沁水盆地煤储层渗透性影响因素研究

Research on permeability influence factors of coal deposit layer in Qinshui Basin

渗透率是评价煤储层渗透性的重要参数,通过对沁水盆地煤储层渗透性影响因素的研究,认为渗透率取决于煤层裂隙特别是煤层割理的发育情况,同时煤级控制了煤层割理的发育,后期方解石等地下流体的充填作用对煤储层割理渗透性产生严重的负面影响,而煤岩成分、煤相、矿物质等因素对割理渗透性的作用有限;有效应力、煤层埋深与渗透率呈负指数关系;随着煤层气的开采煤基质的收缩作用增大了煤层渗透性。

The permeability rate is an important parameter to assess the permeability of the coal deposit layer. With the research on the permeability influence factors of the coal deposit layer in Qinshui Basin, the paper hold that the permeability rate depend on the seam cracking, specially the development of the seam cutting. Meanwhile the coal class controlled the development of the seam cutting, the later filling functions of the calcareous spar and other underground fluids had a serious negative influence to the permeability of the coal deposit layer, but the coal petrology contents, coaly facies, mineral property, and other factors had a limited function to the cutting permeability. There is negative index relationship among the effective stress, seam depth and the permeability. With development of the coalbed methane, the shrinking function of the coal base material would enlarge the permeability of the seam.