Non-spherical single cone bit tooth failure analysis and tooth load test

Abstract

Single cone bit is frequently used in slim-hole drilling field. To solve the problems of the spherical single cone bit during drilling process, a new type of single cone bit is designed, and field test is carried out. In this paper, the statistical analysis of tooth wear is done, and the causes of cutting tooth wear and protects radial tooth eccentric wear are analyzed in detail. In order to figure out the causes of tooth failure, the tooth load of non-spherical single cone bit was measured by experiment method and the change regularity of tooth load was statistically analyzed. The results show that the axial load is greater than the tangential load and radial load during drilling process. The axial load increase is more obvious with increase of weight on bit (WOB), but the tangential load and radial load change less. With increase of axle tilt angle of bit axis, the axial load and tangential load is reduced at the end of cone, but the radial load is increase. However, the axial load, tangential load and radial load of other's tooth is increase with increase of axle tilt angle of bit axis. The experiment results explained the cause of tooth wear, and it was important to understand the mechanism of tooth wear, optimize the structure parameters of bit, and understand the movement of bit in the well.