Comparing different pilot hole diameter two-stage PDC bit bottom-hole stress field, preferably a pilot hole diameter

Downhole drilling process and after the formation of the bottom three states stress field, the preparation of the finite cubic boron nitride program. The analysis has been a series of downhole drill stress field. Contrast double-stage conventional PDC bits PDC bits and downhole stress field studies to improve its mechanical mechanism ROP. abrasive wheels  the different pilot hole diameter two-stage PDC bit bottom-hole stress field, preferably a pilot hole diameter. ② application of non-Newtonian  abrasive grinding , drill string and drill bit hydraulics hydraulics theory deduced two-stage flow distribution system of equations and parameters affecting the simplified formula, prepared a two-stage flow distribution and nozzle combination design process.