| 摘要 |
<p>Electrohydraulic actuators and associated methods are utilized to control the operation of downhole well tool assemblies, representatively flow control devices. In the described embodiment thereof, each actuator (36) is positioned downhole and comprises a self-contained, closed circuit hydraulic system including an electrically operable double action primary pump (58) drivingly coupled to an associated well tool assembly (36) via a first hydraulic circuit, and an electrically operable switching pump (60) coupled to the first hydraulic circuit via a second hydraulic circuit interposed therein and operative to selectively alter the control flow of hydraulic fluid to the well tool assembly in a manner reversing its operation. To provide for selective, more rapid control of the well tool assembly, a chargeable accumulator (108) is connected to the hydraulic circuitry and is selectively and drivably communicatable with the well tool assembly.</p> |
