The influence of coal body structure on adsorption-desorption and releasing characteristics of coalbed methane

The differences of pore and physical-chemical structure of coal body have great effect on adsorption-desorption and releasing characteristics of coalbed methane. Based on understanding of pores, structures and mechanical properties of different coal body structures, the paper analysed coal body structure influencing the releasing of coalbed methane with field measured data. Results show that tectonism makes pore volume and specific surface area of coal body increase, and adsorption capacity enhanced. Gas content and lost gas present positive correlation; relations of rate of lost gas of different coal body structures were:primitive texture coal < reptured coal < fragmented coal < mylonitic coal with the same gas content. Critical desorption pressures of primitive texture coal and reptured coal are more than mylonitic coal's. In 0~45 min、45~95 min、95~185 min, relations of average desorption rate of different coal body structures were:primitive texture coal