SUBMERSIBLE ELECTRIC-HYDRAULIC DRIVE PLANT Russian patent published in 2003 - IPC

FIELD: oil producing industry. SUBSTANCE: invention is designed for marginal wells with complicated characteristics of oil stratum. Proposed plant contains submersible electric motor with hydraulic protection kinematically coupled with driven pump. Working pump is set into action by hydraulic motor. Plunger reciprocating motion mechanism of working pump contains power and return hydraulic cylinders connected by rods and made for changing over positions of hydraulic distributor at end of stroke of hydraulic motor rod. Mechanism connecting rods of hydraulic cylinders is made in form of hinge joints. Hydraulic drive compensator hydraulically coupled with drain main line of hydraulic drive is arranged in upper part of plant over working pump and is furnished with drain valve. Driven pump control unit is provided additionally with device to preclude reversing of electric motor shaft, made in form of check valve. Reliability of plant is increased by derating of driven pump of hydraulic drive and sealing elements of power hydraulic cylinder of hydraulic motor and protection of plant from thermal expansions of working liquid and reverse rotation of electric motor shaft. EFFECT: improved reliability of plant in operation. 3 cl, 1 dwg