Simulation of the cutter arrangement pattern of the arc PDC drill bit

When drilling in a complex heterogeneous formation, due to the limitation of bit crown shape, the cutters of each part of the bit are subjected to non-uniform force, and the cutters at the local location are subjected to large impact load, which lead to the occurrence of bit vortex. In order to solve the problem, a “multi-level force balance” cutter circumferential arrangement scheme is proposed. By establishing the rock breaking finite element simulation model of the bit, the mechanical characteristics of the cutter and the bit under three circumferential cutter distribution modes(clockwise, counterclockwise and “multi-level force balance”) are analyzed. Simulation results show that comparing with the clockwise and counterclockwise circumferential cutter arrangement modes, the load distribution of each blade is more uniform under the “multi-level force balance” cutter arrangement mode, the ability and aggression of the bit are improved, and the rock-breaking efficiency of the bit is improved by more than 28%, for the clockwise circumferential cutter arrangement mode, the lateral force of the bit is the highest and the stability of the bit is the worst; while for the counterclockwise circumferential cutter arrangement mode, the weight on bit is relatively higher, and the bit is less aggressive, the rock-breaking efficiency is the lowest. The above research results can provide a theoretical basis for the design of circumferential cutter distribution of the PDC bit. It is suggested that, in the future, the research on the cutter load distribution along the radial of the bit under the “multi-level force balance” cutter circumferential arrangement scheme should be strengthened, so as to guide the optimal design of the anti-vortex stable PDC bit.