Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
A QUARTER TURN TUBING ANCHOR CATCHER
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Canadian Patent
Application No.
2,854,409 filed June 14, 2014 entitled Quarter Turn Tubing Anchor and
Catcher. This application is also a continuation-in-part of United States
Patent Application No. 14/311,322 filed June 22, 2014 and entitled
Quarter Turn Tubing Anchor and Catcher, which is itself a continuation-
in-part of United States Patent Application No. 13/716,075 filed on
December 14, 2012 and entitled Quarter Turn Tension Torque Anchor.
FIELD OF THE INVENTION
[0002] The present invention relates to a quarter turn tubing anchor
catcher and
its use in a system with a downhole reciprocating rod pump or
progressive cavity pump, within in a well conduit.
BACKGROUND OF THE INVENTION
[0003] A tubing string is used for producing hydrocarbons and to
position
downhole tools proximal to one or more underground geological
formations that contain petroleum fluids of interest. The tubing string
may also be referred to as production tubing or a production string. The
tubing string is made up of sections of individual pipe joints that are
typically threaded together. The tubing string extends within a bore of
the well. The well bore is typically completed with casing or liners. The
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completed well bore may also be referred to as a well conduit. The
tubing string can carry various downhole tools into the well conduit. For
example, downhole tools can be used for various purposes including
anchoring the tubing string and reciprocating rod pump within the
wellbore at a desired location and to limit movement of the tubing string.
[0004] Tubing anchor catchers are used to limit movement axially and
radially in
both directions. Prior art tubing anchor catchers comprise
threads
or helical bearings that require multiple full (i.e. 360 degree) rotations of
the mandrel to either set or unset the tubing anchor catcher.
Disadvantages of such tubing anchor catchers include the expense of
manufacturing the threaded portions, the threads may be susceptible to
corrosion and the threads may be difficult to, or unable to, unset if they
become filled with sand or corroded. With the new technology of
fracing, the industry has adopted a heavier weight casing to be able to
handle the bends and 'S curves that are drilled today. A heavier weight
casing wall makes the interior diameter of the casing smaller. This change
in diameter, combined with the wells drilled with deviations and
horizontally, makes the setting of the older design (multiple revolutions)
tubing anchor catchers difficult.
[0005] Applicant's US application entitled Quarter Turn Tension Torque
Anchor
and assigned US application no. 13/716,075 has improved on these
designs by providing a means for transferring a short longitudinal
movement into actuation of conical surfaces to extend the slips into
gripping engagement with the well conduit. However the apparatus and
method of US 13/716,075 do not provide a means to stop downward
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movement of the tubing string and attached equipment downhole when
tubing joints above such apparatus unexpectedly come apart.
It is therefore desirable to have a tubing anchor catcher that further
improves on these prior designs. Particularly, there is a need for a tubing
anchor catcher that avoids the prior art threads and helical bearing that
require multiple full rotations of the tubing anchor catcher's mandrel to
either set or unset the tool. The tubing anchor catcher should not need
to translate rotational movement into linear movement to engage the
slips with the well conduit, but rather should directly transfer a short
longitudinal movement to extend the slips into gripping engagement with
the well conduit. The tubing anchor catcher should requirement only a
limited rotation. Also, the tubing anchor catcher should have a simple
and effective means to stop the tubing string from downward movement
if tubing joints above such apparatus unexpectedly come apart.
SUMMARY OF THE PRESENT INVENTION
[0006] The present invention provides a tubing anchor catcher that
acts to stop
movement of a tubing string within a wellbore in both directions axially
and radially. The tubing anchor catcher may also catch the tubing string
if a part of the tubing string above the tubing anchor catcher disconnects.
[0007] One example embodiment of the present invention provides a
tubing
anchor catcher tool that is positionable within a well conduit for
preventing movement of a tubing string. The tool comprises: a mandrel
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that is connectible at either end to the tubing string, the mandrel
comprising a groove; a first cone element that is slidably mountable on to
the mandrel, the first cone element comprising a first conical surface; a
drag body that is slidably mountable on the mandrel, the drag body
comprising a drag member that is sized for frictionally engaging an inner
surface of the well conduit, a pin for engaging the groove, and a second
conical surface; a biasing member that is slidably mountable on the
mandrel adjacent the drag body for engaging the first cone element
when the biasing member is compressed; and a slip cage that is slidably
mountable on the mandrel, the slip cage comprising a slip or slips that
are adapted for engaging the inner surface of the well conduit when one
or more of the conical surfaces are disposed underneath the slip or slips.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0008] Embodiments of the invention will now be described, by way of
example
only, with reference to the accompanying drawings, wherein:
[0009] Figure 1 is an elevation side view of a first embodiment of a
tubing
anchor catcher;
[0010] Figure 2 is a mid-line cross-sectional view taken along line 2-
2 in Figure 1;
[0011] Figure 3 is a mid-line cross-sectional view of Figure 1 showing the
tubing
anchor catcher with its slips extended;
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[0012] Figure 4 is a perspective view of an example embodiment of a
mandrel
for use as part of the tubing anchor catcher of Figure 1;
[0013] Figure 5 is an enlarged view of an example embodiment of a
groove that
forms part of the mandrel of Figure 4, showing a pin from the tubing
anchor catcher engaged in the groove, in a run-in position;
[0014] Figure 6 is the view of Figure 5 showing the pin in a set
position;
[0015] Figure 7 is a mid-line cross-sectional view of an example
embodiment of a
tubing anchor catcher, in the run-in position;
[0016] Figure 8 is a mid-line cross-sectional view of the tubing
anchor catcher of
Figure 7, in the set position;
[0017] Figure 9 is a side elevation view of a second embodiment of a
tubing
anchor catcher;
[0018] Figure 10 is a mid-line, sectional view of the tubing anchor
catcher of
Figure 9; and,
[0019] Figure 11 is an exploded isometric view of parts of the tubing
anchor
catcher of Figure 9.
[0020] Figure 12 is a side elevation view of an example of the first
embodiment
of a tubing anchor catcher positioned within a well bore.
[0021] Figure 13 is a cross-sectional view taken along line 13-13 in
Figure 12.
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DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] Figures 1 to 8 depict one example embodiment of a tubing
anchor
catcher 10. The tubing anchor catcher 10 may be inserted within a well
conduit 12 (see Figures 13 and 14), such as a wellbore casing. Figures 1
and 2 depict the tubing anchor catcher 10 in an unset, or "run-in",
orientation in which it can be run inside the well conduit 12 on a tubing
string. Safety subs 14A, B may be attached to a mandrel 20 of the tubing
anchor catcher 10, thus forming a lower pin end 10B and an upper box
end 10A. In this embodiment, the tubing anchor catcher 10 may be run
down the well conduit 12 while being threaded together within the
tubing string in the downhole direction indicated by arrow 17. Arrow 16
indicates the opposite direction within the well conduit 12, namely the
up-hole direction. It is noted, however, those terms such as "up",
"down", "forward", "backward" and the like are used to identify certain
features of the tubing anchor catcher 10 when placed in a well conduit.
These terms are not intended to limit the tubing anchor catcher's use or
orientation.
[0023] The tubing anchor catcher 10 has an upper end 10A and a lower
end 10B.
The tubing anchor catcher 10 may comprise of a drag body 40, a slip cage
60 and a biasing member 94, all of which are mounted about the external
surface of the mandrel 20. The biasing member 94 can be for example, a
coiled spring. The drag body 40 houses a drag means, in the form of one
or more drag springs or drag blocks 42, for spacing the tubing anchor
catcher 10 away from the inner wall 13 of the conduit 12. The drag
blocks 42, for example three or four drag blocks 42, may be generally
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evenly spaced circumferentially about the tubing anchor catcher 10.
Each drag block 42 has a drag block spring 44 to urge the outer surface 46
of the drag block against the well conduit's inner wall. Upper and lower
drag retaining rings 48, 50 keep the drag blocks 42 removably mounted
within the drag body 40. In addition to keeping the tubing anchor catcher
spaced from the well conduit 12, the contact of the drag block surface
46 the well conduit's 12 inner wall or surface 13 causes friction that urges
the drag body 40 to remain stationary while the mandrel 20 moves within
the rest of the tubing anchor catcher 10.
10 [0024] As will be discussed further, the drag body 40 is connected to
the
mandrel 20 by one or more drive pins 88 that extend inwardly from the
drag body's 40 inner surface to engage an externally facing groove 80
that is on the outer surface of the mandrel 20. As described further
below, in one example embodiment, the drive pins 88 are made from a
shearable material.
[0025] The slip cage 60, which may also be referred to as a slip
retainer, is also
mounted on the mandrel 20 adjacent the drag body 40. In particular, the
slip cage 60 is mounted on the mandrel 20 above the drag body 40 (i.e. in
direction 16). The slip cage 60 may house one or more movable slips 62.
For example, three slips 62 are depicted as being evenly spaced about the
slip cage 60, although this is not intended to be limiting as the tubing
anchor catcher 10 described herein may operate with one or more slips
62. Each slip 62 has an outer surface with teeth 63 for gripping the inner
wall 13 upon contact. The teeth 63 comprise upward gripping teeth 63B
and downward gripping teeth 63A. One or more fasteners in the form of
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a cap pin or cap screw 65 is fastened to the drag body 40 and is each
located within one of a plurality of associated elongate slots 66 that are
defined by the slip cage 60 and spaced circumferentially thereabout,
preferably between each slip 62. The cap screw 65 is adapted to travel
within associated slots 66, to permit movement of the slip cage 60
relative to the drag body 40 and to prevent the slip cage 60, and the drag
body 40, from longitudinally separating.
[0026] A cone element 70 is mounted about the mandrel 20 at an upper
end of
the slip cage 60. The cone element 70 comprises an upper edge 70A and
a lower edge 70B. The lower edge 70B forms a first conical surface
whose inclined surface wedges under the slip or slips 62 when the tubing
anchor catcher 10 is moved into a set position. Likewise, an upper edge
of the drag body 40 forms a second conical surface 54 whose inclined
surface also wedges under the slip or slips 62 when the tubing anchor
catcher 10 is moved into a set position. When the tool is in the unset
position, the first and second conical surfaces 70B, 54 do not actuate the
slip or slips 62. A slip spring 76 urges each slip 62 radially inwardly into
the slip cage 60 and away from the well conduit 12 while in the unset
position (Figure 2).
[0027] Figure 3 depicts the tubing anchor catcher 10 in the set position
with the
slip or slips 62 extended outwardly from the slip cage 60 for engaging the
inner surface 13 of the well conduit 12. The slip or slips 62 are extended
due to the conical surfaces 70B, 54 moving underneath the slip or slips
62. The biasing member 94 is compressed due to the movement down of
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the mandrel, which movement forces the first and second conical
surfaces 70B, 54 underneath the slip or slips 62.
[0028] Figure 4 depicts the mandrel 20 as including an upper end 20A
and a
lower end 20B. As described above, the upper and lower ends 20A, B
may each comprise threaded connections for connecting the mandrel 20
to the tubing string, optionally via safety subs 14A and 14B, thus
providing an the upper end 10A comprises a box threading and the lower
end 10B comprises a pin threading. At least one groove 80 is formed on
the mandrel's outer surface 26, as best seen in Figures 4 to 6. The groove
80 is dimensioned (width, depth) to slidingly accommodate a protruding
portion of the drive pin 88 that extends therein threaded through a hole
56 in the drag body 40. The lower retaining ring 50 retains the drag
blocks 42 within the drag body 40. The tubing anchor catcher 10 may
comprise one or more sets of grooves 80 and drive pins 88. For example,
the tubing anchor catcher 10 may have three or four sets of grooves 80
and three or four sets of associated drive pins 88 that are generally
evenly radially spaced about the mandrel 20.
[0029] As depicted in Figures 5 and 6, the groove 80 may comprise a C-
shape
with shoulders 82 and 86 defining a first arm 80A of the groove 80 and
shoulders 84 and 92 defining a second arm 80B of the groove 80. The
two arms 80A, B of the groove 80 are connected by central portion 80C
that is defined by walls 86, 87, 89 and 90. Wall 90 separates the first and
second arms 80A, B.
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[0030] The operation of the tubing anchor catcher may now be
described with
reference to all figures, including figures 5 and 6 showing the drive pin 88
positions of the groove 80. As seen in Figures 5 and 6, which is an
enlarged view of groove 80, a portion 88a of the drive pin 88 protrudes
into the groove 80 and is seated against the shoulder 92 in the run-in
(i.e. un-set) position with the slip or slips 62 retracted within the sip cage
60. To move the drive pin 88 to the set position at shoulder 82, the
tubing string can be manipulated at surface so as to move axially, i.e. by
pulling or pushing, and rotationally, i.e. by turning, so as to similarly
manipulate the mandrel 20. The manipulation at surface may articulate
the tubing anchor catcher 10 between the run-in position and a set
position. Due to the drag blocks 42 frictionally engaging the inner surface
13 of the well conduit 12, the drag body 40 and the slip cage 60 remain
relatively fixed as the mandrel 20 and the rest of the tubing string, are
manipulated from surface. As mandrel 20 is pulled, in direction 16, the
drive pin 88 becomes repositioned in mandrel 20 in direction A towards
shoulder 84. Thereafter, the mandrel 20 can be lowered, and turned, for
example, a quarter turn to the right, or clockwise as viewed from above
(i.e. about 90 degrees). As known in the art, anchor catchers are
commonly right hand set/right hand release for reciprocating rod pumps.
The turning is about the longitudinal axis of the tubing string and,
therefore, the tubing anchor catcher 10. This manipulation causes the
drive pin 88 to be relocated from shoulder 84, generally along walls 89,
87 and 86 to rest in shoulder 86 of the first arm 80A. When the drive pin
88 is in shoulder 86, the tubing anchor catcher 10 is in a pre-set position..
Pulling the tubing string and, therefore, the mandrel 20 upwards, in
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direction 16 will cause the drive pin 88 to be relocated into shoulder 82.
When the drive pin 88 is in shoulder 82, conical surfaces 54 and 70B have
moved under the slip or slips 62 and the tubing anchor catcher 10 is set
with the slip or slips 62 extending outwards from the slip cage 60 to
engage the inner surface 13 of the well conduit 12. At this point, tension
can be applied to the tubing string and the tubing string can be landed in
a tubing hanger.
[0031] Groove 80 is in the shape of a "C", although this is not
intended to be a
literal graphical description of shapes that will work, as other shapes will
work other than exact C-shapes, as may mirror images of the groove 80.
[0032] To release the slip or slips 62, the tubing string and,
therefore, the
mandrel 20 can be manipulated at surface. For example, the mandrel 20
can be moved relative to the rest of the tubing anchor catcher 10, so that
the drive pin 88 is relocated out of shoulder 82. As shown in Figure 6, the
mandrel 20 can be pushed down so that the drive pin 88 is relocated
along line F toward shoulder 86. With a quarter turn to the right the
drive pin 88 will be repositioned along line H and then a straight pulling
up of the tubing string and mandrel 20 will cause the mandrel 20 to move
so that the drive pin 88 ends up in shoulder 84. When the drive pin 88
has been relocated out of the first arm 80A of the groove 80, the conical
surface 54 moves out from under the slip or slips 62 and the springs 76
will cause the slip or slips 62 to retract back into the slip cage 60.
[0033] When the tubing anchor catcher 10 is in the set position and
in the event
of a break in the tubing string, etc., which may cause the tubing string to
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fall down into the well (i.e., in direction 17), the tension in the tubing
string is lost. This causes the weight of the tubing string to bear on the
upper safety sub 14A, which will bear on the biasing member 94. The
biasing member 94 will compress, from the weight of the tubing string
above, and act against the upper edge 70A of the cone 70. This action
causes the downwardly gripping upper teeth 63A to more directly engage
and bite into the inner surface 13 of the well conduit 12. For example,
the greater the amount of tubing string weight that compresses the
biasing member 94, the harder, or more directly, the upper teeth 63A will
engage the inner surface 13 of the well conduit 12. When the upper
teeth 63A are more directly engaged into the inner surface 13 of the well
conduit 12, the upper teeth 63A can hold the weight of the tubing string
above the tubing anchor catcher 10, for example, until such time that the
tubing string can be recovered from the well. The drag blocks 42 are still
in frictional contact with the inner surface 13 of the well conduit 12 and
the lower conical surface 54 is still wedged under the slip or slips 62.
[0034] An alternate means of un-setting the tubing anchor catcher is
now
described. If it is not possible to relocated drive pin 88 in a location in
the
groove 80 so as to unset the slip or slips 62, for example due to packing
of sand or other materials into the groove 80, the slip or slips 62 may be
unset by applying a sufficient upward tension on the tubing string and
the mandrel 20. In one embodiment, the upward tension is of sufficient
amplitude to shear the drive pins 88, which form the primary connection
between the drag body 40 and the mandrel 20. Then the mandrel 20
may then move upward (i.e. in the direction of arrow 16), relative to the
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drag body 40, which causes upper cone 70 to move up and out from
under the slip or slips 62, which then allows slip or slips 62 to move
inwardly as they move away from the second conical surface 54 of the
drag body 40. This allows the slip or slips 62 to retract from contacting
the inner surface of the well conduit. When the slip or slips 62 are
retracted, the tubing anchor catcher 10 may be pulled out of the well
conduit 12. At this time the cap screw 65 may engage the lower shoulder
688 of the slot 66 so that, even though the slip cage 60 is furthest away
from the drag body 40, the slip cage 60 and the drag body 40 do not
separate. Alternatively, or additionally, the lower edge of the drag body
40 may engage the lower safety sub 14b as the tubing string is pulled
upwards towards the surface (i.e. in direction 16).
[0035] Figures 9 to 12 depict an alternative or second embodiment of
a tubing
anchor catcher 100 with an upper end 100A and a lower end 1001 The
tubing anchor catcher 100 may comprise many of the same features as
tubing anchor catcher 10. For example, one difference between the two
tubing anchor catchers 10, 100 is that the drive pin 88 of the tubing
anchor catcher 10 may be sheared as a secondary release mechanism, as
described above. In contrast, the tubing anchor catcher 100 may
comprise a drive pin or drive pins 188 that are not designed to shear as a
secondary release mechanism. The lower cone 41 is formed as a
separate piece to the drag body 40. The tubing anchor catcher 100 may
comprise one or more shear pins 72 that connect the lower end of the
lower cone 41 to drag body 40. The shear pins 72 are made of a material
that will shear in response to a lower shearing force than the shear force
13
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required to shear the pin 188. In this embodiment, the second conical
surface 54 is formed on an upper end of the lower cone 41 (see Figure
12). Lower cone 41 slidably mounts about the external surface of the
mandrel 20 so that conical surface 54 in combination with conical surface
70B on cone 70 compress together along mandrel 20 to force the slip or
slips 62 into the set position, as described above. The shear pins 72
provide a secondary release of slip or slips 62 by the application of a
sufficient pulling force to the tubing string so as to shear the shear pins
72. When the shear pins 72 are sheared, the lower cone 41 is released
from connection with the stationary drag body 40 and can move
downwardly away from its position under the slip or slips 62. The slip or
slips 62 can then retract away from the inner surface 13 of the well
conduit 12.
[0036] The tubing anchor catchers 10, 100 are thus designed to
anchor the
tubing string from movement longitudinally along the well (in both
directions, up and down the well) and from rotating. The anchoring is
= achieved by simple setting and release procedures that require relatively
little movement of the tubing string. In this instance, setting is achieved
by a small pull and right hand rotation of the mandrel 20 (via the tubing
string) that is adequate for the drive pins 88, 188 to travel the short
distances within the groove 80. Further, both tubing anchor catchers 10,
100 can prevent a broken tubing string from falling into the well bore by
the compression of the biasing member 94 causing the downward
gripping teeth 63A to grip the inner surface 13 of the well conduit 12, as
described above.
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[0037] The slip or slips 62 and the diameter of the anchor catcher
10, 100 may
be configured to provide one or more by-pass spaces 78 between the
tubing anchor catchers 10, 100 and the inner surface 13 of the well
conduit 12, which may create high flow areas for fluids (e.g. gas) and
solids (e.g. sand) to pass by the tubing anchor catchers 10, 100.
[0038] This optional embodiment of the tubing anchor catchers 10, 100
configured with by-pass spaces 78 may permit lines, tubes and cables
such as capillary cable to be carried downhole via the large by-pass
spaces 78. In particular, the fact that the tubing anchor catchers 10, 100
is set and unset by longitudinal motion and a quarter turn, permits its use
with the capillary cable since the tubing anchor catchers 10, 100 may
avoid wrapping of the cable around the tubing anchor catchers 10, 100.
In contrast, prior art anchors require multiple full (360 degree) rotations
¨ between two to nine full rotations for setting and unsetting ¨ and cause
an undesirable wrapping of the cable around the tubing anchor catcher
as it is set, which can damage the cable. Alternately, the cables must be
pre-wrapped when installed with these prior art tubing anchor catchers,
so that they unwrap as the tubing anchor catcher is rotated during
setting, which is tedious and undesirable. Also, if cable is required to be
pre-wrapped then on setting the tool, the unwrapped extra cable
becomes available to jam between the tool and the well conduit and it
may be damaged, break or otherwise interfere with reliable wellbore
operations.
[0039] Optionally, the drag blocks 42 may be hardened, in comparison
to prior
art drag springs, for a longer operational life. The slip or slips 62 may
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optionally be made with carbide inserts for teeth for superior durability
and grip on the well conduit wall 13, and lnconelTM type springs 76 are
employed for improved resistance to H2S and CO2. Further, the surface
of the mandrel 20 may optionally be coated with Teflon for improved
resistance to H2S and CO2, and to help maintain mandrel strength.
[0040] While the above disclosure describes certain examples of the
present
invention, various modifications to the described examples will also be
apparent to those skilled in the art. The scope of the claims should not be
limited by the examples provided above; rather, the scope of the claims
should be given the broadest interpretation that is consistent with the
disclosure as a whole.
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