在复杂结构井钻井过程中常有岩屑成床现象发生,容易造成一系列井下复杂问题,严重影响施工效率。目前一种螺旋式工具已被用于解决井眼清洁问题,应用效果较好。针对这种工具的基本结构,通过研究岩屑颗粒在螺旋式工具叶片上的运动,建立数学模型,得出这种工具螺旋角在不同井斜角条件下对岩屑颗粒通过该工具后的轴向、切向速度影响关系。研究结果表明:该螺旋式工具对岩屑颗粒运移有明显的加速作用,利于清除岩屑床;螺旋角作为清除岩屑床螺旋式工具的可控参数对工具性能产生重要影响;随着螺旋角增大,经过螺旋工具作用的岩屑颗粒切向速度逐渐增大,轴向速度逐渐减小,调整螺旋角可以使岩屑颗粒产生所需的速度以提高工具清屑效率。
In the process of drilling complex wells, cutting bed occurs normally, and it always causes a lot of well hole problem, and affect the work efficiency badly. Now a kind of spiral tool is normally used to solve this problem, with some good application effect. By studying the migration process of cuttings through the basic configuration blades, the paper built a mathematical model, and found the influence of blade helical angle on cuttings transport velocity in tangential direction and axial direction. The results show that this kind of tool could accelerate cuttings effectively; as a controllable parameter, blade helical angle has important impact on application effect of the spiral tool; with the increase of the helical angle, cuttings tangential velocity increases and axial velocity decreases. Changing the helical angle could make the cuttings have a necessary velocity to be transported out of the hole efficiently.