Rules study on cuttings migration through wellbore cleaning tools

Abstract： 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.