煤储层基质孔隙和割理孔隙的特征及孔隙度的测定方法

Coal pore properties of matrix & cleat and their porosity measurement methods

以河南安阳和山西柳林两处试验勘查区及附近矿井煤样为例，对煤储层和基质孔隙和割理孔隙特征分析进行了研究，并对孔隙度的测定方法作了探讨。基质孔隙和割理孔隙构成煤储层的双重孔隙介质结构．割理孔隙度一方面随围压增加有降低的趋势，另一方面随孔隙压力降低，气体解吸引起的基质收缩，又有增加的趋势．通过分析实验室条件下，水饱和与气驱水过程基质孔隙的毛管力和润湿性，结合国外学者对气驱水条件下割理内是否有残余水所做的实验，综合分析，认为气驱水法是测定割理孔隙度唯一可行的方法．基质孔隙度只能由总孔隙度和割理孔隙度间接求取．

The properties of matrix pore and cleat pore of coal reservoir and method of determining their porosities are analysed and studied,based on the studying of coal sample in two reconnaissance and experiment areas.Anyang and Liulin in Henan province and Shanxi province.Matrix pore and cleat pore constitute dual-pore medium texture of coal reservoir.Cleat porosity has the tendencies of decreasing with declining of confining pressure and increasing with declining of pore pressure which induce gas desorption and matrix shrinkage.With respect to cleat porosity,by analyzing capillary pressure and moisture-penetrability of matrix pore at the conditions of lab and foreign scholar's measurement analysis about whether residuae water exists in cleat after gas displacing,gas displacing saturated water in sample was thought to be the only feasible method for cleat porosity measurement.Matrix porosity can only be obtained by calculating the total porosity and cleat porosity.