| 摘要 |
<p>A hydraulic actuator is connected between a downhole tool and a hydraulic control line for operating the downhole tool through an actuation sequence. The hydraulic actuator comprises a valve shuttle section having an inlet port in connection with the hydraulic control line, a first function port and a second function port. The hydraulic actuator also has a shuttle movable between positions providing fluid communication between the inlet port and the first function port and the inlet port and the second function port. Additionally, the hydraulic actuator has a pilot assembly in fluid connection with the hydraulic control line and in operational connection with the shuttle. The pilot assembly is movable in response to an actuation cycle comprising applying pressure from the hydraulic control line and bleeding the pressure off.</p> |
