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Surface controlled subsurface control valves for use in wells and methods of controlling the same. In one embodiment, a valve includes a valve body, a bore closure assembly, a mechanical linkage, a drive assembly, and a control assembly. The valve body defines a bore for fluid to flow through when t

Surface controlled subsurface control valves for use in wells and methods of controlling the same. In one embodiment, a valve includes a valve body, a bore closure assembly, a mechanical linkage, a drive assembly, and a control assembly. The valve body defines a bore for fluid to flow through when the bore closure assembly is in an open position. When the bore closure assembly is in its closed position, the bore closure assembly prevents fluid from flowing through the bore. The mechanical linkage is operatively connected to the bore closure assembly and to the drive assembly. The primary control assembly determines a force to apply to the mechanical linkage based on a present operating condition of the valve and causes the drive assembly to apply the determined force to the mechanical linkage. As a result, the mechanical linkage drives the bore closure assembly.

대표청구항 ▼

1. A surface controlled subsurface control valve for operating in a wellbore extending through a subterranean formation, the valve comprising: a valve body defining a bore for fluid to flow through;a bore closure assembly movable between an open position in which the bore closure assembly allows flu

1. A surface controlled subsurface control valve for operating in a wellbore extending through a subterranean formation, the valve comprising: a valve body defining a bore for fluid to flow through;a bore closure assembly movable between an open position in which the bore closure assembly allows fluid flow through the bore and a closed position in which the bore closure assembly prevents fluid flow through the bore;a mechanical linkage operatively coupled to the bore closure assembly;a rotary motor operatively coupled to the mechanical linkage; anda primary control assembly configured to vary the force applied to the bore closure assembly by the rotary motor, such that: during a first portion of movement of the bore closure assembly in a first direction, the rotary motor applies a first amount of force to the bore closure assembly, the first amount of force based on a first present operating condition; andduring a subsequent portion of movement of the bore closure assembly in the first direction, the rotary motor applies a second amount of force to the closure assembly, the second amount of force different than the first amount of force and applied by the rotary motor in the same direction as the first force and during movement of the bore closure assembly in the first direction, the second amount of force based on a second present operating condition. 2. The valve of claim 1, wherein at least one of the first or second present operating condition is at least one of a present bore closure assembly position between the open and closed positions, a present bore closure assembly position at the open or closed position, a fluid flow rate of fluid in the wellbore or valve, a wellbore or valve temperature, a fluid pressure in the wellbore or valve, a load on the rotary motor, a load on the mechanical linkage, a drive force exerted on the mechanical linkage, a drive force exerted on the bore closure assembly, a torque on the rotary motor, a speed of the rotary motor, a speed of the linkage assembly, a speed of the bore closure assembly, and a measured electrical load, current, resistance, or power associated with the rotary motor. 3. The valve of claim 1, wherein the bore closure assembly is selectively movable to incremental positions between the open and closed positions. 4. The valve of claim 1, wherein the second amount of force is greater than the first amount of force. 5. The valve of claim 1 further comprising a first and second sensing assembly operatively connected to the control assembly, the first and second sensing assembly for sensing the first and second present operating conditions. 6. The valve of claim 5, wherein the rotary motor is a component of a drive assembly, and wherein the second sensing assembly comprises a load sensing assembly operatively connected to the drive assembly to sense a load on the drive assembly. 7. The valve of claim 6, wherein the control assembly, in response to signals from at least one sensing assembly, varies the force applied to the mechanical linkage during movement of the mechanical linkage. 8. The valve of claim 7, wherein the rotary motor is electrically powered and wherein the primary control assembly varies the electrical power to the rotary motor. 9. The valve of claim 5, wherein the rotary motor is a stepper motor. 10. The valve of claim 9, wherein the stepper motor is operable to run at various step-rates and wherein the primary control assembly controls the step-rate of the stepper motor and varies the step-rate of the stepper motor in response to signals from at least one of the sensing assemblies. 11. The valve of claim 10, wherein one of the first and the second sensing assemblies comprise a resistance sensing assembly operatively connected to the stepper motor to sense the resistance to operation of the stepper motor. 12. The valve of claim 11, wherein the primary control assembly controls electric power to the stepper motor and wherein the primary control assembly varies the electric power to the stepper motor in response to the resistance sensing assembly. 13. The valve of claim 5, wherein the first or second sensing assemblies is for sensing a parameter of fluid flow rate, temperature, or pressure, each sensing assembly operatively connected to the primary control assembly. 14. The valve of claim 5, wherein the first sensing assembly comprises a plurality of sensors, each sensor operatively connected to the primary control assembly. 15. The valve of claim 5, wherein the second sensing assembly measures a fluid flow rate and wherein the control assembly, in response to the measured flow rate, varies the force applied to the bore closure assembly. 16. The valve of claim 1 further comprising a surface control assembly for controlling the valve, the primary control assembly communicating a first signal to the surface control assembly, the surface control assembly providing a response signal in response to the signal from the control assembly. 17. The valve of claim 16, wherein the primary control assembly emits a second signal to the surface control assembly upon a predetermined set of operating conditions, and wherein the surface control assembly emits control signals to control operation of the valve in response to the signals from the control assembly. 18. The valve of claim 16, wherein the primary control assembly emits further signals to the surface control assembly at predetermined time intervals, and wherein the surface control assembly emits control signals to control operation of the valve in response to the signals from the control assembly. 19. The valve of claim 1, wherein the primary control assembly is further configured to vary at least one of the rate of travel of a present bore closure assembly position, a fluid flow rate of fluid in the wellbore or valve, a wellbore or valve temperature, a fluid pressure in the wellbore or valve, a load on the rotary motor, a load on the mechanical linkage, a drive force exerted on the mechanical linkage, a drive force exerted on the bore closure assembly, a torque on the rotary motor, a speed of the rotary motor, a step rate of the rotary motor, a speed of the linkage assembly, a speed of the bore closure assembly, and a measured electrical load, current, resistance, or power associated with the rotary motor. 20. The valve of claim 1, wherein the primary control assembly is further configured to vary the speed of the bore closure assembly when the valve is proximate a fully closed or a fully open position. 21. The valve of claim 1, wherein the motor speed or torque is optimized such that rotary motor outputs are synchronized with load on the rotary motor. 22. The valve of claim 1, wherein the rotary motor is bi-directional. 23. A method of controlling a surface controlled subsurface control valve for use in a subterranean well, the method comprising: sensing a first present operating condition of the valve, the valve including: a valve body defining a bore for fluid to flow through,a bore closure assembly movable between an open position in which the bore closure assembly allows fluid flow through the bore and a closed position in which the bore closure assembly prevents fluid flow through the bore, anda rotary motor operatively coupled to the bore closure assembly to drive the bore closure assembly;applying a first force to the bore closure assembly by the rotary motor based on the first sensed operating condition;moving the bore closure assembly in a first direction in response to the applied first force;sensing a second present operating condition of the valve; andvarying the force applied to the bore assembly by the rotary motor based on the second present operating condition.