OIL WELL PUMPING UNIT Russian patent published in 2008 - IPC F04B47/02 

FIELD: oil production from wells, particularly pumping units therefore.

SUBSTANCE: pumping unit comprises sucker-rod pump installed in well, flow strings and casing-head stuffing box. Pumping unit includes antiphase device made as cylinder connected to lower part of casing-head stuffing box and arranged inside flow string. Piston is secured to sicker-rod string and cable suspension means. Piston has length providing constant air-tight connection thereof with cylinder and in the case of breakage thereof. Antiphase device cylinder and piston have diameters equal to that of sucker-rod pump body and piston to provide liquid volume to be displaces during working strokes of pumping unit.

EFFECT: decreased power inputs for liquid lifting from well and liquid transportation to oil gathering stations, decreased amplitude of load to be applied to sucker-rod string and conventional pumping unit, which results in reliability and service life increase and extended overhaul life.

1 dwg