DRILL STRING OSCILLATOR Russian patent published in 2024 - IPC E21B28/00 

FIELD: machine building; mining.

SUBSTANCE: invention relates to hydraulic drives for rotary drilling, placed in wells, in particular, to drill string oscillators designed to generate hydromechanical pulses acting on drill string. Drill string oscillator comprises a gerotor hydraulic motor including a stator with an elastomer lining fixed inside with internal helical teeth and a rotor with external helical teeth located inside the stator, and a valve comprising a first valve element with a throttle bushing and a fixed valve element, a plunger module, a radial thrust support of rotation, a transmission shaft, threaded adapter, hydromechanical pulse generator, spring module, thrust bushing, annular piston with seals. Engine rotor is hollow. Transmission shaft arranged between the inlet part of the hollow rotor and the hollow shaft of the radial-thrust support of rotation is made on the attachment side with a hollow rotor with bypass holes and a central flow channel with the possibility of passing part of the fluid flow through the hollow rotor. First valve element attached to the rotor has a central flow channel on the side of the hollow rotor attachment. At the inlet of the central channel of the first valve element there is a dosing jet with possibility of passage of a part of fluid medium flow from the hollow rotor into the inner cavity of the tubular shank of the first valve element. Throttle bushing with a flow channel, the profile of which is made with a critical section at the outlet, attached to the plunger module of the first valve element, contains an annular cavity on the end directed towards the fixed valve element, and the fixed valve element has an annular cavity on the end face directed to the first valve element. Both annular cavities on ends of movable and fixed valve elements contain hard-facing powder from hard alloy.

EFFECT: increased resource and reliability of oscillator, providing the required range of energy characteristics of the pulsating pressure of the fluid medium and the mechanical power of the hydromechanical pulse generator at increased flow rates of the fluid medium – drilling mud, for example, at flow rates of 45 l/s, excluding interference of oscillation frequency and amplitude on operation of downhole telemetric system modules – measurement modules (MWD) and logging (LWD) modules, providing continuous control of the downhole drill string assembly position during well drilling.

6 cl, 13 dwg, 3 tbl