequestration, but high well density penetrating the CO2 storage reservoir could compromise the containment performance in a carbon, capture & sequestration (CCS) project. Based on the available well data, it is crucial to understand the age of the well, materials used for wellbore construction, cement quality, barriers performance, and well integrity. A risk management methodology can be incorporated to evaluate primary and secondary barriers in existing plugged and abandoned (P&A) and development wells to ensure long-term fate of CO2 sequestration project. Existing P&A wells and development wells in a depleted field were drilled 3–5 decades ago. The wellbore construction utilized non-corrosive resistant materials. Health of all wells that ever penetrated the CO2 storage reservoir need to be analyzed from long term perspective of storing CO2. Throughout the lifespan of wells, subsurface barriers should maintain hydraulic isolation to prevent leakage happening from subsurface to environment of reservoir fluids and injected CO2. Deterioration of strength of wellbore construction material due to corrosion, induced by downhole pressure and temperature conditions, should be considered. This study investigated 3 exploration and 21 development wells. Risk register was developed for each well describing causes and CO2 leakage risks, impacts and consequences. Metrics were defined for parameters such as well age, well head materials, wellhead functional test and leak test, sustained casing pressures for risk determination. Wells were risk rated individually based on the assessment. Wells with low risk can be utilized for well conversion. While for high-risk wells, an opportunity risk matrix was developed to mitigate risks in all the wells. This study evaluates the well integrity and CO2 leakage risk along the wells that penetrated the CO2 storage reservoir. The improved rigorous risk assessment exercise evaluates well barrier failure causes and impacts along with estimating the risk number per well. The well risk assessment score calculated was between 9.24 and 13.35 for 21 development wells. Out of these 21 wells, 4 wells with risk score <10 can be utilized for wells conversion. Specific barrier restoration process by additional scope of work such as lower completion removal including packer milling, intermediate casing removal, or installation of downhole permanent barriers with remedial cement is discussed for designing the well abandonment process to minimize leak potential of high-risk wells for ensuring long-term containment security. Improved rigorous well integrity risk assessment for CO2 storage field is decisive for any CCS project economics that utilizes barrier identification process and remedial actions.
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Dell’Era, Giulia, Mehmet Mersinligil, and Jean-François Brouckaert. "Assessment of Unsteady Pressure Measurement Uncertainty: Part 1 — Single Sensor Probe." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-42608.
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With the advancements in miniaturization and temperature capabilities of piezo-resistive pressure sensors, pneumatic probes — which are the long established standard for flow-path pressure measurements in gas turbine environments — are being replaced with unsteady pressure probes. Any measured quantity is by definition inherently different from the ‘true’ value, requiring the estimation of the associated errors for determining the validity of the results and establishing respective confidence intervals. In the context of pressure measurements, the calibration uncertainty values, which differ from measurement uncertainties, are typically provided. Even then, the lack of a standard methodology is evident as uncertainties are often reported without appropriate confidence intervals. Moreover, no time-resolved measurement uncertainty analysis has come to the attention of the authors. The objective of this paper is to present a standard method for the estimation of the uncertainties related to measurements performed using single sensor unsteady pressure probes, with the help of measurements obtained in a one and a half stage low pressure high speed axial compressor test rig as an example. The methodology presented is also valid for similar applications involving the use of steady or unsteady sensors and instruments. The static calibration uncertainty, steady measurement uncertainties and unsteady measurement uncertainties based on phase-locked and ensemble averages are presented in this contribution. Depending on the number of points used for the averaging, different values for uncertainty have been observed, underlining the importance of having greater number of samples. For unsteady flows, higher uncertainties have been observed at regions of higher unsteadiness such as tip leakage vortices, hub corner vortices and blade wakes. Unfortunately, the state of the art in single-sensor miniature unsteady pressure probes is comparable to multi-hole pneumatic probes in size, preventing the use of multi-hole unsteady probes in turbomachinery environments. However, the angular calibration properties of a single sensor probe obtained via an aerodynamic calibration may further be exploited as if a three-hole directional probe is employed, yielding corrected total pressure, unsteady yaw angle, static pressure and Mach number distributions based on the phase-locked averages with the expense of losing the time-correlation between the virtual ports. The aerodynamic calibration and derivation process are presented together with the assessment of the uncertainties associated to these derived quantities by the authors in [1]. In the virtual three-hole mode, similar to that of a single-sensor probe, higher uncertainty values are observed at regions of higher unsteadiness.