主动补气缩短煤层瓦斯压力测定时间分析

Analysis on Active Air Supply Shortening Coal Gas Pressure Measurement Time

能够有效缩短瓦斯压力测定时间是主动式测压的最大优点,因此,对主动补气缩短瓦斯压力测定时间进行分析有着重要意义。首先,构建出了被动式测压钻孔周围流场范围内的煤层瓦斯压力表达式,并对主动式测压和被动式测压流场平衡过程的差异性进行了分析,确定了主动补气缩短的瓦斯压力测定时间;然后,从理论上推导出了主动补气缩短瓦斯压力测定时间的计算公式,并将理论计算结果和现场试验情况进行了对比分析。研究结果显示,二者基本一致,误差只有7.5%,主动补气能够缩短大约50%的测压时间。

The biggest advantage of active pressure determination is that it can effectively shorten the measurement time,thus,it has great significance to analyze how to save the time in gas pressure measurement of active air supply. First,we construct the coal seam gas pressure within the passive expression of the flow field around the borehole pressure measurement range,and the difference between the active and passive load balancing process of the flow field is analyzed,the saving time of active air supply in the measurement of gas pressure is determined; then,the formula of saving time by active air supply in the measurement of gas pressure is deduced theoretically,and the theoretical calculations and the field tests are comparatively analyzed. The results show that two methods are basically the same,the error is only 7. 5%,and the active air supply can save about 50% time in the measurement of gas pressure.