Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02536046 2002-05-14
CASING ATTACHMENT METHOD AND APPARATUS
BACKGROUND OF THE INVENTION
The present invention relates generally to a method and apparatus of attaching
a downhole member
to a cased wellbore and more particularly, to attaching a tool downhole within
a cased wellbore.
As a hydrocarbon well is drilled, the bore hole is lined with a steel pipe
known as casing. This
casing is cemented to an outer casing or the surrounding earth formation and
provides a strong,
continuous lining of the sides of the borehole. A wide variety of downhole
tools may be affixed to
the inside of the casing for conducting a well operation as for example well
reference members,
pipe hangers, anchors, and packers. The connection of the tool to the inside
of the casing is used to
support pipe or other member within the casing, to pack off the flow bore of
the casing, to anchor a
well tool for conducting a well operation, or to resist forces produced by
wellbore pressure, drilling
operations, milling and sidetracking operations, or other downhole well
operations and processes.
Typically downhole members are affixed to the inside of the casing by slips.
Slips are normally
made from a hardened material and are reciprocably supported in windows in a
downhole member.
The slips engage the casing through teeth on the outside of the slip. The
inside of the slip normally
has a tapered surface which interfaces with another tapered surface located on
a cone member.
When run into the wellbore, the slip is positioned outside of the cone with
little or no engagement
between the tapered surfaces. When the downhole member is set in place, the
cone moves toward
the slip forcing the tapered surfaces together. The interfacing tapered
surfaces cam the slip
outwardly into engagement with the wall of the casing. The cone remains in
place behind the slip
to maintain the engagement between the slip and the casing wall.
The cone and the slip are normally located on the outside of a central tubular
body that often
includes an open bore extending through the downhole member. The stacked
location of the slip,
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cone, and body decrease and restrict the diameter of the flowbore through the
casing. It is often ~
advantageous to maximize the through bore in the downhole member in order to
facilitate
operations in the casing below the set downhole member. Many designs have been
developed to
maximize the through bore using the traditional cone and slip system. These
designs often
involved making the slips, cones, and body as thin as possible. These designs
reach a limit in
maximizing the through bore due to the pressures and loads which must be
withstood by the
downhole member.
The present invention overcomes these and other limitations of the prior art.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus to affix a tool to a
cased wellbore. The
apparatus includes a body with an engaging surface for an attaching engagement
to the interior
surface of an existing casing in a borehole. The engaging surface on the body
has a first non-
engaged position where the engaging surface does not engage the casing and an
engaged position
where the engaging surface does engage the casing. The engaging surface may be
any surface
which causes adequate engagement between the body and the casing to dispose
the apparatus
within the casing. The apparatus further includes an actuation member for
actuating the engaging
surface from the non-engaged position to the engaged position. The actuation
member may be an
expansion member which expands the engaging surface into engagement with the
casing or which
expands engaging surfaces, mounted on the body, into engagement with the
casing.
A setting member extends through the body of the apparatus and is attached to
one end of the body
thus mounting the apparatus onto the setting member. That portion of the
setting member
extending through the body includes a piston member attached to the actuation
member on the
apparatus for actuating the movement of the apparatus to the engaging
position. The apparatus is
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actuated to engage with the casing either by expanding the body of the
apparatus into the engaging
position or expanding the engaging surfaces mounted on the body into the
engaging position.
A release member may be used to release the engagement of the apparatus from
the casing. The
release member is attached to one end of the apparatus body thus mounting the
apparatus onto the
release member. A portion of the release member extends through the apparatus
body and that
portion has a lower end which extends below the lower end of the apparatus.
The release member
portion also includes a piston member engaging the top of the actuation member
on the apparatus
for driving the actuation member out of the engagement with the apparatus body
to release the
apparatus from engagement with the casing. The release member is removed with
the release
member engaging the lower end of the apparatus to also remove the apparatus.
One embodiment of the present invention comprises a tubular body with a
longitudinal slot
extending along at least a portion of the longitudinal length of the body and
a wedge member
disposed within the slot. A portion of the slot is V-shaped to accommodate the
wedge member
with a corresponding V-shape. The outside of the tubular body has an engaging
surface such as
integral teeth. To set the apparatus, the wedge member is driven into the V-
shaped slot. This
movement widens the slot and expands the diameter of the tubular body until
the engaging surface
engages the interior surface of the wall of the casing. The teeth on the
outside of the body bite into
the casing wall to affix the apparatus in place within the casing.
The flow bore through the casing is only decreased by the thickness of the
wall of the tubular body.
The forces to be applied to the body determine the thickness of the wail of
the tubular body.
Therefore the thickness of the wall of the tubular body is minimized so as to
be very thin and
consequently provide a very large through bore. In a preferred embodiment, the
diameter of the
through bore of the apparatus in the engaged position is at least 70% of the
diameter of the casing.
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The apparatus of the present invention is well suited for adaptation for use
on any number o3'
downhole tools including but not limited to well reference members, liner
hangers, casing hangers,
anchors, packers, and seal bores.
Thus, the present invention comprises a combination of features and advantages
which enable it to
overcome various problems of prior devices. The various characteristics
described above, as well as
other features, will be readily apparent to those skilled in the art upon
reading the following detailed
description of the prefer-ed embodiments of the invention, and by referring to
the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more detailed description of the preferred embodiment of the present
invention, reference will
now be made to the accompanying drawings, wherein:
Figure 1 is a side elevation view partly in cross section of a preferred
embodiment of the apparatus
of the present invention in the non-engaged position with a casing;
Figure 2 is a cross sectional view taken at plane 2-2 of Figure 1;
Figure 3 is a side elevation view, partly in cross section, of the apparatus
of Figure 1 in the engaged
position with the casing;
Figure 4 is a cross sectional view taken at plane 4-4 of Figure 3;
Figure 5 depicts an embodiment of the present invention that includes two half
circles with a
helical interface;
Figure 6 is a side elevation view of another preferred embodiment of the
apparatus of the present
invention used as a well reference member;
Figure 7 is a cross sectional view taken at plane 7-7 of Figure 6;
Figure 8 shows the embodiment of Figure 6 installed on running tool in running
position;
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Figure 9 is a cross section of Figure 8;
Figure 10 is an enlarged view of the cross section of Figure 9;
Figure 1 lA depicts an embodiment of the present invention as a liner hanger;
Figures 11B-C shows alternative embodiments of the liner hanger of Figure 11A;
and
Figures 12A-12C depict an embodiment of the present invention as a packer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to Figures 1-4, there is shown a preferred embodiment of
the apparatus 10 of the
present invention disposed within a casing 12 in a borehole 14. As will be
more fully hereinafter
described, apparatus 10 may have any one of a number purposes including to
support pipe or other
member within the casing 12, to seal or pack off the flow bore of the casing
12, to anchor a well
tool for conducting a well operation, and/or to resist forces produced by
wellbore pressure, drilling
operations, milling and sidetracking operations, and other downhole well
operations and processes.
Apparatus 10 may be used with a wide variety of downhole tools to affix those
tools to the inside
of the casing 12 for conducting a well operation as for example as a well
reference member, liner
hanger, casing hanger, anchor, packer, or seal bore.
In using the terms "above", "up", "upward", or "upper" with respect to a
member in the well bore,
such member is considered to be at a shorter distance from the surface through
the bore hole 14
than another member which is described as being "below", "down", "downward",
or "lower".
"Orientation" as used herein means an angular position or radial direction
with respect to the axis 16
of the borehole 14. In a vertical borehole, the orientation is the azimuth.
The depth is defined as
that distance between the surface of the cased borehole 14 and the location of
the apparatus 10
within the cased borehole 14. "Drift diameter" is a diameter, which is smaller
than the diameter Dc
of the casing 12, taking into account the tolerance of the manufactured
casing, through which a
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typical well tool will pass. Typically the drift diameter is approximately 1/8
inch smaller than the
nominal diameter of the casing 12.
It is intended that the apparatus 10 be permanently installed within the
borehole 14. Permanent is
defined as the apparatus 10 being maintained in the cased borehole 14 at least
throughout drilling
operations. It should be appreciated that the apparatus 10 may be retrievable.
As shown in Figures 1-4, apparatus 10 includes a body 18 with an engaging
surface 20 for an
attaching engagement to the interior surface 22 of casing 12 in borehole 14.
The engaging surface
20 on body 18 has a first non-engaged position shown in Figures l and 2 where
the engaging
surface 20 does not engage the casing 12 and an engaged position shown in
Figures 3 and 4 where
the engaging surface 20 engages the casing 12. In the non-engaging position,
the engaging
surfaces 20 have an outer dimension Dw thereby providing a radial clearance
with casing 12 of
Dc-Dw. The engaging surface may be any surface which causes adequate
engagement between the
engaging surfaces 20 on body 18 and surface 22 on casing 12 to dispose the
apparatus 10 within
casing 12 for the purposes required of the particular well operation. In the
engaging position,
engaging surface 20 bitingly and/or fiictionally engages surface 22 of casing
12 to maintain
apparatus 10 within casing 12.
The apparatus 10 further includes an actuation member 24 for actuating the
engaging surface 20
from the non-engaged position to the engaged position. The actuation member 24
is an expansion
member which is disposed in a V-shaped slot 26 in body 18. As actuation member
24 is driven
into V-shaped slot 26, body 18 expands with engaging surface 20 into
engagement with inner
surface 22 of casing 12 or expands engaging surfaces mounted on body 18 into
engagement with
casing 12. In the engaged position, Dw approximates Dc. Preferably, the inner
dimension Di of
body 18 in the engaged position is greater than the outer dimension Dw in the
non-engaged
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position such that an apparatus 10 in the non-engaged position will pass
through an apparatus 10 in
the engaged position.
It should be appreciated that only one or the other of the slot 26 and
actuation member 24 need
have tapered edges. For example, the slot 26 may only have parallel edges 34
and no tapered
edges with the actuation member having tapered edges to spread the parallel
edges 34 apart to
expand body 18 as actuation member 24 is forced between parallel edges 34.
Likewise, the
actuation member 24 may have only parallel edges and slot 26 have tapered
edges 35 whereby as
actuation member 24 is driven between tapered edges 35, body 18 expands.
Alternatively, it should
be appreciated that the body 31 may be moved relative to a stationary
actuation member 24 to
expand body 31.
The preferred embodiment of the apparatus 10 has simplicity in that it is thin
walled member
comprised of only two pieces, i.e., a body and an actuation member.
It should also be appreciated multiple wedges may be disposed on the body 18
of apparatus 10.
For example, there may be multiple wedges disposed around body 18, such as
four wedges each
approximately 90° from each other or three wedges each approximately
120° from each other.
Figure 5 shows another embodiment 300 of the apparatus 10. Embodiment 300
includes a body
302 and an actuation member 304 where the actuation member is a wedge member.
Body 302 and
wedge member 304 are substantially the same, each forming one half of
embodiment 300. The
body 302 and wedge member 304 are wedges members which form two halves of a
circle or 180°
in arcuate shape. Body 302 and wedge member 304 each has a helical wedge cut
306 that mates
with the other half so that when the halves are slid along their central axis
308, the outside diameter
of the combination increases.
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Referring now to Figures 6-8, apparatus 10 is shown as a preferred embodiment
of a well referen a
member 30. Well reference member 30 of Figures 6-8 includes a body 31 in the
form of a sleeve
having an engaging surface in the form of a plurality of slips 32 integrally
disposed around the
external surface of body 31. Body 31 also includes a slot 33 having an upper
end with parallel
sides 34 and a lower end having tapered sides or edges 35 forming a V or
truncated cone shaped
slot 36. V-shaped slot 36 receives an actuating member in the form of a wedge
38 having tapered
outer edges 40 which are complimentary to the tapered inner edges 35 of body
31. As wedge 38
moves into slot 36, body 31 expands concentrically radially outward creating a
type of press fit
into the casing 12.
It should be appreciated that slips 32 have teeth which bitingly engage the
inside surface 22 of
casing 12. This engagement may be varied by varying the number of teeth 33 on
slips 32 or by
varying the number of slips 32. The slips 32 place less stress into casing 12
than typical liner
hangers. Because individual slips are not being used in the preferred
embodiment, as in a typical
liner hanger, there is a uniform stress distribution around the body 31 which
is lower than that of
the prior art. Although individual groupings of teeth 33 are shown, it should
be appreciated that
slips 32 may be evenly spaced around the surface of body 31 while achieving
the same load
carrying capacity of a hanger. Thus, the present invention has a more uniform
load distribution of
engagement between body 31 and casing 12. This causes less damage to the
casing. Although
teeth 33 have been shown on slips 32, it should be appreciated that any
frictional surface around
body 31 may be used, such as buttons or other fi-ictional material, instead of
individual pads with
teeth.
As shown in Figure 7, the edges 40, 35 of wedge 38 and body 31, respectively,
are radial cuts
along the radius R of body 31 and along a helical surface so that the inside
chordal length 41 of the
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cut is less than the outside chordal length 42. This causes the inside edges
35a of wedge 38 to
provide a smaller opening than that of the outside edges 35b. As wedge 38
moves upwardly into
V-shaped slot 36, edges 35, 40 interengage, because of chordal lengths 41, 42,
thereby preventing
wedge 38 from moving interiorally of the opening formed by inside chord 41 of
body 31. The
outside surface of wedge 38 is maintained by casing 12. The well reference
member 30 is fixed
into the cased borehole 14 as wedge 38 moves upwardly into the V-shaped slot
36 and expands the
diameter Dw of the body 31 causing the slip's teeth 33 to contact the inside
surface 22 of casing 12.
The wedge 38 is driven into position by a setting tool preferably designed to
be removed from the
well after setting in order to open the wellbore 14 for use by other tools.
It should be appreciated that the wedge 38 may be of any size and edges 35, 40
may have any taper
preferably less than 45° from the axis 16. The smaller the angle of the
taper, the longer the stroke
that is required by wedge 38 to achieve a predetermined radial expansion of
body 31. A smaller
taper angle better maintains wedge 38 within mule shoe V-shaped slot 36 since
a smaller taper
provides more hoop stress for the mechanical force provided by wedge 38. If
the angle is made
larger, less hoop stress is achieved. The preferred range of angles of edges
35, 40 for wedge 38 is
5-15° and most preferably 10° from the axis 16. This provides a
stroke of approximately six
inches by wedge 38 to achieve adequate expansion of well reference member 30
for a 9-5/8 inch
casing 12. This increases the diameter Dw of well reference member 30 by
between 3/8 and 1/2
inches.
The upper end of body 31 includes an upwardly facing orienting surface 44
forming orientation
member 45. The orienting surface 44 of orientation member 45 includes an
inclined surface 46
extending from an upper apex to a lower opening 47 of slot 33. Orientation
member 45 is
sometimes referred to as a mule shoe. The orientation surface 44 is adapted to
engage a
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complimentary mule shoe on a well tool. The complimentary mule shoe surfaces
are radi 1
helixes.
Best shown in Figure 10, the lower terminal end 48 of well reference member 30
is chamfered at
49 so that the lowermost annular pointed end is adjacent casing 12. The lower
terminal end 48 will
be against the casing 12 after the well reference member 30 has been expanded
and set within
casing 12. It is desirable for the lower terminal end 48 to be as close to the
casing wall 22 as
possible to avoid causing any well tools to hang up in the well reference
member 30 as they pass
therethrough, particularly as a well tool passes upwardly through the bore 15
of body 31.
The reference member 30 has a diameter Di forming a central bore 15
therethrough with diameter
Dw, in the engaged position, preferably approximating the drift diameter of
casing 12. Diameter Di
of reference member 30 preferably has a minimum diameter of at least 4 inches.
It can be
appreciated that the inside diameter Di in its contracted position may be
adjustable by sizing the V-
shaped slot 36.
After being expanded to the engaged position, the inside diameter Di of the
well reference member
30 is also large enough to allow the passage of another well reference member
30 in the collapsed
and nonengaged position. By allowing the same sized well reference member in
its contracted
position to pass through the expanded bore of another well reference member,
multiple well
reference members can be disposed anywhere in the well and may be stacked
within the well.
The wall thickness T of body 31 is only as thick as is required to withstand
the forces that will be
applied to well reference member 30. Thus, the body 31 has a minimum wall
thickness providing
a maximum central bore 15 through body 31. Because there are no overlapping
components, wall
39 of body 31 can be as thick as needed to engage and orient a subsequent well
tool. In one
preferred embodiment, the wall thickness T of body 31 is 3/8 of an inch thick.
Thus, the inside
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~ameter Di of body 31 is less than one inch, preferably 3/4 of an inch,
smaller than the diameter Dc
of the casing 12. In a preferred embodiment, the diameter Di of the through
bore of the apparatus
in the engaged position is less than 30% smaller than the diameter Dw of the
casing 12 and at
least 70% of the diameter Dw of the casing 12.
The inside diameter Di of reference member 30 in the engaged position is
maximized with respect
to the inside diameter Dc of casing 12. For example, it is typical to have a 7
inch casing as the
innermost casing string in the well bore. A 7 inch casing has an inside
diameter of approximately
6 inches and in a 7 inch casing, the diameter Di of reference member 30 has an
inside diameter of
at least 5 inches which is only one inch smaller than the diameter of casing
12. More preferably
diameter Di has a diameter of 5-1/2 inches which is only %z inch smaller than
the diameter Dc of
casing 12. It is preferred that the diameter Di be no less than'/a inch
smaller than the diameter Dc
of casing 12. This will allow a 4-1/2 liner with 5 inch couplings to pass
through reference member
30.
Diameter Dw of reference member 30 in the engaged position is sufficiently
large to allow the next
standard sized liner or casing string to pass therethrough. For example, if
casing 12 were a 7 inch
casing, the next standard size pipe would be 4-1/2 inch pipe, such as a liner.
In comparison, a 7
inch big bore packer has a throughbore of less than 4 inches and will not
allow the passage of 5
inch couplings or a 4-1/2 inch Liner: If a big bore packer were used, a
reduced size Liner would be
required such as a 3-1/2 inch liner so as to pass through the bore of the big
bore packer. If casing
12 were 9-5/8 inch casing, reference member 30 would have a nominal diameter
Dw in the
engaged position of 8-1/2 inches and would then accommodate a 7-5/8 inch pipe.
The diameter Di
through reference member 30 would then preferably be between 7-3/4 and 8
inches. With the well
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reference member 30 in the expanded position, its outside diameter Dw is
approximately 8-3/8~
inches.
The embodiment shown does not include a latch for attaching other tools or any
sealing apparatus
for sealing against the wellbore. This embodiment and its uses are further
disclosed in U.S. Patent
Application Serial No. 09/860,870, filed on May 18, 2001, entitled "Well
Reference Apparatus and
Method", hereby incorporated herein by reference. It should be appreciated
that well reference
member 30 may be adapted to latch onto adjacent tools and assemblies as
hereinafter described.
Referring now to Figure 8, there is shown a setting tool 50 for setting well
reference member 30.
Wedge 38 on well reference member 30 is mounted on setting tool 50 by a
plurality of shear
screws 52. As shown, there are four shear screws 52 although there may be any
number of shear
screws 52. Setting tool 50 includes a downwardly facing orienting surface 54
for matingly
engaging with upwardly orienting surface 44 on well reference member 30.
Referring now to Figures 8-10, the setting tool 50 is connected to a splined
assembly 56 which in
turn is connected to a rotary connection 57 attached to the end of a work
string (not shown). The
setting tool 50 includes an upper tubular member 58 threaded at its upper end
to splined assembly
56. A sleeve 59 having a downwardly facing orienting surface 54 is disposed
around a portion of
tubular member 58 and a crossover sub 60 is mounted within the lower end of
upper tubular
member 58. A mandrel 62 is threaded at its upper end to crossover sub 60 and
extends through
well reference member 30 and is attached at its lower end to a cap 64. An
outer tubular member 66
is attached at its lower end to cap 64 and extends upwardly around cap 64. A
hydraulic
passageway 68 extends through crossover sub 60 and mandrel 62 and is closed by
cap 64 at its
lower end. Hydraulic passageway 68 communicates with the surface through
splined assembly 56
and the flowbore of the work string.
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Mandrel 62 and outer tubular member 66 form a cylinder 69 housing a piston 70.
Piston 70
includes seals 71 which sealingly engage the inner surface of outer tubular
member 66 and the
outer surface of mandrel 62 and is held in place on mandrel 62 by shear screws
72 or similar
releasable attachment means. A collet 74 is releasably attached to mandrel 62
by shear screws 75
or a similar releasable attachment means. Collet 74 includes an upper collar
76 having a plurality
of downwardly extending collet fingers 78 with enlarged heads 80 on the end
thereof. Collet heads
80 form an upwardly facing shoulder 81 which engages the lower end 48 of well
reference member
30. As best shown in Figure 8, the wedge member 38 of well reference member 30
is attached to
two of the collet fingers 82 by shear screws 52 or similar releasable
attachment means.
Collet heads 80 project radially outward of the outer surface of well
reference member 30 to
protect the lower end 48 of well reference member 30. The outside diameter of
heads 80 are
slightly greater than the outside diameter of body 31 and are chamfered at 85.
Heads 80 prevent
lower terminal end 48 from hitting anything in the borehole 14 as it passes
therethrough. In
particular, it is important that nothing engage the lower terminal end 86 of
wedge 38 which would
tend to drive wedge 38 prematurely up into slot 36.
In the unactuated position shown in Figures 9 and 10, the downwardly facing
orienting surface 64
and the upwardly facing shoulders 81 of collet heads 80 hold well reference
member 30 in the non-
expanded and non-engaged position. Collet fingers 78 are supported in their
radially outermost
position by the upper end of piston 70 thus preventing collet fingers 78 from
being forced radially
inward by any force applied to the outer surfaces 87 of collet heads 80.
Referring now to Figure 10, upon pressuring up through the hydraulic
passageway 68 from the
surface, fluid passes through passageway 68 and through ports 88 communicating
with cylinder 69.
Pressure is applied to the end of piston 70 causing the piston 70 to be
displaced upwardly. Shear
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screws 72 are sheared by this upward movement. The piston 70 continues its
upward movement
until it engages downwardly facing shoulder 90 on the collar 76 of collet 74.
As can be seen in
Figure 10, in this position a reduced diameter portion 92 around the mid-
portion of piston 70 is
aligned with collet heads 80. This alignment allows the collet heads 80 to
move radially inward
into the annular area formed by reduced diameter portion 92 such that piston
70 no longer supports
collet fingers 78. Surface 81 on fingers 78 assists by caroming fingers 78
inwardly so as to
disengage with the lower end 48 of well reference member 30. As the collet
fingers 78 collapse
and piston 70 engages shoulder 90 of collet 74, shear screws 75 are then
sheared releasing collet 74
from mandrel 62 allowing fiu-ther upward movement of piston 70, collet 74, and
wedge 38. The
well reference member 30 remains stationary because of the engagement of
orienting surfaces 44,
54.
The upward movement of wedge 38 is constrained by edges 35, 40 of V-shaped
slot 36, wedge 38
and the interior surface 22 of casing 12. As piston 70 continues to move
upwardly, wedge 38 is
forced up into V-shaped slot 36 forcing the well reference member 30 to expand
into its engaged
position. Ultimately the force required to move wedge 38 fw-ther into slot 36
reaches the
predetermined shear value of shear screws 52. Once the shear value is reached,
the shear screws
52 shear, therefore releasing wedge 38 from setting tool 50. The hydraulic
actuation of setting tool
50 moves wedge 38 upwardly and into V-shaped slot 36 expanding the outside
diameter Dw of
body 31 causing slips 32 to bitingly engage the interior surface 22 of casing
12. Now all of the
collet fingers 78 move up underneath inside of body 31 and setting tool SO is
completely released
from reference member 30. Setting tool 50 is then retrieved through the inside
diameter Di of body
31.
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Zt should be appreciated that the wedge 38 may be actuated other than by
hydraulic means. For
example, wedge 38 may be actuated mechanically or pyrotechnically.
Referring still to Figures 9-10, the splined assembly 56 allows setting tool
50 to be rotationally
adjusted at the surface so that the orienting surfaces 44, 54 are properly
oriented. The splined
assembly 56 comprises an upper spline sub 93, a spline nut 94, a lower spline
sub 95, and a
retaining ring 96. The lower spline sub 95 threadably engages upper tubular
member 58 of well
reference member 30 at its lower end and has splines on its upper end. The
splines mesh with
mating splines on the upper spline sub 93 that sealingly engages the tubular
member 58. The
spline nut 94 threadably engages the lower spline sub 95 and maintains the
position of the upper
spline sub 93 at a shoulder.
Although apparatus 10 has been described with respect to Figures 6-10 as a
well reference
member, it should be appreciated that member 30 may serve as an anchor for a
well tool assembly
(not shown). To serve as an anchor, the engaging surfaces 32 need to have
sufficient engagement
with casing 12 so as to accommodate the compression and torque required to
withstand the
compression, tension, and torque caused by the well operation, such as the
milling of a window.
Further, apparatus 10 as an anchor includes a latch assembly, such as that
used on setting tool S0,
to latch the well tool assembly onto the anchor. Thus, apparatus 10 may be
used as an anchor.
Apparatus 10 is not limited to its use as a well reference member or anchor
and may be used in
other applications. For example, apparatus 10 can also be used as a casing
hanger, liner hanger,
packer, or any other tool that is to be fixed within the wellbore 14. Another
example is use with
the system described in U.S. patent application Serial No. 60/247,295, filed
November 10, 2000
and entitled Method and Apparatus for Multilateral Completion, hereby
incorporated herein by
reference.
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Refernng now to Figure 11A, apparatus 10 is shown as a preferred embodiment of
a liner hanger
100. The liner hanger 100 has a tubular body 102 with a lower end 112 adapted
to receive and
support a liner (not shown) through a threaded connection or another type of
connection known in
the art. Body 102 has a bore 103 therethrough and a plurality of V-shaped
slots 104 that
accommodate an equal number of wedge members 106. Each V-shaped slot 104 has
tapered sides
or edges 105 for receiving a wedge member 106 having complimentary tapered
sides or edges 107.
The body 102 has cut away portions 114 below V-shaped slots 104 allowing one
end of the
wedges 106 to extend below slots 104. V-shaped slots 104 have an upper end 109
adjacent an
upper annular portion 111 of body 102. Upper annular portion 111 provides a
constant upper
diameter around body 102 whether the hanger 100 is in its contracted or
expanded position. V-
shaped slots 104 are disposed in the mid-portion 113 of body 102 between upper
annular end 111
and lower end 112.
Referring now to Figures 11 B and 11 C, there is shown an alternative
embodiment of the hanger
100. Hanger 150 is substantially the same as hanger 100 except that hanger 150
has a body 152
with a V-shaped slot 154 that extends from cut away portion 114 through the
upper terminal end
156 of body 152. This allows the upper end 156 to expand as hanger 150 moves
from its non-
engaged position to its engaged position. Hanger 150 in Figure 11B shows
multiple wedge
members 106 while hanger 150 in Figure 11C shows a single wedge member 106.
Referring again to Figure 1 lA, the body 102 includes a plurality of teeth 108
extending around the
exterior surface of the mid-portion 113 of body 102 to grip the inside surface
22 of casing 12. The
wedges 106 also have teeth 110 on their exterior surfaces to also engage
surface 22 of casing 12.
Although teeth 110 have been shown on slips 108, it should be appreciated that
any frictional
surface may be disposed on body 102, such as buttons or an abrasive material.
As wedge 106
16
CA 02536046 2002-05-14
moves into slot 104, the mid-portion 113 of body 102 expands and bows radially
outward creating
a type of press fit into the casing 12.
The edges 105, 107 of slot 104 and wedge 106, respectively, are radial cuts
along the radius of
body 102 and along a helical surface so that the inside chordal length of the
cut is less than the
outside chordal length. This causes the opening between inside edges 107 of
wedge 106 to be
smaller than that of the outside edges 107. As wedge 106 moves upwardly into V-
shaped slot 104,
edges 105, 107 interengage, because of the chordal lengths, thereby preventing
wedge 106 from
moving interiorally of the opening formed by the inside chord of body 102. The
outside surface of
wedge 102 is maintained by casing 12.
It should be appreciated that wedge 106 may be of any size and edges 105, 107
may have a
predetermined taper. The smaller the angle of the taper, the longer the stroke
that is required by
wedge 106 to achieve a predetermined expansion of body 102. Further, the taper
on edges 105,
107 may be sized to provide a predetermined press fit between the engaging
surfaces 108 of body
102 and the interior surface 22 of casing 12.
The wall thickness of body 102 is only as thick as is required to support the
liner string in the
borehole 14. Thus, the body 102 has a minimum wall thickness providing a
maximum central bore
103 through body 102. Because there are no overlapping components, the wall of
body 102 can be
as thick as needed to hang the liner.
The liner hanger 100 of Figures 11A-11C is set in a manner similar to the
method described above
for well reference member 30. A setting member, similar to setting tool 50, is
attached to the
upper end of liner hanger 100 and is run in the cased borehole 14 with liner
hanger 100 and a liner
string. The setting member has a mandrel, similar to mandrel 62, which extends
through the bore
103 of the body 102 of liner hanger 100. The mandrel includes a collet,
similar to collet 74, which
17
CA 02536046 2002-05-14
is mounted on a piston, similar to piston 70, and has collet fingers, similar
to collet fingers 78, with
enlarged collet heads, similar to collet heads 82, that extend through cut
aways 114 and engage the
lower terminal end 120 of wedge members 106. Wedge members 106 are mounted on
the collet
fingers by shear members passing through apertures 122 in wedge members 106.
The piston on
the mandrel of the setting member is hydraulically actuated causing wedge
members 106 to move
upwardly in V-shaped slots 104 causing threads 108 to engage with the interior
surface 22 of
casing 12 by expanding the mid-portion 113 of body 102 of liner hanger 100
into the engaging
position. In the engaging position, the threads 110 on wedge members 106 are
approximately
aligned with the threads 108. The setting tool is then removed from the
borehole 14.
The inside diameter Di of body 102 in the engaged position is maximized with
respect to the inside
diameter Dc of casing 12. After being expanded to the engaged position, the
bore 103 of the liner
hanger 100 is large enough to allow the passage of other well tools and pipe
strings.
Refernng now to Figures 12A-12C, apparatus 10 is shown as a preferred
embodiment of a packer
200. The packer 200 comprises an upper body 202 and a lower body 204. The
lower end 222 of
upper body 202 is connected to lower body 204 through a threaded connection
206. The lower
body 204 is a solid cylindrical tube having a bore 226 therethrough. Lower
body 204 has an
annular recess 228 in which is disposed an elastomeric, or other type, of
sealing element 208
preferably bonded to its outside surface. Lower body 204 is also preferably
made of a malleable
metal which will easily expand and contain sealing element 208.
The upper body 202 is a tubular body 210 having a bore 224 therethrough and a
plurality of V-
shaped slots 212 that accommodate an equal number of wedge members 214. V-
shaped slots 212
are disposed in the mid-portion 213 of upper body 202 between upper annular
end 211 and lower
end 222. Each V-shaped slot 212 has tapered sides or edges 230 for receiving a
wedge member
18
CA 02536046 2002-05-14
214 having complimentary tapered sides or edges 232. The upper body 202 has
cut away portions
216 allowing one end of the wedges 214 to extend below slots 212. The upper
body 202 is
equipped with teeth 218 around the outside diameter to grip the inside of the
casing. The wedges
214 may also have teeth 220 on the outside surfaces to enhance attachment to
the casing 12.
Although teeth 208 and 220 have been shown as the engaging surface, it should
be appreciated that
any fi-ictional surface may be disposed on body 202, such as buttons or an
abrasive material.
The edges 230, 232 of slot 212 and wedge members 214, respectively, are radial
cuts along the
radius of body 202 and along a helical surface so that the inside chordal
length of the cut is less
than the outside chordal length. This causes the opening between the inside
edges 232 of wedge
member 214 to be smaller than that of the outside edges 232. As wedge member
214 moves
upwardly into V-shaped slot 212, edges 230, 232 interengage, because of the
chordal lengths,
thereby preventing wedge member 214 from moving interiorally of the opening
formed by inside
chord of body 202. The outside surface of wedge member 214 is maintained by
casing 12.
It should be appreciated that sealing element 208 may be located at various
locations on body 202.
For example, the sealing element 208 may cover and/or be bonded to teeth 218,
220. Further anti-
extrusion rings may be placed on each side of the sealing element 208 to
prevent extrusion. The
sealing element 208 may be upset to ensure that the sealing element 208 spans
any clearance or
gap between the packer body and casing 12.
It should be appreciated that wedge member 214 may be of any size and edges
230, 232 may have
a predetermined taper. The smaller the angle of the taper, the longer the
stroke that is required by
wedge member 214 to achieve a predetermined expansion of body 202. Further,
the taper on edges
230, 232 may be sized to provide a predetermined press fit between the
engaging surfaces 218, 220
on the mid-portion 213 of upper body 202 and the interior surface 22 of casing
12.
19
CA 02536046 2002-05-14
The wall thickness of upper and lower body 202, 204 is only as thick as is
required for the packer
200 to serve its functions in the borehole 14. Thus, upper and lower body 202,
204 has a minimum
wall thickness providing maximum central bores 224, 226 through upper and
lower body 202, 204.
Because there are no overlapping components, the wall of upper and lower body
202, 204 can be
as thick as needed.
The packer 200 of Figures 12A-12C is set in a manner similar to the method
described above for
well reference member 30 and liner hanger 100. A setting member, similar to
setting tool ~0, is
attached to the upper end of packer 200 and is run in the cased borehole 14.
The setting member
has a mandrel, similar to mandrel 62, which extends through the bore 103 of
the body 102 of liner
hanger 100. The mandrel includes a collet, similar to collet 74, which is
mounted on a piston,
similar to piston 70, and has collet fingers, similar to collet fingers 78,
with enlarged collet heads,
similar to collet heads 82, that extend through cut aways 216 and engage the
lower terminal end
234 of wedge members 214. Wedge members 214 are mounted on the collet fingers
by shear
members passing through apertures 236 in wedge members 214. The piston on the
mandrel of the
setting member is hydraulically actuated causing wedge members 214 to move
upwardly in V-
shaped slots 212 causing threads 128, 234 and sealing element 208 to engage
with the interior
surface 22 of casing 12 by expanding the mid-portion 213 of upper body 202 of
packer 200 into
the engaging position. The expansion of upper body 204 compresses the sealing
element 208 into
sealing engagement against the casing 12 to create a seal. In the engaging
position, the threads 220
on wedge members 214 are approximately aligned with the threads 218. The
setting tool is then
removed from the borehole 14.
The inside diameter Di of upper and lower body 202, 204 in the engaged
position is maximized
with respect to the inside diameter Dc of casing 12. After being expanded to
the engaged position,
CA 02536046 2002-05-14
the bores 224, 226 of packer 200 are large enough to allow the passage of
other well tools and pipe
strings.
In each of the embodiments described above, the apparatus 10 may be released
from the casing 12.
A release member may be used to release the engagement of the apparatus from
the casing. The
release member is attached to one end of the apparatus body thus mounting the
apparatus onto the
release member. A portion of the release member extends through the apparatus
body and that
portion has a lower end which extends below the lower end of the apparatus.
The release member
portion also includes a piston member engaging the top of the actuation member
on the apparatus
for driving the actuation member out of the engagement with the apparatus body
to release the
apparatus from engagement with the casing. The release member is removed with
the release
member engaging the lower end of the apparatus to also remove the apparatus.
All of the above-described embodiments feature the benefit of the wedge means
for actuating the
apparatus 10 into engagement with the casing 12. Further, the apparatus 10
provides a large
through bore after setting of the apparatus 10. This expands the range of
tools that can then be run
through the apparatus 10 after it has been set. The bores of any of the
embodiments of the present
invention may contain other features to allow the tools to interface with
other downhole tools.
These types of features include latches and grooves for locking or anchoring
other tools to the
apparatus 10 such as an insert, liner hanger, anchor, packer, or seal bores
for sealing a smaller
diameter tubular against the inside diameter of the apparatus 10, and
orientation surfaces or
muleshoes for orienting other tools, such as whipstocks or mills, within the
wellbore 14.
While preferred embodiments of this invention have been shown and described,
modifications
thereof can be~made by one skilled in the art without departing from the
spirit or teaching of this
invention. The embodiments described herein are exemplary only and are not
limiting. Many
21
CA 02536046 2002-05-14
variations and modifications of the system and apparatus are possible and are
within the scope of
the invention. Accordingly, the scope of protection is not limited to the
embodiments described
herein, but is only limited by the claims that follow, the scope of which
shall include all equivalents
of the subject matter of the claims.
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