Downhole Valve Actuation Methods and Apparatus

Abstract

In some embodiments a method of shifting a downhole-located device between positions with an actuator includes inserting the actuator into the well, engaging the actuator with the shiftable device and actuating the actuator to shift the shiftable device between positions.

Description

This application claims priority to U.S. provisional patent application Ser. No. 61/058,908 filed Jun. 4, 2008, entitled “Remote Hydraulic Shifting Apparatus, Systems and Methods”, which is hereby incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present disclosure relates generally to downhole valves and other devices that are movable between positions and, more particularly, to selectively remotely shifting such valves or other devices.

BACKGROUND OF THE INVENTION

In hydrocarbon recovery operations in subterranean wells, it is often desirable to selectively shift a valve or other device between positions. For example, there are instances when it is necessary or desirable to selectively close a downhole device to isolate the well, such as to remove, repair or replace equipment. Likewise, there are occasions when it is necessary to shift open the downhole device, such as to allow the recovery of produced fluids.

In many applications, it may be particularly useful to be able to selectively remotely shift a valve or other device between positions on multiple occasions. For example, in hydrocarbon producing wells having a generally low bottom-hole pressure, an electric submersible pump is often inserted into the well to assist in drawing produced fluids up into the production tubing. However, these pumps typically have a limited useful life-span as compared to the producing life of the well, so operations must be interrupted to replace the pump. In such instances, it is often desirable to isolate the well below the pump by closing one or more valves during removal and replacement of the pump, and thereafter to re-open the valve(s) and continue production.

Some present techniques for selectively shifting downhole devices require the insertion into the well of a shifting tool carried on pipe, coiled tubing or the like to mechanically shift the valve between positions. This process, which often requires the use of a rig or other equipment, may be time consuming and costly.

It should be understood that the above-described discussion is provided for illustrative purposes only and is not intended to limit the scope or subject matter of the appended claims or those of any related patent application or patent. Thus, none of the appended claims or claims of any related patent application or patent should be limited by the above discussion or required to address, include or exclude all or any of the above-cited examples, features and/or disadvantages merely because of their mention above.

Accordingly, there exists a need for improved systems, apparatus and methods capable of shifting a valve or other device disposed in a subterranean well and having one or more of the attributes, capabilities or features described below or in the subsequent sections of this disclosure, or shown in the appended drawings: may be remotely actuated from the surface with hydraulic pressure; may be remotely actuated from the surface with pneumatic pressure; may be remotely actuated from the surface by electric power; may be capable of both opening and closing the shiftable device multiple times as desired; may be capable of selectively repeatedly shifting the shiftable device between at least two positions; may be connected to a production tubing and releasably engageable with the shiftable device; is not part of the lower completion assembly or components; may be disengaged from the shiftable device, removed from the well, reinserted into the well and re-engaged with the device multiple times; may be capable of shifting the shiftable device without requiring the insertion or manipulation of pipe or coiled tubing in the well, or the use of a rig, wet connect or slick line; allows well zone isolation for quickly replacing, adding, removing or servicing equipment or other operations; does not require the engagement of control lines to the shiftable device; may be useful to quickly open and close off the well at will and repeatedly; is easily engageable and disengageable with the shiftable device; is slideably engageable with the shiftable device; allows the well to be sealed before starting operations; or a combination thereof.

BRIEF SUMMARY OF THE DISCLOSURE

In some embodiments, the present disclosure involves methods of shifting a shiftable device between at least first and second positions with a removable actuator. The shiftable device is anchored within a subterranean well. The actuator is inserted into the well and releasably engaged with the shiftable device. When the shiftable device is in a first position, the actuator may be actuated by providing at least one among hydraulic pressure, pneumatic pressure and electric power thereto to shift the shiftable device into a second position without requiring the use of either a rig or a slick line. The actuator may be disengaged from the shiftable device.

In various embodiments, the present disclosure involves methods of shifting a shiftable device between at least first and second positions with an actuator. The shiftable device is anchored within a subterranean well. These embodiments include coupling the actuator to a production tubing. After the shiftable member is anchored in the well, the production tubing is inserted into the well and the actuator is slideably engaged with the shiftable device. Whenever and as many times as desired, the actuator may be actuated by providing at least one among hydraulic pressure, pneumatic pressure and electric power to the actuator to shift the shiftable device between positions without requiring the use of either a rig or a slick line.

There are embodiments of the present disclosure that involve a method of remotely shifting a downhole valve between open and closed positions with a hydraulic valve actuator. These embodiments include inserting the valve actuator into the well and engaging the valve actuator with the valve (in a closed position). Thereafter and whenever the valve is in a closed position, the valve actuator may be hydraulically actuated to shift the valve into an open position. Likewise, when the valve is in an open position, the valve actuator may be hydraulically actuated to shift the valve into a closed position.

In accordance with the present disclosure, some embodiments involve an apparatus useful for shifting a shiftable device between at least first and second positions. The shiftable device is anchored in a subterranean well. The apparatus includes a housing insertable into and out of the well without disturbing the location of the shiftable device within the well. A hydraulically-driven piston is disposed within the housing. At least two hydraulic control lines are fluidly coupled to the housing and capable of providing hydraulic pressure from the surface to the housing to cause the piston to move up and down within the housing. An engagement arm extends from the piston and is releasably engageable with the shiftable device. The engagement arm moves up and down with the piston and is capable of mechanically shifting the shiftable device between at least first and second positions without requiring the use of either a rig or a slick line. The piston and engagement arm may thus be hydraulically-actuated to selectively remotely shift the shiftable member between positions.

Accordingly, the present disclosure includes features and advantages which are believed to enable it to advance downhole device shifting technology. Characteristics and potential advantages of the present disclosure described above and additional potential features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of various embodiments and referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are part of the present specification, included to demonstrate certain aspects of various embodiments of this disclosure and referenced in the detailed description herein:

FIG. 1 is a partial schematic and partial cross-sectional view of an embodiment of a valve actuator useful for shifting an example valve disposed in a subterranean well in accordance with an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of a portion of an example shifter of an embodiment of a valve actuator in accordance with the present disclosure;

FIG. 3A is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown with the example valve in a closed position;

FIG. 3B is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown with the example valve in an open position;

FIG. 3C is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown with the example valve in a closed position;

FIG. 3D is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown releasing from the exemplary valve in a closed position;

FIG. 4A is a partial schematic and partial cross-sectional view of another embodiment of a valve actuator useful for shifting an example sleeve disposed in a subterranean well in accordance with an embodiment of the present disclosure;

FIG. 4B a partial schematic and partial cross-sectional view of the exemplary valve actuator of FIG. 4A shown shifting the illustrated sleeve into a closed position;

FIG. 5A is a partial perspective and partial cross-sectional view of a portion of another embodiment of a valve actuator having an exemplary engagement arm shifting an example sliding sleeve into an open position in accordance with the present invention;

FIG. 5B shows the exemplary valve actuator of FIG. 5A after having shifted the illustrated sliding sleeve into an open position.

FIG. 5C shows the exemplary engagement arm of FIG. 5A shifting the illustrated sliding sleeve into a closed position; and

FIG. 5D shows the exemplary valve actuator of FIG. 5A after having shifted the illustrated sliding sleeve into a closed position.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Characteristics and advantages of the present disclosure and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of exemplary embodiments of the present disclosure and referring to the accompanying figures. It should be understood that the description herein and appended drawings, being of example embodiments, are not intended to limit the appended claims or claims of any patent or patent application claiming priority hereto. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claims. Many changes may be made to the particular embodiments and details disclosed herein without departing from such spirit and scope.

In showing and describing preferred embodiments, common or similar elements are referenced in the appended figures with like or identical reference numerals or are apparent from the figures and/or the description herein. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.

As used herein and throughout various portions (and headings) of this patent application, the terms “invention”, “present invention” and variations thereof are not intended to mean every possible embodiment encompassed by this disclosure or any particular claim(s). Thus, the subject matter of each such reference should not be considered as necessary for, or part of, every embodiment hereof or of any particular claim(s) merely because of such reference. The terms “coupled”, “connected”, “engaged” and the like, and variations thereof, as used herein and in the appended claims are intended to mean either an indirect or direct connection or engagement. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. Also, the terms “upward” and “downward” as used herein and in the appended claims may be relative to the top and/or bottom of a component, assembly or space and are not necessarily limited to movement in a vertical axis or plane.

Certain terms are used herein and in the appended claims to refer to particular components. As one skilled in the art will appreciate, different persons may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. Also, the terms “including” and “comprising” are used herein and in the appended claims in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Further, reference herein and in the appended claims to components and aspects in a singular tense does not necessarily limit the present disclosure or appended claims to only one such component or aspect, but should be interpreted generally to mean one or more, as may be suitable and desirable in each particular instance.

Referring initially to FIG. 1, an embodiment of a valve actuator 10 useful for shifting a valve 14 or other device disposed in a subterranean well 12 is shown. The illustrated well 12 is vertically oriented, but could instead be horizontal, deviated or have any other orientation. In this embodiment, the valve 14 is a mechanical isolation ball valve 16, which may be shifted between open and closed positions, as desired, with the valve actuator 10. The illustrated ball valve 16 is contained within a valve assembly 18, which is connected within a lower completion arrangement 22 coupled to a casing 24, such as with a seal/locator assembly 28 and packer 30. For example, the lower completion arrangement 22 may be run into and set in the well 12 in one trip with the valve 14 in a closed position before the valve actuator 10 is introduced into the well 12. However, this set of components, configuration and sequence are provided for illustrative purposes only and are not required for, or limiting upon, the present disclosure.

It should be understood that the valve actuator 10 may be used to move any type or configuration of valve 14 or other device between any desired positions. Some examples of such valves and other devices are flapper valves, ball valves, mechanical or hydraulic sliding sleeves, gravel pack closing sleeves and other fluid loss or recovery devices. Thus, the present invention is not limited to use with any particular type of valve or other shiftable device. As used herein and in the appended claims, unless specified otherwise, the term “valve” includes any type of device that is moveable between at least two positions. Further, the present invention is not limited by the number or nature of positions between which the valve may be shifted. Additionally, the valve may be disposed at any desired location in a subterranean well and in any desired downhole arrangement of components. Accordingly, the present disclosure is not limited by the type, configuration, action, purpose or operation of the device(s) that may be shifted in accordance with this disclosure.

Still referring to FIG. 1, the valve actuator 10 may have any desired form, configuration and operation. In this embodiment, the valve actuator 10 includes a shifter 32 which effectively moves the valve 14 between positions. In some embodiments, referring to FIG. 2, the shifter 32 may include at least one balanced piston 34 and at least one engagement arm 38 extending therefrom and moveable therewith. The exemplary piston 34 is disposed and reciprocable within a housing 42 by surface-controlled hydraulic (or pneumatic) pressurization through control lines 46, 48. In other embodiments, the piston 34 may be electrically-actuated. For example, one or more electric power line (not shown) may extend from the surface to an electric motor (not shown) connected with and used for powering the piston 34.

Still referring to FIG. 2, the illustrated piston 34 is shown in a “down” position after hydraulic fluid pressurization in the housing 42 via the control line 46. If it is desired to move the exemplary piston 34 (and engagement arm 38) to an “up” position (not shown), sufficient hydraulic fluid pressurization is provided via the control line 48. Thus, the piston 34 and engagement arm 38 of this embodiment are selectively, remotely moveable via hydraulics (or pneumatics) between “up” and “down” positions. However, the valve actuator 10 of the present disclosure is not limited to this configuration. For example, a different arrangement and number of control lines may be used. For other examples, the piston 34 (and engagement arm 38) may be moveable between more than two positions or actuated in a different manner (other than hydraulics or pneumatics; e.g. electrical power). Further, the piston 34 and engagement arm 38 may be separate components coupled together, integrally formed or part of or contained within other components. Also, in many embodiments, the shifter 32 may include different or additional components. Thus, the present invention is not limited by the type, configuration and operation of the shifter 32 or other embodiments of the valve actuator 10.

Referring back to FIG. 1, the valve actuator 10 may be associated with the valve assembly 18 in any suitable manner and with any desired components to cause the valve 14 to move between positions. In this embodiment, for example, the engagement arm 38 is slideable into and out of the upper end of the valve assembly 18. The exemplary arm 38 includes at least one profile, or rib, 52 that is engageable with upper and lower collets, or ribs, 56, 58 disposed on an internal sleeve 60 in the valve assembly 18. As the engagement arm 38 moves up or down (such as, e.g., by action of the piston 34 of FIG. 2), the profile 52 engages and pushes one of the collets 56, 58 to move the valve 16 between positions.

In FIG. 3A, for example, the engagement arm 38 is engaged with the valve assembly 18 and the ball valve 16 is in a closed position. This position of the engagement arm 38 is between “up” and “down” positions. As the piston (not shown) is actuated to move from an “up” to a “down” position, it causes the exemplary engagement arm 38 to move down (left to right in FIGS. 3A-D). The downward movement of the arm 38 causes the profile 52 to abut the lower collet 58 and push it and the internal sleeve 60 downwardly. FIG. 3A thus illustrates the position of the exemplary profile 52 as it engages the lower collet 58 to begin opening the valve 14.

Continued downward movement of the exemplary arm 38 and internal sleeve 60 will cause the ball valve 16 to be shifted from a closed position to an open position, as shown in FIG. 3B. In this example, with sufficient downward movement to open the valve 16, the lower collet 58 will seat in a lower undercut 66 in the valve assembly 18, allowing the profile 52 to move down past the lower collet 58 (FIG. 3B), such as, for example, to accommodate any overstroke of the piston (not shown).

In this embodiment, the reverse movement of the piston (not shown) and engagement arm 38 with cause the profile 52 to engage the upper collet 56 and drive the internal sleeve 60 in the upward direction to move the valve 14 from an open to a closed position. Referring to FIG. 3B, for example, when the illustrated ball valve 16 is in an open position, the upward movement of the engagement arm 38 will cause the profile 52 to pass by the lower collet 58 (if the profile 52 previously bypassed it) and abut the upper collet 56 (FIG. 3C), pushing it and the internal sleeve 60 upwardly. This movement will shift the ball valve 16 into a closed position. As shown in FIGS. 3C and 3D, in this example, continued upward movement of the engagement arm 38 will cause the upper collet 56 to seat in an upper undercut 64 in the valve assembly 18 and the illustrated profile 52 to pass over the upper collet 56. The engagement arm 58 and, thus, the shifter 32 may thereafter be slideably disengaged from the valve assembly 18, allowing the exemplary valve actuator 10 (e.g. FIG. 1) to be entirely removable from the well 12 without disturbing the location of the valve 14 therein. However, the present disclosure is not limited to this particular operation or arrangement of components.

If desired, the valve actuator 10 may be removed from the well 12, replaced back into the well 12 and again used for shifting the valve 14. This procedure may be repeated as many times as desired, such as for equipment service or replacement, to isolate the well for conducting other downhole operations, or any other desired purpose. Referring back to FIG. 1, for example, the exemplary valve actuator 10 is coupled to the lower end of a production tubing 74, which also carries an electric submersible pump 70. The pump 70 is useful to assist in drawing produced oil and/or gas up into the production tubing 74, such as in a low bottom-hole pressure well, as is and becomes further known. In this arrangement, if it becomes necessary to replace or service the pump 70 (production tubing 74, valve actuator 10, etc.), it may be desirable to close the valve 14, isolate the well 12 and remove the tubing 74 and associated components from the well 12. Accordingly, after the exemplary valve actuator 10 is actuated to shift the valve 14 to a closed position, the production tubing 74 (with submersible pump 70 and valve actuator 10) may be retrieved up and out of the well 12. After the pump 70 (or other equipment) is serviced or replaced, the tubing 74 and connected components may be returned into the well 12.

Still referring to FIG. 1, if desired, one or more re-entry guide 78 may be associated with the valve actuator 10, tubing 74 or other component to assist in alignment and reinsertion of the tubing 74 and valve actuator 10. Also, in the illustrated example, as shown in FIG. 3D, the valve assembly 18 includes a guide 82 to assist in aligning the engagement arm 38 within the valve assembly 18. After the arm 38 is slideably engaged with the valve assembly 18, downward movement of the illustrated arm 38 will cause the exemplary profile 52 to bypass the upper collet 56 and eventually engage the lower collet 58 to shift the valve 16 from a closed to an open position, such as described above. The valve actuator 10 may thereafter be used as needed to shift the exemplary valve 16 between open and closed positions, and the entire process may be repeated as desired.

In FIG. 4A, another embodiment of the valve actuator 10 is shown in a multi-flow production configuration. In this example, the valve actuator 10 is useful to open and close a mechanical closing sleeve 86. The illustrated valve actuator 10 is disposed at the end of the production tubing 74 and includes a shifter 32 having a piston (not shown) disposed in a housing 42 and operable such as described above with respect to FIGS. 1 & 2. In this example, the piston drives a perforated inner pipe 88 upon which the engagement arm 38 is disposed. The illustrated engagement arm 38 is a support mandrel for at least one engager 90 that is engageable with the sleeve 86. The engager 90 may be a collet, retractable finger or any other suitable component or member.

Still referring to FIG. 4A, the illustrated closing sleeve 86 opens and closes at least one port 87 formed in the lower completion arrangement 22, or otherwise provided in the well 12 below a packer 30. The port 87 allows fluid flow from an annulus 92 into the perforated pipe 88 during production, such as shown with flow arrows 94. The lower completion arrangement 22, shown mounted in the well 12, includes a check, or standing, valve 96 that is liftable off a seat 98 by upward fluid pressure to allow fluid flow through the pipe bore 100 in a lower pipe section 102 of the arrangement 22. The illustrated lower pipe section 102 is perforated, so that upwardly flowing fluid may pass both through the bore 100 (e.g. flow arrows 104) and into the annulus 92 (e.g. flow arrows 106). Accordingly, FIG. 4A illustrates the “down” position of the exemplary engagement arm 38 and the open positions of the closing sleeve 86 and check valve 96 during production.

If production ceases or it is desirable to isolate or seal off the well 12 at this interval, such as to replace the submersible pump 70 or other hardware, or for other operations, the piston (not shown) of the shifter 32 may be actuated from surface to move the perforated pipe 88 and engagement arm 38 upwardly. Referring to FIG. 4B, sufficient upward movement of the illustrated engagement arm 38 causes the engager(s) 90 to engage and close the sleeve 86. In this embodiment, continued upward movement of the engagement arm 38 will allow the engager(s) 90 to collapse or otherwise bypass or move above the sleeve 86, allowing removal of the production tubing 74 and all attached equipment (the valve actuator 10, perforated inner pipe 88, submersible pump 70, etc.) from the well 12. Later, the production tubing 74 and other components may be reinserted into the well and the valve actuator 10 used to re-open the sleeve 86 generally similarly as described above with respect to other embodiments.

In FIGS. 5A-D, another embodiment of an engagement arm 38 in accordance with the present disclosure is shown useful for opening and closing a sliding sleeve 110. The illustrated sliding sleeve 110 includes and at least one passageway 112 alignable with at least one port 114 formed in a pipe 116 (or other component), such as to allow fluid flow into or out of a bore 117. The sleeve 110 also includes a B-shifting profile arrangement with upper and lower profiles 124, 126.

The illustrated engagement arm 38 includes a multi-action, collapsible, B-shifting body portion 106 with collets 118, 120. The upper collet 118 is releasably engageable with the lower profile 126 of the sleeve 110 and the lower collet 120 is releasably engageable with the upper profile 124. The illustrated arm 38 is driven by a piston (not shown) as part of a shifter 32 and operates generally similarly as previously described with respect to other embodiments.

In FIG. 5A, the exemplary engagement arm 38 is shown shifting the sleeve 110 into an open-port position. As the arm 38 is moved downwardly (from left to right in FIGS. 5A-D), the upper collet 118 engages the lower profile 126 to move the sleeve 110, aligning the passageway 112 with the port 114, as shown in FIG. 5B. If desired, continued downward movement of the arm 38 may cause the body 106 of the arm 38 to collapse, if necessary, to allow the upper collet 118 to disengage from and bypass the lower profile 126.

Referring now to FIGS. 5C-D, the exemplary engagement arm 38 is shown shifting the sleeve 110 into a closed-port position. As the arm 38 is moved upwardly, the lower collet 120 will engage the upper profile 124 and move the sleeve 110 upwardly until the passageway 112 and port 114 are misaligned and out of fluid communication. If desired, continued upward movement of the arm 38 will cause the body 106 to collapse, if necessary, to allow the lower collet 120 to disengage from and bypass the upper profile 124 and the arm 38 to disengage completely from the sleeve 110 and pipe 116, if desired.

Preferred embodiments of the present disclosure thus offer advantages over the prior art and are well adapted to carry out one or more of the objects of this disclosure. However, the present invention does not require each of the components and acts described above and is in no way limited to the above-described embodiments, methods of operation. Any one or more of the above components, features and processes may be employed in any suitable configuration without inclusion of other such components, features and processes. Moreover, the present invention includes additional features, capabilities, functions, methods, uses and applications that have not been specifically addressed herein but are, or will become, apparent from the description herein, the appended drawings and claims.

The methods that are provided in or apparent from the description above or claimed herein, and any other methods which may fall within the scope of the appended claims, may be performed in any desired suitable order and are not necessarily limited to any sequence described herein or as may be listed in the appended claims. Further, the methods of the present invention do not necessarily require use of the particular embodiments shown and described herein, but are equally applicable with any other suitable structure, form and configuration of components.

While exemplary embodiments of the invention have been shown and described, many variations, modifications and/or changes of the system, apparatus and methods of the present invention, such as in the components, details of construction and operation, arrangement of parts and/or methods of use, are possible, contemplated by the patent applicant(s), within the scope of the appended claims, and may be made and used by one of ordinary skill in the art without departing from the spirit or teachings of the invention and scope of appended claims. Thus, all matter herein set forth or shown in the accompanying drawings should be interpreted as illustrative, and the scope of the disclosure and the appended claims should not be limited to the embodiments described and shown herein.

Claims

1. A method of shifting a shiftable device between at least first and second positions with a removable actuator, the actuator being driven by at least one among hydraulic pressure, pneumatic pressure and electric power, the shiftable device being anchored within a subterranean well, the method comprising:

inserting the actuator into the well;

releasably engaging the actuator with the shiftable device;

when the shiftable device is in a first position, actuating the actuator by providing at least one among hydraulic pressure, pneumatic pressure and electric power to the actuator to shift the shiftable device into a second position without requiring the use of either a rig or a slick line; and

disengaging the actuator from the shiftable device.

2. The method of claim 1 further including, before disengaging the actuator from the shiftable device, actuating the actuator to shift the shiftable device out of the second position.

3. The method of claim 2 wherein the shiftable device is a fluid flow control valve having at least one open-flow position and at least one closed-flow position, wherein the first position of the shiftable device is a closed-flow position and the second position of the shiftable device is an open-flow position.

4. The method of claim 3 further including, before disengaging the actuator from the shiftable device, actuating the actuator to shift the shiftable device back to the first position.

5. The method of claim 1 further including, after disengaging the actuator from the shiftable device, removing the actuator from the well without disturbing the location of the shiftable device within the well.

6. The method of claim 5 further including coupling the actuator to a production tubing, wherein the actuator is insertable into and removable from the well by moving the production tubing into and out of the well.

7. The method of claim 6 further including anchoring the shiftable device in the well as part of a set of lower completion components insertable into the well in a first trip, wherein the actuator is lowered into the well and releasably slideably engaged with the shiftable device in a second trip.

8. The method of claim 6 wherein the well is a low bottom-hole pressure well, further including

coupling at least one submersible pump to the production tubing, and

after removing the production tubing from the well, removing at least one submersible pump from the production tubing, coupling at least one other submersible pump to the production tubing and inserting the production tubing back into the well.

9. The method of claim 1 wherein the actuator is slideable into and out of the shiftable device.

10. The method of claim 9 wherein the actuator includes a piston and an engagement arm, the piston and engagement arm being concurrently moveable between at least first and second positions, further including providing at least one among air, hydraulic fluid and electricity to the piston from the surface to selectively move the piston and engagement arm between their respective first and second positions.

11. The method of claim 10 wherein the engagement arm includes at least one among at least one profile and at least one collect and the shiftable device includes at least one among at least one profile and at least one collect, further including selectively moving the engagement arm to cause at least one profile or collect thereon to engage at least one profile or collet of the shiftable device and move the shiftable device between its respective first and second positions.

12. The method of claim 1 wherein the shiftable device includes at least one among a shiftable sleeve, flapper valve, ball valve, sliding sleeve and gravel pack closing sleeve.

13. A method of shifting a shiftable device between at least first and second positions with an actuator, the actuator being driven by at least one among hydraulic pressure, pneumatic pressure and electric power, the shiftable device being anchored within a subterranean well, the method comprising:

coupling the actuator to a production tubing;

after the shiftable member is anchored in the well, inserting the production tubing into the well;

slideably engaging the actuator with the shiftable device;

when desired and as many times as desired, actuating the actuator by providing at least one among hydraulic pressure, pneumatic pressure and electric power to the actuator to shift the shiftable device between its respective at least first and second positions without requiring the use of either a rig or a slick line.

14. The method of claim 13 further including

when desired and as many time as desired slideably disengaging the actuator from the shiftable device, removing the production tubing and actuator from the well without disturbing the location of the shiftable device within the well, reinserting the production tubing, reengaging the actuator with the shiftable device, and actuating the actuator by providing at least one among hydraulic pressure, pneumatic pressure and electric power to the actuator to shift the shiftable device between its respective at least first and second positions without requiring the use of either a rig or a slick line.

15. The method of claim 13 wherein the shiftable device is a fluid flow control valve having at least one open flow position and at least one closed flow position, wherein the first position of the shiftable device is a closed flow position and the second position of the shiftable device is an open flow position, wherein the shiftable device is in its first position when the actuator is engaged with and disengaged from the shiftable device, whereby the well may be sealed or isolated when the actuator is disengaged from the shiftable device.

16. The method of claim 15 wherein the well is a low bottom-hole pressure well, further including

coupling at least one submersible pump to the production tubing, and

after removing the production tubing from the well, removing at least one submersible pump from the production tubing, coupling at least one other submersible pump to the production tubing and inserting the product tubing back into the well.

17. The method of claim 15 wherein the shiftable device includes at least one among a shiftable sleeve, flapper valve, ball valve, sliding sleeve and gravel pack closing sleeve that is shiftable between open and closed positions, further wherein the actuator includes a balanced hydraulic piston and an engagement arm extending therefrom, further including actuating the hydraulic piston to move the engagement arm up and down, wherein downward movement of the engagement arm causes the shiftable device to move from a closed position to an open position and upward movement of the engagement arm causes the shiftable device to move from an open position to a closed position.

18. A method of remotely shifting a valve between open and closed positions with a hydraulic valve actuator, the valve being disposed in a subterranean well, the method comprising:

inserting the valve actuator into the well;

engaging the valve actuator with the valve, the valve being in a closed position; and

repeatedly, as desired, when the valve is in a closed position, actuating the valve actuator by providing hydraulic pressure to the valve actuator to shift the valve into an open position without requiring the connection of hydraulic control lines directly to the valve, and when the valve is in an open position, actuating the valve actuator by providing hydraulic pressure to the valve actuator to shift the valve into a closed position without requiring the connection of hydraulic control lines directly to the valve.

19. The method of claim 18, further including,

when the valve is in a closed position, repeatedly as desired, disengaging the valve actuator from the valve without disturbing the location of the valve within the well, removing the valve actuator from the well, reinserting the valve actuator into the well, and reengaging the valve actuator with the valve.

20. Apparatus useful for shifting a shiftable device between at least first and second positions, the shiftable device being anchored in a subterranean well, the apparatus comprising:

a housing insertable into and out of the well without disturbing the location of the shiftable device within the well;

a hydraulically-driven piston disposed within said housing;

at least two hydraulic control lines fluidly coupled to said housing and capable of providing hydraulic pressure from the surface to said housing to cause said piston to move between at least a piston up and a piston down position within said housing; and

an engagement arm extending from and being concurrently moveable with said piston and releasably engageable with the shiftable device, said engagement arm capable of mechanically shifting the shiftable device between at least first and second positions without requiring the use of either a rig or a slick line,

wherein said piston and said engagement arm may be hydraulically actuated to selectively remotely shift the shiftable member between at least first and second positions.

21. The apparatus of claim 20 wherein the shiftable device includes at least one profile and said engagement arm includes at least one collect, wherein said at least one collet of said engagement arm is releasably engageable with at least one profile of the shiftable device to cause the shiftable device to move between at least first and second positions.

22. The apparatus of claim 20 wherein the shiftable device includes at least one collet and said engagement arm includes at least one profile, wherein said at least one profile of said engagement arm is releasably engageable with at least one collet of the shiftable device to cause shiftable device to move between at least first and second positions.

23. The apparatus of claim 20 wherein the shiftable device includes at least one among a shiftable sleeve, flapper valve, ball valve, sliding sleeve and gravel pack closing sleeve.