DRILL STRING OSCILLATOR Russian patent published in 2021 - IPC E21B28/00 

FIELD: drilling equipment.

SUBSTANCE: invention relates to drilling equipment, in particular to oscillators of the drill string, designed to create hydro-mechanical pulses acting on the drill string. The oscillator contains a pressure pulse generator, including an upper adapter, a screw pair with working bodies based on a gerotor mechanism: a stator and a rotor placed inside it with an eccentricity, and a valve device, including a movable valve element, a valve and a fixed valve element, a seat. In the fixed part of the valve device, an opening is made, and in the movable part, the valve, a passage hole is made with an offset relative to the axis of the rotor. The first valve element is attached to the rotor and can be moved relative to the second valve element. During operation, the valve elements interact, together forming a variable flow section for the flow of fluid through the valve, the body and the lower adapter. In the lower part of the pressure pulse generator there is a mixing chamber located inside the lower adapter, the upper part of which is connected to the housing and the lower part is connected to the drill pipe string by means of a thread. Above the screw pair there is an adapter connected to the stator through an upper adapter, which serves to connect the pressure pulse generator to the longitudinal displacement generator, which includes an assembly of body parts consisting of a lower adapter, a hollow housing, a middle adapter and an upper adapter. Inside the hollow body is a hollow core connected to the drill pipe string, on the lower part of which an annular piston is installed. A spring is placed inside the hollow housing, which receives force from the pressure pulses produced by the pressure pulse generator through a hydraulic transmission. The annular cavity bounded by the hollow core, hollow housing, upper adapter, middle adapter is filled with oil. The tightness of the oil cavity is ensured by seals and an annular piston. A spline connection is located inside the cavity between the hollow core and the upper adapter to perceive the reactive moment that occurs during the operation of the longitudinal displacement generator. In the upper part of the stator channel there is a limiting ring that restricts the axial movement of the rotor placed inside it with an eccentricity. The working contact surfaces of the valve device parts have wear-resistant elements made in the form of hard alloy plates that form a wear-resistant layer during installation and are bonded to each of the contact surfaces of the valve device by means of a binder made of a powder of a wear-resistant material with a metal binder. Wear-resistant plates are arranged in rows with gaps along concentric circles. The centers of the plates of the adjacent rows are offset relative to each other. To ensure the orientation of the valve axis relative to the rotor axis, an adjustment unit is made in the valve device.

EFFECT: increased reliability and service life of the drill string oscillator structure.

7 cl, 4 dwg