Ball Screw and Electric Brake for a Tubing-Retrievable Safety Valve

Safety valves are installed in wellbores to prevent uncontrolled release of reservoir fluids. Safety valves are typically hydraulically actuated and may be tubing-retrievable. These are typically “fail safe,” meaning that the default unactuated configuration is in a closed position to thereby ensure that in the event of failure, the safety valve closes. Due to environmental concerns, the oil and gas industry has seen a recent shift away from using hydraulically actuated safety valves in favor of using electrically actuated safety valves.

Disclosed herein are systems and methods for regulating the flow of production fluids through wellbores and, more particularly, disclosed are safety valves having an opened and a fail-safe configuration. More particularly, disclosed are safety valves which may include a sliding assembly having an electric brake.

As mentioned, the oil and gas industry has seen a shift away from using hydraulic actuated safety valves in favor of electrically actuated safety valves. One problem associated with some electrically actuated safety valves using electromagnets to hold the valve open is that scale and debris may build up, for example, between an electromagnet and its target. Since the magnetic force of an electromagnet is inversely proportional to the square of the distance between it and its target, built-up debris or scale may significantly hamper the magnet's hold force capability.

The present disclosure may provide a hybrid configuration that involves both a hydraulic piston and an electric brake. This may have the benefit of bypassing the challenges associated with using an electromagnet and target while still allowing the safety valve to be electrically controlled. Specifically, the safety valve may have a sliding assembly that uses a hydraulic piston to open the safety valve but uses an electric brake to hold open the safety valve so that in the event of power loss, the safety valve reverts to the closed fail-safe position. Generally, hydraulic pressure is not utilized to maintain the sliding assembly and thus the safety valve in the open position.

Other advantages may include, without limitation, a reduction in the amount of hydraulic fluid needed to achieve and maintain the open position for the safety valve and thus decreased risk of leaking hydraulic fluid into the formation, greater downhole reliability than safety valves that use only an electromagnet to open and maintain the open position. Another advantage may include the ability to exhaust hydraulic control fluid after a safety valve is open when an electric brake (e.g., electric brakeof) is engaged, which in addition to reducing stress on one or more components of the safety valve, may result in a reduction in overall stress on a hydraulic control system, in general.

is a schematic of an example wellbore environment. Wellbore environmentmay include platformthat supports derrickhaving a traveling blockfor raising and lowering top driveand tool string. Top drivesupports and rotates the tool string as it is lowered through wellhead. In turn, drill bit, located at the end of tool string, may create wellbore. Each of these components is described below.

Platformis a structure which may be used to support one or more other components of wellbore environment(e.g., derrick). Platformmay be designed and constructed from suitable materials which are able to withstand the forces applied by other components (e.g., the weight and counterforces experienced by derrick). In any embodiment, platformmay be constructed to provide a uniform surface for wellbore completions operations in wellbore environment.

Derrickis a structure which may support, contain, and/or otherwise facilitate the operation of one or more pieces of the wellbore completions equipment. In any embodiment, derrickmay provide support for crown block, traveling block, and/or any part connected to (and including) tool string. Derrickmay be constructed from any suitable materials (e.g., steel) to provide the strength necessary to support those components.

Crown blockis one or more simple machine(s) which may be rigidly affixed to derrickand include a set of pulleys (e.g., a “block”), threaded (e.g., “reeved”) with a line (e.g., a steel cable), to provide mechanical advantage. Crown blockmay be disposed vertically above traveling block, where traveling blockis threaded with the same line.

Traveling blockis one or more simple machine(s) which may be movably affixed to derrickand include a set of pulleys, threaded with a line, to provide mechanical advantage. Traveling blockmay be disposed vertically below crown block, where crown blockis threaded with the same line. In any embodiment, traveling blockmay be mechanically coupled to a tool string (e.g., via top drive) and allow for a tool string (and/or any component thereof) to be lifted from (and out of) wellbore. Both crown blockand traveling blockmay use a series of parallel pulleys (e.g., in a “block and tackle” arrangement) to achieve significant mechanical advantage, allowing for the tool string to handle greater loads (compared to a configuration that uses non-parallel tension). Traveling blockmay move vertically (e.g., up, down) within derrickvia the extension and retraction of the line.

Top driveis a machine which may be configured to, e.g., rotate tool string. Top drivemay be affixed to traveling blockand configured to move vertically within derrick(e.g., along with traveling block). In any embodiment, the rotation of tool string (caused by top drive) may allow for tool string to carve wellbore. Top drivemay use one or more motor(s) and gearing mechanism(s) to cause rotations of tool string. In any embodiment, a rotatory table (not shown) and a “Kelly” drive (not shown) may be used in addition to, or instead of, top drive.

Wellheadis a machine which may include one or more pipes, caps, and/or valves to provide pressure control for contents within wellbore(e.g., when fluidly connected to a well (not shown)). In any embodiment, during drilling, wellheadmay be equipped with a blowout preventer (not shown) to prevent the flow of higher-pressure fluids (in wellbore) from escaping to the surface in an uncontrolled manner. Wellheadmay be equipped with other ports and/or sensors to monitor pressures within wellboreand/or otherwise facilitate drilling operations.

Wellboreis a hole in the ground which may be formed by a tool string (and one or more components thereof). Wellboremay be partially or fully lined with casing. As illustrated, a wellboremay be vertical, horizontal, angled, or have any number of vertical, horizontal, or angled sections.

Casingis concrete and/or metal lining that separates wellborefrom the surrounding ground. Casingmay be used to protect the surrounding ground from the contents of wellbore, and conversely, to protect wellborefrom the surrounding ground.

Safety valveis a downhole device that prevents production mishaps that could occur with the producing well. There are various types of safety valves, including for example, surface-controlled subsurface safety valves, tubing-retrievable subsurface safety valves, wireline-retrievable safety valves, flapper-type wireline-retrievable safety valves, injection safety valves, flapper-type injection valves, annular safety valves, and the like.

Systems and methods of the present disclosure may be implemented, at least in part, with information handling system. Information handling systemmay include any instrumentality or aggregate of instrumentalities operable to compute, estimate, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling systemmay be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. Information handling systemmay include random access memory (RAM), one or more processing resources such as a central processing unit (CPU)or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling systemmay include one or more disk drives, one or more network ports for communication with external devices as well as an input device (e.g., keyboard, mouse, etc.) and output devices, such as a video display. Information handling systemmay also include one or more buses operable to transmit communications between the various hardware components.

Alternatively, systems and methods of the present disclosure may be implemented, at least in part, with non-transitory computer-readable media. Non-transitory computer-readable mediamay include any instrumentality or aggregation of instrumentalities that may retain data and/or instructions for a period of time. Non-transitory computer-readable mediamay include, for example, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk drive), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, RAM, ROM, electrically erasable programmable read-only memory (EEPROM), and/or flash memory; as well as communications media such wires, optical fibers, microwaves, radio waves, and other electromagnetic and/or optical carriers; and/or any combination of the foregoing.

As illustrated, communication link(which may be wired or wireless, for example) may be provided that may transmit data (e.g., instructions to open or close safety valve, sensor measurements, etc.) between wellbore environmentand information handling system. Information handling systemmay include a central processing unit, a video display, an input device, and/or non-transitory computer-readable media(e.g., optical disks, magnetic disks, etc.) that may store code representative of the methods described herein. In addition to, or in place of processing at surface, processing may occur downhole. However, in some examples, a safety valve (e.g., safety valve) may comprise simple ON-OFF devices that do not need sophisticated electronics, but may function based on, e.g., simple energizing and de-energizing of the safety valve.

is a schematic of a safety valvethat includes an actuator sectionin an open position, in accordance with some embodiments of the present disclosure. Actuator sectionmay comprise a piston, ball nut, and ball screw, to be discussed and later figures (e.g., referring to). Additionally, an actuator sectionmay comprise an electric brake (e.g., electric brakeof any of) that includes an electromagnet and a target, to be discussed. In examples, actuator sectionmay serve to open and close off flow across a valve. This figure also shows nose springand power springas well as valve. An electric brake (e.g., electric brakeof), or plurality thereof, may be disposed in any suitable region, such as within actuator sectionor in the region of safety valveindicated at, and may comprise an electromagnet and a target, to be discussed later (e.g., referring to). One or more of these may be coupled with one or more gear boxes, to be discussed later (e.g., referring to). Where used, an electromagnet may include a magnetized or magnetizable material such as one or more rare earth elements.

is a schematic of an electromagnet structureof a safety valvein a closed position, in accordance with some embodiments of the present disclosure. As illustrated, an electromagnet structuremay comprise an electromagnetwhich may be, for example, concentrically disposed about a slidable memberhaving a borealong an axis indicated at. In the closed position, an upward flow of fluidthrough boreis stopped by a flapper valve. A targetmay be spaced away from electromagnetin the closed and unenergized position, as shown, and may thus be separated by a distance. Lower and upper regions,are thus not in fluid communication in the closed position. This is but one example configuration of an electromagnetic structure.is a schematic of the electromagnet structureofbut in an open and energized position, in accordance with some embodiments of the present disclosure. As illustrated, in the open position, fluidis free to flow through bore. Accordingly, fluidmay flow to thereby allow fluid communication between lower regionand upper region. In the open position, targetis attracted to electromagnetwhen electromagnet structureis powered, which thereby axially translates the slidable memberdownward by distance. Other designs are possible, such as electromagnetnot being concentrically disposed about slidable member, or with the inducement of linear movement comprising using a magnetic flux to push rather than pull slidable memberto an open configuration, for example. As mentioned, one disadvantage of safety valves that use only an electromagnet structure, e.g., without hydraulic pistonof later figures, is that debris such as scale can build up overtime between electromagnetand target, such as at the region schematically indicated at, reducing or defeating the effectiveness of the safety valve, especially ones using small magnets. Advantageously, incorporating a design that uses a hydraulic piston, ball screw, ball nut, and electric brake, in accordance with one or more embodiments of the present disclosure, addresses this and associated problems.

Accordingly,is a schematic of a sliding assemblybeing used within a safety valve, in accordance with some embodiments of the present disclosure. Sliding assemblymay be disposed within bodyof safety valve, such as part of an actuator section(e.g., referring to). Safety valvemay comprise any suitable type of safety valve, but in this example comprises tubing retrievable safety valve that includes a flow tube, a nose spring, and a power spring. An arrow atindicates the up-hole direction that production fluids of a producing formation may flow when the safety valveis open. Sliding assemblycomprises a hydraulic pistondisposed within a piston housing, a ball nutthat travels axially along a ball screw, and an electric brakethat may comprise, e.g., an electromagnet and a target (analogous to what is shown above in, to be discussed in greater detail in). This design addresses the problems that may be associated with only using an electromagnet structure(e.g., referring to). It should be understood that while these Figures show sliding assemblycomprising a hydraulic pistonattached to a ball nutattached to slidable member, these three components may be rearranged and fixedly attached in any order. For example, hydraulic pistonmay be attached to slidable memberwhich may in turn be attached to ball nut, to use a non-limiting example.

Piston housinghouses a hydraulic piston. Actuation of hydraulic pistonwith a hydraulic pressure of a hydraulic flow line induces hydraulic pistonto extend out from piston housingby a distance (e.g., distanceof). Hydraulic pistonmay be fixedly attached to a ball nutwhich is in turn fixedly attached to slidable member. Actuation of hydraulic pistonmay thus move ball nutaxially along ball screwto thereby induce the desired axial movement of slidable member, e.g., along a central axis of safety valve. A hydraulic flowline may use high pressure below a downhole valve (e.g., flapper valveof) to actuate hydraulic piston, such as via one or more internal conduits (not shown) that allow for fluid communication between a region below the valve and the hydraulic piston. Alternatively, hydraulic pressure may be supplied in any standard fashion, such as with a hydraulic line that is run from the surface.

Ball nutmay be concentrically disposed about a ball screw. Ball nutmay comprise an inner surface with corresponding threads that match the dimensions of ball screwto allow for rotation of the ball screw. In examples, ball nutmay be fixedly attached to slidable member, e.g., at a tubular surface, or in any suitable fashion. Mechanical coupling may be achieved in any suitable fashion, such as with welding, screws, etc. In any embodiment, linear movement of ball nutalong ball screwmay induce parallel movement of slidable member, and vice versa. The purpose of ball nutis to allow hydraulic pistonto energetically communicate with electric brakeby converting the linear movement to rotation via ball screw.

Ball screwmay freely rotate relative to ball nut. Ball screwis threaded such that when ball nutis moved axially by hydraulic piston, the axial movement causes ball screwto rotate. Ball screwis energetically and/or mechanically coupled to electric brakesuch that energizing electric brakeresists or prevents reversal of the linear movement induced by re-expansion of the compressed power spring.

Hydraulic pistoncomprises a single, or multiple, pistons that are hydraulically powered by a supply of pressurized hydraulic fluid. In this example, hydraulic pistonis fixedly attached to a ball nutso that hydraulic actuation induces linear movement of both hydraulic pistonand ball nuttogether. A connectionmay be any suitable mechanical or other connection such as welding, screws, or the like. Other connections may be likewise disposed at one or more locations within bodyto fixedly secure one or more components of a sliding assemblyrelative to bodyor slidable member. Hydraulic pistonand ball nutmay unitarily form a single continuous member, for example. Alternatively, rather than being mechanically coupled directly to ball nut, hydraulic pistonmay be instead configured to push and/or pull on ball nutor a piece fixedly attached thereto, for example.

Linear actuation of ball nutalong ball screwmay thus induce rotation of ball screw. Counter-rotation of ball screwis controlled by an electric brakethat is in electric communication with a power source via an electric line. A power source may be disposed at the surface(e.g., referring to) or at a downhole location to supply power to electric braketo generate magnetic flux needed to hold safety valveopen (e.g., magnetic fluxof).

Electric brakeis mechanically or otherwise energetically coupled to ball screw. When electric brake is powered, it may resist or halt the rotation of ball screw(e.g., by forcing teethofand therefore lock rotation) and thus control or prevent linear movement of ball nutand thus prevent reverse sliding of slidable member. (Prongmay be fixedly connected to, or in mechanical communication with, e.g., “coupled to,” or unitarily formed as part of, ball screw). Electric braketurns ON when power is applied to it and turns OFF when power is removed. Applying power energizes a coil, which may cause a magnet body (e.g., magnet structureof) to attract an armature (e.g., armatureof), to be discussed later (e.g., referring to). In some examples, an electric brakemay be configured with a compression spring (e.g., compression springof) that upon removal of power, may cause the armature to disengage from the magnet body. This may allow sliding assemblyto hold slidable memberin a specific position that allows production fluids to flow uphole through the safety valve. Electric brakemay be configured with a gear box, to be discussed in a later figure (e.g., gear boxof). Various designs of electric brakes are available, such as the example shown in, however in general, electric brakemay be configured to produce a magnetic flux that resists or prevents, a change in position of a magnet relative to a target. As it applies to this figure, this change in position may be used to resist reversal of the linear movement induced by hydraulic piston. Moreover, while only a single electric brake is shown, multiple electric brakes may be used, as well as multiple ball screws, ball nuts, gear boxes, etc., which may all be part of a single, or multiple, sliding assemblies, in some examples.

To prevent shearing between the various components (e.g., connection) of sliding assembly, hydraulic actuation of hydraulic pistonmay induce a rotation of ball screwin a first direction (e.g., clockwise only), whereas electric brakeresists rotation in a second direction (e.g., counterclockwise only) opposite from the first direction. Electric brakemay thus be configured to oppose an upwards biasing force of power springof, and this is achieved without the need to resist rotation of the ball screw during initial actuation of hydraulic pistonfrom the non-extended () to extended () position.

Flow tubeand slidable memberare coupled together (e.g., by nose spring, only) which may allow slidable memberto translate relative to a flow tubeif nose springcompresses or relaxes. This may result in the linear movement induced by actuation of hydraulic pistonto also cause linear movement of slidable memberalong a central axis of safety valve. In the present example, flow tubeis partially disposed within slidable memberbut may alternatively be disposed within flow tubeso that the linear movement induced by hydraulic actuation causes slidable memberto slide with flow tube. In the figure shown, part of slidable memberis shown concentrically disposed about flow tubeso that a force applied by hydraulic pistonis applied to nose springvia a shoulderof slidable member. In addition, force applied by hydraulic pistonmay be applied to power springvia shouldervia an additional concentric memberdisposed, e.g., between slidable memberand shoulder. During opening of safety valve, hydraulic pressure of a hydraulic pistonmay oppose or counteract a spring force of nose springand/or power spring.

Power springis seated against respective shoulderto provide an outward biasing force thereto so that when, for example, power is cut to electric brake, slidable memberis forced back to a closed position so that flow of production fluid is stopped. In some examples, safety valveis configured to change between a first closed position, a second closed position, and an open position, which may involve sliding a conduit (e.g., flow tube) to open a valve, such as a flapper valve (e.g., valveof).

Sliding assemblyand other components of safety valve, e.g., flow tube, power spring, and nose spring, slidable member, etc., may be housed by bodyof safety valve. In alternative examples, sliding assemblymay be housed in a separate compartment or module disposed, for example, within body. In another alternative embodiment, sliding assemblymay be alternatively configured so that slidable memberis translated axially upwards, such as by positioning a spring (e.g., power springand nose springof) uphole from the sliding assemblyinstead of downhole as shown by.

is a schematic of sliding assemblyin a non-extended position, in accordance with some embodiments of the present disclosure. A sliding assemblymay include a piston housingand hydraulic piston, ball nut, and ball screw. In some examples, a safety valvethat includes a sliding assemblymay be characterized as “hybrid” in that it may be both electrically and hydraulically actuated. Sliding assemblyis configured to induce linear movement to a slidable memberwith hydraulic pistonaxially, e.g., along an axis of safety valve. An electric brakecontrols or resists reversal of the linear movement to maintain the slidable memberin a locked position while the electric brakeis powered.

Piston housinghouses a hydraulic piston. Actuation of hydraulic pistonwith a hydraulic pressure of a hydraulic flowlinemay cause hydraulic pistonto extend out from piston housingby a distance (e.g., distanceof). Hydraulic pistonmay be fixedly attached to a ball nut which is in turn fixedly attached to slidable member. Actuation of hydraulic pistonmay thus move ball nutaxially along ball screwto thereby induce the desired axial movement of slidable member. As discussed, hydraulic flowlineuses high pressure below a downhole valve (e.g., flapper valveof) to actuate hydraulic piston, such as via one or more internal conduits (not shown) that allow for fluid communication between a region below the valve and the hydraulic piston. Alternatively, hydraulic pressure may be supplied via hydraulic flowlinein any standard fashion.

Ball screwmay extend, for example, between a pair of endswhich may allow for free rotation of ball screw. Endsmay be, for example, metal housing or other compatible structure that provides a structure within which ball screwfreely rotates and may be disposed on either side of ball screw. Ball screwis threaded such that when ball nutis moved axially by hydraulic piston, the axial movement causes ball screwto rotate. Ball screwis energetically and/or mechanically coupled to electric brakesuch that energizing electric brakeresists or prevents reversal of the linear movement that would be induced by the power spring if not for electric brake.

Hydraulic pistoncomprises a single, or multiple, pistons that are hydraulically powered by a supply of pressurized hydraulic fluid of flowline. In this example, hydraulic pistonis fixedly attached to a ball nutso that hydraulic actuation induces linear movement of both hydraulic pistonand ball nuttogether. A connectionmay be any suitable mechanical or other connection such as welding, screws, or the like. Other connectionsmay be likewise disposed at one or more locations within bodyto fixedly secure one or more components of a sliding assemblyrelative to bodyor slidable member. Hydraulic pistonand ball nutmay unitarily form a single continuous member, for example. Alternatively, hydraulic pistonmay be configured to push and/or pull on ball nutor a piece fixedly attached thereto, for example.

Ball nutmay be concentrically disposed about a ball screw. Ball nutmay comprise an inner surface with corresponding threads that match the dimensions of ball screwto allow for sliding engagement between these. In examples, ball nutmay be fixedly attached to slidable member, e.g., at a tubular surface, or in any suitable fashion. In any embodiment, linear movement of ball nutalong ball screwmay induce parallel movement of slidable member, and vice versa. The purpose of ball nutis to allow hydraulic pistonto energetically communicate with electric brakeby converting the linear movement to rotation via ball screw.

Linear actuation of ball nutalong ball screwmay thus induce rotation of ball screwbetween, for example, two endsCounter-rotation of ball screwis controlled by an electric brakethat is in electric communication with a power source via an electric line. A power source may be disposed at the surface(e.g., referring to) or at a downhole location to supply power to electric braketo generate magnetic flux needed to hold safety valveopen (e.g., magnetic fluxof).

Electric brakeis mechanically or otherwise energetically coupled to ball screwvia a prong (e.g., prongof). When electric brakeis powered, it may resist or halt the rotation of ball screw(e.g., by forcing teethofand therefore lock rotation) and thus control or prevent linear movement of ball nutand thus prevent reverse sliding of slidable member. This may allow sliding assemblyto hold slidable memberin a specific position that allows production fluids to flow uphole through the safety valve. Electric brakemay be configured with a gear box, to be discussed in a later figure (e.g., gear boxof). Various designs of electric brakes are available, such as the example shown in, however in general, electric brakemay be configured to produce a magnetic flux that induces a change in position. As it applies to this figure, this change in position may be used to resist reversal of the linear movement induced by hydraulic piston, for example. Moreover, while only a single electric brake is shown, multiple electric brakes may be used, as well as multiple ball screws, ball nuts, etc., which may all be part of a single sliding assembly, in some examples.

To prevent shearing between the various components (e.g., connection) of sliding assembly, hydraulic actuation of hydraulic pistonmay induce a rotation in a first direction (e.g., clockwise only), whereas electric brakeresists rotation in a second direction (e.g., counterclockwise only) opposite from the first direction. Electric brakemay thus be configured to apply counter torque in a first direction that opposes an upwards biasing force (e.g., of a nose springor power springof) without counteracting the rotation induced during initial actuation of hydraulic piston.

is a schematic of the sliding assemblyof, but in an extended position, in accordance with some embodiments of the present disclosure. As illustrated, slidable memberis translated axially downwards by a distancerelative to the sliding assemblyof. Translation of slidable memberby distancemay open or be concurrent with the opening of one or more fluid conduits or otherwise allow fluid communication of production fluids between a lower regionand an upper regionacross safety valve. Electric brakeengages ball screwto maintain the ball nutand thus slidable memberin the extended open position to enable fluid flow through safety valveas long as electric brakeis powered.

As illustrated, hydraulic pistonis extended out from piston housingby distance. Ball nutis also axially translated downwards by the distance. Ball screwis also rotated relative to. Electric brakeand piston housingare in the same position as in, as are ends,Thus, hydraulic actuation of hydraulic pistonwith hydraulic flow linemay induce linear movement of not only hydraulic pistonbut also ball nutand slidable membertogether as a single body or structure. This may be achieved without inducing any linear movement to the electric brake, piston housing, or ball screwalong a central axis of safety valve, e.g., by virtue of connections.

Hydraulic pistonis extended out from piston housing by distance. Ball nutis axially lowered by the actuation distance, as is slidable member. Even as hydraulic pressure supplied to hydraulic pistonis bled off, electric brakemay hold slidable memberin the actuated position to keep safety valvein the open position.

In some examples, piston housingmay be directly or indirectly attached to a bodyof safety valve. Mechanical coupling between one or more components of sliding assemblymay result in the non-moving parts to be unaffected by the linear movement of the moving parts.

In some examples, ball screwand ball nutmay be contained in a clean fluid and isolated from production fluids. This may prevent debris from clogging sliding assembly. A clean fluid may comprise, for example, hydraulic fluids, atmospheric air, vacuum, or the like. Electric brakemay similarly be isolated from production fluids. Clean fluid may be under pressure, pressurized, or pressure compensated to match a wellbore environment. This may help prevent unwanted fluids from encroaching into sliding assembly. Pressure compensation may be achieved, for example, by disposing one or more (e.g., hydraulic piston, piston housing, ball nut, ball screw, electric brake, and any combination thereof) the various components (and/or their associated connections, e.g., connections,) of a sliding assemblywithin a pressure sealed housing (not shown), and monitoring and controlling fluid pressure within such a housing based on at least one pressure outside the housing (e.g., wellbore pressure, pressure from another region or subregion of safety valve, pressure from either side of a flapper valve, etc.). Pressure compensation and equalization may be achieved using a rubber diaphragm or metal bellows, for example. Where used, a rubber diaphragm or metal bellows may be placed within a bodyof safety valve, for example. A dotted rectangular box schematically shown inmay represent, e.g., a housingcontaining one or more (e.g., all) components of sliding assembly, and which may contain a clean fluid to isolate sliding assemblyor a portion thereof from the production fluids. Where used, housingmay be in communication with or otherwise coupled to suitable devices for achieving pressure compensation and equalization.

An example sequence of operations may be performed as follows. When an electric brakeis switched off, hydraulic pressure is applied to hydraulic piston. Hydraulic pressure may originate from either a surface location or from wellbore pressure below a flapper valve of a safety valve (e.g., valveof). The hydraulic pressure may thus compress one or more springs (e.g., power springand nose springof). The electric brakeis then energized to lock a brake (e.g., prongof) in place, creating a locked position. If pressure from below the flapper is used to actuate hydraulic piston, then pressure from surface would be applied to equalize the pressure across the flapper. This allows the nose spring to relax and open the flapper while power springremains compressed because the electric brakeis on. If power is lost, the electric brakeswitches off and the power spring pushes the safety valveback to the closed position. The sequence of operations may be repeated again and again.

is a schematic of a sliding assemblylike the one shown in, but with a gear boxdisposed between an electric brakeand a ball screw, in accordance with some embodiments of the present disclosure. Linear movement of ball nutalong ball screwis shown by an arrow indicated at. Similarly, rotation of ball screwis shown by an arrow indicated at. This figure also shows one or more connectionsfixedly attached to sliding assembly, e.g., at either end of ball screw, to prevent axial movement of one or more components of sliding assemblyduring movement of ball nutalong ball screw.

Gear boxmay be disposed between ball screwand electric brake. A gear boxmay have any suitable reduction ratio to reduce the power consumption for electric brake, for example, between 1.01:1 and 1000:1, or any ranges therebetween. A connection(e.g., mechanical communication) between ball nutand hydraulic pistonmay cause ball nutto axially move along ball screwupon actuation of hydraulic pistonso that ball screwrotates. This opens safety valve(e.g., referring to) and allows production fluid to flow. Sliding assemblyis then maintained in the open position using electric brakeby supplying electric current thereto, which prevents backwards rotation of ball screwand thus reversion of ball nutto the non-extended position (e.g.,), as discussed. Gear boxis configured with a pre-determined reduction ratio chosen to ensure electric brakefunctions reliably.

is a schematic of an electric brakein a locked position, in accordance with some embodiments of the present disclosure. As shown, electric brakemay comprise a magnet structureand a coil, magnet structurehaving teethseated against corresponding teeth of armaturethat houses an output plate, wherein splinesand release springsmediate extension and retraction of output plate. A magnetic fluxmay hold armature against body when electric brakeis energized. Thus, magnetic fluxmay account for maintaining a safety valve(e.g., referring to) in an open position.

shows the electric brakeofbut in an unpowered and in an unlocked position with teethof armaturedisengaged from those of magnet structure. Release springsare biased compressed against output plateand a rotationof output plateis indicated atalong splines. As mentioned, the electric brakeshown inis but one example of an electric brake.

is a schematic of an electric brake having a compression spring, showing a locked configuration, in accordance with some embodiments of the present disclosure. As shown, electric brakemay comprise a magnet structureand a coil, magnet structurehaving teethseated against corresponding teeth of armaturethat houses an output plate, wherein splinesand compression springsmediate extension and retraction of output plate. A magnetic fluxmay attract armatureagainst magnet structurewhen electric brakeis energized, thereby inducing compression of compression springagainst its relaxed, uncompressed state. Here, de-energizing of electric brakeallows compression springto exert an outward force between output plateand an overhanging regionof armatureaway from magnet structureso that compression springreturns to its relaxed, uncompressed state. Thus, magnetic fluxmay account for maintaining a safety valve(e.g., referring to) in an open position.