构造煤原煤样制作及渗透性试验研究

摘要

In order to study the permeability variation law of the raw coal sample from the structure coal and the difference to the briquette coal sample,with the coal sample preparation method improved,a method to pick up large lump coal from the underground mine and to process the briquette in the lab was applied to successfully prepare the raw coal sample of the structure coal with a Protodyakonov coefficient of 0.4 and the raw coal sample of the structure coal prepared was applied to the permeability experiment.Under the changed confining pressure,gas pressure and other single condition,a study was conducted on the different confining pressure and gas pressure affected to the raw coal sample permeability of the structure coal.A comparison analysis was conducted between the experiment results and the briquette coal samples under the same confining pressure and the gas pressure.The results showed that under the certain gas pressure status,the gas permeability of the two kind coal samples would be decreased with the confining pressure increased and the decreasing speed of the briquette permeability was higher than the raw coal sample of the structure coal.Under the condition of the certain confining pressure,when the scope of the gas pressure was 0.2～0.8 MPa,with the influence of the Klinkenberg effect,the gas permeability of the raw coal sample of the structure coal and the coal sample of the briquette would be reduced with the gas pressure increased.The permeability variation law of the briquette coal sample and the coal sample of the briquette would have the same point,but also would have the different poiut and the raw coal sample of the structure coal could not be fully replaced in the lab.%为了研究构造煤原煤样的渗透率变化规律及其与型煤煤样的异同,通过改进煤样制作方法,采用在井下取大煤块、实验室加工成型的方法,制取了普氏系数为0.4的构造煤原煤样,并进行了渗透性试验.在改变围压、瓦斯压力等单一条件下,分别研究了不同围压和瓦斯压力对构造煤原煤样渗透性的影响,试验结果与同等围压、瓦斯压力条件下的型煤煤样的试验进行了对比分析.结果表明:在瓦斯压力一定的状态下,2种煤样的瓦斯渗透性都随着围压的增大而减小,型煤的渗透率下降速度大于构造煤原煤样;在围压一定的条件下,瓦斯压力为0.2～0.8 MPa时,受到Klinkenberg效应的影响,构造煤原煤样和型煤煤样的瓦斯渗透性随着瓦斯压力的增大而减小.型煤煤样的渗透率变化规律与构造煤煤样既有相同之处,也有不同之处,在试验中不能完全替代构造煤原煤样.