A study on the relationship between anthracite fissure-pore system and the production of coalbed methane in Jincheng

摘要

In Jincheng coalbed methane (CBM) development becomes the first commercial industry in China. Because Jincheng anthracite is high metamorphisM coal, its fissure-pore system is different from bituminous coal. In the paper, 69 samples were collected from 18 CBM wells of coal seam No. 3 in Zhengzhuang in Jincheng. To the naked eyes and by SEM most of the fissures are filled with clay mineral or in a closed state and the opening fissures are not often visible in Jincheng coal. By the Scan Electronic Microscope (SEM) the pores in the coal are abundant in mold pores which exist isolated, shallow, and poor connectivity, and other pores are few. The existing of too many mold pores and filled fissures make the migration passage of methane not available, so hydraulic fracture stimulation is an effective method of adding and connecting fissures to enhance CBM production.