延川南地区煤储层孔裂隙特征研究

Research on the pore-fracture properties of coal reservoirs in South Yanchuan region

借助于显微裂隙分析、压汞孔隙分析和低温氮吸附等手段,研究了延川南地区煤储层孔裂隙特征。研究表明:该区煤储层显微裂隙较不发育,多以宽度小于5μm且长度小于300μm的裂隙为主体;孔隙类型以吸附孔占据主导地位,渗流孔相对不发育,连通性较差;随构造变形强度的增加,开放性孔逐步转化为细颈瓶孔,过渡孔比例下降,微孔大幅度升高,比表面积加大,纳米级孔隙总孔容升高。

By means of microcrack analyses, mercury penetration and cryogenic nitrogen adsorption, this paper studied the pore- fracture properties of coal reservoirs in South Yanchuan region. The results show that the microeraek in the district are not well de- veloped and dominated by the pore size with the width less than 5 μm and the length less than 300 μm. As for pore types, the ad- surption pores are more remarkably developed than the seepage-flow pores, and the pores are always characterized by poor eonnee- tivity. As the tectonic defi）rmation intensity increased, open pores gradually transformed into flask pores, the proportion of transi- tion pores declined. Along with the substantial increase of micropore, specific surthee area and total pore volume of the nano- sealed pore increased.