Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
TITLE
[0001] High Expansion Anti-rotation Anchor Catcher
FIELD
[0002] There is described a high expansion anchor, which was developed for
use with a
progressive cavity pump (PC Pump) for preventing rotation of the PC Pump and
associated
tubing string and vertically arrest ("catch") the PC Pump from falling down
the well, but
potentially has other applications.
BACKGROUND
[0003] An anti-rotation anchor is used with a PC pump to stop rotation of
the tubing
string caused by pump rotation. Rotation of the tubing string can cause a
backing off of
threaded connections and the loss of the PC pump down the well.
[0004] U.S. Patent Publication 215/0233199 (Moore et al) titled "Quarter
Turn Tubing
Anchor Catcher" describes a tubing anchor which is set by rotation in a first
direction and
released by rotation in a second direction.
[0005] U.S. Patent 6,796,380 (Xu) titled "High Expansion Anchor System"
describes an
anchor system that uses linkages to increase the expansion limit of the anchor
system.
SUMMARY
[0006] There is provided a high expansion anti-rotation anchor catcher
which includes a
tubular body having an axis, a first end, a second end, and an exterior
surface. At least one
coupling is positioned at the first end of the tubular body or the second end
of the tubular
body. A helical track is positioned on the exterior surface of the tubular
body. An
expandable gripper cage is provided having an axially fixed hub mounted for
rotation about
the tubular body and an axially movable hub mounted for rotation about the
tubular body.
Pivoting linkages which support outwardly oriented grippers extend between the
axially
fixed hub and the axially movable hub. The axially movable hub has a track
follower that
engages the helical track on the exterior surface of the tubular body.
Rotation of the tubular
body in a first rotational direction causes the track follower to move along
the helical track
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Date Recue/Date Received 2020-10-02
toward the axially fixed hub, thereby placing the expandable gripper cage in
compression
and causing the pivoting linkages and grippers to pivot outwardly away from
the tubular
body. Rotation of the tubular body in a second rotational direction causes the
track follower
to move along the helical track away from the axially fixed hub, thereby
placing the
expandable gripper cage in tension and causing the pivoting linkages and
grippers to pivot
inwardly toward the tubular body.
[0007] The
high expansion anti-rotation anchor catcher, as described above, is easily set
in position downhole by rotation of the tubing string. Should the operation of
the PC pump
impart a further rotational force, any rotation of the tubular body merely
serves to further
expand the expandable gripper cage. The range of expansion of the high
expansion anti-
rotation anchor catcher allows the high expansion anti-rotation anchor catcher
to be used
with different sizes of pipe. It also allows for a measure of safety, as a
high expansion anti-
rotation anchor catcher that is functioning at its outer expansion limit could
become
dislodged if a great enough force is applied. The tool serves as both an anti-
rotation role to
anchor against rotation and a catcher role to vertically arrest ("catch") the
PC pump and
prevent it from falling down the well.
[0008] To
assist in running the high expansion anti-rotation anchor catcher into and out
of the well, it is preferred that centralizers be provided. To fulfil this
function, an expandable
centralizer cage is provided having an axially slidable hub that slides
axially along the
exterior of the tubular body toward a second hub. Pivoting linkages which
support centralizer
blocks extend between the axially slidable hub and the second hub. A spring is
provided
which acts against a shoulder on the exterior surface of the tubular housing
to exert a force
upon the axially slidable hub urging the axially slidable hub along the
exterior of the tubular
body toward the second hub. This places the expandable centralizer cage in
compression and
causes the pivoting linkages and centralizer blocks to pivot outwardly away
from the tubular
body.
[0009] In operation, the spring compresses the expandable centralizer cage
which
causes the centralizer blocks to engage the inside of the pipe as the high
expansion anti-
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Date Recue/Date Received 2020-10-02
rotation anchor catcher is inserted into or drawn out of the well.
[0010] In order to keep the tubular body of the high expansion anti-
rotation anchor
catcher as short as possible, it is preferred that the axially movable hub of
the expandable
gripper cage serve as the second hub for the expandable centralizer cage. This
also plays a
role in deployment of expandable gripper cage, as it maintains the expandable
gripper cage in
a stationary position while the tubular body rotates.
[0011] When the high expansion anti-rotation anchor catcher is to be
positioned below
the PC Pump, it is possible to provide the high expansion anti-rotation anchor
catcher with a
single coupling. However, if the high expansion anti-rotation anchor catcher
is to be
positioned above the PC Pump, two couplings are required. To provide maximum
flexibility, it is preferred that a first coupling be positioned at the first
end of the tubular body
and a second coupling be positioned at the second end of the tubular body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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:
[0013] FIG. 1 is a perspective view of a high expansion anti-rotation
anchor catcher
[0014] FIG. 2 is a detailed side elevation view of the expandable
gripper cage of the high
expansion anti-rotation anchor catcher of FIG. 1.
[0015] FIG. 3 is a detailed side elevation view of the expandable
centralizer cage of the
high expansion anti-rotation anchor catcher of FIG. 1.
[0016] FIG. 4 is a side elevation view of pivotal links and gripper of the
expandable
gripper cage of the high expansion anti-rotation anchor catcher of FIG. 1.
[0017] FIG. 5, is a section view of the pivotal links and gripper, taken
along section lines
A-A of FIG. 4.
[0018] FIG. 6 is a section view of the high expansion anti-rotation
anchor catcher
positioned in a pipe of a producing oil well.
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Date Recue/Date Received 2020-10-02
DETAILED DESCRIPTION
[0019] A high expansion anti-rotation anchor catcher generally identified
by reference
numeral 10, will now be described with reference to FIG. 1 through FIG. 6.
Structure and Relationship of Parts:
[0020] Referring to FIG. 1, high expansion anti-rotation anchor catcher
10 includes
a tubular body 12 having an axis 14 (indicated in broken lines), a first end
16, a
second end 18, and an exterior surface 20. A first coupling 22 is positioned
at first end 16 of
tubular body 12. A second coupling 24 is positioned at second end 18 of
tubular body 12. A
helical track 26 is positioned on exterior surface 20 of tubular body 12.
Positioned around
tubular body 12 is an expandable gripper cage, generally indicated by
reference numeral 30,
which will hereinafter be further described. Also positioned around tubular
body 12 is an
expandable centralizer cage, generally indicated by reference numeral 50,
which will
hereinafter be further described.
[0021] Referring to FIG. 2, expandable gripper cage 30 consists of an
axially fixed hub
32 mounted for rotation about tubular body 12 and an axially movable hub 34
mounted for
rotation about tubular body 12. Pairs of pivoting linkages 36 and 38 which
support
outwardly oriented grippers 40 extend between axially fixed hub 32 and axially
movable hub
34. Axially fixed hub 32 has a track follower 42, in the form of set screws
that engage a
circular track (not shown) on exterior surface 20 of tubular body 12. (Set
screws have been
used for convenience of assembly, it will be understood that track follower 42
can be pins,
protrusions or take other forms as long as they function to follow the track)
This engagement
facilitates rotation of axially fixed hub. Axially movable hub 34 has a track
follower 44, in
the form of set screws, which engages helical track 26 on exterior surface 20
of tubular body
12. (Set screws have been used for convenience of assembly, it will be
understood that track
follower 44 can be pins, protrusions or take other forms as long as they
function to follow the
track)
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Date Recue/Date Received 2020-10-02
[0022] As
will hereafter be further described, rotation of tubular body 12 in a first
rotational direction causes the track follower 44 to move along helical track
26 toward
axially fixed hub 32. This movement places expandable gripper cage 30 in
compression and
causes pivoting linkages 36 and 38 with grippers 40 to pivot outwardly away
from tubular
body 12. Rotation of tubular body 12 in a second rotational direction causes
the track
follower 44 to move along helical track 26 away from axially fixed hub 32,
thereby placing
expandable gripper cage 30 in tension and causing pivoting linkages 36 and 38
and gripper
40 to pivot inwardly toward tubular body 12.
[0023] Referring to FIG. 4, pivoting linkages 36 and 38, with associated
gripper 40, are
illustrated. Gripper 40 has on its surface carbide buttons 45. Referring to
FIG. 5, pivot pins
46 pivotally connect gripper 40 with pivoting linkages 36 and 38. Pivot pins
48 connect
pivoting linkages 36 and 38, with axially fixed hub 32 and axially movable hub
34,
respectively. Gripper 40 has a tooth 41. Tooth 41 is pivotally mounted on a
support pin 43
and is biased outwardly by a torsion spring 47. As will hereinafter be further
described, tooth
41 is serves to prevent gripper 40 from becoming dislodged by rotation as a
result of torque
imparted by the PC pump. Tooth 41 is sometimes referred to in the industry as
a "door",
because tooth 41 pivots and swings outwardly in the manner similar to or
reminiscent of a
door.
[0024]
Referring to FIG. 3, expandable centralizer cage 50 has an axially slidable
hub 52
that slides axially along exterior surface 20 of tubular body 12 toward the
axially movable
hub 34 of expandable gripper cage 30. Pivoting linkages 54 and 56 which
support
centralizer blocks 58 extend between axially slidable hub 50 and the axially
movable hub 34
of expandable gripper cage 30. A spring 60 is provided which acts against a
shoulder 62 on
exterior surface 20 of tubular housing 12 to exert a force upon axially
slidable hub 50 urging
axially slidable hub 50 along exterior 20 of the tubular body 12 toward
axially slidable hub
34. As will hereinafter be further described, this movement places expandable
centralizer
cage 50 in compression and causes pivoting linkages 54 and 56 and centralizer
block 58 to
pivot outwardly away from tubular body 12. Spring 60 has been illustrated as a
coil spring.
It will be understood that a leaf spring or other form of spring could be
used.
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Date Recue/Date Received 2020-10-02
Operation:
[0025] Referring to FIG. 1, first coupling 22 and second coupling 24 are
used to secure
high expansion anti-rotation anchor catcher 10 to a tubing string being run
into a pipe of an
oil producing well. As previously noted, anti-rotation anchor 10 may be
positioned either
above or below a PC pump. During insertion, expandable gripper cage 30 is not
deployed
and is at rest with pivoting linkages 36 and 38 together with grippers 40
positioned as close
as possible to tubular body 12. However, expandable centralizer cage 50
maintains anti-
.. rotation anchor 10 in a central position, to avoid problems during
insertion. Referring to
FIG. 3, spring 60 acts against shoulder 62 on exterior surface 20 of tubular
housing 12 to
exert a force upon axially slidable hub 50 urging axially slidable hub 50
along exterior 20 of
the tubular body 12 toward axially slidable hub 34. This movement places
expandable
centralizer cage 50 in compression and causes pivoting linkages 54 and 56 and
centralizer
blocks 58 to pivot outwardly away from tubular body 12. Referring to FIG. 3,
centralizer
blocks 58 on all sides of tubular body 12 contact pipe 100 of the oil
producing well.
[0026] Once the PC pump has been inserted down the well at the end of the
tubing string
to a desired pumping depth, expandable gripper cage 30 is activated. As
previously
described, that activation involves rotation of tubular body 12 in a first
rotational direction.
This is accomplished by rotating the entire tubing string. As noted above, at
the time of
activation of expandable gripper cage 30, expandable centralizer cage 50 has
already been
deployed and centralizer blocks 58 on all sides of tubular body 12 are in
contact with pipe
100 of the oil producing well. This results in expandable gripper cage 30
remaining in a
stationary position while tubular body 12 rotates. Referring to FIG. 2,
rotation in a first
direction the track follower 44 on axially movable hub 34 to move along
helical track 26
toward axially fixed hub 32. This movement places expandable gripper cage 30
in
compression and causes pivoting linkages 36 and 38 with grippers 40 to pivot
outwardly
away from tubular body 12 to engage pipe 100, as shown in FIG. 6. Rotational
force created
by the PC pump during operation further rotates tubular body 12 results in the
track follower
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Date Recue/Date Received 2020-10-02
44 on axially movable hub 34 moving a little further along helical track 26
toward axially
fixed hub 32 and causes grippers 40 to engage more forcefully. Tooth 41 biased
outwardly
by spring 47, engages pipe 100 to prevent rotational slippage of grippers 40.
Once
expandable gripper cage 30 is deployed with grippers 40 engaged, high
expansion anti-
rotation anchor catcher 10 performs an "anti-rotation" role by preventing
rotation and also
performs a "catcher" role by vertically arresting ("catching") the PC pump so
it does not and
cannot fall down the well.
[0027] From time to time, PC pump will need to be repositioned or brought
up to surface
for servicing. In order to release high expansion anti-rotation anchor catcher
10, it will be
understood that rotation of tubular body 12 in a second rotational direction
causes the track
follower 44 on axially movable hub 34 to move along helical track 26 away from
axially
fixed hub 32, thereby placing expandable gripper cage 30 in tension and
causing pivoting
linkages 36 and 38 and gripper 40 to pivot inwardly toward tubular body 12.
[0028] 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 "a" 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.
[0029] The scope of the claims should not be limited by the illustrated
embodiments set
forth as examples, but should be given the broadest interpretation consistent
with a purposive
construction of the claims in view of the description as a whole.
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Date Recue/Date Received 2020-10-02
