煤系泥岩层钻进反馈信号特征的试验研究

Experimental study on drilling feedback signal characteristics of mudstone seam in coal measures

以煤系顶板泥岩层为研究对象,对不同抗压强度的泥岩层钻孔施工过程中不同推力水平下的钻进反馈信号进行现场试验研究,结果表明:1)试验条件下泥岩钻进全过程推力-钻速特征曲线分区明显,可划分为研磨区、钻削区、阻塞区,推力达一定值时由研磨区跃迁至钻削区,过渡区不明显;2)钻削区内钻速随推力增大呈近似线性增加,功耗最小,为钻机工作的最优区域;3)阻塞区内并非钻速增长率减小而是钻速负增长,钻速随推力的增加而减小,达某一推力水平时钻速骤降为零;4)相同推力水平下,钻进速度与泥岩强度呈负指数关系,泥岩强度增加时,推力-钻速特征曲线表现为钻削区、阻塞区右移,推力区间增加,曲线峰值降低,峰值位置右移且趋于平缓。

Taking the mudstone in the coal measure strata as the research object, this thesis carries out a field test on the drilling feedback signal under different thrust level in drilling process of different compressive strength mudstone seam. The results show that： 1） In test conditions, the thrust-rotational speed characteristic curves of drilling mudstone process can be obviously divided into three ar- eas-grinding area, drilling area and blocking area. The grinding area will jump into the drilling area when the thrust reaches a certain value, but the transition zone is not obvious. 2） Drilling rate approxi- mate increases linearly with the thrust in drilling area, which minimizes power consumption and is the optimal region for drilling rig＇s working; 3） In blocking area, drilling＇s growth rate does not decrease but grow negatively. The drilling rate decreases with the increasing thrust and the drilling rate dips to zero when the thrust reaches a certain level; 4） Under the same thrust, the drilling speed and the mud- stone strength show an exponential relationship. With the increase of the mudstone strength, the charac- teristic curve of the drilling speed and the mudstone strength features show that both the drilling area and the obstructed area shift to right, the area of the thrust increases, the peak value of curve decreases and the position of the peak shifts to right and becomes flat.