METHOD OF CONTROL OF WELL SHAFT TRAJECTORY (ITS VARIANTS ) Russian patent published in 1994 - IPC

FIELD: drilling pinpoint wells. SUBSTANCE: method of control of well shaft trajectory involves superposition of longitudinal oscillations whose frequency is equal to rotation speed. With employment of axial-symmetrical tool one of rock-destruction members is dulled or substituted by bearing member. Curvature of well shaft is controlled in accordance with dependence given in invention formula. When two-step rock-destruction tool is used curvature is in addition to it is controlled by means of changing axial distance between tool steps or by means of changing of angle between rock-destruction and dull members of tool. To enhance intensity of zenith curvature amplitude-modulated longitudinal oscillations are imparted to tool, their carrier frequency is selected to be equal to frequency of its rapid transverse automatic oscillations, and bending frequency is to be equal to speed of the tool rotation. In this case the process of zenith curving is controlled by means of changing bending frequency phase and curving intensity is controlled by means of changing of phase of carrier oscillations. EFFECT: enhanced accuracy. 4 cl, 17 dwg