Note: Descriptions are shown in the official language in which they were submitted.
CA 02576536 2007-01-30
EXPANDABLE FLUTED LINER HANGER AND PACKER SYSTEM
BACKGROUND OF THE INVENTION
Field of the Invention
Embodiments of the invention generally relate to apparatus and methods for
creating an attachment and a seal between two tubular members in a wellbore.
Description of the Related Art
In the drilling of oil and gas wells, a wellbore is formed using a drill bit
that is
urged downwardly at a lower end of a drill string. After drilling a
predetermined depth,
the drill string and bit are removed, and the wellbore is lined with a string
of steel pipe
called casing. The casing provides support to the wellbore and facilitates the
isolation
of certain areas of the wellbore adjacent hydrocarbon bearing formations. The
casing
typically extends down the wellbore from the surface of the well to a
designated depth.
An annular area is thus defined between the outside of the casing and the
earth
formation. This annular area is filled with cement to permanently set the
casing in the
wellbore and to facilitate the isolation of production zones and fluids at
different depths
within the wellbore.
It is common to employ more than one string of casing in a wellbore. In this
respect, a first string of casing is set in the wellbore when the well is
drilled to a first
designated depth. The well is then drilled to a second designated depth and a
second
string of casing or liner is run into the well to a depth whereby the upper
portion of the
second liner is overlapping the lower portion of the first string of casing.
The second
liner string is then fixed or hung in the wellbore usually by some mechanical
slip
mechanism well known in the art and cemented. This process is typically
repeated with
additional casing strings until the well has been drilled to total depth.
A recent trend in well completion has been the advent of expandable tubular
technology. It has been discovered that both slotted and solid tubulars can be
expanded in situ so as to enlarge the inner diameter. This, in turn, enlarges
the path
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CA 02576536 2009-03-31
through which both fluid and downhole tools may travel. Also, expansion
technology
enables a smaller tubular to be run into a larger tubular and then expanded so
that a
portion of the smaller tubular is in contact with the larger tubular
therearound. Tubulars
are expanded by the use of a cone-shaped mandrel or by a rotary expansion tool
with
extendable, fluid actuated members disposed on a body and run into the
weilbore on a
tubular string. An exemplary rotary expansion tool is described in U.S. Patent
Number
6,457,532, issued to Simpson on October 1, 2002. During expansion of a
tubular, the
tubular walls are expanded past their elastic limit. The use of expandable
tubulars as
liner hangers and packers allows for the use of larger diameter production
tubing
because the conventional slip mechanism and sealing mechanism are eliminated.
If the liner hanger is expanded by a cone-shaped mandrel, then a forgiving
material like an elastomer is typically employed between the outer diameter of
the liner
hanger and the inner diameter of the larger tubular to accommodate any
variances in
the inner diameter of the larger tubular. In this particular prior art
embodiment, it is this
forgiving material that provides the mechanism for hanging the weight of the
liner below
the liner hanger. Typically, the forgiving material is made from a nitrile
rubber
compound or a similar material with compliant properties.
When using an expandable liner hanger, it is usually desirable to expand the
liner
hanger to support the weight of a liner and then release the running tool from
the liner
prior to cementing the liner in place. Typically, the use of the cone-shaped
mandrel
requires that circulation ports be cut in the wall of the liner directly below
the liner
hanger section to provide a fluid path for circulating fluid and cement during
the
cementing process. Then following the cementing process, these ports must be
isolated typically by expanding another elastomer clad section below the
ports.
Expanding liner hangers with a cone-shaped mandrel in a weilbore offers
advantages over other technology. However, there exist problems associated
with
using the expandable technology. For example, by using a forgiving material,
such as a
nitrite rubber compound, the liner hanging mechanism may only be effectively
utilized in
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CA 02576536 2007-01-30
a wellbore that has a temperature of less than 2500 F. If the liner hanger is
used in a
higher temperature wellbore, then the rubber's ability to carry a load drops
off
dramatically due to the mechanical properties of the material. More
importantly, the
circulating ports that are cut into the wall of the liner below the liner
hanger diminish the
carrying capacity of the hanger due to a reduction of material through this
section
therefore limiting the length of the liner.
Therefore, there exists a need for systems and methods for an improved
expandable hanger and packer arrangement.
SUMMARY OF THE INVENTION
Embodiments of the invention generally relate to apparatus and methods for
creating an attachment and a seal between two tubular members in a wellbore.
An
expandable assembly includes a packer and liner hanger to be expanded into a
surrounding tubular. The packer can be a longitudinally corrugated packer and
can
have a sealing element disposed on an outer surface thereof. The liner hanger
can
include a plurality of formations extending outward along an outer surface of
the liner
hanger to form interspaces for longitudinal fluid flow between the formations.
In
operation, an expansion tool moves axially through an inner diameter of the
expandable
assembly to expand the liner hanger with a fluted expander and subsequently
the
packer with a substantially uniform outer diameter cone.
BRIEF DESCRIPTION OF THE DRAWINGS
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, some of 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.
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Figure 1 is a cross-sectional view illustrating an expandable hanger with
compliant slip system of the present invention in a run-in position.
Figure 2 is a cross-sectional view illustrating an expander tool partially
expanding
the expandable hanger.
Figure 3 is a cross-sectional view taken along line 3-3 of Figure 1
illustrating the
expander tool in the expandable hanger prior to expansion.
Figure 4 is a cross-sectional view taken along line 4-4 of Figure 2
illustrating the
expander tool during the expansion of the expandable hanger.
Figure 5 is a cross-sectional view illustrating the release of the running
tool prior
to a cementing operation.
Figure 6 is a cross-sectional view illustrating the cementation of the liner
assembly within the wellbore.
Figure 7 is a cross-sectional view illustrating the expansion of the liner
seal after
the cementing operation.
Figure 8 is a cross-sectional view illustrating the fully expanded expandable
hanger after the running tool has been removed.
Figure 9 is a cross-sectional view illustrating a collapsible expander tool in
the
expandable hanger with compliant slip system.
Figure 10 is a cross-sectional view illustrating the collapsible expander tool
in an
activated position prior to the expansion of the expandable hanger.
Figure 11 is a cross-sectional view illustrating the expander tool partially
expanding the expandable hanger.
Figure 12 is a cross-sectional view taken along line 12-12 in Figure 11
illustrating
the expander tool during the expansion of the expandable hanger.
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Figure 13 is a cross-sectional view illustrating the cementation of the liner
assembly within the wellbore.
Figure 14 is a cross-sectional view illustrating the expansion of the liner
seal after
the cementing operation.
Figure 15 is a cross-sectional view taken along line 15-15 in Figure 14
illustrating
the expander tool and the plurality of dogs during the expansion of the liner
seal.
Figure 16 is a cross-sectional view illustrating the fully expanded expandable
hanger after the running tool has been removed.
Figure 17 is a cross-sectional view illustrating an alternative embodiment of
an
expandable hanger with compliant slip system.
Figure 18 is a cross-sectional view illustrating an alternative embodiment of
an
expandable hanger with compliant slip system.
Figure 19 is a cross-sectional view illustrating an expander tool with
compliant
expansion member.
Figure 20 is a perspective view illustrating an expander tool and an
expandable
packer and hanger according to one embodiment of the invention.
Figure 21 is a top view illustrating the expandable packer and hanger prior to
expansion.
Figure 22 is a cross-sectional view illustrating the expandable packer and
hanger
fully expanded in a wellbore after removal of the expander tool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention generally relates to a method and an apparatus for forming an
expandable hanger connection with a surrounding casing. In one aspect, an
expandable hanger with compliant slip system is disclosed. Typically, a liner
assembly
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CA 02576536 2007-01-30
including a liner hanger is disposed in a wellbore proximate the lower end of
the
surrounding casing. Next, an expander tool is urged axially through the liner
hanger to
radially expand the hanger into frictional contact with the surrounding casing
and to form
a plurality of cement bypass ports. Thereafter, cement is circulated through
the
wellbore and eventually through the plurality of cement bypass ports to cement
the liner
assembly within the wellbore. Subsequently, a liner seal is radially expanded
to seal off
the plurality of cement bypass ports. It should be noted, however, that the
expandable
hanger with compliant slip system may be used with any expandable tubular,
such as a
slotted tubular or a screen. In another aspect, a collapsible expander tool
for use with
the expandable hanger with compliant slip system is disclosed. Generally, the
collapsible expander tool includes two opposing cones with a plurality of pads
spaced
radially around the circumference of the tool. During activation of the
collapsible
expander tool, the cones converge thereby extending the pads radially outward.
Thereafter, the activated expander tool may be employed to radially expand the
expandable hanger.
Figure 1 is a cross-sectional view illustrating an expandable hanger 200 of
the
present invention in a run-in position. At the stage of completion shown in
Figure 1, a
wellbore 100 has been lined with a string of casing 110. Thereafter, a
subsequent liner
assembly 150 is positioned proximate the lower end of the casing 110.
Typically, the
liner assembly 150 is lowered into the wellbore 100 by a running tool 115
disposed at
the lower end of a working string 130.
At the upper end of the running tool 115 is an upper torque anchor 140.
Preferably, the torque anchor 140 defines a set of slip members 145 disposed
radially
around the torque anchor 140. In the embodiment of Figure 1, the slip members
145
define at least two radially extendable pads with surfaces having gripping
formations
like teeth formed thereon to prevent rotational movement. As illustrated, the
torque
anchor 140 is in its recessed position, meaning that the pads 145 are
substantially
within the plane of the casing 110. In other words, the pads 145 are not in
contact with
the casing 110 so as to facilitate the run-in of the liner assembly 150. The
pads 145 are
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CA 02576536 2007-01-30
selectively actuated either hydraulically or mechanically or combinations
thereof as
known in the art.
A spline assembly 225 is secured at one end to the torque anchor 140 by a
plurality of upper torque screws 230 and secured at the other end to an
axially movable
expander tool 125 by a plurality of lower torque screws 235. As used herein, a
spline
assembly provides a means of mechanical torque connection between a first and
second member. Typically, the first member includes a plurality of keys and
the second
member includes a plurality of keyways. When rotational torque is applied to
the first
member, the keys act on the keyways to transmit the torque to the second
member.
Additionally, the spline assembly permits axial movement between the first and
second
member while maintaining the torque connection. In this respect, the torque
anchor 140
maintains the expander tool 125 rotationally stationary while permitting the
expander
tool 125 to move axially.
The axially movable expander tool 125 is disposed on a threaded mandrel 135.
Expander tools are well known in the art and are generally used to radially
enlarge an
expandable tubular by urging the expander tool axially through the tubular,
thereby
swaging the tubular wall radially outward as the larger diameter tool is
forced through
the smaller diameter tubular member. In the embodiment shown, the expander
tool 125
includes female threads formed on an inner surface thereof that mate with male
threads
formed on the threaded mandrel 135. As the threaded mandrel 135 is rotated,
the
expander tool 125 moves axially through the hanger 200 to expand it outward in
contact
with the casing 110. It is to be understood, however, that other means may be
employed to urge the expander tool 125 through the hanger 200 such as
hydraulics or
any other means known in the art. Furthermore, the expander tool 125 may be
disposed in the hanger 200 in any orientation, such as in a downward
orientation as
shown for a top down expansion or in an upward orientation for a bottom up
expansion.
Additionally, an expandable tool may be employed. Preferably, the expandable
tool
moves between a first smaller diameter and a second larger diameter, thereby
allowing
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CA 02576536 2007-01-30
for both a top down expansion and a bottom up expansion depending on the
directional
axial movement of the expandable tool.
Disposed below the threaded mandrel 135 is a swivel 120. Generally, the swivel
120 permits the relative rotation of a threaded mandrel 135 while the
supporting torque
anchor 140 and the hanger 200 remain rotationally stationary. A lower anchor
160 with
extendable members 165 is located below the swivel 120.
As shown in Figure 1, the lower anchor 160 is in its extended position,
meaning
that the extendable members 165 are in contact with the inner surface of the
liner
assembly 150 so as to secure the liner assembly 150 to the running tool 115.
The
extendable members 165 are selectively actuated either hydraulically or
mechanically or
both as known in the art. Furthermore, a fluid outlet 170 is provided at the
lower end of
the lower anchor 160. The fluid outlet 170 serves as a fluid conduit for
cement or other
drilling fluid to be circulated into the wellbore 100 in accordance with the
method of the
present invention.
The liner assembly 150 includes the expandable hanger 200 of this present
invention. The expandable hanger 200 comprises of a plurality of formations
that are
illustrated as a plurality of ribs 205 formed on the outer surface of the
hanger 200. The
plurality of ribs 205 are circumferentially spaced around the hanger 200 to
provide
support for the liner assembly 150 upon expansion of the hanger 200. As
illustrated, a
plurality of inserts 210 are disposed on the ribs 205. The inserts 210 provide
a gripping
means between the outer surface of the hanger 200 and the inner surface of the
casing
110 within which the liner assembly 150 is coaxially disposed. The inserts 210
are
made of a suitably hardened material and are attached to the outer surface of
the ribs
205 of the hanger 200 through a suitable means such as soldering, epoxying, or
other
adhesive methods, or via threaded connection. In the preferred embodiment,
inserts
210 are press-fitted into preformed apertures in the outer surface of the ribs
205 of the
hanger 200. After expansion, the inserts 210 are engaged with the inner
surface of the
surrounding casing 110, thereby increasing the ability of the expanded hanger
200 to
support the weight of the liner assembly 150 below the expanded portion.
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CA 02576536 2007-01-30
In the preferred embodiment, the inserts 210 are fabricated from a tungsten
carbide material. However, another fabrication material may be employed, so
long as
the material has the capability of gripping the inner surface of the casing
110 during
expansion of the hanger 200. Examples of fabrication materials for the inserts
210
include ceramic materials (such as carbide) and hardened metal alloy
materials. The
carbide inserts 210 define raised members fabricated into the hanger 200.
However,
other embodiments of gripping means may alternatively be employed. Such means
include, but are not limited to, buttons having teeth (not shown), or other
raised or
serrated members on the outer surface of the ribs 205 of the hanger 200. The
gripping
means may also include a plurality of long inserts defined on the outside
diameter of the
hanger 200, thus creating a plurality of flutes (not shown) between the
plurality of long
inserts. Alternatively, the gripping means may define a plurality of hardened
tooth
patterns added to the outer surface of the ribs 205 of the hanger 200.
In the embodiment shown in Figure 1, the liner assembly 150 includes a liner
seal 155 disposed below the expandable hanger 200. The primary purpose of the
liner
seal 155 is to seal off the expandable hanger 200 after a cementation
operation is
complete, as will be discussed in a subsequent paragraph. Generally, the liner
seal 155
creates a fluid seal between the liner assembly 150 and the casing 110 upon
expansion
of the liner seal 155. In the preferred embodiment, the liner seal 155 is
fabricated from
an elastomeric material. However, other material may be employed that is
capable of
creating the fluid seal sought to be obtained between the expanded portion of
the liner
assembly 150 and the casing 110. Typically, the liner seal 155 is disposed
around the
liner assembly 150 by a thermal process or some other well known means.
Although the liner assembly 150 in Figure 1 shows only one liner seal 155
disposed below the expandable hanger 200, the invention is not limited to this
particular
location or the quantity illustrated. For instance, any number of liner seals
may be
employed with the expandable hanger 200 of the present invention and the liner
seals
may be placed in any location adjacent the expandable hanger 200 to create a
fluid seal
between the liner assembly 150 and the casing 110. For example, the liner seal
155
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CA 02576536 2007-01-30
may be employed above the expandable hanger 200 or both above and below the
expandable hanger 200 to form a fluid seal between the liner assembly 150 and
the
casing 110.
Figure 2 is a cross-sectional view illustrating the expander tool 125
partially
expanding the expandable hanger 200. As shown, the liner assembly 150 is
positioned
proximate the lower end of the casing 110. Thereafter, the upper torque anchor
140 is
actuated, thereby extending the pads 145 radially outward into contact with
the
surrounding casing 110. Subsequently, rotational force is transmitted through
the
working string 130 to the threaded mandrel 135. The swivel 120 permits the
threaded
mandrel 135 to rotate in a first direction while the torque anchor 140, the
spline
assembly 225, expander tool 125, and liner assembly 150 remain rotationally
stationary.
As the threaded mandrel 135 rotates, the expander tool 125 moves axially in a
first
direction through the expandable hanger 200 causing the hanger 200 to expand
radially
outward forcing the inserts 210 to contact the inner surface of the casing 110
as
illustrated. The expander tool 125 continues to expand the entire length of
the
expandable hanger 200 until it reaches a predetermined point above the liner
seal 155.
At that point, the expansion is stopped to prevent expanding the liner seal
155, in
anticipation of cementing.
Figure 3 is a cross-sectional view taken along line 3-3 in Figure 1 to
illustrate the
orientation of the expander tool 125 in the expandable hanger 200. As clearly
shown,
the expander tool 125 includes a plurality of formations illustrated as a
plurality of
expander ribs 175 and a plurality of expander flutes 185 circumferentially
spaced
around the expander tool 125. The plurality of expander ribs 175 are generally
tapered
members defining a first outer diameter at a first location smaller than a
second outer
diameter at a second location. Also clearly shown, the hanger 200 includes a
plurality
of hanger flutes 220 disposed between the plurality of ribs 205.
Figure 4 is a cross-sectional view taken along line 4-4 of Figure 2
illustrating the
expander tool 125 during the expansion of the expandable hanger 200. The
expander
tool 125 is oriented in the expandable hanger 200 by aligning the plurality
flutes 185
CA 02576536 2007-01-30
with the plurality of ribs 205. Therefore, as the expander tool 125 moves
axially through
the hanger 200, the ribs 175 apply a force on the hanger flutes 220, causing
them to
expand out radially, which in turn urges the ribs 205 on the hanger 200 out
radially as
the inserts 210 penetrate the surrounding casing 110. At this point, the
hanger flutes
220 are free to move out radially while the radially stationary ribs 205 are
accommodated by the flutes 185. In other words, the expandable hanger 200
includes
a compliant slip system that allows the hanger ribs 205 to conform to the
surrounding
casing 110 as the expander tool 125 urges the expandable hanger 200 radially
outward.
Given that the radial extension of the hanger flutes 220 are dictated by the
diameter of
the ribs 175, they never contact the surrounding casing 110. In this manner,
the cement
bypass ports 215 are formed therefore providing a fluid passageway between the
hanger 200 and the surrounding casing 110 during the cementing operation.
Figure 5 is a cross-sectional view illustrating the release of the running
tool 115
prior to a cementing operation. It is desirable to release the running tool
115 from the
liner assembly 150 prior to cementing it in the wellbore 100 to prevent the
foreseeable
difficulty of releasing the tool 115 after the cementation operation. As
shown, the torque
anchor 140 is also in its recessed position, meaning that the pads 145 have
been
retracted and are no longer in contact with the casing 110. Furthermore, the
hanger
200 supports the weight of the liner assembly 150 therefore the lower anchor
160 is
deactivated, meaning that the extendable members 165 have been retracted and
are no
longer in contact with the inner surface of the liner assembly 150 so as to
release the
liner assembly 150 from the running tool 115.
Figure 6 is a cross-sectional view illustrating the cementation of the liner
assembly 150 within the wellbore 100. Preferably, cement is pumped through the
working string 130, the running tool 115, and the fluid outlet 170 to a cement
shoe (not
shown) or another means known in the art to distribute the cement. As
indicated by
arrow 180, the cement is circulated up an annulus 190 formed between the liner
assembly 150 and the wellbore 100 and past the liner seal 155 into the cement
bypass
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CA 02576536 2007-01-30
ports (not shown) of the expandable hanger 200. Thereafter, the cement flows
through
the bypass ports and exits into the inner diameter of the surrounding casing
110.
Figure 7 is a cross-sectional view illustrating the expansion of the liner
seal 155
after the cementing operation. As shown, the liner assembly 150 has been
completely
cemented in the wellbore 100. As further shown, the torque anchor 140 and
lower
anchor 160 are once again actuated, thereby extending the pads 145 radially
outward
into contact with the surrounding casing 110. Subsequently, rotational force
is
transmitted through the working string 130 to the threaded mandrel 135. The
swivel
120 permits the threaded mandrel 135 to rotate in the first direction while
the supporting
torque anchor 140, the spline assembly 225, and the expander tool 125 remain
rotationally stationary. As the threaded mandrel 135 rotates in the first
direction, the
expander tool 125 moves axially in the first direction through the expanded
portion of
the hanger 200 to a predetermined location above the liner seal 155.
Thereafter, a plurality of selectively extendable elements (not shown) are
activated. Referring to Figure 4, the plurality of selectively extendable
elements are
preferably disposed in the plurality of expander flutes 185. The plurality of
extendable
elements are constructed and arranged to extend radially outward to
substantially fill in
the expander flutes 185 which results in an expander tool with a substantially
uniform
outer diameter capable of expanding the entire outer perimeter of the liner
seal 155.
The extendable elements may be a selectively movable piston, an extendable dog
assembly, a collet assembly, or any other suitable member to fill the
plurality of
expander flutes 185.
Referring back to Figure 7, the expander tool 125 with the activated
extendable
elements moves axially through the liner seal 155, thereby expanding the
entire
perimeter of the liner seal 155 radially outward forcing the elastomeric
material to form a
fluid seal between the liner assembly 150 and the surrounding casing 110.
Alternatively, a rotary expansion tool with extendable members (not shown) or
a cone
shaped mandrel (not shown) may be employed to expand the liner seal 155.
Additionally, the expander tool 125 could be rotated to expand the liner seal
155. In
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CA 02576536 2007-01-30
either case, the cement bypass ports (not shown) are sealed off to prevent any
further
migration of fluid through the expandable hanger 200 from micro-annuluses that
may
have formed during the cementing operation.
Figure 8 is a cross-sectional view illustrating the fully expanded expandable
hanger 200 after the running tool 115 has been removed. As shown, the
expandable
hanger 200 is fully engaged with the lower portion of the surrounding casing
110 and
consequently supporting the entire weight of the liner assembly 150 by way of
the
inserts 210 on the hanger ribs 205. As further shown, the liner seal 155 has
been
expanded radially outward and is therefore creating the lower fluid seal
between the
liner assembly 150 and the surrounding casing 110.
Creating an attachment and a seal between two tubulars in a wellbore can be
accomplished with methods that use embodiments of the expandable hanger as
described above. A method of completing a wellbore includes placing a first
tubular
coaxially within a portion of a second tubular, the first tubular including a
plurality of
formations on an outer surface thereof to provide a frictional relationship
between the
first tubular and the second tubular while leaving a fluid path through the
expanded
connection. The method also includes positioning an expander tool within the
first
tubular at a depth proximate the plurality of formations on the first tubular.
The method
further includes urging the expander tool axially through the first tubular to
expand the
first tubular into frictional contact with the second tubular and forming a
fluid path
through an overlapped portion between the first and second tubulars.
Therefore, the
apparatus and methods disclosed herein for using embodiments of the expandable
hanger permits the connection of two tubulars within a wellbore.
In another aspect, a collapsible expander tool for use with the expandable
hanger with compliant slip system is disclosed. It should be noted, however,
that the
collapsible expander tool may be employed with other expandable tubulars, such
as
expandable screens and expandable casing.
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Figure 9 is a cross-sectional view illustrating a collapsible expander tool in
the
expandable hanger 200 with compliant slip system. For convenience, the
components
in Figures 9-17 that are similar to the components as described in Figures 1-8
will be
labeled with the same numbers. As discussed in a previous paragraph, a liner
assembly 150 is lowered into the wellbore 100 by a running tool 115 disposed
at the
lower end of a working string 130.
As shown in Figure 9, the collapsible expander tool 300 is in a collapsed run-
in
position. The upper end of the collapsible expander tool 300 is secured to a
spline
assembly 225 by a plurality of lower torque screws 235 while the lower end of
the
collapsible expander tool 300 is temporality attached to the liner assembly
150 by a
plurality of shear pins 320. Additionally, the collapsible expander tool 300
is disposed
on a threaded mandrel 135. Preferably, the expander tool 300 includes female
threads
formed on an inner surface thereof that mate with male threads formed on the
threaded
mandrel 135. Generally, the rotation of the threaded mandrel 135 activates the
expander tool 300 and moves it axially through the hanger 200. It is to be
understood,
however, that other means may be employed to urge the expander tool 300
through the
hanger 200, such as hydraulics, mechanical manipulation, or combinations
thereof as
known in the art. Furthermore, the expander tool 300 may be disposed in the
hanger
200 in any orientation, such as in a downward orientation as shown for a top
down
expansion, an upward orientation for a bottom up expansion, or placed in the
middle of
the hanger 200 for expansion in either direction.
As illustrated in Figure 9, the collapsible expander tool 300 includes an
upper
cone 310 and a lower cone 315. The cones 310, 315 are spaced apart to form a
gap
360 therebetween. The upper cone 310 includes a tapered portion 340 disposed
adjacent a first tapered portion 345 on the lower cone 315 to form a profile.
The lower
cone 315 further includes a second tapered portion 365 formed at the lower end
thereof.
The collapsible expander tool 300 further includes a plurality of selectively
extendable
members, such as a plurality of pads 305 spaced radially around the expander
tool 300.
The inner portion of the pads 305 includes a ramp portion 355 that mates with
a contour
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CA 02576536 2007-01-30
formed by the tapered portions 340, 345. The outer portion of the pads 305
includes a
profile, such as a radius profile, to increase the contact stresses between
the expander
tool 300 and the material to be expanded.
As further illustrated, a dog assembly 370 is disposed below the expander tool
300 and proximate the liner seal 155. The dog assembly 370 includes a
plurality of
dogs 325 constructed and circumferentially arranged around a support 330. A
shearable member, such as a shear ring 335, operatively attaches the support
330 to
the liner assembly 150.
Figure 10 is a cross-sectional view illustrating the collapsible expander tool
300
in an activated position prior to the expansion of the expandable hanger 200.
As
shown, the liner assembly 150 is positioned proximate the lower end of the
casing 110.
Thereafter, the upper torque anchor 140 is actuated, thereby extending the
pads 145
radially outward into contact with the surrounding casing 110. Subsequently,
rotational
force is transmitted through the working string 130 to the threaded mandrel
135. The
swivel 120 permits the threaded mandrel 135 to rotate while the torque anchor
140, the
spline assembly 225, expander tool 300, and liner assembly 150 remain
rotationally
stationary. As the threaded mandrel 135 rotates, the upper cone 310 moves
axially
toward the lower cone 315 closing the gap 360. At the same time, the pads 305
move
radially outward as the ramped portion 355 rides up the tapered portions 340,
345.
After the upper cone 310 is in substantial contact with the lower cone 315,
the entire
expander tool 300 creates a force on the plurality of shear pins 320. At a
predetermined
force, the shear pins 320 fail thereby permitting the expander tool 300 to
move axially
within the hanger 200.
Figure 11 is a cross-sectional view illustrating the expander tool 300
partially
expanding the expandable hanger 200. As the threaded mandrel 135 rotates, the
expander tool 300 moves axially through the expandable hanger 200 forcing the
inserts
210 to contact the inner surface of the casing 110 as the hanger 200 expands
radially
outward. The expander tool 300 continues to expand the entire length of the
expandable hanger 200 until it reaches a predetermined point above the liner
seal 155.
CA 02576536 2007-01-30
At that point, the expansion is stopped to prevent expanding the liner seal
155, in
anticipation of cementing.
Figure 12 is a cross-sectional view taken along line 12-12 in Figure 11
illustrating
the expander tool 300 during the expansion of the expandable hanger 200. As
clearly
shown, the plurality of pads 305 are circumferentially spaced around the
expander tool
300 and the plurality of pads 305 are aligned with the hanger flutes 220.
Therefore, as
the expander tool 300 moves axially through the hanger 200, the plurality of
pads 305
apply a force on the hanger flutes 220, causing them to expand out radially,
which in
turn urges the ribs 205 on the hanger 200 out radially as the inserts 210
penetrate the
surrounding casing 110. At this point, the hanger flutes 220 are free to move
out
radially while the flutes 185 accommodate the radially stationary ribs 205. In
other
words, the expandable hanger 200 includes a compliant slip system that allows
the
hanger ribs 205 to conform to the surrounding casing 110 as the expander tool
300
urges the expandable hanger 200 radially outward. Given that the radial
extension of
the hanger flutes 220 are dictated by the diameter of the pads 305, they never
contact
the surrounding casing 110. In this manner, the cement bypass ports 215 are
formed
thereby providing a fluid passageway between the hanger 200 and the
surrounding
casing 110 during the cementing operation.
Figure 13 is a cross-sectional view illustrating the cementation of the liner
assembly 150 within the wellbore 100. After the hanger 200 is expanded to the
predetermined point above the liner seal 155, the expander tool 300 is moved
proximate
the top of the hanger 200. Thereafter, the torque anchor 140 and lower anchor
160 are
deactivated and then cement is pumped through the working string 130, the
running tool
115, and the fluid outlet 170 to a cement shoe (not shown) or another means
known in
the art to distribute the cement. As indicated by arrow 180, the cement is
circulated up
an annulus 190 formed between the liner assembly 150 and the wellbore 100 and
past
the liner seal 155 into the cement bypass ports (not shown) of the expandable
hanger
200. Thereafter, the cement flows through the bypass ports and exits into an
inner
diameter of the surrounding casing 110.
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CA 02576536 2007-01-30
Figure 14 is a cross-sectional view illustrating the expansion of the liner
seal 155
after the cementing operation. As shown, the liner assembly 150 has been
completely
cemented in the wellbore 100. As further shown, the torque anchor 140 and
lower
anchor 160 are once again actuated, thereby extending the pads 145, 165
radially
outward. Subsequently, rotational force is transmitted through the working
string 130 to
the threaded mandrel 135. The swivel 120 permits the threaded mandrel 135 to
rotate
while the supporting torque anchor 140, the spline assembly 225, and the
expander tool
300 remain rotationally stationary. As the threaded mandrel 135 rotates, the
expander
tool 300 moves axially through the expanded portion of the hanger 200 until
the lower
cone 315 contacts the plurality of dogs 325. At that point, the second tapered
portion
365 urges the plurality of dogs 325 radially outward into contact with the
surrounding
hanger 200 and at the same time creates an axial force on the shear ring 335.
At a
predetermined force, the shear ring 335 fails thereby permitting the expander
tool 300
and the dog assembly 370 to move axially in the liner assembly 150. The axial
movement of the expander tool 300 and the dog assembly 370 expands the liner
seal
155 radially outward forcing the elastomeric material to form a fluid seal
between the
liner assembly 150 and the surrounding casing 110.
Figure 15 is a cross-sectional view taken along line 15-15 in Figure 14
illustrating
the expander tool 300 and the plurality of dogs 325 during the expansion of
the liner
seal 155. As clearly shown, the plurality of dogs 325 are spaced
circumferentially
between the plurality of pads 305 to fill a plurality of spaces 375. It should
be
understood, however, that other components may be employed to fill the spaces
375
between the pads 305, such as collet or any other suitable components known in
the
art.
In the embodiment shown, the entire outer perimeter of the liner seal 155 is
radially expanded into contact with the surrounding casing 110. In other
words, after
the plurality of dogs 325 expand a portion of the liner seal 155 into contact
with the
casing 110 then the plurality of pads 305 expand the remainder of the liner
seal 155 into
contact with the casing 110. In this manner, the cement bypass ports (not
shown) are
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CA 02576536 2007-01-30
sealed off to prevent any further migration of fluid through the expandable
hanger 200
from micro-annuluses that may have formed during the cementing operation.
Figure 16 is a cross-sectional view illustrating the fully expanded expandable
hanger 200 after the running tool 115 has been removed. As shown, the
expandable
hanger 200 is fully engaged with the lower portion of the surrounding casing
110 and
consequently supporting the entire weight of the liner assembly 150 by way of
the
inserts 210 on the hanger ribs 205. As further shown, the liner seal 155 has
been
expanded radially outward and is therefore creating the lower fluid seal
between the
liner assembly 150 and the surrounding casing 110.
Figure 17 is a cross-sectional view illustrating an alternative embodiment of
an
expandable hanger 405 with compliant slip system. In this embodiment, the
expandable hanger 405 includes a plurality of griping members 410 disposed
circumferentially therearound. The gripping members 410 include a reduced
portion
415 that is constructed and arranged to buckle or fail at a predetermined
load. In other
words, the expandable hanger 405 includes a compliant slip system that allows
the
gripping members 410 to conform the hanger 405 to a surrounding casing 110 as
an
expander tool 400 urges the expandable hanger 405 radially outward.
Figure 18 is a cross-sectional view illustrating an alternative embodiment of
an
expandable hanger 505 with compliant slip system. In this embodiment, the
expandable hanger 505 includes a plurality of holes 510 formed in the hanger
505. The
plurality of holes 510 are constructed and arranged to collapse at a
predetermined load.
In other words, the expandable hanger 505 includes a compliant slip system
that allows
the hanger 505 to conform to a surrounding casing 110 as an expander tool 500
urges
the expandable hanger 505 radially outward.
Figure 19 shows a cross-sectional view illustrating an expander tool 450 with
compliant expansion member 455. In this embodiment, the expander tool 450
includes
a forgiving member 460 disposed behind the expansion member 455. The forgiving
member 460 is constructed and arranged to deform at a predetermined load. In
other
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CA 02576536 2007-01-30
words, the expansion member 455 moves radially inward at the predetermined
load to
ensure that a hanger 465 conforms to a surrounding casing 110 as the expander
tool
450 urges the expandable hanger 465 radially outward.
Figure 20 illustrates an expansion tool 600 and an expandable assembly 602.
The expandable assembly 602 is coupled to an upper end of a liner 604. The
expansion tool 600 includes a fluted member 606 separated axially from a cone
608 by
a length of tubing 610. In operation, the expansion tool 600 moves axially
through an
inner diameter of the expandable assembly 602 to expand a liner hanger 612 of
the
expandable assembly 602 and subsequently a packer 614 of the expandable
assembly
602.
The liner hanger 612 can incorporate any of the expandable hangers disclosed
heretofore such as the expandable hanger 200 shown in Figures 1-16. Similarly,
any
arrangement such as the mechanical mechanisms previously described for some
embodiments or other hydraulic force application mechanisms can translate the
expansion tool 600 axially through the expandable assembly 602. For some
embodiments, the cone 608 and fluted member 606 may be independently moveable
and not fixed relative to one another. Accordingly, the fluted member 606 may
be
selectively moved axially and thereafter the cone 608 moved axially at a
desired time.
The liner hanger 602 includes ribs 605 extending outward along an outer
surface
of the liner hanger 602 to an outer diameter slightly less than a drift
diameter of casing
that the liner 604 is to be hung from. Flutes 620 circumferentially separate
each of the
ribs 605. To enhance gripping of the liner hanger 602 upon expansion into
contact with
surrounding casing, inserts 610 disposed along the ribs 605 can embed in the
casing
upon expansion. The inserts 610 can include hardened material pieces that can
be
oriented in substantially one direction to prevent relative movement in
substantially only
one direction. Orientation of the inserts 610 can also be in a multitude of
directions or
randomly along the ribs 605. Expanding the ribs 605 into engaging contact with
surrounding casing advantageously requires a low expansion ratio since the
ribs 605
provide a small gap with the casing prior to expansion. Further, the flutes
620 of the
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CA 02576536 2007-01-30
liner hanger 612 maintain desired fluid bypasses after expansion even though
the ribs
605 enable the low expansion ratio.
Figure 21 shows a top view illustrating the expandable assembly 602 prior to
expansion. Referring to Figures 20 and 21, the packer 614 defines a
longitudinal
corrugated profile with crests 616. For some embodiments, forming a circular
pipe
section inward selectively and then stress relieving the pipe provides the
corrugated
profile of the packer 614. Prior to forming the corrugated profile, the
circular pipe
section can have an outer diameter that is slightly smaller than an inner
diameter of the
casing that the packer 614 is to be expanded against. Accordingly, expanding
the
packer 614 into engaging contact with the surrounding casing also beneficially
requires
a low expansion ratio. Additionally, the corrugated profile with a decreased
outer
diameter and troughs 618 between crests 616 enable fluid bypass around the
packer
614.
Comparatively, the expandable assembly 602 provides improved fluid bypass
while keeping expansion forces required at an achievable level due to the
corrugated
profile of the packer 614 and the flutes 620 and ribs 605 of the liner hanger
612. For
example, a close standoff between an inner diameter of the casing and a tubing
to be
expanded is normally required to keep expansion ratios down. However, this
close
standoff creates a small annular area for limited fluid bypass without
utilizing
embodiments of the invention to increase the fluid bypass.
The packer 614 additionally can include circumferential projections 619 spaced
axially along an outer surface of the packer 614. Elastomer elements 620
disposed
between the circumferential projections 619 provide sealing capability for the
packer
614. The projections 619 prevent extrusion of the elastomer elements 620 and
otherwise provide backup for the elastomer elements 620 upon expansion of the
packer
614. Consequently, a pressure rating of the packer 614 benefits from the
elastomer
elements 620 being disposed between the projections 619.
CA 02576536 2007-01-30
In operation, the fluted member 606 passes axially through the packer 614
without reconfiguring or expanding the packer 614. Due to ribs 175 of the
fluted
member 606 being rotationally aligned in phase with the crests 616 of the
packer 614
and dimensions of the fluted member 606 and packer 614, the leading length of
the
fluted member 606 lacks interfering contact with the packer 614. Further axial
progression of the expansion tool 600 through the expandable assembly 602
occurs
once the expandable assembly 602 is positioned at a desired location in a
wellbore in
order to expand the liner hanger 612 such as shown in Figure 4. As with other
embodiments described herein, the expansion of the liner hanger 612 takes
place by
the ribs 175 of the fluted member 606 contacting an inside surface of the
liner hanger
612 in an area of the flutes 620.
In one embodiment, the tubing 610 between the fluted member 606 and the cone
608 provides sufficient separation such that the cone 608 remains located
outside of the
packer 614 after the fluted member 606 passes through the liner hanger 612 to
secure
the expandable assembly 602 to the casing. At this point in time, cementation
of the
liner 604 can occur with fluid bypass provided across both the liner hanger
602 that is
expanded and the packer 614 that still has the corrugated profile. Activation
once again
moves the expansion tool 600 axially through the expandable assembly 602 after
completing the cementation. As the expansion tool 600 moves relative to the
expandable assembly 602, the cone 608 reconfigures the shape of the packer 614
to
circular and expands the packer 614 in a radial direction such that at least
the elastomer
elements 620 are in substantial contact with an inner surface of the casing.
In another embodiment, expansion of the packer 614 and the liner hanger 612
occurs simultaneously. This can require that the cement is pumped prior to the
expansion of the liner hanger and the packer.
The cone 608 can be any device capable of expanding the packer 614 about
substantially 360 . For example, the cone 608 can be a fixed diameter conical
member
with a uniform maximum outer diameter that is greater than an inner diameter
of the
packer 614. For some embodiments, the cone 608 can be compliant or semi-
compliant
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CA 02576536 2007-01-30
meaning that the diameter of the cone 608 can at least partially fluctuate
inwards to
enable the packer 614 to conform to irregularities in the casing. This
compliancy can be
provided by segments of the cone that are biased in a manner that a
predetermined
load causes the segments to move inward such as occurs upon encountering a
restriction.
Figure 22 illustrates a cross-sectional view of a wellbore 650 looking down on
the
expandable assembly 602 fully expanded into casing 660 after removal of the
expansion tool 600. As shown in Figure 20, an inline polish bore receptacle
670 can be
provided between the liner hanger 612 and the liner 604. The polish bore
receptacle
670 provides a smooth inside surface 672 configured to mate with sealing units
stabbed
into the polish bore receptacle 670. With reference to Figures 21 and 22,
expansion of
the packer 614 and liner hanger 612 opens a bore through the expandable
assembly
602 to provide access to the inside surface 672 of the polish bore receptacle
670
without interference.
For some embodiments, an additional expandable sleeve (not shown) may be
disposed inside the packer 614 and/or the liner hanger 612 to enhance collapse
resistance of the expandable assembly 602. This additional expandable sleeve
contacts an inner surface of the expandable assembly 602 to provide a
cladding.
Further, the additional expandable sleeve can be expanded with the packer 614
and/or
the liner hanger 612 or run in and expanded in a second trip application.
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.
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