利用压汞、低温氮吸附、扫描电镜等手段,分析了织纳煤田珠藏向斜主煤层3件煤样(青山,国安,红岩脚)的孔隙结构与渗流能力。结果表明,3件煤样均以过渡孔为主,大孔与微孔占较大比例,中孔所占比例较低,孔比表面积都集中在过渡孔和微孔上;较大孔隙为开放性孔,较小直径的孔隙主要为半开放性孔,退汞效率高,孔隙连通性较好;青山煤样和国安煤样孔径-孔容分布的连续性较好,煤层气解吸-扩散能力可能更强;红岩脚煤样大孔段孔径分布连续性极差,部分孔隙孤立发育;青山煤样大孔段孔径分布连续性相对较好,发育未被充填的微裂隙和植物细胞孔。孔隙-裂隙的这一发育特征,可能是造成青山煤空气渗透率相对高于红岩脚煤的内在原因。
By use of mercury intrusion, low nitrogen adsorption and scanning electron microscopy, the pore structure and seepage ability of three samples from the major coal seam in the Zhu-Zang syncline of the Zhina coalfield were analyzed. Data show that pore in the samples is dominated by transitional pore, macro- and micro-pores account for a large proportions, with minor mesopore. Pore specific surface area come mainly from the transitional pore and micropore. Pore with large diameter is open and pore with small diamete is semi-open. The sample is higher in withdrawal mercury efficiency and better in the pore connectivity. Distribution of the pore size and volume from the Qinshan and Guo' an coal mines has a well continuity, indicating a stronger desorption and diffusion capacity of coalbed methane. Large size pore of the Hongyanjiao sample has a poor continuity and some isolated pores. Large size pore of the Qinshan sample has a relatively good continuity, which is resulted from open micro-fractures and plant cell pores. Difference of the pores and fractures among three samples may be the reason from which the air permeability of the Qinshan sample is higher than that of the Hongyanjiao sample.