Kinematics of Large-Diameter Multiple Rolling-Cutter Rock Drilling Bits Under the Conditions of Reactive Turbo-Drilling

Special features of the kinematics of large-diameter multiple rolling-cutter rock drilling bits under the conditions of reactive turbo-drilling are considered. An analysis of the kinematics of the rolling cutters of drilling bits functioning with slippage of the cutting structures along the well bottom is undertaken. Factors that influence the magnitude and direction of slippage of the teeth of the cutting structures along the well bottom are determined. Shortcomings of the geometry of the cutting structures of rolling-cutter drilling bits designed for full-diameter drilling when used in reactive turbo-drilling units are identified. On the basis of these studies, it is concluded that fabrication of drilling bits of increased diameter with the use of sections of standard box-type drills is not an efficient approach for full-diameter drilling, since the geometry of the cutting structures of conventional drilling bits does not take into account the specific features that arise in the interaction of the teeth of the cutting structures with the well bottom surface under the conditions of reactive turbo-drilling.