黄陵二号煤矿煤层瓦斯高效预抽技术

High-efficient pre-extraction technology of coal seam gas in Huangling No.2 Coal Mine

为提高顺层钻孔布置钻孔的精准度和科学性,以Fick扩散定律、Darcy定律、理想气体状态方程和广义Langmuir方程为根据,建立含瓦斯煤体流固耦合数学模型,运用COMSOL Multiphysics模拟软件分析钻孔直径、布孔间距对钻孔预抽煤层瓦斯的影响规律。结果表明,在一定范围内钻孔直径越大时,煤层瓦斯压力衰减范围越大,有效影响半径也越大;在不同布置钻孔间距下,靠近钻孔位置的瓦斯压力最小,而远离钻孔位置的方向,瓦斯气体压力逐渐增加;当要求预抽时间内达成预期抽采目标时,预抽钻孔直径90 mm、布孔间距6 m为最优布孔方案。

In order to improve the accuracy and science of drilling arrangement in bedding,a fluid-structure coupling mathematical model of gas-containing coal was established based on Fick’s diffusion law,Darcy’s Law,ideal gas equation of state and generalized Langmuir equation.COMSOL Multiphysics simulation software was used to analyze the influential law of borehole diameter and spacing on coal seam gas pre-extraction of borehole.The results show that the attenuation range and effective influential radius of coal seam gas pressure are larger when the diameter of borehole is larger in a certain range.Under different spacing of borehole,the gas pressure near the borehole is the smallest,while the gas pressure away from the borehole is gradually increased.When the expected extraction target is required to be achieved within the pre-extraction time,the optimal borehole layout is 90 mm in diameter and 6 m in spacing.