OIL-WELL ELECTROHYDRAULIC PUMPING UNIT Russian patent published in 2004 - IPC

FIELD: oil producing industry.

SUBSTANCE: invention relates to pumping units designed for lifting liquids from depth, for instance, oil from wells. Proposed oil well electrohydraulic pumping unit contains oil pump with drive from submersible electric motor with compensator, working piston pump with piston cylinder, suction valve arranged in piston and delivery valve, and hydraulic motor for driving working piston pump. Spaces of hydraulic motor cylinder are connected through oil distributor with input and, through safety valve, with output of oil pump. Rod of hydraulic motor piston is connected through protector with piston of working piston pump. Unit is furnished with oil tank with its volume compensator. Overflow valve, flowmeter and filter are installed in one section of oil tank. Hydraulic motor is furnished with piston travel limiter with line distributor. Working piston pump has bypass line; additional piston cylinder with additional piston and suction spring-loaded valve installed in additional piston. Additional piston is rigidly connected with piston of working piston pump located lower by means of intermediate rod. Spaces of piston cylinders are divided by spool of pumped out medium distributor. Two of holes are made in wall of pumped out medium distributor. Said holes are used to communicate working spaces of pump with bypass main line formed by envelope enclosing both piston cylinders from outer side. Bypass main line is provided with distributing valve located between rows of holes of pumped out medium distributor and it is connected to delivery valve higher than additional piston cylinder.

EFFECT: increased capacity owing to provision of delivery of pumped out medium to consumer during back "idle" stroke of pump piston.

2 dwg