Assessment of wear of diamond core drilling bits

The paper issues from a laboratory research of small-diameter rotary drilling of rocks, which belongs to fundamental means of mechanical rock breaking. Presented results were acquired during extensive experimental research, which was performed at the Institute of Geotechnics SAS, using the laboratory drilling rig with diamond core drilling bits of 46 mm diameter with a view to assess the effect of drill bit wear on their ability to provide appropriate operational parameters in drilling of exploratory boreholes. Changes in drilling speed and energy consumption were observed while keeping different operational parameters (thrust force, revolutions) and the relation between the wear intensity and specific drilling energy was expressed. The experiments were performed while keeping the input parameters constant (i.e. constant regime) and during regime changes.