Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
Mechanically Setting Tool For An Expandable Packer
FIELD
The present application relates to a mechanical setting tool that is used to
set an
expandable packer, such as is used down hole in oil and gas wells.
BACKGROUND
Many expandable packers are expanded through the use of explosive charges.
There
are some applications for expandable packers where the use of explosives is
undesirable and
the expandable packer must be mechanically set.
SUMMARY
There is provided a mechanical setting tool for setting a mechanically set
expandable
packer. The mechanical setting tool includes a tubular housing having a first
end, a second
end, an outer surface and an inner surface, the inner surface defining an
interior bore. There is
an inner mandrel having an outer surface, a first end and a second end, the
inner mandrel
extending into the interior bore and being axially movable relative to the
tubular housing. A
first end connection is adapted to connect the first end of the inner mandrel
to a control
linkage from surface. A second end connection is adapted to connect the second
end of the
inner mandrel to an expandable packer capable of being mechanically set. There
is a track
and follower engagement between the inner surface of the tubular housing and
the outer
surface of the inner mandrel. The follower is adapted to engage the track. The
track includes
a circumferential component and alternating axial components that define at
least one
intermediate position allowing limited axial movement and a release position
allowing
increased axial movement. The follower moves along the track until the inner
mandrel is in
the at least one intermediate position. A further jarring force moves the
follower along the
track until the follower reaches the release position. A set of gripping
elements are positioned
on the outer surface of the tubular housing, the gripping elements being
adapted to expand
outward beyond the outer surface of the tubular housing upon a jarring force
being exerted
upon on the mandrel when the follower is in the release position. The mandrel
is then free to
move axially to set the mechanical setting tool and to set the expandable
packer connected to
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the second end connection.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features will become more apparent from the following
description in
which reference is made to the appended drawings, the drawings are for the
purpose of
illustration only and are not intended to be in any way limiting, wherein:
FIG. 1A, 1B and 1C is a side view, in section, of a mechanical setting tool
for setting
a mechanically set expandable packer in the running position.
FIG. 2A, 2B and 2C is a side view, in section, of a mechanical setting tool
for setting
a mechanically set expandable packer in the set position.
FIG. 3 is a side view of a track and follower arrangement in planar form.
FIG. 4 is an exploded view of the gripper cage and slips ramp.
FIG. 5A and 5B is a side view, in section, of a mechanically set expandable
packer in
the running position.
FIG. 6A and 6B is a side view, in section, of a mechanically set expandable
packer in
the set position.
FIG. 7A and 7B is a side view, in section, of a mechanically set expandable
packer in
the released position.
DETAILED DESCRIPTION
A mechanical setting tool for setting a mechanically set expandable packer
generally
identified by reference numeral 10, will now be described with reference to
FIG. 1A through
3.
Structure and Relationship of Parts of the Mechanical Setting Tool:
Referring to FIG. 1A through 1C, mechanical setting tool 10 includes a tubular
housing 12 having a first end 11, a second end 13, an outer surface 14 and an
inner surface 16.
Tubular housing 12 is divided into a first portion 15 having a first end 17
and a second end
20, and a second portion 22 having a first end 24 and a second end 26. Second
end 20 of first
portion 15 includes a tapered portion 28 that converges toward second end 20
of first portion
15. First portion 15 and second portion 22 are capable of relative axial
movement from an
expanded position shown in FIG. 1A through 1C to a retracted position shown in
FIG. 2A
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through 2C. A spring 23 positioned along inner mandrel 30 biases first portion
15 and second
portion 22 toward the extended position. Inner surface 16 of tubular housing
12 defines an
interior bore 18, wherein an inner mandrel 30 is positioned. Inner mandrel 30
has an outer
surface 32, a first end 34 and a second end 36. Inner mandrel 30 extends into
interior bore 18
and is axially movable relative to tubular housing 12. Referring to FIG. lA
and 2A there is a
first end connection 38 adapted to connect first end 34 of inner mandrel 30 to
a control
linkage from surface (not shown). A centralizer 40 may be connected between
the control
linkage and inner mandrel 30, and elsewhere in the assemblies depicted, as
needed (not
shown). Referring to FIG. 1C and 2C, there is also a second end connection 42
adapted to
connect second end 36 of inner mandrel 30 to an expandable packer (discussed
below,
indicated generally by reference numeral 100) that is capable of being
mechanically set. As
shown, second end connection 42 is a shear collar that is adapted to shear
under certain load
conditions once gripping elements 118 and packer elements 142 of expandable
packer 100
(shown in FIG. 6B) have been set. Referring to FIG. 18, 1C, 2B and 2C, mandrel
30 also a
first shoulder 37 that has a sufficiently large circumference to engage first
portion 15 at a
point indicated by reference number 43 as mechanical setting tool 10 is raised
from a
downhole position.
A track 44 and follower 46 arrangement is also included. Referring to FIG. 1A,
track
44 may be positioned on inner surface 16 of tubular housing 12, while follower
46 is
positioned on outer surface 32 of inner mandrel 30 opposite track 44.
Preferably, track 44 is
milled into tubular housing 12. In the depicted embodiment, referring to FIG.
3, track 44
comprises a slot machined through tubular housing 12, and follower 46 is a pin
positioned on
inner mandrel 30 engaged within the track (slot) 44. FIG. 3 shows track 44
laid out as if
housing 12 were laid out flat. Track 44 has a circumferential component 48 and
alternating
axial components 50. Axial components 50 alternate between being directed
toward first end
11 of housing 12 and second end 13 of housing 12. Track 44 thus defines
intermediate
positions 52 that allow limited axial movement and a release position 54 that
allows increased
axial movement.
Referring to FIG. 1B, a set of gripping elements 56 are positioned on outer
surface 14
at first end 24 of second portion 22 of tubular housing 12 and immediately
adjacent to tapered
_
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portion 28.
A mechanically set expandable packer generally identified by reference numeral
100,
will now be described with reference to FIG. 4 through 7B, as an example of
what may be set
by mechanical setting tool described above.
Structure and Relationship of Parts:
Referring to FIG. 5A through 7C, mechanically set expandable packer 100
includes a
tubular housing 102 having a first end 104, a second end 106, an exterior
surface 108 and an
interior surface 110 defining an interior bore 112. As discussed above with
reference to FIG.
IC and 2C, first end 104 of tubular housing 102 is positioned adjacent to
second end 13 of
tubular housing 12 of mechanical setting tool 10. Second end 106 of housing
102 is attached
to a gripper cage 114. An inner mandrel 124 extends through interior bore 112
of tubular
housing 102, inner mandrel 124 having an external surface 126, a first end
128, and a second
end 130 extending past second end 106 of housing 102. First end 128 is adapted
to connect to
second end connection 42 of mechanical setting tool 10 by connection 42.
Mandrel 30 of
mechanical setting tool 10 can be seen connected to mandrel 124 in FIG. IC and
2C.
Referring to FIG. 4, gripper cage 114 has circumferentially spaced windows 116
in
which radially movable gripping elements 118 are positioned. Referring to FIG.
5B, 6B, and
7B, each gripping element 118 has a pair of inwardly converging opposed ramp
surfaces 120,
and housing 102 has a fixed gripper ramp 122 protruding into gripper cage 114.
A movable
gripper ramp 134 has a ramp portion 136 that faces, and is in spaced relation
to, fixed gripper
ramp 122, which is movable with inner mandrel 124. Referring to FIG. 4,
movable gripper
ramp 134 is axially movable in relation to gripper cage 114 along a track or
slot 138 as
shown, while remaining secured to gripper cage 114 by means of a pin 140,
which is able to
travel along slot 138. Referring to FIG. 5B, 6B, and 7B, elastomer packing
elements 142 are
positioned at second end 130 of inner mandrel 124 between a first stop
shoulder 144 that
remains with tubular housing 102 and a second stop shoulder 146 that moves
with inner
mandrel 124.
Referring to FIG. 5A through 7C, inner mandrel 124 is secured to tubular
housing
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102 by shear screws 148, such that upon shear screws 148 being sheared by an
axial force
exerted via mechanical setting tool 10, second end 130 of mandrel 124 is able
to move toward
second end 106 of housing 102.
5 A ratchet
collar 150 is provided that has a first ratchet profile 152 which engages a
second ratchet profile 154 on exterior surface 126 of inner mandrel 124 to
maintain the
relative telescopic position of inner mandrel 124 and housing 102. A sliding
ratchet release
sleeve 156 is positioned behind ratchet collar 150 that is secured to housing
102 by shear
screws 158. When a sufficient axial force is exerted upon housing 102 by a
fishing tool (not
shown), shear screws 158 shear and ratchet release sleeve 156 moves out from
behind ratchet
collar 150. First ratchet profile 152 is then free to disengage from second
ratchet profile 154.
As housing 102 is lifted further, gripper elements 118 are released and
allowed to retract
inwardly, and pin 140 engages the bottom of slot 138, lifting ramp 146 and
therefore allowing
elastomer packing elements to release.
Operation:
The operation of mechanical setting tool 10 in combination with mechanically
set
expandable packer 100 will now be discussed. Mechanical setting tool 10 and
mechanically
set expandable packer 100 are provided as describe above with reference to
FIG. lA through
3 and FIG. 4 through 7C, respectively. When the tools are to be run downhole,
setting tool
10 is configured as shown in FIG. 1A through IC, and packer 100 is configured
as shown in
FIG. 5A and 58. As the tool is being run downhole, spring 23 biases first
portion 15 and
second portion 22 of housing 12 in the extended position, such that gripping
elements 56
remain retracted to prevent setting tool 10 from catching as it is being
positioned. Once the
desired position has been reached, a jarring force is exerted upon on mandrel
30 via the
control linkage by a jarring tool (not shown). This first jarring force causes
follower 46 to
move along track 44 until inner mandrel 30 is in one of the intermediate
positions 52 shown
in FIG. 3. As further jarring forces are applied, follower 46 moves up along
track 44, then
back down as the force is released. Because of the diagonal portions of track
44, this
movement causes follower 46 to progress along track 44 until it reaches
release position 54.
Intermediate positions 52 prevent a premature setting of setting tool 10. As
the next jarring
force is applied, first portion 15 and second portion 22 of housing 12 move
from the extended
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position shown in FIG. 1B to the retracted position shown in FIG. 2B, such
that gripping
elements 56 travel up tapered portion 28 to expand outward. Gripping elements
56 thus
engage the wellbore to hold setting tool 10 and packer 100 in position. The
weight of the
weight bar 58 and tapered portion 28 overcome the resistance of spring 23 to
keep gripping
elements 56 in contact with the wellbore 160. Further jarring forces cause
mandrel 30 to
move axially with sufficient axial movement to set expandable packer 100
connected to
second end connection 42, as described below.
Packer 100 remains in the configuration shown in FIG. 5A and 5B as setting
tool 10
is positioned, follower 46 progresses through all intermediate positions 52,
and gripping
elements 56 are engaged. Jarring forces are then applied to mandrel 124
through mandrel 30
of setting tool 10 by the jarring tool. Referring to FIG. 6A and 6B, as these
axial forces are
exerted via mechanical setting tool 10, shear screws 148 shear, and second end
130 of
mandrel 124 moves toward second end 106 of housing 102. This causes elastomer
packing
elements 142 to compress between first stop shoulder 144 and second stop
shoulder 146 and
therefore expand outwardly beyond exterior surface 108 of housing 102 to form
a high
pressure seal against the sides of the borehole 160. The movement of mandrel
124 also
causes movable gripper ramp 134 to move toward fixed gripper ramp 122, such
that movable
gripper ramp 134 and fixed gripper ramp 122 act against ramp surfaces 120 of
gripper
elements 118, thereby forcing gripper elements 118 to move outwardly beyond
exterior
surface 108 of housing 102, and engage the sides of borehole 160. The pair of
ramp surfaces
120 and the shape of gripper elements 118 with two sets of gripping teeth 149
act to hold
against forces that may be applied in either axial direction. Referring to
FIG. 4, gripper
elements 118 may also have a smooth gripper 151 to help in the setting and
release of gripper
elements 118.
Referring again to FIG. 6A and 6B, once packer 100 is set within borehole 160,
a
further jarring force causes shear collar 42 to shear, freeing setting tool 10
to be removed.
Referring to FIG. 2A and 2B, as mandrel 30 is lifted, shoulder 37 engages
shoulder 43 of first
portion 15, such that grippers 56 are no longer held in the expanded position
by weight bar 58
and friction against tapered portion 28. Grippers 56 are then able to retract,
and setting tool
10 is free to be lifted out.
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Refeiring to FIG. 7A and 7B, when packer 100 is to be removed from dor.vnhole,
fishing tool (not shown) engages first end 104 of tubular housing 102, which
may be referred
to as a fishing neck, and an upward force is applied until shear screws 158
shear. Further
upward force lifts release sleeve 156 from behind ratchet collar 150, which
releases the first
ratchet profile 152 from second ratchet profile 154. As tubular housing 102 is
lifted further,
opposed ramps 120 return to the expanded position, allowing gripper elements
118 to retract
inwardly. Referring to FIG. 4, further lifting also causes the bottom of slot
138 to engage pin
140, which allows packing elements 142 to be released as well. Packer 100 can
then be
removed from borehole 160.
In this patent document, the word "comprising" is used in its non-limiting
sense to
mean that items following the word are included, but items not specifically
mentioned are not
excluded. A reference to an element by the indefinite article at does not
exclude the
possibility that more than one of the element is present, unless the context
clearly requires that
there be one and only one of the elements.
The scope of the following claims should not be limited by the preferred
embodiments
set forth in the examples above and in the drawings, but should be given the
broadest
interpretation consistent with the description as a whole.
