HYDRAULIC DRIVE FOR DEEP-WELL SUCKER-ROD PUMP Russian patent published in 1998 - IPC

FIELD: oil field equipment. SUBSTANCE: hydraulic drive includes hydraulic cylinder mounted on rigid bearing plate. Working load is transmitted to plate by means of movable carriage connected with rod of hydraulic cylinder through hinge and with sucker rod string through flexible rod. Hydraulic cylinder is mounted with rod outlet vertically upward; cavity of rod outlet is under low pressure and is connected with working fluid reservoir. Under-piston cavity of hydraulic cylinder which is under high pressure is tightly connected with delivery line whose volume is low. Such arrangement of hydraulic cylinder practically fully eliminates leakage of working fluid. Upright- pyramid is made from pipes whose interior is also used for working fluid and for performing function of heat exchanger for cooling the working fluid and keeping its temperature at required level. EFFECT: enhanced efficiency. 2 cl, 1 dwg