深孔定点取样装置稳定性优化研究

Research on Stability Optimization of Deep Hole Fixed-point Sampling Device

针对SDQ定点取样装置在煤层较硬或地应力较小时,钻孔孔壁与双壁钻杆间的阻力不能稳定大于双壁钻杆内管阻力,导致取样效果较差甚至取样失败的问题,提出了在双通道尾辫中加入环形喷射器的解决方案。采用数值分析与现场实验相结合的方法,对双通道尾辫中环形喷射器喷嘴直径参数进行研究,数值分析结果表明,当内置喷嘴直径为2.5 mm时环形喷射器产生的负压最大,是降低系统阻力的最优参数;现场实验结果表明,内置喷嘴直径为2.5 mm的环形喷射器的双通道取样尾辫的取样时间明显缩短,取样深度显著增加,取样成功率增大。

In view of the problem that for SDQ fixed-point sampling device, when the coal seam is hard or the ground stress is small, the resistance between hole wall and double wall drill pipe can not stable greater than inner pipe resistance of double wall drill pipe, which leads to poor sampling performance or even sampling failure, this paper proposes solution of adding ring injector to the double channel tail. By means of numerical analysis and field experiment, parameters of ring injector nozzle diameter in double channel tail were studied. The numerical analysis shows that when the inner nozzle diameter is 2.5 mm, the negative pressure of ring injector is the largest, and it is the optimal parameter to reduce the system resistance;the field experiment result shows that when the inner nozzle diameter is 2.5 mm, for the double channel tail of ring ejector, the sampling time shortens, the sampling depth increases and the sampling success rate increases.