DEEP WELL ROD PUMPING UNIT Russian patent published in 1998 - IPC

FIELD: oil production industry. SUBSTANCE: this pumping unit ensures stable operation in wells infested with paraffin and high concentration of solid mechanical impurities contained in liquid to be pumped out and also at abnormal blowouts of gas to pump inlet. Device has string of lift pipes with overflow valve. Pump is mounted on rod string. It is provided with plunger and tail-piece at inlet and is located in housing of gas separator. Tail-piece at pump inlet has sleeve with open top and tapered bottom. Made in outer surface of sleeve are circular bores with sharp protrusions. Volume of circular space between inlet part of tail-piece and sleeve is equal to volume of liquid withdrawn by one operating cycle of pump. Each circular space is connected with pump inlet through holes in tail-piece. Total area of their bores is equal to bore of circular space. Mounted on lift pipe string below overflow valve is additional overflow valve. Given in description of invention is formula for determining distance from additional overflow valve to first valve. EFFECT: high efficiency. 1 dwg