大城-文安地区页岩储层孔隙结构特征

Characteristics of Shales Reservoir Pores in Dacheng-Wenan Area

为了探讨大城-文安地区石炭-二叠系地层页岩储层储集能力,运用扫描电镜、高压压汞测试、低温氮气吸附试验等技术手段,研究了页岩储层孔裂隙结构、孔体积和孔比表面积等存储特征,研究结果表明:大城-文安地区石炭-二叠系页岩孔隙类型复杂,主要发育有微裂缝、粒内孔隙、粒间孔隙和有机质孔隙;孔隙度小,微孔和过渡孔所提供的大量比表面积和体积有助于页岩气体贮存及吸附;中孔和大孔不甚发育,对气体流通不利,后期开采过程中需进行储层压裂改造等措施增产。

In order to study on adsorption capacity of shales reservoir pores of carboniferous-permian formation in Dacheng-Wenan area,the paper investigated storage characteristics such as fissures structure,volum and specific surface area of poer of shales reservoir,using SEM,high pressure Hg injection and low temperature nitrogen adsorption.The results show that pore types of shale are complex in carboniferous-permian formation of Dacheng-Wenan area,microcrack,intergranular porespace,inter grain and organic pore are developed.Porosity is small,micropores with diameters less than 100nm and transition pores provide most of the pore volume and specific surface area,and this is favorable for gas adsorption and storage.The mercury injection method shows that the mesopore and macropore of the sample are relatively undeveloped,which is not conducive to gas seepage,and productions in the later period need stimulation measures.