基于改进的单动双管钻具在破碎泥岩地层中的应用

Application of improved single acting double-tube core barrel in fractured mudstone formation

单动双管钻具可提高岩芯采取率,反映岩体结构特征,但对于破碎泥岩地层单动双管钻具钻进效率低下,通过对单动双管钻具结构和工作原理进行深入研究,在此基础上对单动双管钻具进行加工改造,通过加大钻头水槽截面、增加滤水管孔数和卡簧底座间隙,从而达到增大过水面积,改善冲洗液循环环境的目的,有效地提高了单动双管钻具在破碎泥岩地层中的钻进效率和岩芯采取率。

The single-acting double-tube drilling tool is in favor of improving the core recovery rate and reflecting the structural characteristics of rock mass,but the drilling efficiency is low in broken mudstone formation.Based on the deep study of the structure and work principle of single-acting double-tube core barrel,a improved way is developed with increasing flows rate of intake and reducing blockage of outlet through increasing the cross section of drill water tank,the number of filter holes and the gaps of spring base.It improves the environment of drilling fluid circulation and promotes the drilling efficiency in fractured mudstone formation effectively as well as core recovery.