Simulation and Experimental Study on Rock Disintegration Characteristics of Special-shaped PDC Cutters

In order to analyze the rock disintegration characteristics of special-shaped Polycrystalline Diamond Compact (PDC) cutters, numerical simulation and micro-drilling test on four kinds of special-shaped PDC cutters are carried out. Simulation results show that, the surface stress of each PDC cutter is quite different. For the dual-chamfer PDC cutter, the second chamfer can expand the stress on the cutting edge to a larger area; for the conical PDC cutter, the maximum stress is concentrated at the tip of the cone; for the ridged PDC cutter, the stress is distributed in a triangular fan shape from the lower edge of the cutting edge upward along the ridge, and for the triangular ridge PDC cutter, the stress is mainly distributed on the lowermost ridge. The conical PDC cutter has advantages in rock disintegration stability and efficiency, but it requires a higher weight on bit; the ridged PDC cutter has advantage in rock disintegration efficiency, but it tends to swing sideways when breaking rock; the dual-chamfer structure of PDC cutter is beneficial to extend the cutter's life, but its rock disintegration efficiency is poor. Anchor bits with these special-shaped PDC cutters are produced, and electro-hydraulic micro-drilling test are carried out, the results of micro-drilling test and numerical simulation show the same law excluding conical PDC cutter. The research results can provide guidance for the application of special-shaped PDC cutters in drill bit.