Casing corrosion during CO2 injection or storage results in significant economic loss and increased production risks.Therefore,in this paper,a corroded casing risk assessment model based on analytic hierarchy process ...Casing corrosion during CO2 injection or storage results in significant economic loss and increased production risks.Therefore,in this paper,a corroded casing risk assessment model based on analytic hierarchy process and fuzzy comprehensive evaluation is established to identify potential risks in time.First,the corrosion rate and residual strength characteristics are analyzed through corrosion tests and numerical simulations,respectively,to determine the risk factors that may lead to an accident.Then,an index system for corroded casing risk evaluation is established based on six important factors:temperature,CO2 partial pressure,flow velocity,corrosion radius,corrosion depth and wellhead pressure.Subsequently,the index weights are calculated via the analytic hierarchy process.Finally,the risk level of corroded casing is obtained via the fuzzy comprehensive evaluation.The corroded casing risk assessment model has been verified by a case well,which shows that the model is valuable and feasible.It provides an effective decision-making method for the risk evaluation of corroded casing in CO2 injection well,which is conductive to improve the wellbore operation efficiency.展开更多
This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristic...This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption （PSA）, chemical absorption （CA）, and membrane absorption （MA）. Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.展开更多
On the basis of the essential connotation of the training effect on human resource development and the basic principles of setting up a index system, the evaluation index system of the training effect on human resourc...On the basis of the essential connotation of the training effect on human resource development and the basic principles of setting up a index system, the evaluation index system of the training effect on human resource development in enterprises has been established. It evaluates the training effect on human resource development with the method of fuzzy comprehensive evaluation and achieves better results. It also provides a scientific, practical and quantitative method for the systematic analysis and comprehensive evaluation of the training effect on human resource development.展开更多
Nowadays,clear evaluation models and methods are lacking in classified protection of information system,which our country is making efforts to promote.The quantitative evaluation of classified protection of informatio...Nowadays,clear evaluation models and methods are lacking in classified protection of information system,which our country is making efforts to promote.The quantitative evaluation of classified protection of information system security is studied.An indicators system of testing and evaluation is established.Furthermore,a model of unit testing and evaluation and a model of entirety testing and evaluation are presented respectively.With analytic hierarchy process and two-grade fuzzy comprehensive evaluation,the subjective and uncertain data of evaluation will be quantitatively analyzed by comprehensive evaluation.Particularly,the variable weight method is used to model entirety testing and evaluation.It can solve the problem that the weights need to be adjusted because of the relationship role which enhances or reduces security of information system.Finally,the paper demonstrates that the model testing and evaluation can be validly used to evaluate the information system by an example.The model proposed in this paper provides a new valuable way for classified protection of information system security.展开更多
Bridge quality assessment is an important part in the final acceptance of new bridge construction,and it is also the main basis for the reinforcement or removal of old bridges.We evaluated the weight of each affecting...Bridge quality assessment is an important part in the final acceptance of new bridge construction,and it is also the main basis for the reinforcement or removal of old bridges.We evaluated the weight of each affecting factor to the upper events using progressive analytical hierarchy process(AHP)with the adoption of 3 scaling,reduced the calculation in analytical process,and precluded the nonuniformity of the scaling system.We obtained a comprehensive evaluation system of bridge quality, and verified its pra...展开更多
Drilling engineering has great uncertainty and it always involves huge investment and high risk. Risk analysis of extended reach drilling （ERD） is very important to prevent complex failures and to improve drilling e...Drilling engineering has great uncertainty and it always involves huge investment and high risk. Risk analysis of extended reach drilling （ERD） is very important to prevent complex failures and to improve drilling efficiency. Nowadays there are few reports on how to analyze quantitatively the drilling risk for extended reach wells （ERWs）. Based on the fuzzy set theory, a comprehensive fuzzy evaluation model for analyzing risks of ERD is proposed in this paper. Well B6ERW07 is a planned 8,000-meter ERW with a high ratio of horizontal displacement （HD） to vertical depth （VD） in the Liuhua Oilfield, the South China Sea, China. On the basis of the evaluation model developed in this study, the risk for drilling Well B6ERW07 was evaluated before drilling. The evaluation result shows that the success rate of drilling this well is predicted to be 51.9%, providing important rational and scientific information for the decisionmakers.展开更多
To deal with the radio frequency threat posed by modern complex radar networks to aircraft,we researched the unmanned aerial vehicle(UAV)formations radar countermeasures,aiming at the solution of radar jamming resourc...To deal with the radio frequency threat posed by modern complex radar networks to aircraft,we researched the unmanned aerial vehicle(UAV)formations radar countermeasures,aiming at the solution of radar jamming resource allocation under system countermeasures.A jamming resource allocation method based on an improved firefly algorithm(FA)is proposed.Firstly,the comprehensive factors affecting the level of threat and interference efficiency of radiation source are quantified by a fuzzy comprehensive evaluation.Besides,the interference efficiency matrix and the objective function of the allocation model are determined to establish the interference resource allocation model.Finally,A mutation operator and an adaptive heuristic are integtated into the FA algorithm,which searches an interference resource allocation scheme.The simulation results show that the improved FA algorithm can compensate for the deficiencies of the FA algorithm.The improved FA algorithm provides a more scientific and reasonable decision-making plan for aircraft mission allocation and can effectively deal with the battlefield threats of the enemy radar network.Moreover,in terms of convergence accuracy and speed as well as algorithm stability,the improved FA algorithm is superior to the simulated annealing algorithm(SA),the niche genetic algorithm(NGA),the improved discrete cuckoo algorithm(IDCS),the mutant firefly algorithm(MFA),the cuckoo search and fireflies algorithm(CSFA),and the best neighbor firefly algorithm(BNFA).展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.2016ZX05042004)the Joint Funds of the National Natural Science Foundation of China(Grant no.U1762104)+3 种基金the Major Scientific and Technological Projects of CNPC(Grant No.ZD2019-184-004)the Fundamental Research Funds for the Central Universities(20CX02306A)the Opening Fund of National Engineering Laboratory of Offshore Geophysical and Exploration EquipmentThe authors also would like to express their sincere gratitude to Dr.Zhang Dalei for his assistance in corrosion tests.
文摘Casing corrosion during CO2 injection or storage results in significant economic loss and increased production risks.Therefore,in this paper,a corroded casing risk assessment model based on analytic hierarchy process and fuzzy comprehensive evaluation is established to identify potential risks in time.First,the corrosion rate and residual strength characteristics are analyzed through corrosion tests and numerical simulations,respectively,to determine the risk factors that may lead to an accident.Then,an index system for corroded casing risk evaluation is established based on six important factors:temperature,CO2 partial pressure,flow velocity,corrosion radius,corrosion depth and wellhead pressure.Subsequently,the index weights are calculated via the analytic hierarchy process.Finally,the risk level of corroded casing is obtained via the fuzzy comprehensive evaluation.The corroded casing risk assessment model has been verified by a case well,which shows that the model is valuable and feasible.It provides an effective decision-making method for the risk evaluation of corroded casing in CO2 injection well,which is conductive to improve the wellbore operation efficiency.
基金the China University of Petroleum Foundationthe Research Institute of Safety and Environment TechnologyChina National Petroleum Corporation
文摘This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption （PSA）, chemical absorption （CA）, and membrane absorption （MA）. Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.
文摘On the basis of the essential connotation of the training effect on human resource development and the basic principles of setting up a index system, the evaluation index system of the training effect on human resource development in enterprises has been established. It evaluates the training effect on human resource development with the method of fuzzy comprehensive evaluation and achieves better results. It also provides a scientific, practical and quantitative method for the systematic analysis and comprehensive evaluation of the training effect on human resource development.
基金supported in part by National Natural Science Foundation of China under Grant No. 60970115 and 91018008Science and Technology Foundation of Guizhou Province,China under Grant No. 20112213+1 种基金2010 Doctoral Scientific Research Foundation of Guizhou Normal University,ChinaNatural Science Research Project of Education Department of Guizhou Province,China under Grant No. 20090034
文摘Nowadays,clear evaluation models and methods are lacking in classified protection of information system,which our country is making efforts to promote.The quantitative evaluation of classified protection of information system security is studied.An indicators system of testing and evaluation is established.Furthermore,a model of unit testing and evaluation and a model of entirety testing and evaluation are presented respectively.With analytic hierarchy process and two-grade fuzzy comprehensive evaluation,the subjective and uncertain data of evaluation will be quantitatively analyzed by comprehensive evaluation.Particularly,the variable weight method is used to model entirety testing and evaluation.It can solve the problem that the weights need to be adjusted because of the relationship role which enhances or reduces security of information system.Finally,the paper demonstrates that the model testing and evaluation can be validly used to evaluate the information system by an example.The model proposed in this paper provides a new valuable way for classified protection of information system security.
基金Funded by the Development Foundation of Key Laboratory in Bridge-structure Engineering Ministry of Communication,P.R.China(No.CQSLBF-Y07-3)
文摘Bridge quality assessment is an important part in the final acceptance of new bridge construction,and it is also the main basis for the reinforcement or removal of old bridges.We evaluated the weight of each affecting factor to the upper events using progressive analytical hierarchy process(AHP)with the adoption of 3 scaling,reduced the calculation in analytical process,and precluded the nonuniformity of the scaling system.We obtained a comprehensive evaluation system of bridge quality, and verified its pra...
基金support from the project of CNOOC China Limited-Shenzhen (Grant No. Z2007SLSZ-034)the foundation project of the State Key Laboratory of Petroleum Resource and Prospecting (Grant No. PRPDX2008-08) is gratefully acknowledged
文摘Drilling engineering has great uncertainty and it always involves huge investment and high risk. Risk analysis of extended reach drilling （ERD） is very important to prevent complex failures and to improve drilling efficiency. Nowadays there are few reports on how to analyze quantitatively the drilling risk for extended reach wells （ERWs）. Based on the fuzzy set theory, a comprehensive fuzzy evaluation model for analyzing risks of ERD is proposed in this paper. Well B6ERW07 is a planned 8,000-meter ERW with a high ratio of horizontal displacement （HD） to vertical depth （VD） in the Liuhua Oilfield, the South China Sea, China. On the basis of the evaluation model developed in this study, the risk for drilling Well B6ERW07 was evaluated before drilling. The evaluation result shows that the success rate of drilling this well is predicted to be 51.9%, providing important rational and scientific information for the decisionmakers.
文摘To deal with the radio frequency threat posed by modern complex radar networks to aircraft,we researched the unmanned aerial vehicle(UAV)formations radar countermeasures,aiming at the solution of radar jamming resource allocation under system countermeasures.A jamming resource allocation method based on an improved firefly algorithm(FA)is proposed.Firstly,the comprehensive factors affecting the level of threat and interference efficiency of radiation source are quantified by a fuzzy comprehensive evaluation.Besides,the interference efficiency matrix and the objective function of the allocation model are determined to establish the interference resource allocation model.Finally,A mutation operator and an adaptive heuristic are integtated into the FA algorithm,which searches an interference resource allocation scheme.The simulation results show that the improved FA algorithm can compensate for the deficiencies of the FA algorithm.The improved FA algorithm provides a more scientific and reasonable decision-making plan for aircraft mission allocation and can effectively deal with the battlefield threats of the enemy radar network.Moreover,in terms of convergence accuracy and speed as well as algorithm stability,the improved FA algorithm is superior to the simulated annealing algorithm(SA),the niche genetic algorithm(NGA),the improved discrete cuckoo algorithm(IDCS),the mutant firefly algorithm(MFA),the cuckoo search and fireflies algorithm(CSFA),and the best neighbor firefly algorithm(BNFA).
