煤系地层顶板岩溶地下水赋存特征研究

煤层瓦斯测压下向钻孔积水会导致测压不准，研究既能排水又不影响测压进程和测压结果的装置是下向钻孔测压亟待解决的难题。设计了自动排水装置，利用弹性膜实时感知排水时机, 实现了自动化排水；试验研究了弹性膜弹性参数，确定膜的最佳厚度为0.3~1.0 mm；基于气体压力差与毛细作用力原理，推算了最优排水区间；在此基础上研制出一种煤层瓦斯测压下向钻孔自动排水实验装置并开展排水试验。试验结果表明：在测压气室气压为0.152×10⁵ Pa，排水管管径为15 mm，毛细管内径为0.2 mm、数量为950根时，排水速度为0.444 3 cm³/s，该装置可以实现连续缓慢排水。

Development of automatic drainage device for downward drilling of coal seam gas pressure measurement

When measuring pressure in coal seam gas, water accumulation in downward boreholes will lead to inaccurate pressure measurement.It is an urgent problem to be solved to develop a device that drainage without affecting pressure measurement in and its result downward drilling pressure measurement. Therefore, the automatic drainage module was designed, and the elastic membrane was used to sense the drainage time in real time to realize the automatic drainage. The elastic parameters of the elastic membrane were studied experimentally, and the membrane thickness of 0.3 mm to 1.0 mm was selected. Based on the principle of gas pressure difference and capillary force, the optimal drainage interval was calculated. On this basis, an automatic drainage experimental device for downward drilling of coal seam gas pressure measurement was developed and the drainage test was carried out. The test results show that when the pressure of pressure chamber is 0.152 × 10⁵ Pa, the diameter of drainage pipe is 15 mm, the inner diameter of capillary is 0.2 mm, and the number of capillary is 950, the drainage speed is 0.444 3 cm³/s, the device can achieve continuous slow drainage.