注气驱替煤层甲烷的有效影响半径研究

为了确定井下煤层注气有效影响半径,以煤层瓦斯渗流理论、瓦斯扩散理论、多元气体竞争吸附、能量守恒以及理想气体状态方程为基础,以钻孔周围煤体瓦斯流动场为研究对象,建立了井下注气驱替煤层甲烷的数学模型,并以石港煤矿的实测参数为计算依据,利用Comsol软件对抽采钻孔在不同注气时间、不同注气压力下瓦斯流动进行了数值模拟,发现注气有效影响半径随注气时间和注气压力的增大而增大,为现场注气提供依据。

Study on Effective Influence Radius of Borehole Air Injection to Remove and Replace Coal Bed Methanes in Seam

In order to determine the effective influence radius of the seam air injection,based on the seam gas seepage theory,gas diffusion theory,multi element gas competitive adsorption,energy conservation and ideal gas status equation,taking the seam gas flow filed around the borehole as the study object,a mathematics model of the air injection to remove and replace seam methane was established.Taking the measured parameters of Shigang Mine as the calculation basis,the Comsol software was applied to the numerical simulation on the gas flow equation of the gas drainage borehole under different air injection time and different air injection pressure.The simulation showed that the effective influence radius of the air injection would increase with the air injection time and air injection pressure increased and could provide the basis to the site air injection.