Numerical Calculation Method of Effective Drainage Radius For Gas Drainage Borehole

Taking the Chongqing Tainfu No.3 Mine as an example,in combination with the site measurements,the lab measured and theoretical calculated coefficients,a study was conducted on the effective drainage radius of different borehole pattern(including the drainage borehole along the seam and the drainage borehole passing strata),and proposed that the varied coefficient and non-linear gas seepage formula would be applied to the numerical calculation method to rapidly and accurately measure the gas drainage radius.The results showed the method could be convenient and rapid to measure the borehole space and the gas drainage time and would have certain actual significances to save the measuring time of the gas drainage radius and to rationally set up the borehole layout.