Risk analysis of extended reach wells in the Liuhua Oilfield,South China Sea,based on comprehensive fuzzy evaluation method

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.

Spectral purification improves monitoring accuracy of the comprehensive growth evaluation index for film-mulched winter wheat

In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter wheat.Based on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral UAV.Four machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried out.The results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth status.The accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of 6.53.Spectral purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral purification.The results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.

Analysis of Landscape Vitality of Historical and Cultural Blocks Based on AHPFuzzy Comprehensive Evaluation Method:A Case Study of Daopashi Street in Anqing City

Historical and cultural blocks are witnesses of history and inheritors of culture. As one of the main spaces for outdoor interaction in historical and cultural blocks, the improvement of its vitality is of great significance for the improvement of residential environment and the better inheritance of history and culture. Taking Daopashi Street in Anqing City as an example, an evaluation model of landscape spatial vitality of historical and cultural blocks was constructed from three aspects of viewing function, store status and service facilities, and analytic hierarchy process was used to determine the index weight and vaguely evaluate the landscape spatial vitality of historical and cultural blocks. The results show that through the comparison of weight, architectural style(0.317), the practicability of service facilities(0.168) and plant landscape(0.165) had a significant impact on the landscape spatial vitality of historical and cultural blocks,and the landscape spatial vitality of historical and cultural blocks in Daopashi Street in Anqing City was at a good level.

Operation State of theWind Turbine Pitch System Based on Fuzzy Comprehensive Evaluation

To ensure wind turbine(WT)safe operations and improve the utilization rate of wind energy,effective evaluation of the operation state of the pitch system is critical.Therefore,a new method was proposed to evaluate the operation state of the pitch system of WT based on fuzzy comprehensive evaluation.Firstly,based on SCADA data,the working state of the pitch system under rated power state and power state of WT were analyzed.Secondly,through the analysis of characteristic parameters and physical mechanism of the pitch system,the consistency principle of characteristic parameters,the stability principle of power under rated state,and the stability principle of blade angle underpowered state were obtained.Next,based on the aforementioned principles,the evaluation indexes were established,and the fuzzy comprehensive evaluation method was used to establish the operation state evaluation model of the pitch system under rated power state and under power state of the WT.Finally,an example was provided to verify the effectiveness of the method.The evaluation model established in this study can be used as a technical reference for the online monitoring of WT pitch systems to ensure the safe and stable operation of WTs.

Evaluation of Water Resources Carrying Capacity in Gansu Section of Yellow River Basin Based on Fuzzy Comprehensive Evaluation Model

As a basic natural resource and strategic economic resource,the development and utilization of water resources is an important issue related to the national economy and people's livelihood.How to scientifically evaluate the water resources carrying capacity is the premise to improve the regional water resources carrying capacity and ensure the regional water security.The Gansu section of the Yellow River basin is an important water conservation and recharge area.Whether the water resources in this area can ensure the normal operation of the ecosystem and whether it can carry the sustainable development of social economy is the key to realize the high-quality development of the Yellow River basin.In this study,from the three dimensions of water consumption per capita,water consumption of 10000 yuan GDP and ecological water use rate,by constructing the evaluation index system and index grading standard of water resources carrying capacity,the fuzzy comprehensive evaluation model was used to evaluate the water resources carrying capacity of Gansu section of the Yellow River Basin,in order to provide theoretical decision-making basis for the comprehensive development,utilization and planning management of water resources in Gansu section of the Yellow River basin and even the whole basin,and help the high-quality development of the Yellow River basin.

Risk assessment of corroded casing based on analytic hierarchy process and fuzzy comprehensive evaluation

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.

A Grey Fuzzy Comprehensive Model for Evaluation of Geological Structure Complexity

Several structure sets （faults and folds） are characterized by their self-similarity properties. Herein, we discuss the degrees of complexity of fractures by introducing the box-counting fractal dimension of faults as a key criterion to be used in comprehensive fuzzy analysis model for evaluation of the complexity of structures. Totally, eight criteria including density, intensity, length of faults, types and box-counting fractal dimension of faults, the intersection angle between faults and coal beds, gradient coefficients, dip angles of the coal beds, and variation coefficients of dip angles of the coal seams, were used for the evaluation purpose. The grey fuzzy comprehensive assessment model was used to rank the relative importance of these criteria. Scores indicating the complexity of structure were calculated on the base of criteria values and their weights for each sub-area of the study area in the Pansan （潘三） coal mine district in the southern Anhui （安徽） Province, China. The result on the calculated complexity of structure is useful for mining planning in the study area.

Fuzzy Comprehensive Evaluation for Decision Making of Water Saving Irrigation System

A model of fuzzy comprehensive evaluation for water saving irrigation system (WSIS) decision making is proposed based on establishing an index system affected by six kinds of basic factors including qualitative and quantitative indexes. The object function of WSIS is set up by using the concept of fuzzy membership degree, it is to transform characteristic vector matrix into unify membership matrix and extending the least square method to the least of weighted distance square. The optimum weighted membership degree and the inferior weighted membership degree are used to solve the object function. This method effective solves the problem of classify for fuzzy attributive indexes and the problem of optimum for the set of different attributive indexes. A case study shows that the fuzzy comprehensive evaluation model is reasonable and effective in decision making for water saving irrigation system planning.

Optimization of CO_2 separation technologies for Chinese refineries based on a fuzzy comprehensive evaluation model

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.

Comprehensive Evaluation Model of Livable City Based on Fuzzy Comprehensive Evaluation Method

This paper firstly introduced the degree of livability of a city from the social civilization,economic affluence,environmental beauty,resource carrying capacity,and life convenience. Based on the principle of the fuzzy comprehensive evaluation,it analyzed the connection between influencing factors,and established a comprehensive evaluation model for calculation of the livability index of a city. Finally,it obtained the relative livability of each city and the ranking of livability of each city.

Evaluation on Environment State of Breeding Area in Shuidong Bay by Using Fuzzy Comprehensive Evaluation Method

Fuzzy comprehensive evaluation method was used to develop a standard model to analyze and evaluate nearness degree of water environment quality at breeding area of Shuidong Bay in China.Results showed that certain environment contamination factors in some areas seriously exceeded the standard value and led to the whole water quality at the third class level.The measurements should be taken to promote the sustainable development of breeding area in Shuidong Bay.

Equipment Development Risk Evaluation Based on Fuzzy Comprehensive Evaluation

The equipment development risk evaluation refers to evaluating the equipment risks in the equipment development phase based on risk analysis,risk score calculation,and risk level identification.The results could lead the direction of future work.The risk management in equipment development phase was studied.The risk management model in equipment development phases was established on the base of basic theories in risk management and some interrelated risk management models in other fields.The application of the established model was illuminated by an instance.

Evaluation of water resources carrying capacity of Gonghe basin based on fuzzy comprehensive evaluation method

Gonghe Basin belongs to arid and semi-arid climatic zone, where water resource is relatively scarce and desertification is serious, so it is necessary to find out water resources carrying capacity. By using fuzzy comprehensive evaluation method, the assessment on water resources carrying capacity in Gonghe Basin was conducted: Water resource carrying capacity of Gonghe County is less, while that of Guinan County and Chaka Town of Wulan County are greater; water resources of Gonghe Basin could sustain cultivated land of 652.6 thousand acres and grassland of 2 368.6 thousand acres respectively in 2020, water resources of Gonghe Basin could sustain cultivated land of 948.2 thousand acres and grassland of 2 247.6 thousand acres respectively in 2030.

Suitability Evaluation of Hydrogen Production and Hydrogenation Station Based on AHP-Fuzzy Comprehensive Evaluation Method

Since there are multiple influencing factors and lack of evaluation standards for the construction of hydrogen production and hydrogenation station in China,this paper establishes the suitability evaluation index system of hydrogen production and hydrogenation station from four aspects of technology,economy,environment and safety.Combined with actual conditions,this paper uses Analytic Hierarch Process(AHP)and Fuzzy Comprehensive eval-uation to evaluate water electrolysis hydrogen and hydrogenation production station and natural gas reformation hydrogen production and hydrogenation station.The results show that hydrogen producing by water electrolysis is more efficient than natural gas reformation in hydrogen production and hydrogenation station,and it should be choose firstly.Furthermore,natural gas reformation hydrogen producing is inferior in technology,environment and safety,but it is superior to water electrolysis hydrogen producing in economy.In the future,we can strengthen development of the hydrogen production from renewable energy sources,so as to enhance the economic benefit of that by water electrolysis.In addition,we can also adopt two ways of hydrogen production in hydrogen production and hydrogenation station to achieve favorable integrative benefits.

Fuzzy Comprehensive Evaluation and Prediction of Air Quality in Baoding City

Nowadays,the quality of the air environment is closely related to the health of the ecosystem and the safety of people living. With more and more attention attached to the quality of the air environment,it is imminent to analyze the future development trend of air quality. In this paper,the grey correlation analysis was used to determine the weights of 6 pollution indexes,namely PM10,PM2. 5,SO2,NO2,CO and O3. The fuzzy comprehensive assessment method was applied to determine the air quality eigenvalues H（ 2. 145,1. 926,and 1. 805） of Baoding City in 2014-2016,suggesting that the air quality in Baoding is getting better and better. In addition,the grey forecasting model GM（ 1,1） was used to forecast and test the air quality of Baoding City. The results show that the prediction is good.

Evaluation of Green Development Level of Electric Energy in Distribution Network Based on Multilevel Fuzzy Comprehensive Evaluation

At present,there are few studies on the comprehensive evaluation of green power grid development in China,and all aspects of green power grid need to be evaluated.Therefore,this paper studies the green development level of power distribution network.This paper proposes a multi-level fuzzy comprehensive evaluation method,which first needs to classify the influencing factors.Therefore,this paper constructs an indicator system for the evaluation of green development of power distribution network from three dimensions.In order to avoid the influence of subjective factors,this paper adopts the model combining analytic hierarchy process and entropy weight method to give weight to indexes.Finally,five typical regions are selected for empirical analysis.The results show that the model established in this paper can reflect the green development level of power distribution network in each region and put forward relevant improvement suggestions for each region.

Fuzzy Comprehensive Evaluation of Air Quality in Shijiazhuang City Based on Grey Correlation

[Objectives]This study was conducted to evaluate the air quality of Shijiazhuang City,in order to facilitate the government to correctly formulate measures to prevent and control air pollution and protect Shijiazhuang's ambient air quality. [Methods] With the air quality data of Shijiazhuang City from February to March in 2019 as the research object,the gray correlation analysis method was used to determine weight A of each pollutant factor first,and then a single factor evaluation matrix R was constructed. The weight A and the single factor evaluation matrix R were synthesized using the M( ·,+) fuzzy composite operator,obtaining a fuzzy matrix B between the factor set and the evaluation level. [Results] The eigenvalue of air quality was calculated according to matrix B: H = 2. 259 5.[Conclusions]The air quality in Shijiazhuang City from February to March was between grade 2 and grade 3,closer to grade 2,indicating that the air quality was good.

Evaluation of Agricultural Industry Safety in Hunan Province——Based on Factor Analysis and Fuzzy Comprehensive Evaluation

By constructing the index system of " four forces" and adopting the fuzzy comprehensive evaluation model under the new membership function,this paper makes an empirical analysis on the safety of agricultural industry in Hunan Province from 2001 to 2013. The results show that the safety degree of Hunan agricultural industry is always in the range of " basically safe" and above,it was in the range of " safe" in 2010 and 2011,in the range of " very safe" in 2013,and in the range of " basically safe" in the other years; the indices of productive force,competitiveness and dependency of agricultural industry is always in the state of " basically safe" or above,while the index of control force of agricultural industry is in the trend of changing from " basically safe" to " unsafe". Therefore,it is necessary to accelerate the innovation process of agricultural industry and improve the export quality of agricultural products,especially to establish a stricter market mechanism for foreign capital entry and foreign capital merger and acquisition,improve the control power of agricultural industry,and provide favorable guarantee for the safety of agricultural industry.

Tourists' Demand for Heritage Utilization Based on Fuzzy Comprehensive Evaluation:A Case Study of the Summer Palace

Under the background of whole-region tourism,heritage is utilized in a more diversified and various way.With the continuous deepening of the experience economy,the integration of various technical means such as VR and AR,and the construction of Internet platforms,it is more necessary to integrate various utilization methods,so that tourists can get more humanized and personalized experience in addition to traditional displays,and more intuitively feel the space,history,allusions,handicrafts and other aspects of Chinese heritage,showing the charm of Chinese traditional culture.In this paper,based on literature analysis,the utilization methods of heritage were sorted out,and the survey questionnaires were analyzed by analytic hierarchy process (AHP).A model was established to obtain the weight of various utilization methods,and the fuzzy comprehensive evaluation method was used to conduct empirical research with the Summer Palace as an example.It is concluded that in the future utilization of heritage,on the basis of heritage protection as much as possible,combining traditional festivals,special themes,etc.to carry out various forms of activity and experience utilization will more effectively improve the satisfaction of tourists and achieve the purpose of inheriting culture.

Evaluation Model of Rural Drinking Water Project Based on Entropy Weight and Fuzzy Comprehensive Evaluation Method

Based on Measures for Assessment of Rural Drinking Water Standard Raising Action in Zhejiang Province,this study established an evaluation system for rural drinking water project in Zhejiang Province,covering three primary indicators of project construction,project management and project performance,and 18 secondary indicators.It proposed an evaluation model based on entropy weight and fuzzy evaluation method.It solved the problems of the objectivity of the indicator weight and the quantification of the indicators,and can well achieve the coordination and unity of fuzziness and accuracy.Using this model,it evaluated a rural drinking water project in a county and concluded that both accuracy and feasibility of the model are high.