Research On SF₆Gas Tracer Analysis To Determine The Effective Radius Of The Drilling Auxiliary By Computer Simulation

Gas extraction is the key technology to solve the problems of safety production andthe effective method to control the gas accident in coal mine. At present, gas extractionin special seam is the the most commonly technology measure used in high gas mineand coal and gas outburst mine’s coalface.It plays a crucial role in the lower coal seamgas.The gas extraction effective radius is the main basis to design and layout thedrilling of coal seam. In order to accurately determine the gas extraction effective radius.To achieve the optimal design and the best of extraction effect.This article, based on theresearch on current drilling extraction method. A comparative analysis of all kinds oftest method. To explore a simple operation, high efficiency and can be accuratelydetermine the coal seam gas extraction effective method for the determination of theradius——SF₆gas tracer analysis to determine the effective radius of the drillingauxiliary by computer simulation.This paper apply SF₆gas tracer analysis to determine the gas extraction effectradius in306coalface of Huang Ling NO.1coal mine3th. panel. At the same time,according to the flow theory of gas in the coal seam and the deformation theory of rockmass. A mathematical model is established for describe the flow of gas in the coal seamunder gas-solid coupling. And to simulate the migration rule of SF₆in the gas seepagefield by using COMSOL Multiphysics software. Through comparative analysis with thetest result, proved the validity of the model. Based on the right mathematical model.Combined with the simulation results by using the similar laws, In the conditions of thedrilling diameter is94mm and the negative pressure of the drainage is15kPa.In thiscoal seam, a function of the relationship between the drilling extraction effective radiusand punping time is: r=0.1804t^1.0242; According to the formula, pre-pumping30days,the drilling extraction effective radius is5.88m. In order to verify the correctness of theformulas,with conduct research the extraction effect investigation at307coalface of thesame panel.After30days, The position that the vertical distance to the drilling is5.8m.The recovery factor is44%⁵2%.It shows that this method can be applied to thedesign and decorate of the drilling. This method is feasible,and can be accurately determine the extraction effective radius of the coal seam.