可解吸瓦斯含量的影响因素及修正补偿研究

针对定点取样过程中压风进钻的风压扰动对煤层瓦斯原始含量的影响以及停风后取样测定含量的时间,采用现场测定和实验室研究相结合的方法展开研究。压风进钻见煤后直接取煤样测定含量过程中,破碎解吸量会小于停风一段时间后的解吸量,在停止压风进钻后破碎解吸量迅速上升,2 h后上升的速度逐渐减小直至趋于恒定;井下直接解吸量的测定在压风进钻停风1.5 h后开始用取芯管取煤样为宜。为了加快进度,也可以在直接测定后采用y=24.74+0.26x(其中,y为恒定后的井下直接煤层瓦斯解吸量,x为修正时间)对井下煤层瓦斯解吸量进行修正;实验室破碎解吸量的测定在压风进钻停风后2 h取煤样测定为宜,也可以在不停风测定的基础上加上瓦斯含量为0.2 m³/t的修正量。

Research on influencing factors and correction compensation of desorbable gas content

Aiming at the influence of the wind pressure disturbance caused by the compressed air entering the drilling during the fixed-point sampling process on the original coal gas content and the time of sampling and measuring the content after the wind was stopped,a combination of on-site measurement and laboratory research was used to conduct research.In the process of directly taking a coal sample to measure the content after the compressed air enters the drilling,the amount of crushing and desorption would be less than the desorption after a period of time when the air was stopped.After the air was stopped,the amount of crushing and desorption increases rapidly,and the rate of increased gradually after 2 h decrease until it tended to be constant;it was advisable to start to take coal samples with the core tube after the compressed air enters the drilling for 1.5 h after the direct desorption amount was measured.In order to speed up the progress,you could also use y=24.74+0.26 x(where y is the constant underground coal seam gas desorption amount after constant,and x is the correction time)to correct the underground coal seam gas desorption amount after direct measurement;The determination of the amount of crushing and desorption in the laboratory was appropriated to take a coal sample 2 h after the compressed air enters the drilling and stoped the wind,or the gas content was corrected to 0.2 m³/t on the basis of the continuous wind measurement.