| 摘要 |
A hydraulically actuated bore or well pump in which a driving unit (1) at the bore or well surface comprises interconnected pistons (6 and 7) arranged to hydraulically actuate a slave piston (27) in a submerged well or bore unit (2) through a hydraulic pressure line (40) and a pump delivery line (42). The driving unit (1), being double-acting, imparts both pumping and return movement to the slave piston (27) and a coupled pumping piston (28) as the driving unit (1) is reciprocated. A valve (50) in the pump delivery line (42) allows outflow from the pump during the pumping stroke and also allows the pump delivery line (42) to be pressurised by the driving unit (1) for the return stroke of the coupled slave and pump pistons (27, 28). A controlled hydraulic drive motor (13) is preferred for actuating the driving unit (1). |
