Patent ID: 6845958
Filing Date: 2005-01-25
Classification: E21B

Abstract:
1. An apparatus capable of resisting the flow of fluids through a bore, the apparatus comprising: at least one actuator assembly, the or each actuator assembly having a first and second end and being adapted to move between a first configuration wherein fluids are permitted to flow through the bore, and a second configuration wherein fluids are resisted from flowing through the bore, wherein the actuator assembly comprises a hydraulic fluid chamber and a well pressure chamber and wherein the first and second ends are each exposed to the pressure in the bore; wherein a locking member is provided to abut with a portion of the actuator assembly when it is in the second configuration in order to resist movement of the actuator assembly from the second configuration to the first configuration, wherein the portion of the actuator assembly is coupled to the rest of the actuator assembly at a location within the hydraulic fluid chamber.