Note: Descriptions are shown in the official language in which they were submitted.
CA 02610606 2007-11-14
PACKER CUP SYSTEMS FOR USE INSIDE A WELLBORE
BACKGROUND
Field of the Invention
[0m] Implementations of various technologies described herein generally relate
to
packer cups for use in a wellbore.
Description of the Related Art
[0002] The following descriptions and examples are not admitted to be prior
art by virtue
of their inclusion within this section.
[0003] Packer cups are often used to straddle a perforated zone in a wellbore
and divert
treating fluid into the formation behind the casing. Packer cups are commonly
used
because they are simple to install and do not require complex mechanisms or
moving
parts to position them in the wellbore. Packer cups seal the casing since they
are
constructed to provide a larger diameter than the casing into which they are
placed,
thereby providing a slight nominal radial interference with the well bore
casing. This
interference, "swabbing," or "squeeze," creates a seal to isolate a geologic
zone of
interest and thereby diverts the treating fluid introduced into the casing
into the
formation.
[0004] Packer cups were developed originally to swab wells to start a well
production.
In recent years, packer cups have been used in fracturing or treatment
operations
carried out on coiled tubing or drill pipe. Such operations may require higher
pressures
and may require multiple sets of packer cups or isolations across various
individual
zones. At such high pressures, the rubber portion of the packer cups may
deteriorate
and extrude in the direction of the pressures, thereby jeopardizing the seal
with the
casing. Accordingly, a need exists in the industry for a system of packer cups
that are
capable of withstanding the high differential pressures encountered during
fracturing or
treatment operations.
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Attorney Docket No.: 25.0427
SUMMARY
[0005] One embodiment of the present invention provides a packer cup system
for use
inside a wellbore comprising a packer cup and a backup component coupled
thereto.
The backup component further comprises a support member and a rubber ring
disposed between the support member and the packer cup. The support member is
configured to prevent the rubber ring from moving toward the support member. A
tapered element is disposed between the rubber ring and the packer cup to
facilitate
uniform expansion of the rubber ring.
[0006] Still another embodiment of the present invention provides a packer cup
system
for use inside a wellbore comprising a packer cup and a backup component
coupled
thereto. The backup component further comprises a support member having an
angled
surface, a piston moveably disposed against the support member and a rubber
ring
disposed between the piston and the packer cup. The piston is configured to
move
between the support member and the rubber ring.
[0007] Yet another embodiment of the present invention provides a method of
treating a
formation. The method comprises the steps of isolating a zone with a packer
cup
having a backup system and pumping a treating fluid into the isolated zone.
The
backup system of the packer up comprises a support member and a rubber ring
disposed between the support member and the packer cup, wherein the support
member is configured to prevent the rubber ring from moving toward the support
member. The backup system further comprises a tapered element disposed between
the rubber ring and the packer cup.
mom The claimed subject matter is not limited to implementations that solve
any or all
of the noted disadvantages. Further, the summary section is provided to
introduce a
selection of concepts in a simplified form that are further described below in
the detailed
description section. The summary section is not intended to identify key
features or
essential features of the claimed subject matter, nor is it intended to be
used to limit the
scope of the claimed subject matter.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Implementations of various technologies will hereafter be described
with
reference to the accompanying drawings. It should be understood, however, that
the
accompanying drawings illustrate only the various implementations described
herein
and are not meant to limit the scope of various technologies described herein.
mom Figure 1 illustrates a schematic diagram of a formation interval straddle
tool that
may be used in connection with one or more embodiments of the invention.
[0011] Figure 2 illustrates a cross sectional view of a packer cup system in
accordance
with one implementation of various technologies described herein.
[0012] Figure 3 illustrates a cross sectional view of a packer cup system in
accordance
with another implementation of various technologies described herein.
[0013] Figure 4 illustrates a cross sectional view of a packer cup system in
accordance
with yet another implementation of various technologies described herein.
[0014] Figure 5 illustrates a cross sectional view of a packer cup system in
accordance
with still another implementation of various technologies described herein.
[0015] Figure 6 illustrates a cross sectional view of a packer cup system in
accordance
with still yet another implementation of various technologies described
herein.
[0016] Figure 7 illustrates a cross sectional view of a packer cup system in
accordance
with still yet another implementation of various technologies described
herein.
[0017] Figure 8 illustrates a cross sectional view of a packer cup system in
accordance
with yet another implementation of various technologies described herein.
(0018] Figure 9 illustrates an embodiment of a wedge shim of the present
invention.
[0019] Figure 10 illustrates an embodiment of the present invention having a
wedge
shim adjacent the rubber element.
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[0020] Figure 11 illustrates an embodiment of a rubber element of the present
invention
having a chamfer at two distinctive angles.
[0021] Figure 11A is an enlarged view illustration of the chamfered surfaces
of Figure
11.
[0022] Figure 12 illustrates an embodiment of the present invention having an
angled
support element.
[0023] Figure 13 illustrates an embodiment of the present invention having a
wedge
shim and an angled support member.
[0024] Figure 14 illustrates an embodiment of the present invention having a
wedge
shim, a chamfered rubber element and an angled support member.
[0025] Figure 15 illustrates an embodiment of the present invention having a
wedge
shim, a double chamfered rubber element and an angled support member.
DETAILED DESCRIPTION
[0026] As used here, the terms "up" and "down"; "upper" and "lower";
"upwardly" and
downwardly"; "below" and "above"; and other similar terms indicating relative
positions
above or below a given point or element may be used in connection with some
implementations of various technologies described herein. However, when
applied to
equipment and methods for use in wells that are deviated or horizontal, or
when applied
to equipment and methods that when arranged in a well are in a deviated or
horizontal
orientation, such terms may refer to a left to right, right to left, or other
relationships as
appropriate.
[0027] Figure 1 illustrates a schematic diagram of a formation interval
straddle tool 10
that may be used in connection with implementations of various technologies
described
herein. The straddle tool 10 is of the type typically employed for earth
formation zone
fracturing or other formation treating operations in wellbores. Figure 1
illustrates the
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straddle tool 10 as being positioned within a cased wellbore 12, which has
been drilled
in an earth formation 14. The straddle tool 10 may be lowered into the
wellbore 12 on a
string of coiled or jointed tubing 16 to a position adjacent a selected zone
18 of the
earth formation 14. The wellbore 12 may be cased with a casing 20, which has
been
perforated at the selected zone 18 by the firing of perforating shaped charges
of a
perforating gun or other perforating device, as illustrated by the
perforations 22.
[0028] Once the straddle tool 10 is in position adjacent the selected
formation zone 18,
the straddle tool 10 may be operated from the earth's surface to deploy anchor
slips 24
to lock itself firmly into the casing 20 in preparation for fracturing or
treating the selected
formation zone 18. The straddle tool 10 may further include one or more packer
cup
systems 100 disposed on a mandrel 50. Each packer cup system 100 may include a
packer cup 26 and a backup component 110. When pressurized fracturing or
treating
fluid is pumped from the earth's surface through the string of coiled or
jointed tubing 16
and the straddle tool 10 toward the formation zone 18, the pressure of fluid
exiting the
straddle tool 10 may force the packer cups 26 to engage the casing 20 at one
or more
treating ports 28. The open ends 29 of the cup packers 26 may be arranged to
face
each other and straddle an interval 30 of the wellbore 12 between the packer
cups 26.
Although Figure 1 illustrates the straddle tool 10 without any other
attachments, it
should be understood that in some implementations the straddle tool may have
other
tools or components attached thereto, such as a pressure balance system, a
slurry
dump valve, a scraper and the like.
[0029] When the packer cups 26 have fully engaged the casing 20, the formation
zone
18 and the straddled interval 30 between the packer cups 26 will be
pressurized by the
incoming fracturing or treating fluid. Upon completion of fracturing or
treating of the
formation zone 18, the pumping of fracturing or treating fluid from the
earth's surface
may be discontinued, and the straddle tool 10 may be operated to dump any
excess
fluid, thereby relieving the pressure in the straddled interval 30.
CA 02610606 2014-05-28
79628-109
[0030] In general, the packer cups 26 may be configured to seal against
extreme
differential pressure. The packer cups 26 may also be flexible such that it
may be run
into a well without becoming stuck and durable so that high differential
pressure may be
held without extrusion or rupture. As such, the packer cups 26 may be
constructed
from strong and tear resistant rubber materials. Examples of such materials
may
TM TM
include nitrite, VITON, hydrogenated nitrite, natural rubber, AFLAS, and
urethane (or
polyurethane).
[0031] Figure 2 illustrates a cross sectional view of a packer cup system 200
in
accordance with one ,implementation of various technologies described herein.
The
packer cup system 200 may include a packer cup 226 having a metal support 220
attached thereto. Both the packer cup 226 and the metal support 220 may be
coupled
to the mandrel 50. In one implementation, the packer cup system 200 may
include a
backup component 210 having a rubber ring 240 coupled to the metal support
220. In
another implementation, the rubber ring 240 may be supported by a support
member
250 coupled to the mandrel 50. The rubber ring 240 may be made from strong and
tear
TM
resistant rubber materials, such as nitrite, VITON, hydrogenated nitrite,
natural rubber,
TM TM
AFLAS, urethane (or polyurethane), high DURO atid the like. The support member
250
may be permanently coupled to the mandrel 50. It should be understood that in
some
embodiments, the support ring 240 can be coupled to the packer cup 226 by
molding
onto the packer cup 226 to form an integral component.
[0032] The backup component 210 may be activated as a differential pressure is
applied across the packer cup 226. Such differential pressure may be caused by
the
difference between the pressure of the treatment fluid against the open ends
29 of the
packer cup 226 and the pressure inside the annulus 260. This difference in
pressure
across the packer cup 226 may move the packer cup 226 along the mandrel 50
towards the lower pressure side, i.e., towards the left side of the packer cup
226 in
Figure 2. As a result of this movement, the rubber ring 240 may be compressed
and
radially expand toward the casing 20 to close the annular gap 260 between the
packer
cup 226 and the casing 20. In this manner, the backup component 210 may be
used to
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prevent the packer cup 226 from extruding under pressure, thereby enabling the
packer
cup 226 to operate under a high differential pressure environment.
[0033] Figure 3 illustrates a cross sectional view of a packer cup system 300
in
accordance with another implementation of various technologies described
herein. The
packer cup system 300 may include a packer cup 326 having a metal support 320
attached thereto. Both the packer cup 326 and the metal support 320 may be
coupled
to the mandrel 50. In one implementation, a backup component 310 may be
positioned
to support the packer cup 326. The backup component 310 may include a support
member 350 coupled to a rubber ring 340 having a helical spring 325 embedded
along
the circumference of the rubber ring 340. In one implementation, the helical
spring 325
may be covered with a wire mesh 330, which may be configured to minimize the
amount of rubber material entering into the helical spring 325 during its
expansion. The
helical spring 325 may be configured to be more elastic than the rubber ring
340. It
should be understood that in some embodiment, the the rubber ring 340 having
the
embedded helical spring 325 (with or without the wire mesh 330) can be coupled
to the
packer cup 326 by molding onto the packer cup 326 to form an integral
component. As
mentioned above, the support member 350 may be permanently coupled to the
mandrel 50.
[0034] The backup component 310 may be activated by the differential pressure
across
the packer cup 326. This difference in pressure across the packer cup 326 may
move
the packer cup 326 along the mandrel 50 towards the lower pressure side, i.e.,
towards
the left side of the packer cup 326 in Figure 3. As a result of this movement,
the rubber
ring 340 may be compressed and the helical spring 325 may expand radially
toward the
casing 20 to close the annular gap 360 between the packer cup 326 and the
casing 20.
In this manner, the backup component 310 may be used to prevent the packer cup
from
extruding under pressure.
[0035] Figure 4 illustrates a cross sectional view of a packer cup system 400
in
accordance with yet another implementation of various technologies described
herein.
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The packer cup system 400 may include a packer cup 426 having a metal support
420
attached thereto. Both the packer cup 426 and the metal support 420 may be
coupled
to the mandrel 50. In one implementation, a backup component 410 may be
positioned
to support the packer cup 426. The backup component 410 may include a support
member 450 coupled to a wave spring 470. It should be understood that in some
embodiment, the wave spring 470 can be coupled to the packer cup 426 by
molding
onto the packer cup 426 to form an integral component. The support member 450
may
be permanently coupled to the mandrel 50.
[0036] The backup component 410 may be activated by the differential pressure
across
the packer cup 426. This difference in pressure across the packer cup 426 may
move
the packer cup 426 along the mandrel 50 towards the lower pressure side, i.e.,
towards
the left side of the packer cup 426 in Figure 4. As a result of this movement,
the wave
spring 470 may be compressed and expand radially toward the casing 20, i.e.,
its inside
diameter (ID) and outside diameter (OD) may radially expand toward the casing
20, to
close the annular gap 460 between the packer cup 426 and the casing 20. In
this
manner, the backup component 410 may be used to prevent the packer cup 426
from
extruding under pressure.
[0037] Figure 5 illustrates a cross sectional view of a packer cup system 500
in
accordance with still another implementation of various technologies described
herein.
The packer cup system 500 may include a packer cup 526 having a metal support
520
attached thereto. Both the packer cup 526 and the metal support 520 may be
coupled
to the mandrel 50. In one implementation, a backup component 510 may be
positioned
to support the packer cup 526. The backup component 510 may include a support
member 550 coupled to a wave spring 570 coupled to a rubber ring 540. It
should be
understood that the wave spring 570 and rubber ring 540 can be coupled to the
packer
cup 526 by molding onto packer cup 526 to form an integral component.
[0038] The backup component 510 may be activated by the differential pressure
across
the packer cup 526. This difference in pressure across the packer cup 526 may
move
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the packer cup 526 along the mandrel 50 towards the lower pressure side, i.e.,
towards
the left side of the packer cup 526 in Figure 5. As a result of this movement,
both the
rubber ring 540 and the wave spring 570 may be compressed and cause the inside
diameter (ID) and outside diameter (OD) of the wave spring 570 to expand
radially
toward the casing 20, thereby closing the annular gap 560 between the packer
cup 526
and the casing 20. In this manner, the backup component 510 may be used to
prevent
the packer cup 526 from extruding under pressure.
[0039] Figure 6 illustrates a cross sectional view of a packer cup system 600
in
accordance with still yet another implementation of various technologies
described
herein. The packer cup system 600 may include a packer cup 626 having a metal
support 620 attached thereto. Both the packer cup 626 and the metal support
620 may
be coupled to the mandrel 50. In one implementation, a backup component 610
may
be positioned to support the packer cup 626. The backup component 610 may
include
a support member 650 coupled to a mandrel 50. In one implementation, the
support
member 650 may be permanently coupled to the mandrel 50. The backup component
610 may further include a rubber ring 640 having a helical spring 625 embedded
along
the circumference of the rubber ring 640 and a piston 655 disposed between the
support member 650 and the rubber ring 640. In one implementation, the helical
spring
625 may be covered with a wire mesh 630, which may be configured to minimize
the
amount of rubber material entering into the helical spring 625 during its
expansion. . It
should be understood that the rubber ring 640 having the embedded helical
spring 625
(with or without the wire mesh 630) can be coupled to the packer cup 626 by
molding
onto the packer cup 626 to form an integral component.
[0040] In one implementation, the backup component 610 may be activated by
fluid
pressure flowing through a slot 685 to move the piston 655 against the rubber
ring 640
having the helical spring 625 embedded therein such that both the helical
spring 625
and rubber ring 640 may expand radially toward the casing 20, thereby closing
the
annular gap 660 between the packer cup 626 and the casing 20. The fluid
pressure
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may be generated by the treatment or fracturing fluid flowing from the surface
through
the tubing 16.
Nom] The backup component 610 may further include a spring 670 configured to
exert
a predetermined amount of force against the piston 655. As such, the piston
655 may
have to overcome this force before the piston 655 can press against the rubber
ring 640
and cause the helical spring 625 to expand radially. In this manner, the
backup
component 610 may be activated only when the force generated by fluid pressure
communicated through the slot 685 and acting on the piston 655 is greater than
the
amount of force exerted by the spring 670.
[0042] The backup component 610 may further include a holding pin 680
configured to
prevent the packer cup 626 from moving toward the piston 655. A shoulder 690
may
also be provided to prevent the packer cup 626 from moving away from the
piston 655.
As such, the packer cup 626 may be held stationary by the holding pin 680 and
the
shoulder 690. Implementations of various technologies described with reference
to the
packer cup system 600 may reduce the likelihood the backup component 610 from
being activated during a run in-hole operation.
[0043] Figure 7 illustrates a cross sectional view of a packer cup system 700
in
accordance with still yet another implementation of various technologies
described
herein. The packer cup system 700 may include the same or similar elements or
components as the packer cup system 600, except that the rubber ring 640 and
the
helical spring 625 have been replaced with a wave spring 720 and a rubber ring
740
coupled thereto. Consequently, other details about those same or similar
elements
may be provided in the above paragraphs with reference to the packer cup
system 600.
When the backup component 710 is activated, the piston 755 presses against the
wave
spring 720 and the rubber ring 740, causing the inside diameter (ID) and
outside
diameter (OD) of the wave spring 720 to expand radially toward the casing 20,
thereby
closing the annular gap 760 between the packer cup 726 and the casing 20. In
this
manner, the backup component 710 may be activated by pressure applied from the
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surface to prevent the packer cup 726 from extruding under pressure. It should
be
understood that the wave spring 720 and rubber ring 740 can be coupled to the
packer
cup 726 by molding onto packer cup 726 to form an integral component.
[0044] Figure 8 illustrates a cross sectional view of a packer cup system 800
in
accordance with yet another implementation of various technologies described
herein.
The packer cup system 800 may include the same or similar elements or
components
as the packer cup system 700 with the exception of the rubber ring 740.
Consequently,
other details about those same or similar elements may be provided in the
above
paragraphs with reference to the packer cup system 700. When the backup
component
810 is activated, the piston 855 presses against the wave spring 820, causing
the
inside diameter (ID) and outside diameter (OD) of the wave spring 820 to
expand
radially against the casing 20, thereby closing the annular gap 860 between
the packer
cup 826 and the casing 20. In this manner, the backup component 810 may be
activated by pressure applied from the surface to prevent the packer cup 826
from
extruding under pressure.
[0045] As described with reference to Figures 9-16 below, alternate
embodiments of the
present invention further facilitate the uniform expansion of the rubber rings
(240, 340,
540, 640, and 740). Such uniform and full expansion inside the wellbore is
accomplished even at low pressures.
[0046] Although the alternate embodiments described with reference to Figures
9-16
have applicability to all of the previously described embodiments detailed in
Figures 2-
8, for simplicity of description, the alternate embodiments will be described
with primary
reference to Figure 6. For example, the expansion element of the backup system
(240,
340, 540, 640 and 740) will collectively be described with reference to the
rubber ring
640 of Figure 6 and the packer cups (226, 326, 526, 626 and 726) will be
collectively be
described with reference to the packer cup 626 of Figure 6.
[0047] Figure 9 illustrates an embodiment of a wedge shim 900 having a tapered
surface 910 that can be used to advantage by the present invention. For
example, as
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shown in Figure 10, the wedge shim 900 can be disposed between the rubber ring
640
and the packer cup 626 to facilitate expansion of the rubber ring 640. In the
embodiment shown, the rubber ring 640 additionally comprises a chamfered
surface
642 adapted to engage the angled surface 910 of the wedge shim 900.
[0048] Although the wedge shim 900 is illustrated as an element separate from
the
packer cup 626, it should be understood that in alternate embodiments, the
wedge shim
900 can be integrated into the packer cup 626. It should further be understood
that the
term "wedge shim" is intended to encompass any element having a tapered
surface
that further facilitates uniform expansion of the rubber element 640.
[0049] Figures 11 and 11A illustrate another embodiment of the present
invention
having a wedge shim 900 disposed between the rubber ring 640 and the packer
cup
626 to facilitate expansion of the rubber ring 640. As best described with
reference to
Figure 11A, which is an enlarged view of the interface between the wedge shim
900
and the rubber ring 640, the rubber ring 640 has chamfers 642 and 644 at two
distinct
angles. The chamfers 642, 644 are adjacent a wedge shim 900 such as that
illustrated
in Figure 9.
pow Figure 12 illustrates another embodiment of the present invention
described with
reference to the embodiment of the packer cup system depicted in Figure 6. As
described above, when activated the piston 655 exerts a force on the rubber
ring 640 to
force expansion. As shown, a support element 646 is disposed between the
piston 655
and the rubber ring 640; thus the support element 646 transmits the force
generated by
the piston 655 to the rubber ring 640. In the embodiment of Figure 12, the
support
element 646 further comprises an angled surface 648 that interacts with the
rubber ring
640 to facilitate the uniform expansion of the rubber ring 640.
[0051] Although the support element 646 of Figure 12 is shown as an element
independent of the piston 655, it should be understood that in alternate
embodiments,
the support element 646 can be integral with the piston 655.
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[0052] It should be understood that any combination of the above identified
features can
be provided while remaining within the scope of the present invention. One
such
example combination is illustrated in Figure 13. Similar to Figure 12, the
embodiment of
Figure 13 includes a support element 646 having an angled surface 648 that
interacts
with the rubber ring 640 to facilitate the uniform expansion of the rubber
ring 640. The
embodiment illustrated in Figure 13 further comprises a wedge shim 900
disposed
between the rubber ring 640 and the packer cup 626.
[0053] Figure 14 illustrates yet another embodiment of the present invention.
Similar to
Figure 13, the embodiment of Figure 14 includes a support element 646 having
an
angled surface 648 that interacts with the rubber ring 640 to facilitate the
uniform
expansion of the rubber ring 640 and comprises a wedge shim 900 disposed
between
the rubber ring 640 and the packer cup 626. The embodiment illustrated in
Figure 14
further comprises a chamfered surface 642 on the rubber ring 640 adapted for
engagement with the wedge shim 900.
[0054] Figure 15 illustrates still another embodiment of the present
invention. Similar to
Figure 14, the embodiment of Figure 15 comprises a support element 646 having
an
angled surface 648 that interacts with the rubber ring 640 to facilitate the
uniform
expansion of the rubber ring 640, a wedge shim 900 disposed between the rubber
ring
640 and the packer cup 626, and a chamfered surface on the rubber ring 640
adapted
for engagement with the wedge shim 900. In the embodiment illustrated in
Figure 15,
however, the chamfered surface of the rubber ring 640 comprises two chamfers
642,
644 at distinct angles.
[0055] Although the subject matter has been described in language specific to
structural
features and/or methodological acts, it is to be understood that the subject
matter
defined in the appended claims is not necessarily limited to the specific
features or acts
described above. Rather, the specific features and acts described above are
disclosed
as example forms of implementing the claims.
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