钻孔抽放瓦斯渗流特性的气固耦合模型

Gas- solid Coupled Model Based on Gas Seepage Characteristics of Drilling Drainage

随着矿井开采深度的增加,地应力、瓦斯压力、煤体特性等因素的变化对瓦斯渗流的影响越来越明显。根据钻孔抽放瓦斯的渗流特性与固体变形的基本理论,引入了固体力学和多孔介质流耦合的控制方程,同时考虑了分子滑脱效应对渗流的影响。建立了考虑抽放钻孔在不同的地应力、不同初始渗透率和不同抽放负压条件下,瓦斯运移与煤体变形相耦合作用的数学模型。通过研究钻孔抽放瓦斯过程中,在不同地应力和瓦斯压力的影响下,得出煤层渗透率和瓦斯运移的变化规律。

With the increase of mining depth of mine, ground stress, gas pressure, the influence of factors change such as coal proper- ties on gas seepage is more and more obvious. According to the basic theory of solid deformation and gas seepage characteristics of drill- ing drainage, the article introduced the control equations of solid mechanics and the coupling of porous media flow; at the same time, it considered the effect of molecular slippage on seepage. It established mathematical model coupled gas migration and coal deformation phase by considering the drainage borehole in different in - situ stress, different initial permeability and drainage negative pressure con- dition. By studying borehole drainage of gas in the process, the change laws of permeability of coal seam and gas migration are achieved under the influence of different ground stress and gas pressure.