SUSPENSION DE COLONNE PERDUE POURVUE DE DISTANCES ANNULAIRES

LINER HANGER WITH STANDOFFS

Abrégé français

L'invention concerne un appareil et un procédé pour réaliser ou réparer un tubage de puits (110) par l'expansion radiale d'une colonne perdue tubulaire (250) pourvue de distances annulaires (260a-h).

Abrégé anglais

An apparatus and method for forming or repairing a wellbore casing by
radially expanding a tubular liner having standoffs.

Revendications

7
Claims
1. In a wellbore that traverses a subterranean formation and includes a cased
section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a method of coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
positioning a solid tubular liner and an expansion cone within the wellbore
with the solid tubular liner overlapping the wellbore casing;
during the positioning of the solid tubular liner within the wellbore,
preventing
the portion of the solid tubular liner that does not overlap with the wellbore
casing
from contacting the porous subterranean zone of the uncased section of the
wellbore;
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and
preventing the portion of the solid tubular liner that does not overlap with
the
wellbore casing from contacting the porous subterranean zone of the uncased
section
of the wellbore during the radial expansion of the portion of the solid
tubular liner that
does not overlap with the wellbore casing.
2. The method of claim 1, further comprising:
during the positioning of the solid tubular liner within the wellbore,
preventing
the portion of the solid tubular liner that does not overlap with the wellbore
casing
from adhering to the porous subterranean zone of the uncased section of the
wellbore;
and
preventing the portion of the solid tubular liner that does not overlap with
the
wellbore casing from adhering to the porous subterranean zone of the uncased
section
of the wellbore during the radial expansion of the portion of the solid
tubular liner that
does not overlap with the wellbore casing.

8
3. In a wellbore that traverses a subterranean formation, the wellbore
including a
cased section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a method of coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
positioning a solid tubular liner and an expansion cone within the wellbore
with the solid tubular liner overlapping the wellbore casing;
during the positioning of the portion of the solid tubular liner that does not
overlap with the wellbore casing within the wellbore proximate the porous
subterranean zone, maintaining the longitudinal center line of the expansion
cone in a
position that is substantially coincident with the longitudinal center line of
the portion
of the solid tubular liner that does not overlap with the wellbore casing;
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and
maintaining the longitudinal center line of the expansion cone in a position
that is substantially coincident with the longitudinal center line of the
portion of the
solid tubular liner that does not overlap with the wellbore casing during the
radial
expansion of the portion of the solid tubular liner that does not overlap with
the
wellbore casing proximate the porous subterranean zone.
4. In a wellbore that traverses a subterranean formation, the wellbore
including a
cased section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a method of coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
positioning a solid tubular liner and an expansion cone within the wellbore;
overlapping a portion of the solid tubular liner with the wellbore casing;
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and

9
during the radial expansion of the portion of the solid tubular liner that
does
not overlap with the wellbore casing, applying substantially equal stresses to
the
interior surface of the portion of the solid tubular liner that does not
overlap with the
wellbore casing using the expansion cone proximate the porous subterranean
zone.
5. In a wellbore that traverses a subterranean formation and includes a cased
section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a system for coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
means for positioning a solid tubular liner and an expansion cone within the
wellbore with the solid tubular liner overlapping the wellbore casing;
means for during the positioning of the solid tubular liner within the
wellbore,
preventing the portion of the solid tubular liner that does not overlap with
the
wellbore casing from contacting the porous subterranean zone of the uncased
section
of the wellbore;
means for radially expanding the solid tubular liner by injecting a fluidic
material into the tubular liner to pressurize the interior of the solid
tubular liner and
displace the expansion cone relative to the solid tubular liner; and
means for preventing the portion of the solid tubular liner that does not
overlap with the wellbore casing from contacting the porous subterranean zone
of the
uncased section of the wellbore during the radial expansion of the portion of
the solid
tubular liner that does not overlap with the wellbore casing.
6. The system of claim 5, further comprising:
means for during the positioning of the solid tubular liner within the
wellbore,
preventing the portion of the solid tubular liner that does not overlap with
the
wellbore casing from adhering to the porous subterranean zone of the uncased
section
of the wellbore; and
means for preventing the portion of the solid tubular liner that does not
overlap with the wellbore casing from adhering to the porous subterranean zone
of the

10
uncased section of the wellbore during the radial expansion of the portion of
the solid
tubular liner that does not overlap with the wellbore casing.
7. In a wellbore that traverses a subterranean formation, the wellbore
including a
cased section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a system for coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
means for positioning a solid tubular liner and an expansion cone within the
wellbore with the solid tubular liner overlapping the wellbore casing;
means for during the positioning of the portion of the solid tubular liner
that
does not overlap with the wellbore casing within the wellbore, maintaining the
longitudinal center line of the expansion cone in a position that is
substantially
coincident with the longitudinal center line of the portion of the solid
tubular liner that
does not overlap with the wellbore casing;
means for radially expanding the solid tubular liner by injecting a fluidic
material into the tubular liner to pressurize the interior of the solid
tubular liner and
displace the expansion cone relative to the solid tubular liner; and
means for maintaining the longitudinal center line of the expansion cone in a
position that is substantially coincident with the longitudinal center line of
the portion
of the solid tubular liner that does not overlap with the wellbore casing
during the
radial expansion of the portion of the solid tubular liner that does not
overlap with the
wellbore casing.
8. In a wellbore that traverses a subterranean formation, the wellbore
including a
cased section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a method of coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
positioning a solid tubular liner and an expansion cone within the wellbore;
overlapping a portion of the solid tubular liner with the wellbore casing;

11
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and
during the radial expansion of the portion of the solid tubular liner that
does
not overlap with the wellbore casing proximate the porous subterranean zone,
applying substantially equal stresses to the interior surface of the portion
of the solid
tubular liner that does not overlap with the wellbore casing using the
expansion cone.
9. An apparatus for coupling a tubular liner to a wellbore casing within a
wellbore that traverses a porous subterranean formation, wherein the operating
pressure of the wellbore is greater than the operating pressure of the porous
subterranean zone, comprising:
a tubular support member defining a first internal passage;
an expansion cone coupled to the tubular support member defining a second
internal passage fluidicly coupled to the first internal passage;
a tubular expansion cone launcher movably coupled to and mating with the
expansion cone;
a solid tubular liner coupled to an end of the tubular expansion cone
launcher;
and
a shoe coupled to another end of the tubular expansion cone launcher
including a valveable passage;
means for during a positioning of the solid tubular liner within the wellbore,
preventing a portion of the solid tubular liner that does not overlap with the
wellbore
casing from contacting the porous subterranean zone of the wellbore; and
means for preventing the portion of the solid tubular liner that does not
overlap with the wellbore casing from contacting the porous subterranean zone
of the
wellbore during a radial expansion of the portion of the solid tubular liner
that does
not overlap with the wellbore casing.

12
10. The apparatus of claim 9, further comprising:
means for during the positioning of the solid tubular liner within the
wellbore,
preventing the portion of the solid tubular liner that does not overlap with
the
wellbore casing from adhering to the porous subterranean zone of the wellbore;
and
means for preventing the portion of the solid tubular liner that does not
overlap with the wellbore casing from adhering to the porous subterranean zone
of the
wellbore during the radial expansion of the portion of the solid tubular liner
that does
not overlap with the wellbore casing.
11. An apparatus for coupling a tubular liner to a wellbore casing within a
wellbore that traverses a porous subterranean formation, wherein the operating
pressure of the wellbore is greater than the operating pressure of the porous
subterranean zone, comprising:
a tubular support member defining a first internal passage;
an expansion cone coupled to the tubular support member defining a second
internal passage fluidicly coupled to the first internal passage;
a tubular expansion cone launcher movably coupled to and mating with the
expansion cone;
a tubular liner coupled to an end of the tubular expansion cone launcher;
a shoe coupled to another end of the tubular expansion cone launcher
including a valveable passage;
means for during a positioning of a portion of the solid tubular liner that
does
not overlap with the wellbore casing within the wellbore, maintaining a
longitudinal
center line of the expansion cone in a position that is substantially
coincident with a
longitudinal center line of the portion of the solid tubular liner that does
not overlap
with the wellbore casing; and
means for maintaining the longitudinal center line of the expansion cone in a
position that is substantially coincident with the longitudinal center line of
the solid
tubular liner during a longitudinal displacement of the expansion cone
relative to the
tubular liner.

13
12. An apparatus for coupling a tubular liner to a wellbore casing within a
wellbore that traverses a porous subterranean formation, wherein the operating
pressure of the wellbore is greater than the operating pressure of the porous
subterranean zone, comprising:
a tubular support member defining a first internal passage;
an expansion cone coupled to the tubular support member defining a second
internal passage fluidicly coupled to the first internal passage;
a tubular expansion cone launcher movably coupled to and mating with the
expansion cone;
a tubular liner coupled to an end of the tubular expansion cone launcher; and
a shoe coupled to another end of the tubular expansion cone launcher
including a valveable passage; and
means for during a radial expansion of a portion of the solid tubular liner
that
does not overlap with the wellbore casing, applying substantially equal
stresses to the
interior surface of the portion of the solid tubular liner that does not
overlap with the
wellbore casing using the expansion cone.
13. In a wellbore that traverses a subterranean formation and includes a cased
section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a method of coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
positioning a solid tubular liner and an expansion cone within the wellbore
with the solid tubular liner overlapping the wellbore casing, wherein the
solid tubular
liner includes a resilient helical standoff coupled to the exterior surface of
the solid
tubular liner;
during the positioning of the solid tubular liner within the wellbore, the
resilient helical standoff preventing the portion of the solid tubular liner
that does not
overlap with the wellbore casing from contacting the porous subterranean zone
of the
uncased section of the wellbore;

14
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and
the resilient helical standoff preventing the portion of the solid tubular
liner
that does not overlap with the wellbore casing from contacting the porous
subterranean zone of the uncased section of the wellbore during the radial
expansion
of the portion of the solid tubular liner that does not overlap with the
wellbore casing.
14. In a wellbore that traverses a subterranean formation and includes a cased
section having a wellbore casing and an uncased section that traverses a
porous
subterranean zone, wherein the operating pressure of the wellbore is greater
than the
operating pressure of the porous subterranean zone, a method of coupling a
tubular
liner to the wellbore casing of the cased section of the wellbore, comprising:
positioning a solid tubular liner and an expansion cone within the wellbore
with the solid tubular liner overlapping the wellbore casing, wherein the
solid tubular
liner includes a plurality of spaced apart resilient standoffs coupled to the
exterior
surface of the solid tubular liner between the opposite ends of the solid
tubular liner;
during the positioning of the solid tubular liner within the wellbore, the
resilient standoffs preventing the portion of the solid tubular liner that
does not
overlap with the wellbore casing from contacting the porous subterranean zone
of the
uncased section of the wellbore;
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and
the resilient standoffs preventing the portion of the solid tubular liner that
does
not overlap with the wellbore casing from contacting the porous subterranean
zone of
the uncased section of the wellbore during the radial expansion of the portion
of the
solid tubular liner that does not overlap with the wellbore casing.

15
15. In a wellbore that traverses a subterranean formation, the wellbore
including a
cased section having a wellbore casing and an uncased section, a method of
coupling
a tubular liner to the wellbore casing of the cased section of the wellbore,
comprising:
determining that the uncased section traverses a porous subterranean zone;
determining that the operating pressure of the wellbore is greater than the
operating pressure of the porous subterranean zone;
positioning a solid tubular liner and an expansion cone within the wellbore
with the solid tubular liner overlapping the wellbore casing;
during the positioning of the solid tubular liner within the wellbore,
preventing
the portion of the solid tubular liner that does not overlap with the wellbore
casing
from contacting the porous subterranean zone of the uncased section of the
wellbore;
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and
preventing the portion of the solid tubular liner that does not overlap with
the
wellbore casing from contacting the porous subterranean zone of the uncased
section
of the wellbore during the radial expansion of the portion of the solid
tubular liner that
does not overlap with the wellbore casing.
16. In a wellbore that traverses a subterranean formation, the wellbore
including a
cased section having a wellbore casing and an uncased section, a method of
coupling
a tubular liner to the wellbore casing of the cased section of the wellbore,
comprising:
determining that the uncased section traverses a porous subterranean zone;
determining that the operating pressure of the wellbore is greater than the
operating pressure of the porous subterranean zone;
if the uncased section is determined to traverse a porous subterranean zone
having an operating pressure that is less than the operating pressure of the
wellbore,
then adding a passive structural means to the solid tubular liner;
positioning a solid tubular liner and an expansion cone within the wellbore
with the solid tubular liner overlapping the wellbore casing;
during the positioning of the solid tubular liner within the wellbore, the
passive structural means preventing the portion of the solid tubular liner
that does not

16
overlap with the wellbore casing from contacting the porous subterranean zone
of the
uncased section of the wellbore;
radially expanding the solid tubular liner by injecting a fluidic material
into
the tubular liner to pressurize the interior of the solid tubular liner and
displace the
expansion cone relative to the solid tubular liner; and
the passive structural means preventing the portion of the solid tubular liner
that does not overlap with the wellbore casing from contacting the porous
subterranean zone of the uncased section of the wellbore during the radial
expansion
of the portion of the solid tubular liner that does not overlap with the
wellbore casing.

Description

CA 02414428 2006-11-01
1
LINER HANGER WITH STANDOFFS
Background of the Invention
This invention relates generally to wellbore casings, and in particular to
wellbore casings that are formed using expandable tubing.
Conventionally, when a wellbore is created, a number of casings are installed
in the borehole to prevent collapse of the borehole wall and to prevent
undesired
outflow of drilling fluid into the formation or inflow of fluid from the
formation into
the borehole. The borehole is drilled in intervals whereby a casing which is
to be
installed in a lower borehole interval is lowered through a previously
installed casing
of an upper borehole interval. As a consequence of this procedure the casing
of the
lower interval is of smaller diameter than the casing of the upper interval.
Thus, the
casings are in a nested arrangement with casing diameters decreasing in
downward
direction. Cement annuli are provided between the outer surfaces of the
casings and
the borehole wall to seal the casings from the borehole wall. As a consequence
of this
nested arrangement a relatively large borehole diameter is required at the
upper part
of the wellbore. Such a large borehole diameter involves increased costs due
to heavy
casing handling equipment, large drill bits and increased volumes of drilling
fluid and
drill cuttings. Moreover, increased drilling rig time is involved due to
required
cement pumping, cement hardening, required equipment changes due to large
variations in hole diameters drilled in the course of the well, and the large
volume of
cuttings drilled and removed.
The present invention is directed to overcoming one or more of the limitations
of the existing procedures for forming wellbores and wellheads.
Summary of the Invention
According to one aspect of the present invention, a method of forming a
casing in a wellbore having a cased section and an open hole section is
provided that
includes positioning a tubular liner within the wellbore, overlapping the
tubular liner

CA 02414428 2006-11-01
2
and the cased section, centering the tubular liner within the wellbore, and
radially
expanding the tubular liner into contact with the cased section.
According to another aspect of the present invention, a radially expandable
tubular member for repairing an opening in a wellbore casing is provided that
includes a tubular member, and one or more standoffs coupled to the exterior
surface
of the tubular member.
According to another aspect of the present invention, an apparatus for
repairing an opening in a wellbore casing is provided that includes a tubular
support
member including a first passage, an expansion cone coupled to the tubular
support
member including a second passage fluidicly coupled to the first passage, an
expansion cone launcher coupled to the expansion cone including a shoe having
an
exhaust passage, and an expandable tubular member coupled to the expansion
cone
launcher including one or more standoffs.
According to another aspect of the present invention, an apparatus is provided
that includes a wellbore including a preexisting casing and an open hole
section, and a
radially expanded tubular member coupled to the preexisting casing including
one or
more standoffs.
Brief Description of the Drawings
FIG. 1 is a cross-sectional view illustrating a wellbore including a wellbore
casing and an open hole section that traverses a porous subterranean layer.
FIG. 2 is a fragmentary cross-sectional view illustrating the introduction of
an
apparatus for casing the open hole section of the wellbore of FIG. 1.
FIG. 3 is a fragmentary cross-sectional view illustrating the injection of a
fluidic material into the apparatus of FIG. 2.
FIG. 4 is a fragmentary cross-sectional view illustrating the placement of a
plug into the exhaust passage of the shoe of the apparatus of FIG. 3.
FIG. 5 is a fragmentary cross-sectional view illustrating the pressurization
of
the interior portion of the apparatus below the expansion cone of FIG. 4.

CA 02414428 2006-11-01
3
FIG. 6 is a fragmentary cross-sectional view illustrating the completion of
the
radial expansion of the tubular member of the apparatus of FIG. 5.
FIG. 7 is a fragmentary cross-sectional view illustrating the removal of the
shoe from the apparatus of FIG. 6.
Detailed Description of the Illustrative Embodiments
An apparatus and method for casing an open hole section of a wellbore within
a subterranean formation is provided. The apparatus and method provides a
system
for casing an open hole section of a wellbore within a subterranean formation
in
which a tubular member having a plurality of radially oriented standoffs is
radially
expanded into contact with the preexisting wellbore casing and the open hole
section.
The standoffs provided on the exterior surface of the tubular member
preferably
position the tubular member away from the interior walls of the open hole
section
during the radial expansion process. In this manner, the tubular member does
not
adhere to underpressurized sections of the open hole section of the wellbore.
In this
manner, the process of radial expansion is more reliable.
Referring initially to FIG. 1, a wellbore 100 positioned within a subterranean
formation 105 includes a preexisting casing 110 and an open hole section 115
that
traverses a porous region 120. When the operating pressure within the wellbore
PBORE
is greater than the operating pressure within the porous region PPORE, fluidic
materials
will flow from the wellbore 100 into the porous region 120. As a result of the
flow of
fluidic materials from the wellbore 100 into the porous region 120, downhole
equipment will tend to adhere to, or at least be drawn toward, the interior
surface of
the wellbore 100 in the vicinity of the porous region 120. This can have
serious and
adverse consequences when radially expanding a tubular member in such an
operating
environment.
Referring to FIG. 2, an apparatus 200 for forming a wellbore casing in the
open hole section of the wellbore 100 may then be positioned within the
wellbore
in an overlapping relationship with the lower portion of the preexisting
wellbore
casing 110.

CA 02414428 2006-11-01
4
The apparatus 200 includes a tubular support member 205 having a
longitudinal passage 210 and a transverse passage 215 that is coupled to an
expansion
cone 220 having a longitudinal passage 225 that is fluidicly coupled to the
longitudinal passage 210. The expansion cone 220 is at least partially
received within
an expansion cone launcher 230 that includes a thin-walled annular member 235
and a
shoe 240 having an exhaust passage 245. An expandable tubular member 250
extends
from the expansion cone launcher 230 that includes a sealing member 255 and a
plurality of standoffs 260a-260h affixed to the exterior surface of the
expandable
tubular member. In a preferred embodiment, the standoffs 260 are fabricated
from a
resilient material. A sealing cup 265 is attached to the exterior surface of
the tubular
support member 205 for preventing foreign materials from entering the interior
of the
expandable tubular member 250.
In a preferred embodiment, the apparatus 200 is provided as disclosed in one
or more of the following: U.S. Patent No. 6,328,113; U.S. Patent No.
6,497,289;
U.S. Patent No. 6,575,240; U.S. Patent No. 6,640,903; U.S. Patent No.
6,604,763;
and U.S. Patent No. 6,568,471.
As illustrated in FIG. 2, during placement of the apparatus 200 within the
wellbore 100, fluidic materials displaced by the apparatus 200 are conveyed
through
the longitudinal passages 210 and 225 to the transverse passage 215. In this
manner,
surge pressures during the placement of the apparatus 200 within the wellbore
100
are minimized. Furthermore, as illustrated in FIG. 2, the apparatus 200 is
preferably
initially positioned with upper portion of the tubular member 250 in opposing
relation
to the lower portion of the preexisting wellbore casing 110. In this manner,
the
upper portion of the tubular member 250 may be radially expanded into contact
with the lower portion of the preexisting wellbore casing 110. In a preferred
embodiment, during the placement of the apparatus 200 within the wellbore 100,
the
standoffs 260a-260h prevent the apparatus 200 from adhering to, or being drawn
toward, the interior surface of the wellbore 100 in the vicinity of the porous
region 120. In this manner, the apparatus 200 is approximately centered within
the
wellbore 100.

CA 02414428 2006-11-01
As illustrated in FIG. 3, the transverse passage 215 may then be closed and
fluidic materials injected into the apparatus 200 through the longitudinal
passage 210.
In this manner, any blockages within any of the passages 210, 225, and 245
maybe
detected by monitoring the operating pressure whereby an increase in operating
5 pressure above nominal, or predetermined, conditions may indicate a blockage
of one
of the passages.
As illustrated in FIG. 4, a plug 270 or other conventional stop member may
then be introduced into the fluidic materials injected into the apparatus 200
through
the passage 210, and the plug 270 may be positioned within the exhaust passage
245.
In this manner, the exhaust passage 245 may be sealed off. Thus, continued
injection
of fluidic materials into the apparatus 200 through the passage 210 may
thereby
pressurize a region 275 below the expansion cone 220.
As illustrated in FIGS. 5 and 6, continued pressurization of the region 275
causes the expansion cone 220 to radially expand the expandable tubular member
250
off of the expansion cone. In this manner, the upper portion of the radially
expanded
tubular member 250 is coupled to the lower portion of the preexisting wellbore
casing 110. In a preferred embodiment, during the radial expansion process,
the
tubular support member 205 is raised out of the wellbore 100.
In a preferred embodiment, throughout the radial expansion process, the
standoffs 260a-260h prevent the exterior surface of the apparatus 200 from
adhering
to, or being drawn toward, the interior surface of the wellbore 100 in the
vicinity of
the porous region 120. In this manner, the apparatus 200 is preferably
substantially
centered within the wellbore 100. Furthermore, in this manner, the
longitudinal
center axis of the expansion cone 220 is preferably maintained in a position
that is
substantially coincident with the longitudinal center axis of the tubular
member 250.
In addition, in this manner, the stresses applied to the interior surface of
the tubular
member 250 by the axial displacement of the expansion cone 220 are
substantially
even. Finally, in this manner, overstressing of the tubular member 250 is
prevented
thereby eliminating catastrophic failure of the tubular member 250.
As illustrated in FIG. 7, the shoe 240 may then be removed using a
conventional milling device.

CA 02414428 2006-11-01
6
In a preferred embodiment, upon radially expanding the expandable tubular
member 250, the standoffs 260a-260h seal and isolate intervals within the open
hole
section 115. In several alternative embodiments, the standoffs 260 maybe
provided,
for example, by annular members spaced along the length of the expandable
tubular
member 250 and/or a continuous member that is wrapped around the expandable
tubular member 250 in helical fashion.
It is understood that variations may be made in the foregoing without
departing from the scope of the invention. For example, the apparatus 200 may
be
used to form and/or repair, for example, a wellbore casing, a pipeline, or a
structural
support.
Although illustrative embodiments of the invention have been shown and
described, a wide range of modification, changes and substitution is
contemplated in
the foregoing disclosure. In some instances, some features of the present
invention
may be employed without a corresponding use of the other features.
Accordingly, it
is appropriate that the appended claims be construed broadly and in a manner
consistent with the scope of the invention.

Dessin représentatif