Study On Effective Radius Of Gas Extraction In ?₁ Coal Seam Of Wangxingzhuang Mine

Coal is the basic energy in our country,the development of energy in our country still occupies its main position.The depth of mine mining gradually increases with the development of time,leading to prominent problems such as the amount of gas gushing from the mine and complex geological structure conditions,etc.,while the pre-extraction of coal seam gas is to solve the excessive pressure of coal mine gas,reduce the concentration of gas,and plays an important role in ensuring safe mining.In this paper,through theoretical analysis,laboratory simulation and field measurement,the method of combining the gas effective radius of extraction and the extraction time,extraction hole aperture,the influence of the relationship between permeability of coal seam is analyzed,and the content of the gas flow rate,method and two methods for determining the method of gas pressure reducing gas extraction effective radius measurement analysis.By using COMSOL Multiphysics simulation software,combining with the relevant parameter Wang Xingzhuang?₁ coal seam in coal mine,the simulation from the gas extraction effective radius,and through the field measurement,by comparison with the test results of two methods,the content of the gas flow rate,method determination results more accurate,gas pressure reducing method in the site construction technology demand is higher,and the affected factors.Through the verification of simulation results and field measurement results,it is concluded that the effective extraction radius,time,pore diameter and permeability of coal seam gas all satisfy the power function relations of Rc=AxB.It is concluded that the effective gas extraction radius increases with the increase of the extraction time during the pre-extraction period.Within 75mm-130mm hole aperture range,with the increase of the aperture,the extraction radius also increases,and the larger the aperture,the more obvious the increase range of the effective extraction radius;Under the condition of a certain extraction time and aperture,the effective extraction radius of gas also has a direct proportional relationship with the permeability of coal seam,and has a great influence on the effective extraction radius.