Abstract: A pressure equalization apparatus can include separate longitudinal bores which form a continuous flowpath, the flowpath alternating direction between the bores, and the bores being interconnected at opposite ends thereof. A well system can include a well tool with a chamber therein containing an assembly in a dielectric fluid, and a pressure equalization apparatus including a flowpath having one end connected to the chamber, and the other end connected to a source of a another fluid, the flowpath extending in opposite directions between the flowpath ends through multiple separate bores. A method of installing a well tool can include attaching a mandrel to the well tool, then lowering the well tool at least partially into the well suspended from the mandrel, and then securing a pressure equalization apparatus to the mandrel, a flowpath of the apparatus being connected to a chamber of the well tool containing an assembly.

Abstract: A method of actuating multiple valves in a well can include applying a pressure cycle to the valves without causing actuation of any of the valves, and then simultaneously reducing pressure applied to the valves, thereby actuating the valves. Another method can include releasing a locking device of each valve which prevents actuation, and then reducing pressure applied to the valves, thereby actuating the valves. A valve can include a port which provides for fluid communication between an exterior and an interior of the valve, a closure member which selectively permits and prevents fluid flow through the port, the closure member permits flow through the port in response to a decrease in a pressure differential from the interior to the exterior of the valve, and a locking device which prevents displacement of the closure member, the locking device being released in response to mechanical force applied to the locking device.

Abstract: In an embodiment, a work string for downhole use in a well comprises a safety valve comprising a sealable flow path; a first electrical connection disposed above the safety valve; a second electrical connection disposed below the safety valve; and a jumper electrically coupling the first electrical connection and the second electrical connection, wherein the jumper does not pass through the sealable flow path of the safety valve.

Abstract: A safety valve with a flapper/flow tube friction reducer. A safety valve for use in a subterranean well includes a closure assembly, an operating member which engages the closure assembly, and at least one of the closure assembly and the operating member including a friction reducing device which provides rolling contact between the closure assembly and the operating member. Another safety valve includes a flapper which rotates about a pivot relative to a seat, a flow tube which engages the flapper to rotate the flapper, and a friction reducing device which with rolling contact biases the flow tube toward the pivot when the flow tube engages the flapper. Yet another safety valve is described in which at least one of the flapper, the seat and the flow tube has a friction reducing device attached thereto which provides rolling contact between the flapper and the flow tube, or between the flow tube and the seat.

Abstract: Electrically operated well tools. A well system includes a well tool positioned in a wellbore. The well tool includes an actuator and an operating member displaceable to operate the well tool. The actuator includes a series of longitudinally distributed electromagnets, in which current is controllable in a predetermined pattern to thereby variably control longitudinal displacement of the operating member. In another well system, the operating member is displaceable between opposite maximum limits of displacement to operate the well tool, and an electromagnet is operative to displace the operating member to at least one position between the opposite maximum limits of displacement. In a method of operating a well tool, the well tool is operated by controlling current in a series of longitudinally distributed electromagnets of an actuator in a predetermined pattern, thereby causing corresponding longitudinal displacement of an operating member.

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 plug is provided for use in well plugging applications. In a described embodiment, the plug has a metal to metal seal on a hollow spherical structure. A change in contact pressure between the seal and a bore due to a change in differential pressure across the plug is regulated by changing characteristics of the plug structure.

Abstract: A plug is provided for use in conjunction with a subterranean well. In a described embodiment, a wellhead plug includes multiple outwardly extendable lugs for engagement with corresponding multiple oppositely facing shoulders formed internally on a bore extending in a wellhead. The lugs engage the shoulders to thereby resist pressure applied to the plug in the bore from above or below.

Abstract: A plug is provided which is specially adapted for statically setting a plug portion within an internal profile formed in a wellhead. In an illustrated preferred embodiment, the plug portion is set by application of fluid pressure to a running tool portion. When set in the profile, the plug portion is secured statically relative to the profile, thereby permitting advantageous utilization of a metal-to-metal seal on the plug portion. The plug portion includes features which maintain its set configuration in the profile. The running tool portion includes multiple pistons which enhance operation of the running tool portion. A disclosed verification tool provides an indication that the plug portion has been properly set.