U.S. patent application number 11/171061 was filed with the patent office on 2007-01-04 for axial compression enhanced tubular expansion.
This patent application is currently assigned to Weatherford/Lamb, Inc.. Invention is credited to Simon Harrall, David Hillis, Paul Metcalfe, Lev Ring.
Application Number | 20070000664 11/171061 |
Document ID | / |
Family ID | 36888403 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070000664 |
Kind Code |
A1 |
Ring; Lev ; et al. |
January 4, 2007 |
Axial compression enhanced tubular expansion
Abstract
Methods and apparatus for expanding a tubular with the aid of a
compressive force are disclosed. A tubular is run into a wellbore.
While the tubular is in a compressive state, the tubular is
expanded into its desired form. The expanded tubular can be used
for multiple downhole functions such as completing multilateral
junctions in a wellbore, patching apertures in a wellbore and
lining a wellbore.
Inventors: |
Ring; Lev; (Houston, TX)
; Metcalfe; Paul; (Crathes, GB) ; Harrall;
Simon; (Houston, TX) ; Hillis; David;
(Balmedie, GB) |
Correspondence
Address: |
PATTERSON & SHERIDAN, L.L.P.
3040 POST OAK BOULEVARD, SUITE 1500
HOUSTON
TX
77056
US
|
Assignee: |
Weatherford/Lamb, Inc.
|
Family ID: |
36888403 |
Appl. No.: |
11/171061 |
Filed: |
June 30, 2005 |
Current U.S.
Class: |
166/277 ;
166/207; 166/380 |
Current CPC
Class: |
E21B 41/0042 20130101;
E21B 43/105 20130101; E21B 43/103 20130101 |
Class at
Publication: |
166/277 ;
166/380; 166/207 |
International
Class: |
E21B 23/00 20060101
E21B023/00 |
Claims
1. A method of expanding a tubular in a wellbore, comprising:
positioning the tubular in the wellbore; affixing at least first
and second locations spaced along a length of the tubular to
desired locations in the wellbore; and expanding a portion of the
tubular between the locations outward radially with a rotary
expander tool, such that the tubular is in axial compression while
expanding.
2. The method of claim 1, wherein affixing the second location
includes supporting a lower end of the tubular on a bottom of the
wellbore.
3. The method of claim 1, wherein affixing the at least first and
second locations includes expanding the tubular into frictional
contact with a surrounding surface.
4. The method of claim 1, wherein affixing the at least first and
second locations includes setting slips on an outer surface of the
tubular.
5. The method of claim 1, wherein affixing the second location
includes supporting a lower end of the tubular on a plug.
6. The method of claim 1, wherein the tubular is longitudinally
corrugated.
7. The method of claim 1, wherein the tubular includes shaped
pipe.
8. The method of claim 1, wherein the compression is at least
partly as a result of the expanding.
9. A method of lining a drilled wellbore, comprising: running a
tubular into a wellbore; applying a compressive force to at least a
portion of the tubular; and applying fluid pressure to an inside
surface of the tubular in an area of the tubular that is in
compression to expand the tubular to a larger diameter.
10. The method of claim 9, further comprising supporting a lower
end of the tubular on a bottom of the wellbore.
11. The method of claim 10, wherein applying the compressive force
includes placing weight on an upper end of the tubular.
12. The method of claim 9, wherein applying the compressive force
includes operating a compressive force apparatus.
13. The method of claim 9, wherein applying the fluid pressure to
the inside surface of the tubular expands a lower portion of the
tubular into a bell shaped configuration.
14. The method of claim 9, wherein running the tubular includes
positioning the tubular in the wellbore proximate to a window in
the wellbore.
15. The method of claim 14, wherein applying the fluid pressure to
the inside surface of the tubular forms a bulge in a wall of the
tubular that extends into a lateral junction which starts at the
window.
16. The method of claim 15, further comprising drilling out a
portion of the wall of the tubular that is extended into the
lateral junction.
17. The method of claim 16, further comprising hanging a liner from
the tubular extended into the lateral junction.
18. An apparatus for wellbore completion, comprising: a tubular
coupled to a conveyance member; one or more compression pistons for
applying a compressive load to at least a length of the tubular;
and first and second seals for isolating an inside of the tubular
corresponding to at least a portion of the length of the tubular
having the compressive load applied thereto, wherein a port to the
inside of the tubular supplies hydraulic pressure for acting on a
inner surface of the tubular and expanding the tubular.
19. The apparatus of claim 18, further comprising a radially
extendable expander for expanding sections of the tubular proximate
the first and second seals.
20. The apparatus of claim 18, wherein the tubular is
longitudinally corrugated.
21. The apparatus of claim 18, wherein the tubular is shaped
pipe.
22. A method of expanding a tubular in a wellbore, comprising:
positioning the tubular in the wellbore; applying a compressive
force to at least a portion of the tubular; and expanding the
portion of the tubular in compression outwardly, wherein expanding
includes translating an expansion tool axially while the tubular is
in compression.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments of the invention generally relate to expanding
tubulars in a wellbore. More particularly, embodiments of the
invention relate to the expansion of the tubulars enhanced by use
of compressive forces applied to the tubulars.
[0003] 2. Description of the Related Art
[0004] Hydrocarbon and other wells are completed by forming a
borehole in the earth and then lining the borehole with pipe or
casing to form a wellbore. After a section of wellbore is formed by
drilling, a section of casing is lowered into the wellbore and
temporarily hung therein from the surface of the well. Using
apparatus known in the art, the casing is cemented into the
wellbore by circulating cement into the annular area defined
between the outer wall of the casing and the borehole. The
combination of cement and casing strengthens the wellbore and
facilitates the isolation of certain areas of the formation behind
the casing for the production of hydrocarbons.
[0005] Recent developments in the oil and gas exploration and
extraction industries have included using expandable bore lining
tubing. Apparatus and methods are emerging that permit tubulars to
be expanded in situ. The most common expansion apparatus is a cone
or a swedge. Some expansion apparatus include expander tools which
are fluid powered and are run into the wellbore on a working
string. These hydraulic expander tools can include radially
extendable members which, through fluid pressure, are urged outward
radially from the body of the expander tool and into contact with a
tubular therearound. As sufficient pressure is generated on a
piston surface behind these extendable members, the tubular being
acted upon by the expansion tool is expanded past its point of
plastic deformation. In this manner, the inner and outer diameter
of the tubular is increased in the wellbore. By rotating the
expander tool in the wellbore and/or moving the expander tool
axially in the wellbore with the extendable members actuated, a
tubular can be expanded along a predetermined length in a wellbore.
Other methods include using hydraulic pressure inside the tubular
to expand the tubular past its point of plastic deformation.
[0006] Multiple uses for expandable tubulars are being discovered.
For example, an intermediate string of casing can be hung off a
string of surface casing by expanding a portion of the intermediate
string into frictional contact with the lower portion of surface
casing therearound. This allows for the hanging of a string of
casing without the need for a separate slip assembly. Additional
applications for the expansion of downhole tubulars exist. These
include the use of an expandable sand screen, employment of an
expandable seat for seating a diverter tool, and the use of an
expandable seat for setting a packer.
[0007] There are problems associated with the expansion of
tubulars. One particularly associated with rotary expander tools is
that the rotary expansion of the tubular makes the wall of the
tubular thinner. This then increases the overall length of the
tubular which is problematic when trying to determine location in
the well. Further, expandable tubulars are currently limited to an
expansion of 10%-25% of their original diameter using existing
expansion techniques that are constrained by the tubular burst
pressure and friction applied thereto. Also when using hydraulic
pressure to expand the tubular, due to the high pressure required,
weaknesses in the tubular are exploited limiting the amount of
expansion that can be achieved before the tubular ruptures.
[0008] There exists a need for an improved method and apparatus for
expanding casing or other tubulars within a wellbore. Further,
there exists a need for method and apparatus for expanding a
tubular which requires less outward force or hydraulic pressure on
the tubular with increased expansion. There exists yet a further
need for an apparatus and method for expanding a tubular which
reduces the risk of uneven expansion of the tubular by reducing the
amount of force needed for the expansion operation. Further, there
exists a need for a method of expanding a tubular and accurately
controlling the location of the tubing.
SUMMARY OF THE INVENTION
[0009] Embodiments of the invention generally relate to methods and
apparatus for expanding tubulars in a wellbore enhanced by
compressive force applied to the tubulars. According to one aspect
of the invention, a method of expanding a tubular in a wellbore
includes positioning the tubular in the wellbore, affixing at least
two locations spaced along a length the tubular to desired
locations in the wellbore, and expanding a portion of the tubular
between the two locations outward radially with a rotary expander
tool, such that the tubular is in compression while expanding.
According to another aspect of the invention, methods and apparatus
provide for expanding a tubular run into a wellbore by applying a
compressive force to at least a portion of the tubular and applying
fluid pressure to an inside surface of the tubular to expand the
tubular to a larger diameter. The tubular can be located proximate
to a window in the wellbore such that expanding the compressed
portion of the tubular covers the window and may form a bulge
extending through the window.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] So that the manner in which the above recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments thereof which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0011] FIG. 1 is a sectional view of a wellbore having a tubular
disposed therein for expansion according to aspects of the
invention;
[0012] FIG. 2 is a sectional view of a tubular and an expansion
assembly attached to a work string and disposed in a wellbore;
[0013] FIG. 3 is a sectional view of the tubular of FIG. 2 after
expansion with hydraulic pressure applied to an inside surface
thereof;
[0014] FIG. 4 is a sectional view of the tubular of FIG. 2 after
completing expansion with hydraulic pressure;
[0015] FIG. 5 is a sectional view of the tubular of FIG. 4 after
being expanded in a wellbore with a multilateral junction;
[0016] FIG. 6 is a sectional view of the tubular of FIG. 5 after
being fully expanded;
[0017] FIG. 7 is a sectional view of the multi-lateral junction of
FIG. 5 completed with the tubular expanded and drilled out; and
[0018] FIGS. 8 to 11 are schematic illustrations of steps in the
process of lining a bore in accordance with embodiments of the
invention.
DETAILED DESCRIPTION
[0019] FIG. 1 illustrates a cross-sectional view of a wellbore 100
and a tubular 110 disposed therein. The tubular 110 can be casing
or any other type of tubular used in downhole drilling operations,
such as a liner or a patch. First and second fixed locations 120,
130 spaced apart along the length of the tubular 110 substantially
prevent axial movement of the tubular 110 in the wellbore 100 such
that the distance between the fixed locations 120, 130 cannot vary.
The fixed locations 120, 130 can be achieved by any method or
combination of methods known in the art, such as by using anchors
or slips on an outside of the tubular 110 to engage a surrounding
surface, by selectively expanding the tubular 110 at one or both of
the fixed locations 120, 130 into frictional contact with the
surrounding surface or by locating the bottom of the tubular 110 on
a stop such as a plug, a packer or a bottom of the borehole (see,
FIGS. 9-12). In the embodiment shown in FIG. 1, the fixed locations
120, 130 have been expanded to place the outside surface of the
tubular 110 into contact with a surrounding surface. Expansion of
the fixed locations 120, 130 can be performed by either using a
rotary expander tool 140 or additional expander(s) (not shown),
such as one or more inflatable members or packers, capable of
selective expansion at the fixed locations 120, 130. The fixed
locations 120, 130 create an annular space between the tubular 110
and the wellbore 100. To facilitate expansion of the tubular 110,
fluid in the annular space can escape through apertures (not shown)
in a surrounding casing and into a formation, through apertures in
the tubular 110, across flow paths at one or both of the fixed
locations 120, 130 such as by only partial circumferential
expansion, and/or directly into the surrounding formation when in
an open wellbore. For example, the tubular 110 may serve as a patch
to remedy excessive mud loss in an open hole such that fluid from
the annular space can easily be pushed into the formation.
[0020] U.S. Pat. No. 6,457,532, which is herein incorporated by
reference in its entirety, discloses an exemplary rotary expander
tool that can be used as the rotary expander tool 140 schematically
illustrated in FIG. 1. The rotary expander tool 140 operates to
expand the length of the tubular 110 between the fixed locations
120, 130. Typically, the rotary expander tool 140 starts at one
fixed location (e.g., the first fixed location 120) and progresses
to the other fixed location (e.g., second fixed location 130)
expanding the tubular 110 along the way. If only one location along
the tubular is initially fixed, expansion can start a distance from
that location to thereby provide the other fixed location prior to
the rotary expander tool 140 moving toward the initially fixed
location. The tubular need not be placed in compression prior to
starting expansion of the tubular 110 between the two fixed
locations 120, 130 since a compressive load in the tubular 110
develops as expansion with the rotary expander tool 140 progresses.
This is due to the fact that use of the rotary expander tool 140
lengthens the tubular 110 by thinning of the tubular wall which,
because the fixed locations 120 130 are set to prevent the
elongation of the tubular 110, compresses the tubular 110. In
contrast, a cone used to expand a tubular typically causes the
tubular to shorten during expansion such that tension and not
compression develops if the cone is used to expand a section
between two fixed locations. The compression in the tubular 110
enhances the expansion process by increasing the expansion possible
and decreasing the amount of force required by the rotary expander
tool 140.
[0021] Before both of the two fixed locations 120, 130 are set, the
tubular 110 can optionally be placed in compression either through
use of gravity or a mechanical, electrical, or hydraulic device
adapted to apply a compressive load on the tubular. Since the
tubular 110 is expanded between end points that are fixed, this
increases accurate location of the tubular 110 in the wellbore 100.
Thus, this process enables accurate placement of liners, patches
and other tubulars in the wellbore without the side effects of
having the liner elongate or shorten during expansion.
[0022] FIG. 2 shows a section of the wellbore 100 with a liner 230
and expandable tubing 200. The expandable tubing 200 can be casing,
liner, a patch, or any other type of tubing used in downhole
operations for expansion into the liner 230, casing or an open
wellbore. FIG. 2 depicts the expandable tubing 200 as a patch used
for closing an aperture 235 in the wellbore 100 that is lined. The
patch can include a seal 256 and an anchoring element 257 on the
outside of the expandable tubing 200.
[0023] The expandable tubing 200 attaches to a work string 210 via
a setting tool 220. The lower end of the expandable tubing 200
attaches to the work string 210 by a carrying mechanism 240 of the
setting tool 220. The carrying mechanism 240 is any suitable
temporary connection known in the art such as carrying dogs,
collets, threads, latches, slips etc. In one embodiment the
carrying mechanism 240 is a set of pre-set slips 231. The pre-set
slips 231 engage the inside diameter of the expandable tubing 200
with a series of teeth 232. The pre-set slips 231 support the
weight of the expandable tubing 200 and the piston assembly. The
pre-set slips 231 are held in place by wedges 233 and 234. Wedge
234 is fixedly attached to the work string 210. Wedge 233 is
attached to a slip release assembly 236. The slip release assembly
236 connects to a seat 237. The seat 237 holds a sealing member
such as a dart, or ball 270 at its upper end in order to
hydraulically seal the work string 210. The seat 237 connects to
the work string 210 with a shear pin 238. Above the pre-set slips
231 is a lower pressure seal cup 239 for hydraulically sealing the
interior of the expandable tubing 200. At the upper end of the
expandable tubing 200, a compression piston 250 of the setting tool
220 attaches the expandable tubing 200 to the work string 210. The
compression piston 250 has a shoulder 253 which engages the upper
end of the expandable tubing 200. The compression piston 250 moves
relative to the work string 210 and a piston base 251. The piston
base 251 fixedly attaches to the work sting 210, thus as fluid
flows in to an annulus 252, the piston 250 pushes the expandable
tubular 200 down relative to the work string 210. With the lower
end of the expandable tubular 200 fixed to the work string 210 by
carrying mechanism 240, the expandable tubular 200 is in
compression. More than one compression piston can be used in order
to increase the compressive force applied to the expandable tubing
200, as is known in the art. The carrying mechanism 240 and the
compression piston 250 can be adapted to seal the top and bottom of
the expandable tubing 200.
[0024] As illustrated in FIG. 3, the work string 210 lowers into
the wellbore 100 to a desired location for the expandable tubing
200. Once at the desired location, the compression piston 250
actuates upon application of hydraulic pressure through the work
string 210, which can be selectively plugged by a stopper, such as
a ball 270 dropped onto the seat 237, a diverter valve such as that
disclosed in U.S. patent application Ser. No. 10/954,866 assigned
to Weatherford/Lamb, Inc. which is hereby incorporated by
reference, could also be used. The compression piston 250 urges the
attached top of the expandable tubing 200 toward the carrying
mechanism 240. This places the expandable tubing 200 in compression
since the attachment of the top of the expandable tubing 200 via
the compression piston 250 permits relative movement between the
work string 210 and the expandable tubing 200 while the attachment
of the expandable tubing 200 at the carrying mechanism 240 prevents
relative axial movement between the lower end of the expandable
tubing and the work string 210. Simultaneously, hydraulic pressure
provided through port 245 acts on an inside surface of the
expandable tubing 200 to cause radial expansion of the expandable
tubing 200 along a length of the expandable tubing 200 between the
lower pressure seal cup 239 and an upper pressure seal cup 254.
[0025] The expandable tubing 200 can utilize changes in material
and configuration in order to enhance expansion. In one embodiment,
the tubing thickness at the two fixed end points, the piston 250
and carrying mechanism 240 is larger that the expandable tubing 200
wall thickness between the fixed points. Further, in another
embodiment the yield strength and/or elastic modulus of the
expandable tubular 200 is changed between the fixed points. In
another embodiment the expandable tubular 200 is longitudinally
corrugated between the fixed points. In yet another embodiment the
expandable tubular 200 has a different material than the material
at the fixed points. Further, any of these methods can be used in
combination to enhance expansion of the expandable tubular 200.
These embodiments ensure the expandable tubular 200 expands from
the middle portion first and then outwards toward both ends. This
ensures that fluids are not trapped in the annulus between the
Expandable tubular 200 and the liner 230.
[0026] After expansion of the expandable tubing 200 with hydraulic
pressure it is necessary to ensure the expandable tubular 200 is
secure in the wellbore by pulling or pushing on the work string
210. The setting tool 220 then releases the expandable tubular 200
at the carrying mechanism 240. By increasing the hydraulic pressure
in the work string 210 the seat 237 shears the shear pin 238. This
causes the slip release assembly 236 to move down which moves the
lower wedge 233 down, releasing the pre-set slips 231 as shown in
FIG. 4. Additionally, an expander 265 (shown schematically)
actuates to an extended position having an increased outer
diameter. The expander 265 can be any type of expandable cone or
hydraulically actuated rotary expander tool, such as those
disclosed in U.S. Pat. No. 6,457,532, U.S. patent application Ser.
No. 10/808,249 and U.S. patent application Ser. No. 10/954,866,
which are hereby incorporated by reference.
[0027] FIG. 4 shows the expandable tubing 200 while the expander
265 completes expansion of the expandable tubing 200 along its
entire length. In operation, lowering the work string 210 moves the
expander 265 through the expanded section of the expandable tubular
200 and across the end of the expandable tubular 200 where
expansion was previously prevented by the carrying mechanism 240.
As the expander 265 moves through the expandable tubular 200, the
expander 265 insures proper expansion and/or further expands the
previously expanded length of the expandable tubular 200 and
expands the bottom end of the expandable tubular 200. Accordingly,
the previously unexpanded top end of the expandable tubular 200
where expansion was previously prevented due to attachment to the
compression piston 250 occurs upon pulling the expander 265 out of
the expandable tubular 200 during removal of the work string 210.
For some embodiments, the expander 265 may not be required if it is
not desired to expand the ends of the expandable tubular 200 where
the expandable tubular attaches to the setting tool 220. Further,
the expander 265 can be arranged to work in conjunction the
hydraulic expansion in order to enhance the expansion process.
Further, the expander 265 can be attached either below or above the
expandable tubular 200 or on another tool and actuated once
hydraulic expansion is complete. The work string 210 is removed
upon completion of the expansion leaving the expandable tubing 200
in place. Thus, the expandable tubing 200 can be used to patch
apertures in the casing, liner or the wellbore itself with no
liner. In another embodiment, the unexpanded portions of the
expandable tubular 200 could be removed by the apparatus and
methods disclosed in U.S. Pat. No. 6,598,678 assigned to
Weatherford/Lamb, Inc. or as disclosed U.S. Pat. No. 6,752,215
assigned to Weatherford/Lamb, Inc which are hereby incorporated by
reference. This procedure can be done multiple times in the
wellbore in order to control production from the formations.
[0028] FIGS. 5-7 depict an embodiment of the invention that
utilizes an assembly similar to that illustrated in FIGS. 2-4. FIG.
5 shows the wellbore 100 with a window 310 cut in the side to
provide an opening for a lateral junction 320. An expandable tubing
300 is shown expanded so that it covers the lateral junction 320.
The expandable tubular 300 expands using the methods described
above. Thus, the expandable tubing 300 is compressed. While in
compression, the expandable tubing 300 is expanded by fluid
pressure acting on an inside surface of the expandable tubing to
initially expand the expandable tubing 300 up to an inner diameter
of the wellbore 100, as shown in FIG. 5. The expansion process
continues by further application of hydraulic pressure to cause a
wall of the expandable tubing 300 to bulge at the window 310 and
enter the lateral junction 320, as shown in FIG. 6. For enhanced
expansion, the expandable tubing may comprise any suitable material
which can sustain an expansion ratio of greater than 20%. Further,
the expandable tubing can be initially longitudinally corrugated in
order to facilitate a high expansion ratio. The expander 265 is
removed from the wellbore. The lateral junction 320 can then be
drilled out using techniques known in the art providing a
multi-lateral junction, as shown in FIG. 7. A subsequent liner (not
shown) can be run into the lateral junction 320 and suspended off
of the tubing 300 therein.
[0029] FIGS. 8-11 depict an embodiment of the invention used to
line a wellbore 400. FIG. 8 shows the lower end of the wellbore 400
including an unlined bore section 410. Above the unlined section
410, casing 420 lines the wellbore 400. As shown, the lower end of
the casing 420 includes a larger diameter end section 425, or
bell-end, however, the lower end of the casing 420 can be straight
pipe.
[0030] An expandable tubing or liner 430 is run into the wellbore
400 on a work string 440. The liner 430 is initially coupled to the
work string 440 via a setting tool 450. The liner 430 is located in
the wellbore 400 such that the upper end of the liner 430 overlaps
the larger diameter casing end section 425. The lower end of the
liner 430 is positioned at the end of the wellbore 400. The liner
430 itself or a shoe 460 contacts the bottom of the wellbore 400.
Next, weight can optionally be set down on the liner 430. The
weight can be from the length of the work string 440, or any other
method that places the liner 430 in a compressive state.
[0031] As shown in FIG. 9, once the liner 430 is in compression, an
anchor 470 is set. The anchor 470 can be any type of liner hanger
known in the art. With the anchor 470 set, the liner 430 is held in
compression between the anchor 470 and the end of the wellbore 400.
For some embodiments, the compressive state, as discussed above
with regard to FIG. 1, may be caused solely by the expansion
process itself and not initially applied to the liner 430 prior to
setting of the anchor 470.
[0032] Next, as shown in FIG. 10, a rotary expander tool 480 moves
downwardly through the liner 430 to expand the liner 430 to a
larger diameter such that the expanded inner diameter of the liner
430 corresponds to the inner diameter of the casing 420. A more
detailed description of the setting tool and expansion tool can be
found in U.S. Patent Application Publication No. 2003/0127225,
which is herein incorporated by reference in its entirety. The
compressive state of the liner 430 enhances the expansion process
and requires less force from the rotary expander tool 480 than
conventional methods. Once the desired expansion of the liner is
complete, the liner 430 can be cemented in place, and the annulus
between the liner 430 and the casing 420 proximate the anchor 470
can be sealed.
[0033] FIG. 11 shows creation of a bulge formed monobore shoe,
which can be an additional step to the method described in FIGS.
8-10. Once the liner 430 is on the bottom of the wellbore 400,
weight is applied to the liner 430 to place the liner 430 in
compression. The bottom of the liner 430 is then expanded by fluid
pressure applied to the inner surface of the liner 430 to form a
bell shaped end 500. For some embodiments, the material used at the
bell shaped end 500 of the liner 430 has a thinner wall thickness
than the rest of the liner 430 and/or is shaped pipe in order to
facilitate expansion thereof and provide the bell shaped end 500
upon expansion. Further, the bell shaped end 500 may be
hydraulically isolated from the rest of the liner such that the
fluid pressure is applied to only the bell shaped end 500.
Additional bell shaped ends (not shown) having smaller diameters
than the bell shaped end 500 may be located above the bell shaped
end 500. These additional bell shaped ends may be formed by
application of a different fluid pressure than applied to the bell
shaped end 500 and/or they may be formed of a different material
than the bell shaped end 500. The remainder of the liner 430 can be
expanded using any expansion method such as a rotary expansion, a
swedge or cone, hydraulic pressure and any methods described
above.
[0034] Any of the expandable tubing described above can be
longitudinally corrugated tubing or shaped pipe in order to further
facilitate expansion. Using shaped pipe or corrugated tubing also
reduces the tendency for pipe to buckle. This allows for
compression of longer lengths of pipe enhancing the expansion
process further.
[0035] Further, the methods described above can be used in any type
of down hole tubular expansion including but not limited to liner
hangers, packers, straddles, PBRs, drilling-with-liner, etc.
[0036] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
* * * * *