OIL-WELL PUMPING UNIT Russian patent published in 2012 - IPC F04B47/00 

FIELD: engines and pumps.

SUBSTANCE: unit includes a pump installed in a pipe string with movable working element, suction and delivery valve connected to the wellhead power unit by means of a bypass channel for supply of drive medium. Movable working element is made in the form of buffer liquid arranged in lower part of pump chamber of the pump housing below suction valve, so that hydraulic lock is formed, with possibility of interaction with pumped liquid supplied to pump chamber through the side opening made in the pump housing, and suction valve. Bypass channel is made in the form of a flexible tube located outside or inside. Wellhead power unit is represented in the form of hydraulic pump or gas compressor. As drive medium there used is mineral or synthetic oil, light hydrocarbons or liquids with small specific weight, and as movable working element there used is mercury, solution of zinc bromide - calcium bromide or liquid with large specific weight or their alternation. When gas compressor is used as additional drive medium, inert gas is used. One power unit operates with several wells, and electrical wires, heater cable and hydraulic channel is arranged in addition in flexible tube.

EFFECT: increasing overhaul period, simplifying the design and improving the reliability.

10 cl, 8 dwg