BOTTOM-HOLE FINE FILTER Russian patent published in 2012 - IPC E21B43/08 

FIELD: oil and gas industry.

SUBSTANCE: device includes metal pipe with holes, in upper part of which coupling with valve element and filter element arranged inside the pipe with a gap and coaxially to it is installed. Element is made in the form of individual sections connected to each other by means of cylindrical centralisers. Thrust bushings are installed on ends of assembled sections. Centralisers are made in the form of a stepped bushing with a belt in middle part along the bushing axis. Cylindrical part of bushing of smaller diameter is adjacent to inner surface of filter element. Thrust bushings are provided with a collar on outer surface with diameter equal to inner diameter of metal pipe.

EFFECT: increasing efficiency of device and time between overhauls.

2 cl, 6 dwg