钻具旋转对岩屑运移的影响规律研究

Study on influences of the drilling tools rotating to cuttings removal in building inclined section

本文通过岩屑运移的启动条件及悬浮条件分别建立考虑钻具旋转影响的岩屑颗粒翻滚、上升的临界启动速度模型,分析钻具旋转对岩屑临界启动速度的影响规律,通过计算发现:在150RPM下,宽间隙处最大影响率为38%,窄间隙处最大影响率为47%;最后根据岩屑临界启动速度模型,考虑钻具旋转作用对偏心环空不同间隙处岩屑启动与运移规律的影响,真实的描述了岩屑在环空中不同位置处的运动状态,提出了评价井眼清洗效果的新方法。

In this paper,the critical startup velocity models of debris rolling and floating,considering the effect of drillingstring rotation,were respectively established in accordance with the startup condition and suspension condition of debris migration.Through calculating,we find that： At 150RPM,the biggest effect rate to the wide annular tolerance is 38%,to the narrow annular tolerance is 47%;at last,in accordance with the critical toggle speed model of rock debris,with the effect of drill rotating function to rock debris start and migration law at different eccentric annulus,describe the cuttings motion state of different position in annular,and a new method of evaluate borehole cleaning effect is proposed.