US20110220367A1

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Publication number: US20110220367A1
Application number: US12/721,163
Authority: US
Inventors: Paul L. Browne
Original assignee: Halliburton Energy Services Inc
Current assignee: Halliburton Energy Services Inc
Priority date: 2010-03-10
Filing date: 2010-03-10
Publication date: 2011-09-15
Also published as: WO2011110815A3; WO2011110815A2

Abstract

A method of controlling operation of multiple valves interconnected in a tubular string in a subterranean well can include opening each of the valves, and then closing the valves in response to an application of pressure to the tubular string. A well system can include multiple valves interconnected in a tubular string, each of the valves including an actuator, and a valve control device interconnected in the tubular string. The valve control device may be connected to each of the valve actuators via multiple flow paths, whereby a pressure differential generated between the flow paths is also generated in each of the valve actuators.

Description

BACKGROUND

This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an example described below, more particularly provides for operational control of multiple valves in a well.

It is sometimes beneficial to be able to open each of multiple valves in succession in a well. For example, it is desirable in some cases to individually stimulate each of multiple zones traversed by a wellbore, so that optimum pressure and flow of stimulation fluids can be delivered to each zone. For this purpose, multiple valves which can be individually opened may be interconnected in a casing, liner or tubing string.

Unfortunately, if subsequent stimulation operations are needed for the zones, it is typically inconvenient, time-consuming and expensive to close the open valves. Therefore, it will be appreciated that improvements are needed in the art of operational control of multiple valves in a well.

SUMMARY

In the disclosure below, well systems and associated methods are provided which bring improvements to the art of operational control of multiple valves in a well. One example is described below in which the valves can be conveniently closed after having been opened. Another example is described below in which multiple valves can be opened and/or closed together.

In one aspect, a method of controlling operation of multiple valves interconnected in a tubular string in a subterranean well is provided to the art by this disclosure. The method can include opening each of the valves, and then closing the valves in response to an application of pressure to the tubular string.

In another aspect, the disclosure provides a well system to the art. The well system can include multiple valves interconnected in a tubular string, each of the valves including an actuator, and a valve control device interconnected in the tubular string. The valve control device may be connected to each of the valve actuators via multiple flow paths, whereby a pressure differential generated between the flow paths is also generated in each of the valve actuators.

These and other features, advantages and benefits will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative examples below and the accompanying drawings, in which similar elements are indicated in the various figures using the same reference numbers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic partially cross-sectional view of a well system and associated method embodying principles of the present disclosure.

FIGS. 2A & B are enlarged scale cross-sectional views of successive axial sections of a valve which may be used in the system and method ofFIG. 1.

FIG. 3 is an enlarged scale schematic cross-sectional view of a valve control device which may be used in the system and method ofFIG. 1.

FIG. 4 is a further enlarged scale schematic cross-sectional view of another configuration of the valve control device having a flow path reversing plug installed therein.

FIG. 5 is a schematic cross-sectional view of yet another configuration of the valve control device having a flow path testing plug installed therein.

DETAILED DESCRIPTION

Representatively illustrated inFIG. 1 is awell system10 and associated method which embody principles of this disclosure. In thewell system10, multiple valves12 (indicated inFIG. 1 aselements12a-d) are interconnected in atubular string14. Thetubular string14 could be a casing, liner, tubing or other type of tubular string.

Thevalves12 are used to control flow between the interior of thetubular string14 and each of corresponding multiple zones16 (indicated inFIG. 1 as elements16a-d) intersected by awellbore18. Thewellbore18 is depicted inFIG. 1 as being uncased or open hole, but the wellbore could be cased or lined in other examples.

Packers20 are used to isolate the zones16 from each other in thewellbore18. Representatively, thepackers20 are swellable packers, in that they include a material which swells when exposed to an activating fluid. However, other types of packers (e.g., external casing packers, inflatable packers, mechanically or hydraulically set packers, etc.) may be used, and other means of isolating the zones16 from each other (e.g., cement, gel, etc.) may be used, in keeping with the principles of this disclosure.

Although fourvalves12, four zones16 and fourpackers20 are depicted inFIG. 1, it should be clearly understood that any number of each of these elements may be used, and it is not necessary for the same number of valves, zones or packers to be used, in keeping with the principles of this disclosure. Indeed, the principles of this disclosure are not limited at all to any of the details of thesystem10 and method representatively illustrated inFIG. 1 and described herein.

Thevalves12 are preferably similar in some respects to the DELTA STIM (TM) valves marketed by Halliburton Energy Services, Inc. of Houston, Tex. USA. Each such valve can be individually opened in succession by dropping a ball, dart or other plugging device, which engages a seat in a valve. A pressure differential is then applied across the plugging device to open the valve. Different sized seats and plugging devices (smaller to larger in succession from the distal end of the tubular string) are used to provide selectivity as to which valve is opened when a particular plugging device is used.

In the configuration ofFIG. 1, the method in which a stimulation operation is performed would proceed as follows:

1. Thetubular string14 is assembled with the valves12 (initially closed),packers20, alanding collar22 and avalve control device24 interconnected therein. Thelowermost valve12ais preferably of the type which opens in response to pressure applied to thetubular string14, without any plug being installed in the tubular string. Theother valves12b-dare preferably of the type which open in response to an appropriately sized plug being sealingly engaged with a seat therein, and a pressure differential being applied across the plug. Thevalves12b-dare positioned so that the smallest seat is farthest from the surface, and then in succession from smallest to largest.

2. Thetubular string14 is installed in thewellbore18, so that thevalves12 are adjacent the respective zones16.

3. An activating fluid is pumped through thetubular string14 and into anannulus26 formed radially between the tubular string and thewellbore18. This will initiate swelling of thepackers20. Of course, if swellable packers are not used, then there is no need for circulating an activating fluid to the packers.

4. A dart follows the activating fluid and lands in thelanding collar22, thereby sealing off the lower end of thetubular string14. Thetubular string14 is then pressure tested.

5. If aliner hanger28 is used, it is now set. Then sufficient time is allowed for thepackers20 to swell into sealing contact with thewellbore18.

6. Thelowermost valve12ais opened by applying a predetermined pressure to thetubular string14. Thecorresponding zone16ais treated by flowing fluids through thetubular string14, out through theopen valve12a, and into thezone16a.

7. After thezone16atreatment is completed, a first plug is dropped at the beginning of the pad of the next zone's16btreatment and is pumped down to land in the seat of thevalve12b. When the plug lands, thezone16ais isolated from the treatment fluids delivered to thezone16b, a pressure differential applied across the first plug causes thevalve12bto open, and treatment of thezone16bcommences.

8. The preceding step is repeated for each of the

next zones

16c,16d, with a larger plug being landed in each of the

valves

12c,12dwhen it is desired to treat the corresponding zone.

9. At the end of the stimulation operation, all of the plugs are flowed to the surface. All of thevalves12a-dare now open and available for production or injection flow. If full bore access is desired, the ball seats in thevalves12b-dmay be drilled or milled through. However, if the ball seats are drilled or milled through, then thevalves12b-dcan later be closed as described below, but the valves cannot then be individually reopened using plugs landed in each of the valves—they will either need to be reopened together (e.g., using thevalve control device24 configuration ofFIG. 4), or individually reopened via intervention (e.g., using a mechanical or hydraulic shifting tool).

10. If a further selective stimulation operation is desired, all of thevalves12b-dcan be again closed by use of thevalve control device24. A plug is installed in thedevice24, so that it sealingly engages a seat therein, and a pressure differential is applied across the plug, thereby closing all of thevalves12b-d(preferably simultaneously). Thevalves12b-dcan then be opened individually, if needed, for individual treatments of the correspondingzones16b-d.

Note that thedevice24 is connected to actuators of each of thevalves12b-dbylines30. Theselines30 provide flow paths to each of the actuators of thevalves12b-d. Although thelines30 are depicted inFIG. 1 as being external to thetubular string14, it will be appreciated that they could be formed in a sidewall of the tubular string, etc.

Although the method is described above as being performed for a stimulation operation, thevalves12 may be used in other types of operations (e.g., production, conformance, injection, steam flood, geothermal, etc.) in keeping with the principles of this disclosure.

Referring additionally now toFIGS. 2A & B, one of thevalves12 is representatively illustrated at an enlarged scale, apart from the remainder of thewell system10. It should be understood, however, that thevalve12 could be used in other well systems and methods in keeping with the principles of this disclosure. For example, it is not necessary for thevalve12 to be used in a stimulation operation, or for the valve to be used with any particular number of other valves in a tubular string, etc.

Thevalve12 includes a slidingsleeve32 which can be displaced between open and closed positions by various means. Thevalve12 can be opened or closed mechanically using internal shifting profiles34. Thevalve12 can be opened by sealingly engaging aplug36 with aseat38, and applying a pressure differential across the plug. Thevalve12 can also be opened or closed by applying pressure differentials across apiston40.

Thepiston40 is part of anactuator42 of thevalve12. Theactuator42 also includes

chambers

44,46 on opposite sides of thepiston40. The

chambers

44,46 are connected to flow

paths

30aand30bof thelines30, thereby connecting thevalve12 to thedevice24, and enabling a pressure differential to be applied across thepiston40 to actuate the valve between its open and closed configurations.

Note that thevalve12 is depicted inFIGS. 2A & B in its open configuration (after a pressure differential has been applied across theplug36 to thereby shift thesleeve32 to its open position). Theplug36 may then be circulated out of thevalve12, if desired.

To close thevalve12, a pressure differential can be applied from thechamber46 to thechamber44 to thereby bias thepiston40 to displace thesleeve32 to its closed position. To open thevalve12, a pressure differential can be applied from thechamber44 to thechamber46 to thereby bias thepiston40 to displace thesleeve32 to its open position.

Referring additionally now toFIG. 3, an enlarged scale view of thevalve control device24 is representatively illustrated, apart from the remainder of thewell system10. It should be understood, however, that thedevice24 could be used in other well systems and methods in keeping with the principles of this disclosure. For example, it is not necessary for thedevice24 to be used in a stimulation operation, or for the device to be used with any particular number of valves in a tubular string, etc.

In this view it may be seen that thedevice24 has the

flow paths

30a,30bconnected thereto, with aseat48 formed longitudinally between

ports

50,52 connecting aninterior flow passage54 to the respective flow paths. It will be appreciated that, if aplug56 is sealingly engaged with theseat48, then pressure applied to thetubular string14 above thedevice24 will generate a pressure differential across the plug, and will generate a pressure differential from theflow path30bto theflow path30a.

If theplug56 is not sealingly engaged with theseat48, the

flow paths

30a,30bwill be pressure balanced. This is preferred, so that pressure fluctuations in the interior of the tubular string14 (in the passage54) do not cause inadvertent operation of theactuator42.

When theplug56 is sealingly engaged with theseat48, and pressure is increased in thepassage54 above the plug, fluid in theflow path30ais permitted to flow into the passage below the plug via theport50. This enables thepiston40 to displace thesleeve32 to its closed position in response to the pressure differential created from thechamber46 to thechamber44, thereby exhausting fluid from thechamber44.

Referring additionally now toFIG. 4, another configuration of thedevice24 is representatively illustrated. In this configuration, theseat48 is in the form of a seal bore, and adifferent plug56 is used. Theplug56 directs pressure from thepassage54 above the plug to theport50, and communicates theport52 with thepassage54 below the plug.

Using theplug56, thevalve12 can be closed by applying increased pressure to the interior of the tubular string14 (in the passage54) above theplug56. The increased pressure will generate a pressure differential from thechamber44 to thechamber46 in thevalve12, thereby biasing thepiston40 to displace thesleeve32 to its open position.

As thesleeve32 displaces, fluid in thechamber46 will be exhausted to thepassage54 below theplug56 via theport52. It will be appreciated that another plug (similar to the plug56) could be easily constructed, so that the plug would communicate theport52 to thepassage54 above the plug, and would communicate theport50 to the passage below the plug (similar to the configuration ofFIG. 3).

Referring additionally now toFIG. 5, another configuration of thevalve control device24 is representatively illustrated. Thedevice24 ofFIG. 5 is similar to the device ofFIG. 3, in that it includes the taperedseat48, instead of the cylindrical seat ofFIG. 4. However, thedevice24 ofFIG. 5 is also similar to the device ofFIG. 4, in that it includes seal bores60,62 straddling theseat48 and

ports

50,52.

As depicted inFIG. 5, atest plug64 is installed in thedevice24 for pressure testing the device and flow

paths

30a,30bduring installation in a well. The test plug64 includes alatch66 which engages alatch profile68 in thedevice24, so that the test plug remains secured in the device during the pressure testing.

Pressure is applied via anexternal port70 in communication with theflow passage54 longitudinally betweenseals72 carried on thetest plug64. Thus, pressure applied via theport70 will be communicated to the

After pressure testing, thetest plug64 is removed from thedevice24. Theport70 is plugged prior to lowering thedevice24 into the well. After installation, theplug56 may be engaged with theseat48 to open and/or close thevalves12b-das described above.

Note that any of the features of any of the configurations of thevalve control device24 described above may be included, or substituted for, any of the features of any of the other configurations of the device. For example, the configuration ofFIG. 5 could be provided with thecylindrical seat48 of the configuration ofFIG. 4, the seal bores60,62 andlatch profile68 could be provided in the configuration ofFIG. 3, etc.

In any of the configurations described above, after thevalves12b-dhave been successfully opened or closed, as desired, theplug56 can be circulated out of thetubular string14. If thevalves12b-dwere closed, then at this point, thevalves12b-dcan be individually opened using theplugs36 as described above, allowing for repeated selective stimulation, etc.

It may now be fully appreciated that the above disclosure provides several advancements to the art of controlling operation of multiple valves in a well. By interconnecting thedevice24 to theactuators42 of thevalves12, the valves can be conveniently, economically and quickly closed when desired. Thedevice24 can also be used to open thevalves12. Thevalves12 can be simultaneously closed and/or opened, if desired.

The above disclosure provides to the art a method of controlling operation ofmultiple valves12b-dinterconnected in atubular string14 in a subterranean well. The method can include opening each of thevalves12b-d, and then closing thevalves12b-din response to an application of pressure to thetubular string14.

Closing thevalves12b-dcan include closing all of thevalves12b-din response to only the single application of pressure to thetubular string14.

Closing thevalves12b-dcan include closing all of thevalves12b-dsimultaneously in response to the application of pressure to thetubular string14.

The method may include installing aplug56 in thetubular string14 after opening each of thevalves12b-d, and prior to closing thevalves12b-d. Installing theplug56 can include sealing theplug56 in avalve control device24 connected via at least one

flow path

30a,30bto anactuator42 of each of thevalves12b-d. Closing thevalves12b-dmay include generating a pressure differential across theplug56, the pressure differential also being generated in theactuator42 of each of thevalves12b-d, thereby closing the valves.

The method can include, after closing thevalves12b-d, then opening the valves in response to another application of pressure to thetubular string14. Opening thevalves12b-dafter closing the valves may include opening all of the valves simultaneously.

The method can include installing aplug56 in thetubular string14 after closing thevalves12b-d. Opening thevalves12b-dafter closing the valves may include generating a pressure differential across theplug56, the pressure differential also being generated in anactuator42 of each of thevalves12b-d, thereby opening the valves.

Also provided by the above disclosure is awell system10. Thewell system10 can includemultiple valves12b-dinterconnected in atubular string14, each of the valves including anactuator42, and avalve control device24 interconnected in thetubular string14. Thevalve control device24 is connected to each of thevalve actuators42 via

multiple flow paths

30a,30b, whereby a pressure differential generated between the

flow paths

30a,30bis also generated in each of thevalve actuators42.

Thewell system10 may also include aplug56 which sealingly engages aseat48 in thevalve control device24. Theseat48 may be disposed between the

flow paths

30a,30bin thevalve control device24, whereby the pressure differential generated between the

flow paths

30a,30bis generated across theplug56.

Each of thevalves12b-dmay also include aseat38, which is sealingly engaged by aplug36 to thereby open the valve. Each of thevalves12b-dcan be opened by an application of pressure to thetubular string14 when therespective plug36 is sealingly engaged with thecorresponding seat38.

The pressure differential generated between the

flow paths

30a,30bmay open thevalves12b-d. Thevalves12b-dmay open simultaneously in response to the pressure differential generated between the

flow paths

30a,30b.

The pressure differential generated between the

flow paths

30a,30bmay close thevalves12b-d. Thevalves12b-dmay close simultaneously in response to the pressure differential generated between the

flow paths

30a,30b.

The pressure differential generated between the

flow paths

30a,30bmay open thevalves12b-dwhen oneplug56 is sealingly engaged in thevalve control device24, and the pressure differential generated between the

flow paths

30a,30bmay close thevalves12b-dwhen anotherplug56 is sealingly engaged in thevalve control device24.

It is to be understood that the various examples described above may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present disclosure. The embodiments illustrated in the drawings are depicted and described merely as examples of useful applications of the principles of the disclosure, which are not limited to any specific details of these embodiments.

In the above description of the representative examples of the disclosure, directional terms, such as “above,” “below,” “upper,” “lower,” etc., are used for convenience in referring to the accompanying drawings. In general, “above,” “upper,” “upward” and similar terms refer to a direction toward the earth's surface along a wellbore, and “below,” “lower,” “downward” and similar terms refer to a direction away from the earth's surface along the wellbore.

Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are within the scope of the principles of the present disclosure. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.

Claims

1. A method of controlling operation of multiple valves interconnected in a tubular string in a subterranean well, the method comprising:

opening each of the valves; and

then closing the valves in response to an application of pressure to the tubular string.

2. The method ofclaim 1, wherein closing the valves further comprises closing all of the valves in response to only the single application of pressure to the tubular string.

3. The method ofclaim 1, wherein closing the valves further comprises closing all of the valves simultaneously in response to the application of pressure to the tubular string.

4. The method ofclaim 1, further comprising installing a plug in the tubular string after opening each of the valves, and prior to closing the valves.

5. The method ofclaim 4, wherein installing the plug further comprises sealing the plug in a valve control device connected via at least one flow path to an actuator of each of the valves.

6. The method ofclaim 5, wherein closing the valves further comprises generating a pressure differential across the plug, the pressure differential also being generated in the actuator of each of the valves, thereby closing the valves.

7. The method ofclaim 1, further comprising, after closing the valves, then opening the valves in response to another application of pressure to the tubular string.

8. The method ofclaim 7, wherein opening the valves after closing the valves further comprises opening all of the valves simultaneously.

9. The method ofclaim 7, further comprising installing a plug in the tubular string after closing the valves.

10. The method ofclaim 9, wherein opening the valves after closing the valves further comprises generating a pressure differential across the plug, the pressure differential also being generated in an actuator of each of the valves, thereby opening the valves.

11. A well system, comprising:

multiple valves interconnected in a tubular string, each of the valves including an actuator; and

a valve control device interconnected in the tubular string, the valve control device being connected to each of the valve actuators via multiple flow paths, whereby a pressure differential generated between the flow paths is also generated in each of the valve actuators.

12. The well system ofclaim 11, further comprising a plug which sealingly engages a seat in the valve control device.

13. The well system ofclaim 12, wherein the seat is disposed between the flow paths in the valve control device, whereby the pressure differential generated between the flow paths is generated across the plug.

14. The well system ofclaim 11, wherein each of the valves further includes a seat, which is sealingly engaged by a plug to thereby open the valve.

15. The well system ofclaim 14, wherein each of the valves is opened by an application of pressure to the tubular string when the respective plug is sealingly engaged with the corresponding seat.

16. The well system ofclaim 11, wherein the pressure differential generated between the flow paths opens the valves.

17. The well system ofclaim 16, wherein the valves open simultaneously in response to the pressure differential generated between the flow paths.

18. The well system ofclaim 11, wherein the pressure differential generated between the flow paths closes the valves.

19. The well system ofclaim 18, wherein the valves close simultaneously in response to the pressure differential generated between the flow paths.

20. The well system ofclaim 11, wherein the pressure differential generated between the flow paths opens the valves when a first plug is sealingly engaged in the valve control device, and wherein the pressure differential generated between the flow paths closes the valves when a second plug is sealingly engaged in the valve control device.