DOWNHOLE PUMP UNIT Russian patent published in 2015 - IPC F04B47/02 

FIELD: oil and gas industry.

SUBSTANCE: unit consists of tubing string, long movable and flexible rod placed inside long fixed and flexible rod thus forming annular space filled with lubricating fluid. The flexible rod is coupled by its upper end to source of reciprocal movement and by its lower end to plunger of displacement pump hydraulic drive. Drive fluid in processing chamber of the hydraulic drive is simultaneously used as processing fluid of submersible displacement pump. The plunder upper part of submersible hydraulic drive is placed in cavity of annular space with lubricating fluid, which is coupled with cavity of hydraulic drive processing chamber by a channel made inside the plunger. Inside it there is at least one bypass valve calibrated to design pressure.

EFFECT: increased operational efficiency, increased service life between overhauls.

4 cl, 7 dwg