DEVICE FOR CLEANING OIL WELL TUBING STRING FROM PARAFFIN Russian patent published in 2020 - IPC E21B37/02 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry, in particular, to devices for removal of paraffin from surface of tubing string. Proposed device comprises winch with drum and electric motor connected through control unit to control unit connected with sensor, wire with scraper at end, control system consisting of lever, roller and transducer to track wire tension and scraper position whereto weighting material is attached. Wire passes through stuffing box and at well outlet is thrown through control system roller and wound on winch drum. Drum winding point of wound wire faces away from roller. Roller is installed on spring-loaded lever telescopically connected to bar installed with possibility of movement along axis in guides in well. On roller there installed are scraper location detector and roller rotation direction detector in the form of two hermetic contacts and magnets. Magnets are installed on roller, and reed relays are installed on roller lever. On the end of the rod, which is telescopically articulated with the spring-loaded lever of the roller, a sensor of minimum weight is installed in the form of a reed relay and magnets, and the reed switch is mounted on the end of the rod from nonmagnetic material, and magnets are mounted on the rod end with the possibility of their separation from the reed switch by the guide pipe. Scraper is designed as a screw divided in two parts, which form complete profile of screw when assembled on general axis. Each of the parts of the screw of mutually opposite rotation is equipped with a rotation lock ensuring free rotation of the screw during scraper movement downwards and fixation from rotation of the screw during scraper movement upwards. Screw surfaces of screw parts are made with possibility of its rotation on shaft with clearance along longitudinal axis of hollow rod, which allows screw with its cylindrical surface to be centered relative to inner surface of tubing string, regardless of non-concentricity of tubing in coupling connections. Screw scraper is made in the form of hollow multiple-thread screws, the profiles of which are formed by annular sectors of the pre-cleaning circle and the circle of cleaning of the full pipe profile. Ends of screws are interconnected by hollow rods. Screws are sharpened on the side of screw and end surfaces.

EFFECT: higher reliability of device under load due to optimal configuration of working elements of scraper, reduced operating costs.

1 cl, 8 dwg