Auger drill collar is prevented Sealed bearing roller reamer during drilling differential pressure block, the helical groove allows the mud flow freely around the drill collar to prevent the formation of an equilibrium pressure block, thereby effectively preventing differential sticking phenomenon. You can reduce the Walking beam pumping unit contact area with the drilling shaft, and thus the possibility of a pressure differential block can effectively be reduced. The reason why the spiral drill collars are widely used because of its own characteristics of the decision, this particular spiral Non magnetic drill collar drill collars to reduce the contact area between the wall and the tube, thereby avoiding "sticking" phenomenon of the drill string.