Experimental and theoretical evaluation of solid particle erosion in an internal flow passage within a drilling bit

Abstract

In this study, a pragmatic and robust technique has been developed to experimentally and numerically evaluate solid particle erosion in an internal flow passage within a drilling bit. Experimentally, a field-scaled three-dimensional (3D) experimental setup is developed to perform erosion experiments, while the erosion rate of the internal flow passage is continuously monitored and measured. Numerically, a two-way coupled Eulerian-Lagrangian approach is employed to describe the liquid-solid flow in the internal flow passage, while a commonly used erosion model is then utilized to quantify solid particle erosion. The good agreements between experimental measurements and theoretical calculation results indicate that such integrated techniques can be used to accurately evaluate the complicated erosion behaviour. The erosion is found to be mainly distributed on the contraction surface, while, at the inlet velocity greater than 6.0 m/s, the average erosion rate is dramatically increased. The maximum unit erosion rate is increased quickly as the particle concentration is smaller than 5.0 vol%, while it is increased as the inlet angle is smaller than 23°. At a low erosion rate, the optimal particle diameter is found to be 2.0 mm.