OIL-WELL SUCKER-ROD PUMPING UNIT Russian patent published in 2015 - IPC E21B43/00 E21B47/00 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to chemical and thermal treatment of a bottom-hole formation zone in developing high-viscosity oil deposits. A hollow cylinder rod is connected to a line of hollow pumping rods. A unit has also a working substance supply unit. This unit is stationary and isolated from a well production gathering line. An inside below an intake screen of the pump, between the cylinder wall and the surface of the hollow rod is divided into two sections. The cylinder rod is common for both sections and extends through a cylinder rod packing. The packing is provided between the sections. The bottom of the cylinder is connected to a tail piece with outlet holes. The tail piece comprises a hollow discharge rod. It is connected to the hollow rod of the pump. A non-return spring-loaded valve is arranged on the outlet of the hollow discharge rod of the pump.

EFFECT: unit comprises the differential sucker-rod pump, a cylinder of which is connected to a flow column; it ensures more reliable operation of the bore-hole sucker-rod pump unit and reducing serviceability.

1 dwg