Abstract: A safety valve having a mono spring closure mechanism. The closure mechanism may be free of any spiral wound spring. The closure mechanism may include a spring having a beam which bends along its length to apply a biasing force to the closure member at its fully closed position and at its fully open position. The closure mechanism may include only a single spring, with the spring having at least two legs, the legs being joined to each other at an end of each leg, and each leg including at least one beam.

Abstract: Apparatus and methods are provided for actuation of downhole tools. In one example, a deep set safety valve uses a magnetic coupling which permits a portion of the safety valve at control line pressure to be isolated from tubing string internal pressure, without requiring the use of a dynamic seal therebetween. A piston of the safety valve may be displaced in response to a differential between control line pressure and pressure in an annulus surrounding the tubing string, pressure in another control line, or pressure in the tubing string. Other types of well tools may benefit from actuation using principles of the invention.

Abstract: A formation isolation valve for underbalanced drilling applications. A system for operating a formation isolation valve includes the valve interconnected in a casing string. An assembly displaces through the casing string, thereby causing the valve to open prior to the assembly reaching the valve. An operating system includes a well tool with an actuator positioned downhole. A device for causing the actuator to operate the well tool is also positioned downhole remote from the actuator. A method of operating a well tool includes the steps of: positioning the well tool in a well, the well tool including an actuator; positioning a power source for the actuator in the well; and at a downhole position remote from the actuator, causing the actuator to operate the well tool.

Abstract: A valve system for use in a subterranean well, the valve having multiple closure devices, or a closure device and a device for protecting the closure device. A valve system includes a valve with a closure assembly. The closure assembly has a closure device and a protective device which alters fluid flow through a flow passage of the valve prior to closure of the closure device to thereby protect the closure device. A safety valve system includes a safety valve with a closure assembly having at least two closure devices arranged in series for controlling flow through a flow passage of the safety valve. Another safety valve system includes a safety valve assembly including multiple safety valves arranged in parallel. One portion of fluid from a fluid source flows through one of the safety valves, while another portion of fluid from the fluid source flows through another safety valve.

Abstract: A safety valve with extension springs. In a described embodiment, a valve for use in a subterranean well includes a closure member having open and closed positions. A structure displaces to cause the closure member to displace between the open and closed positions. A biasing device has a length which decreases as the structure displaces to cause the closure member to displace toward the closed position.

Abstract: Apparatus and methods are provided for actuation of downhole tools. In one example, a deep set safety valve uses a magnetic coupling which permits a portion of the safety valve at control line pressure to be isolated from tubing string internal pressure, without requiring the use of a dynamic seal therebetween. A piston of the safety valve may be displaced in response to a differential between control line pressure and pressure in an annulus surrounding the tubing string, pressure in another control line, or pressure in the tubing string. Other types of well tools may benefit from actuation using principles of the invention.

Abstract: Apparatus and methods are provided for actuation of downhole tools. In one example, a deep set safety valve uses a magnetic coupling which permits a portion of the safety valve at control line pressure to be isolated from tubing string internal pressure, without requiring the use of a dynamic seal therebetween. A piston of the safety valve may be displaced in response to a differential between control line pressure and pressure in an annulus surrounding the tubing string, pressure in another control line, or pressure in the tubing string. Other types of well tools may benefit from actuation using principles of the invention.

Abstract: A safety valve having an extension spring closure mechanism. In a described embodiment, a valve for use in a subterranean well is provided which includes a biasing device and a closure member having open and closed positions. The biasing device has a length which decreases as the closure member displaces toward the closed position. The biasing device may be an extension spring.

Abstract: A lock assembly includes radially movable engagement or latch members configured to engage a profile within a subsurface nipple, and further includes one or more sealing assemblies. The sealing assemblies are radially expandable by enlarging the interior of diameter of the elements of the sealing assembly, such as by placing a mandrel of relatively enlarged diameter through an internal diameter of elements of the sealing assembly.