OSCILLATOR FOR DRILLING STRING Russian patent published in 2018 - IPC E21B28/00 

FIELD: mining.

SUBSTANCE: invention relates to hydraulic rotary drilling drives located in wells, in particular to oscillators for a drill string, designed to create hydromechanical impulses acting on a drill string. Oscillator contains a gerotor screw hydraulic motor and a valve, as well as a plunger module, a transmission shaft and a hydromechanical pulse generator, a spring module, a thrust bushing, an annular piston, seals and a working fluid (oil) chamber. First valve member fastened to the rotor is provided with a tubular shank directed to the valve and the inner cavity of which is configured to communicate with the fluid flow at the outlet from the gerotor screw hydraulic motor and to form a flow channel through the inner cavity of the tubular shank to the valve. Plunger module comprises an elastomeric plate fixed therein and is mounted on the tubular shank with the possibility of rotation and longitudinal displacement relative to it. First valve plate is made in the form of a throttle sleeve fastened to the plunger module with a flow channel, the internal profile of which is made converging downstream. Maximum displacement of the central longitudinal axis of the flow channel of the throttle sleeve relative to the central longitudinal axis of the elastomer plate in the stator is twice the value of the eccentricity of the central longitudinal axis of the rotor relative to the central longitudinal axis of the elastomer plate in the stator. Maximum displacement of the central longitudinal axis of the flow channel of the second fixed sleeve relative to the central longitudinal axis of the elastomer plate in the stator is equal to the eccentricity of the central longitudinal axis of the rotor relative to the central longitudinal axis of the elastomer plate in the stator.

EFFECT: service life and reliability of the oscillator is increased, the range of energy characteristics of the pulsating pressure of the fluid and mechanical power of the hydromechanical impulse generator is increased with a smaller level of pressure loss, friction forces of the drill string on the borehole wall are reduced, torsional stresses in the drill string are reduced while drilling horizontal wells, probability of sticking the drill string is reduced, bit service life and well penetration rate are increased.

5 cl, 12 dwg, 1 tbl