Experimental Study of Down-the-Hole Percussive Drilling

Abstract

In the literature of percussive drilling, several laboratory and field experimental studies have reported the existence of optimum drilling states. The rate of penetration increases with axial thrust (weight-on-bit) up to an optimal value, beyond which it decreases with further increase of thrust. In this research project, novel laboratory and field experiments were carried out to investigate whether the occurrence of optimum drilling states stems from an intrinsic property of the bit-rock interface.