Wellbore system having an annulus safety valve
AssigneeSilverwell Technology Limited
InventorJoel David Shaw
Life of this patent
Estimating the term…
Abstract
An annulus safety valve assembly for controlling gas flow in a wellbore annulus that includes a passage, a check valve in the passage, and an actuator that is selectively changed between first and second states. The actuator is bi-stable, and requires no energy to remain in either state. When the actuator is put into one of the states, the check valve configuration is changed from one way flow to two way flow. Reconfiguring the check valve into the two way flow configuration vents lift gas from inside the annulus that is below the check valve.
Claims12
A system for use with a wellbore comprising:
- an annulus defined between tubulars disposed in the wellbore;
- and
- an annulus safety valve disposed in the annulus that comprises,
- a body,
- a bistable actuator comprising an electrically powered motor and a shaft coupled with the motor, the bistable actuator being selectively changeable between deployed and retracted operational states, and
- a check valve comprising a valve member, a valve seat, and a spring biasing the valve member against the seat, the check valve being maintained in an open position by interfering contact with the shaft when the bistable actuator is in the deployed operational state, and the check valve in a closed position when the actuator is in the retracted operational state and the shaft is spaced away from the check valve.
A method of operating a wellbore comprising:
- handling lift gas in an annulus of the wellbore in which an annulus safety valve is disposed and that comprises
- a body,
- a passage in the body,
- a check valve in the passage that comprises a spring and a valve member, the spring biasing the valve member against a valve seat to automatically put the check valve into a closed position when pressure downhole of the check valve exceeds pressure uphole of the check valve, and
- an actuator;
- venting from the wellbore by providing a supply of electricity to the actuator to change the actuator from a retracted configuration to a deployed configuration which biases the check valve into an open position;
- reconfiguring the actuator from the deployed operational configuration to the retracted operational configuration by energizing the actuator,
- removing the supply of electricity to the actuator;
- and
- maintaining the actuator in the deployed configuration while the actuator is isolated from a power source.
Dependencies are inferred from the claim text.