China has recently established a new policy for the energy use of the Arctic region.Even though it is not a part of the Arctic Council,China has started a series of partnerships with public and private entities of cou...China has recently established a new policy for the energy use of the Arctic region.Even though it is not a part of the Arctic Council,China has started a series of partnerships with public and private entities of countries that are geographically and politically members of the Arctic polar Circle.The project has to be carried out within the“Belt and Road Initiative”,by establishing new trade routes between China and the rest of the world.The study aims at assessing the fuel consumption for the Arctic shipping routes and comparing them to the traditional ones,in terms of cost reduction and time efficiency.Moreover,a brief consideration on oil&gas arctic fields has been carried out,in order to understand how the energy policy of China is changing the resource utilization.展开更多
In a previous work it has been shown that a one-dimensional,hyperbolic,transient five equations twofluid model is able to numerically describe stratified,wavy,and slug flow in horizontal and nearhorizontal pipes.Slug ...In a previous work it has been shown that a one-dimensional,hyperbolic,transient five equations twofluid model is able to numerically describe stratified,wavy,and slug flow in horizontal and nearhorizontal pipes.Slug statistical characteristics can be numerically predicted with results in good agreement with experimental data and well-known empirical relations.In this model some approximated and simplified assumptions are adopted to describe shear stresses at wall and at phase interface.In this paper,we focus on the possibility to account for the cross sectional flow by inserting shape factors into the momentum balance equations of the aforementioned model.Velocity profiles are obtained by a pre-integrated model and they are computed at each time step and at each computational cell.Once that the velocity profiles are known,the obtained shape factors are inserted in the numerical resolution.In this way it is possible to recover part of the information lost due to the one-dimensional flow description.Velocity profiles computed in stratified conditions are compared against experimental profiles measured by PIV technique;a method to compute the velocity profile during slug initiation and growth has been developed and the computed velocity distribution in the liquid phase was compared against the one-seventh power law.展开更多
The Oil&Gas industry has continuously increased its requirements and together with the high complexity of technological systems and the higher competitiveness of markets,has compelled providers to implement adequa...The Oil&Gas industry has continuously increased its requirements and together with the high complexity of technological systems and the higher competitiveness of markets,has compelled providers to implement adequate management strategies for these systems in order to improve their availability and productivity to meet those more demanding criteria.In this context,the complex of RAM factors constitute a strategic approach for integrating reliability,availability and maintainability,by using methods,tools and engineering techniques(Mean Time to Failure,Equipment down Time and System Availability values)to identify and quantify equipment and system failures that prevent the achievement of the productive objectives.The application of such methodologies requires a deep experience and know-how together with the possibility of acquiring and processing data in operating conditions.This paper presents the most relevant aspects and findings of a study conducted for assessing the operational performance of a reciprocating compressor system package installed and used in the oil and gas'industries.The study was based on the analysis of the behaviour of states defined for each individual parts and component of reciprocating compressor and also aimed to identify and evaluate the effects of RAMtype factors and was conducted in collaboration with a private company that,for privacy reasons,will be named RC company.The Methodologies procedures used in this descriptive study were the bibliographical research,documentary and content analysis of the main literature.Adopting the most suitable maintenance strategy is one of the main challenges that maintenance managers face.The main purpose of this work is to propose a new approach to evaluate maintenance strategies.In this study,three criteria called reliability,availability and maintainability(RAM)have been employed to compare to future maintenance strategies.展开更多
文摘China has recently established a new policy for the energy use of the Arctic region.Even though it is not a part of the Arctic Council,China has started a series of partnerships with public and private entities of countries that are geographically and politically members of the Arctic polar Circle.The project has to be carried out within the“Belt and Road Initiative”,by establishing new trade routes between China and the rest of the world.The study aims at assessing the fuel consumption for the Arctic shipping routes and comparing them to the traditional ones,in terms of cost reduction and time efficiency.Moreover,a brief consideration on oil&gas arctic fields has been carried out,in order to understand how the energy policy of China is changing the resource utilization.
文摘In a previous work it has been shown that a one-dimensional,hyperbolic,transient five equations twofluid model is able to numerically describe stratified,wavy,and slug flow in horizontal and nearhorizontal pipes.Slug statistical characteristics can be numerically predicted with results in good agreement with experimental data and well-known empirical relations.In this model some approximated and simplified assumptions are adopted to describe shear stresses at wall and at phase interface.In this paper,we focus on the possibility to account for the cross sectional flow by inserting shape factors into the momentum balance equations of the aforementioned model.Velocity profiles are obtained by a pre-integrated model and they are computed at each time step and at each computational cell.Once that the velocity profiles are known,the obtained shape factors are inserted in the numerical resolution.In this way it is possible to recover part of the information lost due to the one-dimensional flow description.Velocity profiles computed in stratified conditions are compared against experimental profiles measured by PIV technique;a method to compute the velocity profile during slug initiation and growth has been developed and the computed velocity distribution in the liquid phase was compared against the one-seventh power law.
文摘The Oil&Gas industry has continuously increased its requirements and together with the high complexity of technological systems and the higher competitiveness of markets,has compelled providers to implement adequate management strategies for these systems in order to improve their availability and productivity to meet those more demanding criteria.In this context,the complex of RAM factors constitute a strategic approach for integrating reliability,availability and maintainability,by using methods,tools and engineering techniques(Mean Time to Failure,Equipment down Time and System Availability values)to identify and quantify equipment and system failures that prevent the achievement of the productive objectives.The application of such methodologies requires a deep experience and know-how together with the possibility of acquiring and processing data in operating conditions.This paper presents the most relevant aspects and findings of a study conducted for assessing the operational performance of a reciprocating compressor system package installed and used in the oil and gas'industries.The study was based on the analysis of the behaviour of states defined for each individual parts and component of reciprocating compressor and also aimed to identify and evaluate the effects of RAMtype factors and was conducted in collaboration with a private company that,for privacy reasons,will be named RC company.The Methodologies procedures used in this descriptive study were the bibliographical research,documentary and content analysis of the main literature.Adopting the most suitable maintenance strategy is one of the main challenges that maintenance managers face.The main purpose of this work is to propose a new approach to evaluate maintenance strategies.In this study,three criteria called reliability,availability and maintainability(RAM)have been employed to compare to future maintenance strategies.
