基于低温液氮吸附实验的成庄井田3号煤孔隙特征研究

Study on pore characteristics of No.3 coal in Chengzhuang Mine Field based on low temperature liquid nitrogen adsorption experiment

煤的孔隙特征控制着煤的吸附、扩散和渗流特性,采用低温液氮吸附实验对成庄井田3号煤孔隙特征进行了研究。结果表明:煤中孔径小于4 nm的孔隙多为一端开口孔,孔径大于4 nm的孔隙多为两端开口的孔、墨水瓶孔和少量一端开口的孔;煤中孔隙主要为过渡孔和微孔,大孔、中孔不甚发育,使得煤孔比表面积相对较大、孔容相对较小,有利于煤层气的吸附、凝聚储集和扩散运移。

The pore characteristics of coal control the adsorption,diffusion and seepage characteristics of coal.The author studied the pore characteristics of No.3 coal seam in Chengzhuang Mine Field by low temperature liquid nitrogen adsorption experiment.The results showed that the pores with pore diameter less than 4 nm in coal are mostly open pores at one end,and the pores with pore diameter greater than 4 nm were mostly open pores at both ends,ink bottle pores and a small number of pores with one end open;the pores in coal are mainly transition pores and micropores.The macropores and mesopores were not well developed,which made the specific pore surface area of coal pores relatively large and the pore volume relatively small,which was beneficial to the adsorption,coalescence and diffusion of coalbed methane.