OIL-WELL ELECTROHYDRAULIC PUMPING UNIT Russian patent published in 2005 - IPC

FIELD: oil producing industry.

SUBSTANCE: invention relates to pumping units designed for lifting liquids from depth, for instance, oil from wells. Proposed electrohydraulic pumping unit contains oil pump drive from submersible electric motor with compensator, working piston pump with piston cylinder, suction valve arranged in piston and delivery valve, and hydraulic motor to drive working piston pump. Cylinder spaces of hydraulic motor are connected through oil distributor with inlet and, through safety valve, with outlet of oil pump. Hydraulic motor piston rod is connected through protector with piston of working piston pump. Pumping unit is furnished with oil tank its volume compensator. Overflow valve, flow regulator and filter are installed in one section of oil tank. Hydraulic motor is furnished with piston travel limiter with distributor. Pumping unit has screw pump and additional hydraulic motor to drive this pump arranged lower than submersible electric motor. Pressure pipeline of additional hydraulic motor is connected with hydraulic pressure regulator installed on lower end of submersible electric motor. Two rows of intake holes are made in wall of cylinder of working piston pump at distance of 0.1 of length of working stroke of piston from its bottom dead center, summary area of holes is 1.5-2 times greater than area of cross section of piston. Intake holes are made in staggered order relative to each other. One more row of holes is made in lower part of cylinder in its wall below piston.

EFFECT: increased capacity owing to provision of delivery of pumped out medium into piston cylinder with lower hydraulic resistance.

2 cl, 1 dwg