METHOD FOR STABILIZING OF WELL DIRECTIONAL DRILLING Russian patent published in 1994 - IPC

FIELD: well drilling. SUBSTANCE: method includes determination of well zenith angle, friction coefficient of drilling tool assembly against well walls, distributed mass, drilling tool assembly bending rigidity, well diameter, radial gap between drilling tool assembly and well. Drilling tool assembly is deflected in middle part in form of spiral line over length of not less than its one spacing and conjugated with middle part end parts of assembly having no contact with well. Using calculation formulas, coefficient of thrust of assembly, value of radius of helical line of assembly axis in its middle part, initial assembly deflection and its length are determined. During drilling, stable operation is ensured within whole range of rotation speed up to 800 rpm. EFFECT: higher efficiency. 1 dwg