Study On Risk Comprehensive Assessment And Countermeasures Of UCG

The exploitation and utilization of coal resources have huge effects to the prosperity and development of the society,but the long-term and extensive exploitation and utilization has caused a series of safety,environmental and social problems.Because of excess capacity,air pollution,surface subsidence,soil erosion,occupational diseases,high mortality,coal mining and utilization methods need to be improved.UCG is a green chemical mining technology which integrates safe and green mining with clean and efficient utilization.It has the characteristics of wide adaptability,safety,cleanliness,high efficiency and low carbon.Research on risk assessment of UCG can help enterprises and decision makers to control the risk factors and sources.And it has certain guiding significance for the project by making reasonable measures and measures to reduce project risks.To form a multi-factor and multi-level comprehensive risk assessment system and countermeasures based on qualitative and quantitative guidelines for UCG,Variable weight-fuzzy hierarchy comprehensive evaluation method is used.The research contents of this paper are as follows.1.The risk characteristics and classification of UCG projects are studied.And the key factors of the project are identified from eight aspects: policies and regulations,resource conditions,technical and technological conditions,investment and income,external construction conditions,organization and management,safety factors and environmental pollution.Through questionnaire survey,reliability and validity test and expert consultation,the project risk item is obtained.Risk factors include 8 key factors and 28 two level indicators.2.The risk assessment index based on the life cycle of UCG project is studied.The division of the life cycle of the project and the definition of the key influencing factors are defined.The characteristics,advantages and disadvantages of various evaluation methods are introduced.Using variable weight-fuzzy hierarchical evaluation method,seven steps to evaluate project risk are put forward.And the calculation method of initial value of index factor,definition of risk grade,membership function and membership degree are given.3.The UCG project in Shanjiaoshu coal mine is briefly introduced.Based on the specific conditions of the Shanjiaoshu UCG project and the results of the project leader's score,initial values of 65 index factors and specific values for risk definition were determined,and weight values and consistency tests were calculated.The risk membership vector(0.5250 0.3602 0.1148)is obtained by comparing the variable weight with the constant weight,which indicates that the project is in a low risk level.And the data characteristics are analyzed.4.The risk prevention and control methods and shortcomings of UCG projects are briefly described.And the framework of project risk prevention and control is established.The paper puts forward general measures for risk prevention of UCG projects.The Countermeasures for typical risks of UCG are studied from four aspects: strip mining layout process,gas injection process selection,consolidation method of pollutants in burned area,safety isolation and airtight.There are 59 tables,66 tables and 199 references in the paper.