煤层气越流固气耦合数学模型的SIP分析

应用煤岩固体变形与煤层气（瓦斯）越流相互作用的新观点,认识双层系统煤层气越流运移的机理。在地球物理场作用下,双层系统煤层气越流实质上是可压缩性气体在各向异性且非均质的孔隙与裂隙双重可变形介质中的渗透与扩散的混合非稳定流动过程。依据这一新认识,建立了双层系统煤层气越流与煤岩弹性变形的固气耦合数学模型,并成功地应用该耦合模型于邻近层煤层气涌出的数值模拟实例中。经实测结果验证,该固气耦合模型是符合实际的;同时,也表明解算该类固气耦合数学模型的计算机模拟方法－－SIP算法是有效的。

SIP analysis on coupled models for coal seam deformation and gas leakage flow

Based on the new viewpoint of the solid and gas interaction mechanics, the mechanism on gas leakage in a double deformable coal seam could be understood in this paper. That is, under the action of geophysical fields, the coal seam methane flow in a double deformable coal seam could be essentially considered to be the compressionable gas flowing with time dependent and mixed permeation and diffusion through a pore cleat deformable medium of the heterogeneous and anisotropic coal seam. Then based on this new viewpoint, the coupled mathematical model for coal seam deformation and gas leakage flow in a double coal seam was formulated and the practical numerical simulations for gas emission from area of closer to up (down) coal seam was successfully achieved. Therefore the conclusion could be drawn from this study that the coupled models might be closer to actual situation. Meanwhile it is effective for SIP analysis on the coupled models for coal seam deformation and gas leakage flow.