Theory and engineering practice raised a lot about the state of motion in the underground drillstring different assumptions

For decades, research drillstring mechanics and foreign scholars based on different research objectives and methods, theory and engineering practice raised a lot about the state of motion in the underground drillstring different assumptions, of guiding  Diamond blade  for the engineering  abrasive grinding  so drillstring dynamics theory developed rapidly, but most force on the drill string and drill string movement's findings are based on theoretical analysis,cubic boron nitride and other methods come. In actual drilling equipment using existing data measured in the field with a certain one-sidedness, up from the economic considerations quite feasible.