DEVICE FOR ELIMINATION OF PARAFFIN-CRYSTAL HYDRATE PLUG IN WELL Russian patent published in 2002 - IPC

FIELD: oil producing industry, particularly, designs of devices for elimination of paraffin and crystal hydrate plugs in wells equipped with oil-well sucker-rod pumps. SUBSTANCE: device includes oil-well sucker-rod pump, sucker-rod string with polished sucker-rod, lifting mechanism and plug heating unit in the form of exciter of longitudinal vibrations. Exciter has control unit and movable and fixed parts located in common casing. Exciter fixed part- stator is made in the form of hollow cylinder from magnetically soft material shaped in axial direction. Wound on internal surface of hollow cylinder is single-phase winding having even number of sections with alternating direction of magnetic flux north-south-north-south, etc. along stator axis. Movable part of exciter - induction heater is made also in the form of flat stepped cylinder from magnetically soft material. Secured to external protruding surface of stepped cylinder in a spaced relation to winding are radially magnetized circular permanent magnets whose number is equal to that of stator winding sections. Direction of magnetization alternates along longitudinal axis of induction heater to form bands north-south-north-south, etc. Length of pole division along induction heater axis formed by one circular magnet is equal to length of zone occupied by one section of single-phase winding of stator. EFFECT: increased depth of heating, higher safety in work involved in elimination of paraffin-crystal hydrate plugs. 4 cl, 2 dwg