DOUBLE-ACTION SUCKER-ROD WELL PUMP

摘要

The invention relates to the oil production industry. The pump comprises a cylinder, which has a lower intake valve and is connected to a tubing string with the aid of a sub, which is equipped with an upper intake valve and an upper discharge valve. A hollow plunger is arranged in the cylinder so that cavities are formed below and above the plunger. The plunger is connected to a hollow rod and has a lower discharge valve. The cylinder is a stepped cylinder. A through-hole is provided in the lateral wall of the plunger above the lower discharge valve in order to provide communication between the plunger cavity and a chamber formed as said plunger is moved downwards in the lower step of the cylinder. The upper step of the cylinder is formed with an inner diameter which is smaller than the inner diameter of the tubing string. The upper discharge valve is in the form of a bush arranged on the rod with the possibility of longitudinal movement upwards along said rod given an excess pressure in the cylinder cavity above the plunger and of movement downwards in the liquid under its own weight, and is equipped with a seat. A stop capable of interacting with the upper discharge valve is arranged on the rod between the plunger and the upper discharge valve.