Study on Methods of Determining Gas Extraction Radius with Numerical Simulation

This paper did research on determination of extraction radius; the experimental area was No. 3 coal seam in Changcun Coal Mine. This paper put forward the method of numerical simulation, this method which determined gas extraction radius was based on the FLAC3D, and we used pressure drop index method to test the calculation results. The results showed that numerical simulation based on FLAC3D could determine the radius of the gas drainage quickly and accurately, it is meaningful for saving the time in testing extraction radius and decorating the drilling reasonably.