变温条件下深部煤层瓦斯分布规律的数值模拟

深部煤层瓦斯运移过程及分布规律与温度场、瓦斯渗流场及应力场耦合密切相关.基于深部煤层瓦斯运移的热流固耦合模型,结合实际的煤层条件和实测数据,开展了煤层瓦斯赋存规律的数值模拟,研究了瓦斯压力和瓦斯含量分布规律的影响因素.结果表明:煤层渗透率是影响瓦斯压力分布的主要因素,其中煤体的有效应力系数、初始孔隙率、弹性模量以及吸附应变系数均对渗透率有着重要的影响;煤层瓦斯含量受瓦斯压力和煤层温度的共同影响,不考虑煤层温度预测得到的瓦斯含量结果偏大.

Numerical Simulation on Methane Distribution Legularity in Deep Coal Seam Under Variable Temperatures

Methane migration and distribution in deep coal seam is closely related to the coupled process among thermal， gas flow and mechanical fields. Based on the THM (thermal hydraulic mechanical)coupling model， coal seam condition and in-situ test data， numerical simulation was conducted to examine the factors affecting the distribution of methane pressure and content. It is shown that， permeability of coal seam is the main factor affecting gas pressure distribution， where the effective stress coefficient， initial porosity， elastic modulus and adsorption swelling coefficient all have important impacts on permeability. Methane content distribution is controlled by both gas pressure and coal temperature. Methane content may be overestimated without considering the coal seam temperature.