Analysis of drilling response under ultra-high-speed diamond drilling: Theory and experiment

Abstract

The ultra-high-speed diamond drilling (UHSDD) technology represents a groundbreaking and effective approach to deep hard rock drilling. This innovative method addresses the critical need for reduced weight on bit (WOB) while simultaneously achieving remarkable enhancements in drilling velocities. However, the absence of a comprehensive fundamental theory poses challenges, such as drill wear and inconsistent rock crushing efficiency. In this paper, the experimental data obtained from UHSDD was processed and analyzed by leveraging the drilling response model under standard rotational speeds (D-D model). The interface laws of diamond bit based on rate-relatedness were proposed. Notably, the depth of cut per revolution d of the bit is influenced by a complex interplay of rotational speed and weight on bit variables. A new variable Γ was introduced to measure the force required per revolution for d at ultra-high speeds. Within the proposed model framework, the quantitative information from drilling data was extracted, encompassing the wear state of the bit, drilling parameters, and rock properties. To validate the accuracy of the new model, a series of extensive laboratory experiments on the UHSDD test experimental platform was conducted. The reliability of the model was preliminary verified. The results of this study enhanced our understanding of the drilling response of UHSDD in practical drilling applications.