| Under the policy background of carbon neutrality and carbon peaking,gas as a clean energy has high social value,and the development and utilization of waste coal mine gas resources can generate high economic value.Through literature review and field research,the evaluation indicators were determined from the perspectives of technical feasibility and economic rationality,and an evaluation index system for the feasibility of gas extraction in goafs of abandoned coal mines was established.Based on the game theory,the subjective and objective weights of the indicators determined by the AHP and the entropy method are combined and weighted,combined with the fuzzy comprehensive evaluation method and the TOPSIS method to construct a qualitative and quantitative evaluation model for the feasibility of gas extraction in the goaf of abandoned coal mines.Taking Gushuyuan Mine and Yanmazhuang Mine as examples,the case application of the evaluation model is carried out respectively.The study draws the following main conclusions::(1)The feasibility evaluation index system for gas extraction in goafs of abandoned coal mines was constructed,and combined with previous research results and the current status of gas utilization in abandoned coal mines,the influence of gas resource conditions,gas preservation conditions,gas extraction conditions,and economic conditions was determined.Four major categories of gas extraction feasibility in goafs of abandoned coal mines.Around 4 categories,24 secondary indicators were expanded to construct a feasibility evaluation system for gas drainage in goafs of abandoned coal mines.By consulting literature,relevant normative documents and enterprise production data,the index data is classified into grades,and the critical values of 24 secondary indicators under different evaluation levels are determined at the same time,and the scoring standards are formulated according to the critical values.(2)Based on the game theory,the weight of the feasibility index of gas drainage in the goaf of abandoned coal mine is determined.The weight results after comprehensive weighting by game theory show that the gas resource conditions C1 and gas preservation conditions C2 have higher weights in the first-level indicators,which are0.4391 and 0.3836 respectively;in the second-level indicators,the surface borehole methane belonging to the gas resource conditions Concentration D2 and mine water inflow D12 belonging to gas preservation conditions have higher weights,0.091 and0.087,respectively.(3)A feasibility evaluation model for gas drainage in goafs of abandoned coal mines is established.On the basis of theoretical analysis and data statistics,the game theory-fuzzy comprehensive qualitative evaluation model and the game theory-TOPSIS quantitative evaluation model are constructed respectively.The two evaluation models are compared and verified in the process of field application.(4)Taking Gushuyuan Mine and Yanmazhuang Mine as the evaluation objects,the field application of the gas extraction feasibility evaluation model in the goaf of abandoned coal mines was completed.The Gushuyuan Mine in Jincheng Mining Area and the Yanmazhuang Mine in Jiaozuo Mining Area are selected as the evaluation objects,and the two abandoned coal mines are evaluated qualitatively and quantitatively on the basis of collecting and improving their production geological data.The evaluation results show that the qualitative and quantitative evaluation grades for the feasibility of gas extraction in the gobs of Yanmazhuang Mine are "poor" and "poor",and the qualitative and quantitative evaluation levels for the feasibility of gas extraction in the gobs of Gushuyuan Mine are "excellent".","good".In the field survey,the Yanmazhuang Mine has a large amount of water inflow,strong groundwater fluidity,serious gas escape with groundwater,and low development value,which verifies the rationality of the evaluation model.There are 12 pictures,55 tables and 72 references in this paper. |
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