For two-stage PDC bit more comprehensive study has important significance

With the increase in deep and ultra-deep, φ311mm diameter hole section and a larger increase and improve the deep wells of large diameter section of ROP has become an urgent need to solve the main problem. Two-stage PDC bit drilled through a  polycrystalline diamond  release stress and  cubic boron nitride  free surface, effectively improve the ROP. In this paper, two-stage PDC bit more comprehensive study has important significance. ① In rock excavation and finite element theory and method, based on the established two-stage conventional PDC bits PDC bits and bottomhole finite element model. Proposed using three time steps simulated truthfully spud.