Patent ID: 7766088
Filing Date: 2010-08-03
Classification: E21B

Abstract:
1. A method for actuating a wellbore tool, comprising: conveying the wellbore tool and an actuator into a wellbore using a tubular, the actuator being operatively coupled to the wellbore tool, wherein the actuator includes a first pressure chamber adapted to generate a motive force for activating the actuator and a second pressure chamber adapted to generate a resistive force for resisting the activation of the actuator; generating the resistive force at least partially using an applied pressure of a fluid in the wellbore; isolating the first pressure chamber from the second pressure chamber using an occlusion member; activating the actuator by increasing an applied pressure uphole of the occlusion member while the second pressure chamber is in communication with a fluid downhole of the occlusion member; and increasing the pressure uphole of the occlusion member to displace the occlusion member.