Bottom-hole cleaning is a major factor affecting the rate of penetration. At the bit face, fluid flows through the nozzles, across the bottom, and back to the surface through the annulus. The resultant friction and turbulence of mixing causes a great loss of energy. Efficient bottom-hole cleaning must accomplish at least three basic functions:

  1. Washing at the mud-rock interface

  2. Controlling "crossflow" and avoiding the regrinding of cuttings

  3. Fast-lifting of cuttings around the bit face

The objective of this laboratory student is to investigate the main parameters that control or effect bottom-hole cleaning, which is closely related to the rate of penetration and to point out how each parameter is related to bottom-hole cleaning. In this study the fluid dynamic forces on the cuttings were investigated in the vicinity of the bit.

A better understanding of bottom-hole cleaning should allow an engineer to improve the rate of penetration and minimize drilling costs per foot.

You can access this article if you purchase or spend a download.