Research on Anthracite Desorption Character and Applycation in Prevention and Treatment Gas Outburst in Mine
|School||Xi'an University of Science and Technology|
|Keywords||Anthracite Desorption Characteristics Outburst hazard Gas Pore structure|
At present,coalbed methane is very important in China’s energy structure. In the pastthree decades，coalbed methane exploration and development of results show that China’scoalbed methane resources are very rich，high，medium and low metamorphic grade of thecoal reservoir contain a large number of coalbed methane resources. However, the currentdomestic commercial development only have made a breakthrough in the Qinshui Basin.Therefore, from reality, it’s the most urgent task to be CBM industry researchers thatsearching a reasonable technical method for CBM exploration and development in otherregions. One of the researching differences anthracite became one of the main topics.In the thesis, we respectively collected coal samples from the south Qinshui3#,Rujigou2#、Lengshuijiang3#，causes of three different formation anthracite coal reservoir,and did experiments，Analysis of aspects from the chemical composition of samples from thecoal, causes the pore type, pore size distribution, specific surface area, pore volume and poredistribution characteristics, adsorption characteristics of coal bed methane and desorptionanalysis of the performance, Using thermodynamics method to calculate the adsorption,desorption process adsorption heat and compared the result，mathematical methods used to fitthe experimental results，and obtained differences in understanding of the reservoir,on theanalysis of the differences the anthracite of plutonic metamorphism of Ceshui Formation andthe anthracite of hydrothermal metamorphism ofYan’an Formation.From the point of view that composition of coal samples, the three coal samples belongto the high rank anthracite, all have good ability to generat methane,in these, Qinshui South3#coal is the best; from the coal sample to pore characteristics and surface features analysis,Qinshui South3#and Lengshuijiang3#coal sample are the majority of the open hole, while the surface area of Qinshui south3#coal reservoir is bigger and it’s benefit of storing forCBM. Rujigou2#coal contains more closed pores, specific surface area and pore volume issmall, so it is not conducive to store the coalbed methane;the isothermal desorptionexperiments show that changes of the adsorption heat great impact than the pressure higherpressure In the high pressure stage; By calculating the heat of adsorption，we can concludedthatthe heat of adsorption in desorption process is greater than the adsorption process，this isthe other evidence in the desorption lag.