SUCKER-ROD SUBSURFACE PISTON PUMP Russian patent published in 2019 - IPC F04B47/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to sucker-rod subsurface piston pumps for oil extraction with high content of mechanical impurities. Pump includes cylinder with installed inside plunger, adapters – upper and lower, connecting cylinder with tubing string, suction and discharge valves, two piston-pairs – piston-cylinder – upper and lower. Upper piston pair is installed inside the plunger connected to its cylinder on the thread and are at different levels in height and length. Piston is equipped with cover with connecting element with rod. In the wall of the piston and the cylinder there are openings at different levels along the height in the longitudinal direction with identical geometrical dimensions, which are matched when the piston is in the lowest position, thus forming a pressure valve. Bottom piston pair is installed in the lower part of the cylinder of the pump with openings in the wall of the piston and its cylinder with formation of the suction valve at alignment, at the piston of this pair in the upper position, and the piston from below is plugged. Pistons of both piston pairs are connected to each other by means of a coupling. Openings are made above and under the coupling to communicate piston cavities with under-plunger cavity. Lower adapter is stepped. Plunger of the pump is made in the form of two bushes screwed to end sections of the cylinder of the upper piston pair. Lower cylinder of piston pair is equipped with centering element with perforated holes.

EFFECT: improving pump efficiency, operating reliability, increasing overhaul period, simplifying design and manufacturing technology.

1 cl, 3 dwg