基于压敏效应瓦斯煤岩渗透率影响因素研究

Research of coal permeability factor based on Pressure-sensitive effect

本文通过煤岩流固耦合实验、瓦斯运动控制理论推导、单孔瓦斯抽放模型数值分析,研究原岩应力场下影响瓦斯渗透率的主要因素。研究表明:1煤岩瓦斯渗透率与有效应力之间有很强的相关性,用压敏效应指数可以定量描述有效应力对渗透率的影响;2基于Klinkenberg效应和基质收缩效应的基础上,考虑到煤岩体瓦斯渗透率压敏效应的影响,总结出煤岩体瓦斯渗透率的表达式;3在模型中使用推导得出的控制方程,得出单孔模型下各因素对渗透率及瓦斯压力的影响。

According to the fluid-solid coupling coal experiments, theoretical derivation of gas motion control differential equations and sin-gle-span numerical model of gas drainage, this paper researches the main factors affecting the coal gas permeability rate under in-situ rockstress field conditions. The research shows that： （1）there is a strong relationship between coal gas permeability and effective stress, as a result,it can be quantitative to describe the effective stress on permeability by using pressure-sensitive effect index. （2）Based on the permeabilityvalue ptive effect of gassy coal, and giving full consideration to the influence of the Klinkenberg effect and the matrix shrinkageeffect, to deduce the mathematical expressions of fluid flow motion control equations. （3）The numerical model added in the control equationconcludes the influence of various factors on the permeability and the gas pressure through simulation results of the single-span model.