US20040256098A1 - Apparatus for and a method of anchoring an expandable conduit - Google Patents

Abstract

The present invention provides apparatus and a method of anchoring an expandable conduit. A formation is provided on an outer surface of the conduit, the formation comprising a number of bands of a friction and/or sealing material. When the expandable conduit is radially expanded, the friction and/or sealing material engages a second conduit in which the expandable conduit is located. The engagement of the friction and/or sealing material provides an anchor for the expandable conduit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of co-pending U.S. patent application Ser. No. 10/069,990, filed Jul. 8, 2002, which claims priority to Great Britain patent application number 9920936.3, filed Sep. 6, 1999. Each of the aforementioned related patent applications is herein incorporated by reference.[0001]
BACKGROUND OF THE INVENTIONField of the Invention
• The present invention relates to apparatus for and a method of anchoring an expandable conduit, particularly, but not exclusively, to a second conduit in which the expandable conduit is located.[0002]
SUMMARY OF THE INVENTION
• A borehole is conventionally drilled during the recovery of hydrocarbons from a well, the borehole typically being lined with a casing that is cemented into place. Casings are installed to prevent the formation around the borehole from collapsing. In addition, casings prevent unwanted fluids from the surrounding formation from flowing into the borehole, and similarly, prevent fluids from within the borehole escaping into the surrounding formation.[0003]
• It is known to use a pliable casing that can be radially expanded so that an outer surface of the casing contacts the formation around the borehole. The pliable casing undergoes plastic deformation when expanded, typically by passing an expander device, such as a ceramic or steel cone or the like, through the casing. The expander device is propelled along the casing in a similar manner to a pipeline pig and may be pushed (using fluid pressure for example) or pulled (using drill pipe, rods, coiled tubing, a wireline or the like).[0004]
• Lengths of expandable casing are coupled together (typically by threaded couplings) to produce a casing string. The casing string is inserted into the borehole in an unexpanded state and is subsequently expanded using the expander device. However, the unexpanded casing string requires to be anchored either at an upper end or a lower end thereof before and/or during the expansion process.[0005]
• According to a first aspect of the present invention, there is provided apparatus for anchoring an expandable conduit, the apparatus comprising at least one formation provided on an outer surface of the expandable conduit, the formation being capable of engaging a second conduit in which the expandable conduit is located, the formation providing an anchor and/or seal for the expandable conduit when the expandable conduit is at least partially expanded.[0006]
• According to a second aspect of the present invention, there is provided a method of anchoring an expandable conduit, the method comprising the steps of providing an expandable conduit having at least one formation on an outer surface thereof, the formation being capable of engaging a second conduit in which the expandable conduit is located to provide an anchor and/or seal for the expandable conduit, anchoring the expandable conduit to the second conduit, and expanding at least a portion of the expandable conduit to force the formation into contact with the second conduit.[0007]
• The invention also provides expandable conduit such as casing or the like, the conduit having a formation on its outer surface adapted to engage a second member when the expandable conduit is expanded.[0008]
• The formation typically comprises resilient material, typically first and second bands of a first resilient material such as rubber, the first and second bands being axially spaced apart, with a third band of a second resilient material such as a second rubber being located between the first and second bands. The first material is preferably harder than the second material. The first and/or second materials may be profiled on an outer surface thereof to enhance anchoring and/or sealing.[0009]
• In one specific embodiment of the invention, the first and second bands comprise 2 inch (approximately 51 millimetres) wide bands, spaced apart by 10 inches (approximately 250 millimetres). The third band typically comprises a 10 inch (approximately 250 millimetres) wide band. The first rubber is typically a 60 durometer rubber. The second rubber is typically a 40 durometer rubber. The bands of rubber can be of any suitable hardness and width. Alternatively, the first rubber can be a 90 durometer rubber, and the second rubber can be a 60 durometer rubber.[0010]
• In an alternative embodiment, the formation comprises a band of rubber or other suitable resilient material. The band preferably defines a zigzag pattern on the outer surface of the conduit. The rubber can be of any suitable hardness, but is typically in the order of 40 to 90 durometers, although values of hardness beyond this range may also be used.[0011]
• The material properties and configuration of each formation can be chosen to suit the particular application.[0012]
• The expandable conduit typically comprises an expandable casing or liner. However, the expandable conduit may be any suitable expandable pipe or the like.[0013]
• The formation is optionally detachable and preferably applied to the outer surface of the conduit before the conduit is expanded. The formation optionally comprises two or more axially spaced formations.[0014]
• The second conduit typically comprises a borehole, casing, liner or the like. The expandable casing may engage any type of conduit. The method of the invention typically includes the additional step of providing an expander device to radially expand the expandable conduit.[0015]
• The expander device typically comprises a cone. The expander device may be manufactured from steel. Alternatively, the expander device may be manufactured from a ceramics material, or a combination of steel and a ceramics material. The expander device is optionally flexible.[0016]
• The expandable conduit is typically temporarily anchored to the second conduit using a mechanical or other anchoring device (e.g. a slip).[0017]
BRIEF DESCRIPTION OF THE DRAWINGS
• Embodiments of the present invention shall now be described, by way of example only, with reference to the accompanying drawing in which:[0018]
• FIG. 1 is a schematic cross-section of an exemplary embodiment of apparatus for anchoring an expandable conduit to a borehole;[0019]
• FIG. 2[0020]ais a front elevation showing a first configuration of a formation applied to an outer surface of the apparatus of FIG. 1;
• FIG. 2[0021]bis an end elevation of the formation of FIG. 2a;
• FIG. 2[0022]cis an enlarged view of a portion of the formation of FIGS. 2aand2bshowing a profiled outer surface;
• FIG. 3 is a schematic cross-section of an alternative embodiment of apparatus for anchoring an expandable conduit to a borehole having a different formation on an outer surface;[0023]
• FIG. 4[0024]ais an front elevation of the formation of FIG. 3; and
• FIG. 4[0025]bis an end elevation of the formation of FIG. 4a.
DETAILED DESCRIPTION
• Referring to the drawing, FIG. 1 shows an exemplary embodiment of apparatus for anchoring an[0026]expandable conduit12. Theexpandable conduit12 is shown located within a casing orliner14. Conventionally, casing orliner14 is used to line or case a borehole that is drilled into aformation16 to facilitate the recovery of hydrocarbons. It should be noted however, that theexpandable conduit12 may be a liner or casing used to case or line the borehole.
• The[0027]expandable conduit12 may be any type of suitable conduit that is capable of sustaining plastic deformation whereby it can be radially expanded by at least 10%, although it may be radially expanded by a value more or less than this.
• The upper portion of FIG. 1 shows the[0028]expandable conduit12 in unexpanded form, with anexpander device18 located therein used to impart a radial expansion force. The lower portion of FIG. 1 shows a portion of theexpandable conduit12 radially expanded by theexpander device18.
• The[0029]expander device18 typically comprises a cone. Theexpander device18 may be manufactured from steel, or alternatively may be manufactured from a ceramics material, or a combination of steel and a ceramics material. Theexpander device18 is optionally flexible, although this is advantageous where theexpander device18 is required to expand an expandable conduit that includes a curvature or the like. Any conventional type ofexpander device18 may be used.
• As shown in FIG. 1, the[0030]expandable conduit12 is provided with at least one formation, generally designated20, (only oneformation20 shown in FIG. 1) on anouter surface12sthereof. Theformation20 typically comprises first andsecond bands22,24 that are axially spaced apart along alongitudinal axis26 of theexpandable conduit12. The first andsecond bands22,24 are typically axially spaced by some distance, for example 10 inches (approximately 250 mm). The first andsecond bands22,24 are preferably annular bands that extend circumferentially around theouter surface12sof theexpandable conduit12, although this configuration is not essential. The first andsecond bands22,24 typically comprise 2 inch wide (approximately 51 mm) bands of a first type of rubber. Theformation20 need not extend around the full circumference of thesurface12s.
• Located between the first and[0031]second bands22,24 is athird band28 of a second type of rubber. Thethird band28 preferably extends between the first andsecond bands22,24 and is thus typically 10 inches (approximately 250 mm) wide. The first andsecond bands22,24 are typically of a first depth. Thethird band28 is typically of a second depth. The first depth is typically larger than the second depth, although they may be the same. Thus, the first andsecond bands22,24 protrude further from thesurface12sthan thethird band28, as shown schematically in FIG. 1.
• The first type of rubber (i.e. first and[0032]second bands22,24) is preferably of a harder consistency than the second type of rubber (i.e., third band28). The first type of rubber is typically 60 durometer rubber, whereas the second type of rubber is typically 40 durometer rubber. Durometer is a conventional hardness scale for rubber.
• The particular properties of the rubber may be of any suitable type and the hardnessess quoted are exemplary only. It should also be noted that the relative dimensions and spacings of the first, second and[0033]third bands22,24,28 are exemplary only and may be of any suitable dimensions and spacing.
• Referring to FIGS. 2[0034]ato2c, there is shown analternative formation50 that is substantially the same asformation20. In the embodiment shown in FIGS. 2ato2c, theformation50 comprises first andsecond bands52,54 of a first resilient material, with athird band56 of a second resilient material located therebetween.
• The first and[0035]second bands52,54 are around 1 inch (approximately 25.4 mm) wide, and are spaced-apart by around 3 inches (approximately 76 mm); thethird band56 is thus 3 inches wide.
• The first resilient material of the first and[0036]second bands52,54 is typically harder than the second resilient material of thethird band56. In the embodiment shown in FIGS. 2ato2c, the first resilient material comprises a rubber with a 90 durometer hardness, and the second resilient material comprises a rubber with a 60 durometer hardness.
• Unlike[0037]formation20, the depths of thebands52,54,56 are substantially the same. As can be seen from FIG. 2cin particular, anouter face56sof thethird band56 can be profiled. Theouter face56sis ribbed to enhance the grip of thethird band56 on an inner face of a second conduit (e.g. a preinstalled portion of liner, casing or the like, or a wellbore formation) in which theexpandable conduit12 is located. It will be appreciated that an outer surface on the first andsecond bands52,54 may also be profiled (e.g. ribbed).
• The two[0038]outer bands52,54 being of a harder rubber provide a relatively high temperature seal and a back-up seal to the relatively softer rubber of thethird band56. Thethird band56 typically provides a lower temperature seal.
• In use, the[0039]formation20,50 is applied to theouter surface12sof the (unexpanded)expandable conduit12. Theformation20,50 may be applied at axially spaced-apart locations long the length of theexpandable conduit12, the spacings and number offormations20,50 being chosen to suit the particular application.
• The[0040]expandable conduit12 is then run into a borehole, casing orliner14, or some other conduit onto which theexpandable conduit12 is to be attached. As can be seen in FIG. 1 (upper portion) when theexpandable conduit12 is run into the casing orliner14, anannulus30 is created between theouter surface12sof theexpandable conduit12 and aninner surface14iof the casing orliner14. Theexpander device18 is typically located in an expandedportion12eof theexpandable conduit12 before theconduit12 is run into the casing orliner14. It should be noted that theconduit12 is of the non-interference type wherein theannulus30 remains (although reduced in size) even when theexpandable conduit12 is radially expanded i.e., there is a gap between theexpandable conduit12 and the casing orliner14.Expandable conduit12 need not be of the non-interference type.
• As the[0041]outer surface12sof theexpandable conduit12 is not in direct contact with theinner surface14iof the casing orliner14, a mechanical or other type of anchoring device32 (e.g. a slip) is used to provide a temporary anchor whilst at least a portion of theexpandable conduit12 is radially expanded. The mechanical or other type of anchoringdevice32 may be of any conventional type and is typically attached at or near, the expandedportion12eof theexpandable conduit12. When the mechanical or other type of anchoringdevice32 is set, theexpander device18 is pushed or pulled through theexpandable conduit12 in the direction ofarrow34. Theexpander device18 may be propelled through theexpandable conduit12 using fluid pressure, or may be pigged along theexpandable conduit12 using a conventional pig or tractor (not shown). Theexpander device18 may alternatively be propelled using a weight (from a string for example), or may by pulled through the expandable conduit12 (e.g. using drill pipe, rods, coiled tubing, a wireline or the like).
• As the[0042]expander device18 is propelled along the expandable conduit12 (using any conventional means), it radially expands theconduit12, as illustrated in the lower portion of FIG. 1. As theconduit12 is expanded, theformation20,50 is also expanded whereby theformation20,50 (i.e. first, second andthird bands22,24,28,52,54,56 of rubber) engage with a portion of theinner surface14iof casing orliner14. It is advantageous to have an outer surface of the first and second rubbers (i.e.bands22,24,52,54), and optionally the third rubber (i.e.band28,56), profiled (e.g. ribbed or the like) to enhance the anchoring and/or sealing.
• As the first, second and[0043]third bands22,24,28,52,54,56 of rubber engage theinner surface14iof the casing orliner14, they provide an anchor point due to the friction caused between the first and/or second rubbers and theinner surface14i. This anchor point anchors theexpandable conduit12 to the casing orliner14.
• Additionally, the first and/or second rubbers may also act as a seal that results in an annular pressure seal that seals the[0044]annulus30. Where two ormore formations20,50 are provided at axially spaced-apart locations, the portions of theannulus30 between theformations20,50 will be isolated from one another.
• After the[0045]formation20,50 has been expanded whereby the first and second rubbers provide at least an anchor point for the expandable casing12 (and optionally a seal for annulus30), the mechanical or other type of anchoringdevice32 can be released, and optionally removed from the casing orliner14.
• Referring to FIG. 3, there is shown an alternative[0046]expandable conduit100, that is a second embodiment of apparatus of the present invention.Expandable conduit100 is substantially the same asexpandable conduit12, but has a furtheralternative formation150 on anouter surface100sthereof.
• The[0047]expandable conduit100 may be any type of suitable conduit that is capable of sustaining plastic deformation whereby it can be radially expanded by at least 10%, although it may be radially expanded by a value more or less than this.
• As can be seen from FIG. 3, the[0048]expandable conduit100 is provided with apre-expanded portion100ein which an expander device (e.g. expander device18) may be located whilst theconduit100 is run into a borehole or the like. It should be noted that the expander device need not be located in theconduit100 whilst it is being run into the borehole, and can be located in theconduit100 once it is in place.
• As shown in FIG. 3, the[0049]expandable conduit100 is provided with at least one formation, generally designated150. A number offormations150 are shown applied to theouter surface100sof theconduit100, each formation being axially spaced from one another by around 12 inches (approximately 305 mm).
• The[0050]formation150 is best shown in FIGS. 4aand4b. Thealternative formation150 is in the form of a zigzag. In this embodiment, the or eachformation150 comprises a single (preferably annular) band of rubber that is, for example, of 90 durometers hardness and is about 2.5 inches (approximately 28 mm) wide by around 0.12 inches (approximately 3 mm) deep.
• To provide a zigzag pattern and hence increase the strength of the grip and/or seal that the[0051]formation150 provides in use, a number ofslots152a,152b(e.g.20) are milled into the band of rubber. Theslots152a,152bare typically in the order of 0.2 inches (approximately 5 mm) wide by around 2 inches (approximately 50 mm) long.
• The[0052]slots152aare milled at around 20 circumferentially spaced-apart locations, with around 18° between each along oneedge150aof the band. The process is then repeated by milling another20slots152bon theother side150bof the band, the slots on the other side being circumferentially offset by 9° from theslots152aon the other side.
• In use, the[0053]formation150 is applied to theouter surface100sof the (unexpanded)expandable conduit100. Theformation150 may be applied at axially spaced-apart locations along the length of theexpandable conduit100, as shown in FIG. 3, the spacings and number offormations100 being chosen to suit the particular application.
• The[0054]expandable conduit100 is then run into a borehole, casing orliner14, or some other conduit onto which theexpandable conduit100 is to be attached, and is used in substantially the same way asconduit12 described above.
• Using the method and apparatus described herein for anchoring an expandable conduit to a second conduit, it is possible to case a wellbore using an expandable conduit provided with the formation, without the use of cement. This has significant advantages, particularly in terms of cost due to the reduction of materials required and rig down-time.[0055]
• Thus, there is provided a method and apparatus of anchoring an expandable conduit to a second conduit. Certain embodiments of the apparatus and method optionally provide a seal between the expandable conduit and the second conduit. Certain embodiments of the apparatus include a formation of different layers or bands of resilient materials that are specially arranged and composed to provide a good anchor and/or seal between the expandable conduit and the second conduit.[0056]
• Modifications and improvements may be made to the foregoing without departing from the scope of the present invention.[0057]

Claims (20)

1. A method of expanding a tubular in a wellbore, comprising:

expanding a portion of the tubular, the tubular having at least one resilient member disposed around its outer surface in the expanded area; and

causing the resilient member to contact the wellbore in a sealing and frictional relationship while leaving an annular area defined between the outer tubular wall and the wellbore.

2. The method ofclaim 1, further comprising setting an anchor that temporarily retains the tubular prior to causing the resilient member to contact the wellbore.

2. The method ofclaim 1, further comprising setting a slip that temporarily retains the tubular prior to causing the resilient member to contact the wellbore.

3. The method ofclaim 1, further comprising:

setting an anchor that temporarily retains the tubular prior to causing the resilient member to contact the wellbore; and

releasing the anchor after causing the resilient member to contact the wellbore.

4. The method ofclaim 1, wherein the at least one resilient member includes a plurality of resilient members.

5. The method ofclaim 1, where the at least one resilient member includes a plurality of resilient members spaced from one another.

6. The expandable liner hanger ofclaim 1, wherein the resilient member includes profiles on an outer surface thereof.

7. The expandable liner hanger ofclaim 1, wherein the resilient member includes ribs on an outer surface thereof.

8. The expandable liner hanger ofclaim 1, wherein the resilient member is a rubber material.

9. An expandable liner hanger for use in a wellbore, comprising:

a tubular body, the body expandable at an upper end thereof;

an resilient ring disposed around the upper end; and

the hanger constructed and arranged to retain and seal the expanded body in the wellbore while leaving an annular area between an outer wall of the expanded body and the wellbore.

10. The expandable liner hanger ofclaim 9, wherein the resilient ring includes profiles on an outer surface thereof.

11. The expandable liner hanger ofclaim 9, wherein the resilient ring includes ribs on an outer surface thereof.

12. The expandable liner hanger ofclaim 9, further comprising at least one additional resilient ring disposed around the upper end.

13. The expandable liner hanger ofclaim 9, further comprising at least one additional resilient ring disposed around the upper end, the resilient rings spaced from one another.

14. The expandable liner hanger ofclaim 9, further comprising a temporary anchor separate from the resilient ring.

15. The expandable liner hanger ofclaim 9, further comprising a temporary anchor separate from the resilient ring, wherein the temporary anchor includes a slip.

16. The expandable liner hanger ofclaim 9, wherein the resilient ring is a rubber material.

17. A method of expanding a first tubular in a second tubular located in a wellbore, comprising:

locating a portion of the first tubular within the second tubular, the portion of the first tubular having a resilient member on a section of an outside surface thereof; and

expanding the first tubular at least along the section to a predetermined diameter, the predetermined diameter selected to compress the resilient member in a sealing and frictional relationship between the first and second tubular that remain concentrically spaced from one another.

18. The method ofclaim 17, wherein the resilient member includes profiles on an outer surface thereof.

19. The method ofclaim 17, further comprising at least one additional resilient member, the resilient members spaced from one another.

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