National Engineering Research Center of Coalbed Methane Development and Uilization, China University of
Geosciences (Bejing)

为了分析煤阶对黔西滇东地区煤储层孔隙性和渗透性的控制作用,对不同煤阶煤样的孔-裂隙结构、吸附能力和孔渗特征进行了探讨。结果表明:镜质组反射率小于2.5%时,随着煤阶升高,煤岩压实程度不断增强,煤中吸附孔含量逐渐增多,BET比表面积和BJH总孔体积逐渐增大,致使煤岩吸附能力逐渐增强,而渗流孔含量相对减少,渗流孔隙结构变差,渗透率随煤阶升高而减小;镜质组反射率大于2.5%时,随着煤阶升高,煤中吸附孔含量减少,BET比表面积和BJH总孔体积呈下降趋势,吸附能力减弱,而煤岩后期演化过程中产生了再生孔隙,致使煤岩渗流孔含量增加、渗流孔隙结构变好,总孔隙度升高,渗流能力增强。

In order to analyze the control role of the coal rank to the physical properties of coal reservoir, taking the samples from western Guizhou and eastern Yu nnan area as examples, many different experiment methods were applied to discuss the pore and crack structure, adsorption and desorption capacity and pore permea bility features of the different coal rank coal samples.The results showed that when the reflection rate of vitrinite was less than 2.5%, with the coal rank improved, the C ompaction degree of the coal and rock would be continuously increased, the gas content of the adsorption pores in seam would be steadily increased, the BET specific surface area and BJH total pore volume would be steadily increased.Thus the adsorption capacity of the coal and rock would be steadily enhanced, the content of the s eepage pores would be relatively reduced, the crack structure of the seepage pore would be getting poor, the seepage capacity of the coal and rock would be reduced a nd the permeability would be reduced with the coal rank increased.When the reflection rate of vitrinite was higher than 2.5%, with the coal rank improved, the gas conte nt of the adsorption pores in seam would be reduced, the BET specific surface area and BJH total pore volume would be in a reducing tendency and the adsorption cap acity would be reduced.However, regenerated cracks occurred in the late evolution process of the coal and rock would make the content of the seepage pores in the Co al and rock increased, the structure would be better, the total cracks of the pore would be increased and the seepage capacity would be improved.

国家自然科学基金资助项目(41272175)；国家科技重大专项资助项目(2008ZX05034)；