Hydraulically operated fluid metering apparatus for use in a subterranean well

摘要

A hydraulically operated fluid metering apparatus (54, 56) provides discharge of a known volume of fluid to an actuator (22) of a well tool. In one described embodiment, the fluid metering apparatus (54, 56) is connected to a hydraulic input of a well tool actuator (22). Discharge of the known volume of fluid to the actuator input causes a piston (42) of the actuator to displace a known distance, thereby producing a known increment of actuation of the well tool. The discharge of the known volume of fluid may be repeated to produce a desired total degree of actuation of the well tool.