DEVICE FOR WELL CLEANOUT FROM PARAFFIN DEPOSITS Russian patent published in 2015 - IPC E21B21/10 E21B34/10 

FIELD: oil and gas industry.

SUBSTANCE: device consists of a barrel, a case, ring chamber, a valve as well as ring piston and pusher. The ring chamber is coupled hydraulically to radial openings made in the barrel with its axial channel and openings made in the case over the valve with annular space in the well. From overhead the valve is fixed rigidly to the ring piston with potential sealed shutoff of radial openings in the barrel from outside. The packing is made self-sealing and above it, at hydraulic actuator, there is a centring skid with outside longitudinal channels. Upstream the centring skid between the hydraulic actuator and pusher there is a packer made assembled of alternating rubber and metal rings. Rubber rings of the packer may be compressed axially and expanded radially outward.

EFFECT: higher reliability of the device.

2 dwg