Numerical simulation of rock-breaking mechanisms by triple-ridged PDC cutter in hard rocks

Abstract

As basic cutting element of PDC bit, PDC cutters play crucial roles in breaking rocks for PDC bit. Conventional PDC cutter usually gets broken when drilling into deep formations due to high hardness and strong abrasion. To help solve such a problem, triple-ridged PDC cutters have been developed and utilized in the design of hybrid-cutters PDC bit, which have achieved enhanced rate of penetration and high life cycle. Nevertheless, few researches have focused on the rock-breaking mechanisms of triple-ridged PDC cutter. Thus, this research carries out a series of numerical simulations to reveal the rock-breaking mechanisms of the triple-ridged PDC cutter. The numerical analysis and the visualization of the rock-breaking process are shown in the paper. Parametrical analyses have also been conducted to reveal effects of cutting parameters, rock strength, and cutter structural parameters on the rock-breaking performances of the triple-ridged PDC cutter. Numerical results show that the triple-ridged PDC cutter is more easily to break the rock than the conventional PDC cutter by combining the shearing and the crushing effects, predominantly leading to much smaller cutting force. Given the same cutting depth and the cutting angle, the triple-ridged PDC cutter can exhibit higher rock-breaking efficiency than that of the conventional PDC cutter. Also, optimal analysis should be done for the structural design of the triple-ridged PDC cutter. These research findings help the readers understand the rock-breaking mechanisms and the further application of the triple-ridged PDC cutter in deep hard formations.