Research On The Laws Of Improving The Permeability Of Coalbody Due To Gas Blasting Technology

CBM is dangerous to the safe production of coal mine.Meanwhile it is also green and cleanenergy.But the permeability of coalbed methane in coal is low and it also has strong ability ofabsorption, it is difficult to produce CBM by routine improvement and depressurization.To solvethe above problem, this paper adopts research method which combine the theoretical research,experimentalstudy and numerical simulation.The methord of improving the gas permeability is studied,and on the base ofthe experimental study.This paper puts forward a methord of improving coal permeability. And obtainedthe following results:①The gas explosion experimental device is designed and manufactured by myself. At the sametime, the coal seam’s reservoir characteristics and coal adsorption theory of low permeability isgiven. Discussing the coalbed methane in coal seams in the migration and the output mechanism indetail.②Through the gas explosion experimental study,it can be found: In different axial pressure, thecoal permeability are all increased after the gas explosion.But the permeability of increasing is notobvious.That is to say the effect of axial pressure on coal gas explosion is very small; Under theclose pressure and the same permeability cases, to the bigger hardness factor and the smallerpermeability,the effect of gas explosion is stronger, the permeability of coal body increases to tentimes.The detonation position of gas explosion is1/3to the free surface,the effect of gas explosionis better.The pressure of gas explosion is also an important factor, The greater pressure of gasexplosion,the antireflection effect is more obvious.③The paper analyses the dynamic load of coal body under the function of mechanicalproperties in depth, Elaborated the dynamic load of coal body under the function of the damage and thepower dissipation,the function of deep hole gas explosion, coal seam gas pressure on the crack propagation,the procession of deep hole splitting gas burst gap region forming, At last, the paper elaborates coal seamdeformation and the model of coalbed gas migration coupling dynamics.④Simulating the stress field,deformation field and deformation destruction of coal district incoal body afte gas explosion by using LS-DYNA. Showing some laws of coal permeability increase aftergas explosion.