U.S. patent application number 14/484378 was filed with the patent office on 2015-03-12 for downhole tool having slip composed of composite ring.
The applicant listed for this patent is Weatherford/Lamb, Inc.. Invention is credited to Wesley C. Pritchett, James A. Rochen, Matthew R. Stage, Jonathan A. Young.
Application Number | 20150068728 14/484378 |
Document ID | / |
Family ID | 52624374 |
Filed Date | 2015-03-12 |
United States Patent
Application |
20150068728 |
Kind Code |
A1 |
Stage; Matthew R. ; et
al. |
March 12, 2015 |
Downhole Tool Having Slip Composed of Composite Ring
Abstract
A single piece composite slip component is disclosed, making it
easier and more feasible for milling up a composite plug after use.
Moreover, because the composite slip component is one piece during
deployment, and not in segments like conventional slip segments, it
can better withstand the high speeds and higher fluid velocities
and pressures downhole.
Inventors: |
Stage; Matthew R.; (Houston,
TX) ; Young; Jonathan A.; (Houston, TX) ;
Pritchett; Wesley C.; (Liberty, TX) ; Rochen; James
A.; (Waller, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Weatherford/Lamb, Inc. |
Houston |
TX |
US |
|
|
Family ID: |
52624374 |
Appl. No.: |
14/484378 |
Filed: |
September 12, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61877113 |
Sep 12, 2013 |
|
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|
Current U.S.
Class: |
166/134 ;
166/217 |
Current CPC
Class: |
E21B 33/1293 20130101;
E21B 33/134 20130101 |
Class at
Publication: |
166/134 ;
166/217 |
International
Class: |
E21B 33/129 20060101
E21B033/129; E21B 23/06 20060101 E21B023/06; E21B 33/124 20060101
E21B033/124; E21B 23/01 20060101 E21B023/01 |
Claims
1. A downhole apparatus, comprising: a mandrel; a cone disposed on
the mandrel; a first slip having a cylindrical body with first and
second surfaces and first and second ends, the cylindrical body
disposed with the first surface about the mandrel and with the
first end adjacent the cone, the cylindrical body defining only a
single slit extending partially from the first end toward the
second end, the cylindrical body radially expandable outward from
the mandrel through interaction of the first end with the cone; and
one or more inserts disposed on the cylindrical body and exposed at
the second surface.
2. The apparatus of claim 1, wherein the first surface defines an
incline at the first end.
3. The apparatus of claim 1, wherein the single slit extends a
greater distance along the second surface than along the first
surface of the cylindrical body.
4. The apparatus of claim 1, wherein the cylindrical body at the
second end comprises an interconnection at the single slit, the
interconnection hinging one side of the single slit with an
opposite of the single slit.
5. The apparatus of claim 1, wherein the interconnection defines a
triangular cross-section.
6. The apparatus of claim 1, wherein the apparatus comprises a
plug, a packer, a liner hanger, an anchoring device, or a downhole
tool.
7. The apparatus of claim 1, comprising a packing element disposed
on the mandrel, wherein the cone and the first slip are disposed on
an uphole end of the mandrel adjacent the packing element.
8. The apparatus of claim 7, comprising a second slip disposed on a
downhole end of the mandrel adjacent an opposite side of the
packing element.
9. The apparatus of claim 8, wherein the second slip comprises a
plurality of independent segments disposed about the mandrel.
10. A downhole apparatus, comprising: a mandrel; a cone disposed on
the mandrel; a cylindrical body having first and second surfaces
and having first and second ends, the cylindrical body disposed
with the first surface about the mandrel and with the first end
adjacent the cone, the cylindrical body defining only two slits
extending partially from the first end toward the second end, the
cylindrical body radially expandable outward from the mandrel
through interaction of the first end with the cone; and one or more
inserts disposed on the cylindrical body and exposed at the second
surface.
11. The apparatus of claim 10, wherein the first surface defines an
incline at the first end.
12. The apparatus of claim 10, wherein each of the two slit extends
a greater distance along the second surface than along the first
surface of the cylindrical body.
13. The apparatus of claim 10, wherein the cylindrical body at the
second end comprises interconnections at each of the two slits, the
interconnections hinging one side of the each slit with an opposite
of the each slit.
14. The apparatus of claim 10, wherein each of the interconnections
defines a triangular cross-section.
15. The apparatus of claim 10, wherein the apparatus comprises a
plug, a packer, a liner hanger, an anchoring device, or a downhole
tool.
16. The apparatus of claim 10, comprising a packing element
disposed on the mandrel, wherein the cone and the first slip are
disposed on an uphole end of the mandrel adjacent the packing
element.
17. The apparatus of claim 10, comprising a second slip disposed on
a downhole end of the mandrel adjacent an opposite side of the
packing element.
18. The apparatus of claim 17, wherein the second slip comprises a
plurality of independent segments disposed about the mandrel.
19. The apparatus of claim 10, wherein the only two slits are
disposed on radially opposite sides of the cylindrical body.
20. A method of setting a downhole tool against an adjacent
surface, the method comprising: interacting a first end of a
cylindrical body with a surface of the tool; expanding the
cylindrical body radially outward from the tool with the
interaction as at least one and not more than two arcuate members
by separating the cylindrical body along at least one and not more
than two slits extending partially from the first end toward a
second end of the cylindrical body; engaging one or more inserts on
the cylindrical body against the adjacent surface; transmitting
load from the surface to the cylindrical body; and transmitting the
load from the cylindrical body to the one or more inserts.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Prov. Appl.
61/877,113, filed 12 Sep. 2013, which is incorporated herein by
reference.
BACKGROUND OF THE DISCLOSURE
[0002] An oil or gas well includes a bore extending into a well to
some depth below the surface. Typically, the bore is lined with
tubulars or casing to strengthen the walls of the bore. To further
strengthen the walls of the bore, the annular area formed between
the casing and the bore is typically filled with cement to
permanently set the casing in the bore. The casing is then
perforated to allow production fluid to enter the bore and to be
retrieved at the surface of the well.
[0003] Typically, downhole tools with sealing elements are placed
within the bore to isolate the production fluid or to manage
production fluid flow through the well. For example, a plug or
packer is placed within a bore to isolate upper and lower sections
of production zones. Thus, by creating a pressure seal in the bore,
these plugs allow pressurized fluids or solids to treat an isolated
formation. These tools are usually constructed of cast iron,
aluminum, or other alloyed metals, but have a malleable, synthetic
element system. The plug or packer system can also be composed of
non-metallic components made of composites, plastics, and
elastomers.
[0004] Slips are a part of these downhole tools, such as plugs and
packers, and the slips can also be composed of metallic or
non-metallic components. However, metallic slips can cause problems
during mill-up operations of the downhole tools in horizontal
wells. As one solution to these problems, slip segments composed of
composite material can be held on a mandrel of a downhole tool,
such as a plug. These composite slip segments are typically held
together with bands on the tool's mandrel until actuated to engage
the surrounding casing downhole. Additionally, the composite slips
segments can have inserts or buttons that are composed of metallic
materials (e.g., tungsten carbide or the like) that grip the inner
wall of the surrounding casing or tubular. Examples of downhole
tools with slip segments with inserts are disclosed in U.S. Pat.
Nos. 6,976,534 and 8,047,279.
[0005] FIG. 1A illustrates a fracturing system 10 having a
composite plug according to the prior art disposed in a bore. As
shown, the system 10 can having at least one of the composite plugs
100 disposed within the casing 12 lining the bore. Casing 12, as
known in the art, is used to further strengthen the walls of the
bore, and therefore the area formed between the casing 12 and the
bore is typically filled with cement to permanently set the casing
12 within the bore. Also as shown, the casing 12 is perforated 15
to allow production fluid to enter the casing 12 so the produced
fluids can be retrieved at the surface of the well. The casing 12
is perforated 15 in formation zones 14 as shown. The formation
zones 14 indicate zones where production fluid potentially exists.
Accordingly, the casing 12 at these zones 14 is perforated 15 in
order to allow fluid to flow into the casing 12 and eventually to
the surface.
[0006] FIG. 1B illustrates a composite plug 100 of the prior art in
more details. As shown, the plug 100 has a mandrel 102. As known in
the art, the mandrel 102 is designed with a cylindrical hole (i.e.,
bore) through the center to allow for pressure equalization and
well flow back prior to milling up the plug 100 after its use
downhole. Also as shown, the plug 100 has uphole and downhole slip
assemblies 104a-b, each having slip segments 110, inserts 114, and
bands 112. The plug 100 also has uphole and downhole cones 106a-b,
a setting or push ring 105, and a packing element 109, which will
be discussed in detail below.
[0007] Conventional composite slips 104a-b include multiple slip
segments 110 disposed around the mandrel 102. Bands 112 typically
hold the slip segments 110 in place, and the composite segments 110
include one or more metallic inserts 114 in order to engage the
casing (12).
[0008] During operation, the slip segments 110 move away from the
mandrel 102 and compress the inserts 114 against the surrounding
casing (12) when the plug 100 is compressed. Examples of the
operation of conventional slip components of such a plug 100 are
disclosed in U.S. Pat. No. 7,124,831 which is incorporated within
in its entirety.
[0009] As mentioned, the conventional slip assemblies 104a-b may be
composed of cast iron, aluminum, or other alloyed metals. However,
in one problem associated with such metallic slip assemblies, it is
often times less desirable to use such metallic components due to
the mill-ability of the components. For example, plugs 100 are
sometimes intended to be temporary and must be removed to access
the casing (12). Rather than de-actuating the plug 100 and bringing
it to the surface of the well, the plug 100 is typically destroyed
with a rotating milling or drilling device.
[0010] As the mill contacts the plug 100, the plug 100 is "drilled
up" or reduced to small pieces that are either washed out of the
bore or simply left at the bottom of the bore. The more metal parts
making up the plug 100, the longer the milling operation takes.
Furthermore, metallic components like aluminum also typically
require numerous trips in and out of the bore to replace worn out
mills or drill bits. Also, aluminum mandrels are typically composed
of very expensive aerospace grade materials, and are thus not
economically feasible for such use.
[0011] In another problem, the conventional slip assemblies even if
composed of composite materials are oftentimes difficult to
manufacture. For example, the conventional slip assemblies 104a-b
are often manufactured as multiple, independent segments 110. Then,
the slip segments 10 are positioned around the mandrel 102 of the
plug 100 and are held together with restraining bands 112 to keep
the segments 110 against the mandrel 102 for deploying in the
casing 110 until actuated. Although this form of manufacture may
work, it is often time-consuming and involves a very complicated
manufacturing and assembly process.
[0012] Further, other problems associated with using slip segments
110 held by restraining bands 112 arise when the tool 100 is
deployed downhole. As is known in the art, downhole conditions
vary, and high pressures and high fluid velocities may disengage or
render unusable conventional slip assemblies 104a-b. For example,
during the deployment of the plug 100, the fluid in the bore may
have a high enough pressure and/or may have an increased velocity
as it transitions past the slip assembly 104a-b that the slip
assembly 104a-b can be damaged and disengage from the mandrel 102,
despite being held together by bands 112. That is, the bands 112
may not be strong enough to hold the segments 110 together in
certain downhole conditions.
[0013] Accordingly, there is a need for a non-metallic slip
component that will effectively handle the high temperatures and
the high pressures downhole. There is also a need for a slip
component that is easier and faster to manufacture, while remaining
economically feasible. Finally, there is a need for a non-metallic
slip assembly that can withstand the high speeds and fluid
velocities during run in on a downhole tool through casing.
[0014] The subject matter of the present disclosure is directed to
overcoming, or at least reducing the effects of, one or more of the
problems set forth above.
SUMMARY OF THE DISCLOSURE
[0015] Conventional slip components of downhole tools are typically
composed of cast iron, aluminum, or other alloyed metals. However,
the more metal parts making up the plug (i.e., slip components) the
longer the milling operation takes. Also, metallic components like
aluminum also typically require numerous trips in and out of the
bore to replace worn out mills or drill bits and are typically
composed of very expensive aerospace grade materials, and are thus
not economically feasible for such use. Therefore, a single piece
composite slip component is disclosed, making it easier and more
feasible for milling up a plug after use. Moreover, because the
composite slip component is one piece during deployment, and not in
segments like conventional slip segments, it can better withstand
the high speeds and higher fluid velocities and pressures downhole.
This is important aspect when pumping down extended reach
horizontals.
[0016] A downhole apparatus have a mandrel with a cone disposed
thereon. In general, the apparatus can be a plug, a packer, a liner
hanger, an anchoring device, or a downhole tool.
[0017] The single piece composite slip component is disposed on the
mandrel and has a cylindrical body with first and second surfaces
and first and second ends. The cylindrical body is disposed with
the first surface about the mandrel and with the first end adjacent
a cone on the mandrel of the downhole tool. In one arrangement, the
cylindrical body defines only a single slit extending partially
from the first end toward the second end. In another arrangement,
the cylindrical body defines only two slits extending partially
from the first end toward the second end. These two slits can be
disposed on radially opposite sides of the cylindrical body.
[0018] The cylindrical body is radially expandable outward from the
mandrel through interaction of the first end with the cone, and one
or more inserts disposed on the cylindrical body and exposed at the
second surface engage in the surrounding tubular wall of casing or
the like.
[0019] When interacting the first end of the cylindrical body with
the cone, the cylindrical body expands radially outward from the
tool with the interaction as at least one and not more than two
arcuate members by separating the cylindrical body along the one
and not more than two slits extending partially from the first end
toward a second end of the cylindrical body. The one or more
inserts on the cylindrical body engage against the adjacent
surface. Load is transmitted from the cone to the cylindrical body,
and the load is transmitted from the cylindrical body to the one or
more inserts.
[0020] To interact with the cone, the first surface can define an
incline at the first end. The single or two slits extend a greater
distance along the second surface than along the first surface of
the cylindrical body. The cylindrical body at the second end can
have an interconnection at the slit so that the interconnection can
hinge one side of the single slit with an opposite of the single
slit. The interconnection can define a triangular
cross-section.
[0021] A packing element can be disposed on the mandrel, and the
cone and the single piece composite slip component can be disposed
on an uphole end of the mandrel adjacent the packing element. A
second slip can also be disposed on a downhole end of the mandrel
adjacent an opposite side of the packing element. This second slip
can include a plurality of independent segments disposed about the
mandrel.
[0022] The foregoing summary is not intended to summarize each
potential embodiment or every aspect of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1A illustrates a plug disposed in a bore according to
the prior art.
[0024] FIG. 1B illustrates a plug of the prior art.
[0025] FIG. 2A illustrates an elevational view a plug having a
composite slip component according to the present disclosure.
[0026] FIG. 2B illustrates an elevational view of another side of
the plug offset 90-degrees from FIG. 2A.
[0027] FIG. 2C illustrates a detailed view of the disclosed slip
component on the plug.
[0028] FIGS. 3A-3C illustrates an end view, a cross-sectional view,
and a perspective view of the disclosed slip component.
[0029] FIG. 3D is a detailed view of a hole for an insert of the
disclosed slip.
[0030] FIGS. 4A-4B schematically illustrates the disclosed slip
component in different engagements with the surrounding casing
during operation.
[0031] FIG. 5 illustrates an elevational view of another plug
having two composite slips according to the present disclosure.
[0032] FIGS. 6A-6C illustrates an end view, a cross-sectional view,
and a perspective view of another composite slip component
according to the present disclosure.
[0033] FIG. 6D schematically illustrates the disclosed slip
component engaged with the surrounding casing during operation.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0034] FIGS. 2A-2B illustrate elevational views a composite plug
100 having a composite slip component 120 according to the present
disclosure. The two views in FIGS. 2A-2B show sides of the plug 100
at 90-degree offset from one another. As shown, the plug 100
includes a mandrel 102 and sealing elements 104a-b, 106a-b, 108a-b,
and 109. In general, the plug 100 can be a bridge plug intended to
contain pressure from above and below when setting in casing, or it
can be a fracture plug intended mainly to contain pressure from
above during a fracture operation.
[0035] Disposed on the mandrel 102, the plug 100 has uphole and
downhole slip assemblies 104a-b, cones 106a-b, and backups 108a-b
with a packing element 109 disposed between them. The uphole slip
assemblies 104a as shown includes the composite slip component 120
according to the present disclosure, while the downhole assembly
includes a conventional slip assembly having segments 110 with
inserts 114 and held by bands 112.
[0036] As best shown in the detailed view of FIG. 2C, the slip
component 120 has a cylindrical body or 122 with insert holes 128
for holding inserts 130. As discussed in more detail below, the
composite slip component 120 has one or more slits 124 and
interconnecting portions or hinging areas 127. Preferably, the
cylindrical body 122 has only one or at most two slits 124 so that
the cylindrical body 122 forms a practically continuous ring or
cylinder with only one or at most two arcuate portions divided by
the slit(s) 124.
[0037] Regarding the disposition of the slip component 120 and the
conventional slip assembly 104b at uphole and downhole ends of the
plug 100, the disclosed plug 100 is not limited to this particular
configuration. That is, the plug 100 may comprise composite slip
components 120 on both uphole and downhole ends, or the plug 100
may comprise a slip component 120 at the downhole end, while having
a conventional slip assembly 104b uphole. Accordingly, any other
combination of slip component 120 with or without conventional slip
assembly 104b can be used on the plug 100.
[0038] However, regardless of which is deployed uphole or downhole,
it is desired to deploy a slip assembly having greater structural
stability (e.g., the disclosed slip component 120) at the uphole
end of the plug 100 and to deploy a slip assembly with increased
strength at the downhole end of the plug. This is due in part to
what the uphole assembly 104a may encounter during run in at high
speeds. The uphole assembly 104a may experience more adverse
effects from fluid flow or friction during run in of the plug 100
in the casing (12) which could damage a conventional slip assembly
with segments. Because the slip component 120 is a continuous
cylindrical component, it is less prone to damage during run
in.
[0039] Choice of what type of assembly to use at the downhole end
is also based on the operation of the plug 100. For example,
because the downhole slip assembly has to remain in place, braking
and engaging the inner bore, while the uphole slip is compressed
toward the downhole slip, the downhole slip assembly may experience
certain pressures or effects that the uphole slip assembly may not
experience. Thus, if the downhole slip assembly cannot withstand
certain forces, the downhole slip assembly may disengage from the
casing. As a result, the plug 100 may fail during use. For these
reasons, the uphole assembly 104a of the present disclosure may use
the disclosed slip component 120, while the downhole assembly 104b
may use other types of segments 110 and the like.
[0040] In operation, the element system 103 of the plug 100 shown
in FIGS. 2A-2B is compressed, and expands radially outward from the
plug 100 to sealingly engage a surrounding tubular or casing (not
shown). To obtain this expansion, forces are exerted on the push
ring 105. As the slip component 120 moves down in relation to
downhole slip assembly 104b, the packing element 109 is compressed,
and the slip component 120 and slip assembly 104b are driven up
their adjacent cones 106a-b. The movement of the cones 106a-b and
the slip component 120 and assembly 104b axially compress and
radially expand the packing element 109, thereby forcing the
packing element 109 radially outward from the plug 100 to contact
the inner surface of the casing (12). In this manner, the
compressed packing element 109 provides a fluid seal to prevent
movement of fluids across the plug 100.
[0041] Further, as the packing element 109 expands to provide a
fluid seal between the plug 100 and the casing (12), the slip
component 120 and assembly 104b move along the surface of cones
106a-b. As a result, the slip component 120 and assembly 104b will
expand outward with respect to the plug 100, thereby being driven
into the casing to hold plug 100 in place.
[0042] With particular reference to the offset views of FIGS.
2B-2C, one of the at least one or two slits 124 of the slip
component 120 of the plug 100 can be more easily shown. Here, the
slit 124 extends from the bottom of the slip component 120 all the
way to the top, where an interconnecting portion 127 holds the
component 120 together around the mandrel 102. Further, as can be
seen in FIGS. 2A-2C, the slip component 120 has a cylindrical body
122 that surrounds the plug 100.
[0043] Also, the slip component 120 comprises insert holes 128 that
contain inserts 130 disposed within them. In this embodiment, the
inserts 130 may be disposed around the cylindrical body 122 of the
slip component 120 in a variety of different ways. For example, the
inserts 130 can be disposed around the cylindrical body 122 in a
way that the inserts 130 are separated by an equal space.
Furthermore, the inserts 130 may be aligned in rows, aligned
diagonally along cylindrical body 122, or any other configuration.
The purpose of the configuration of the inserts 130 around the
cylindrical body 122 is to allow as many inserts 130 as possible to
be disposed therein, while maintaining the structural soundness of
the composite material.
[0044] The slip component 122 is manufactured in a manner similar
to the continuous fiber winding process described in U.S. Pat. No.
7,124,831, which is used for manufacturing plugs and is
incorporated herein by reference. In general, the manufacturing
process involves wet winding a continuous fiber around a temporary
mandrel to form the cylindrical body 122 of the slip component. The
fiber is preferably wound in an overlapping lattice structure. The
resin impregnated fiber is then heated, cured, and cooled so the
cylindrical body 122 can be removed from the temporary mandrel and
machined. The outer and inner diameters of the cylindrical body 122
may be machined to a certain size, tolerance, or smoothness. Also,
any of the various slits 124, holes 128, and the like may be
machined in the cylindrical body 122. These and any other
additional steps available in the art can be used so that slip
component can be installed on the mandrel 102 of the plug 100 with
other components for future deployment in the harsh environment
downhole.
[0045] As show in FIGS. 2A-2C, the holes 128 for the inserts 130
may be arranged in a staggered pattern intended to maintain the
overall strength of the component's material. Thus, any fibers in
the winding making up the body 122 of the component 122 that have
been cut to form one of the holes 128 may be cut elsewhere on the
body 122 to form another of the holes 128. In this way, a number of
fiber windings will remain intact around the body 122 and maintain
the body's overall strength.
[0046] As can be seen in FIG. 2C, the insert holes 128 are not
necessarily disposed parallel to the surface of the slip component
120 itself, although they can be. As will be described in detail
later, the inserts 130 are preferably disposed within or through
the cylindrical body 122 of the slip component 120 at an angle.
This angle allows the inserts to more thoroughly engage the bore
casing (12) in a way that will allow the inserts 130 to provide the
most stability for the slip component 120, and consequently the
bridge plug 100 itself, after the plug 100 has been engaged and has
formed a seal within the casing (12).
[0047] With an understanding of the plug 100 and the disclosed slip
component, discussion turns to further details of the slip
component 120. FIGS. 3A-3C illustrate an end view, a
cross-sectional view, and a perspective view of the disclosed slip
component 120. With respect to FIG. 3A, the end view of the slip
component 120 shows the cylindrical body 122 of the slip component
120. As shown, there are numerous insert holes 128 having the
inserts 130 disposed within them. Furthermore, FIG. 3A shows how
the slip component 120 has at least two slits 124 disposed on
opposite sides of the cylindrical component 120. Consistent within
the present disclosure, there can be at least one or two slits 124
disposed around the cylindrical body 122. More slits are not
preferred, but may be used if desired.
[0048] FIG. 3B shows a cross-sectional view of the slip component
120. As best shown in this view, the slip component 120 contains a
ramp 126 on the inside surface 121 at one end of the cylindrical
body 122. Also, the body 122 has two slits 124 and interconnecting
portions 127. The ramp 126 serves the purpose of easing the
transition of the slip component 120 over the cones (i.e., the ramp
126 allows the slip component 122 to be more easily transitioned
over the outer surface of cones 106a-b on the plug 100 of FIGS.
2A-2C).
[0049] Furthermore, when the slip component 120 is compressed over
its adjacent cone (106a), the slip component 120 will separate
along the slits 127 and will fracture, break, or tear along the
interconnecting portions 127, creating slip element halves (125a-b)
that allow the slip component 120 to expand more efficiently over
the conical surface (107a) of the cone (106a). Due to the material
makeup of the slip component 120 (i.e., continuous fiber winding as
described in U.S. Pat. No. 7,124,831), when the slip component 120
is pushed over the cone (106a), the slip component 120 flexes and
conforms to the larger radius of the casing (12), while the inserts
(130) penetrate the casing (12) and anchor the slip component 120
in place.
[0050] Also, since the slip component 120 is one piece during
running in the hole, and does not comprise independent segments
like a conventional slip assembly of the prior art held together by
bands, the slip component 120 can better withstand the high speeds
and higher fluid velocities encountered during run in the plug 100.
In this regard, allowing the slip component 120 to expand more
efficiently over its cone (106a) will allow the slip component
halves (125a-b) to more succinctly engage the casing (12). In turn,
allowing the slip component 120 to more succinctly engage the
casing (12) will allow the inserts (130) to engage the inner
surface of the casing (12) and provide an anchor for the plug
100.
[0051] FIG. 3C shows a perspective view of the slip component 120.
In this view, the slip component 120 has the cylindrical body 122,
the one or more slits 124, and one or more insert holes 128. As can
be shown in this embodiment, the slits 124 extend from the bottom
of the slip component 120 to the top of the slip component 120.
However, rather than completely separating the cylindrical body
122, the slits 124 preferably stop at the interconnecting portions
127 of the slip component 120. However, the slip component 120 is
not limited to the one or more slits 124 of the slip component 120
having a single interconnecting portion 127. The slip component 120
may further comprise more than one interconnecting portion 127. For
example, an interconnecting portion 127 may be disposed at each end
of the one or more slits 124, forming slot-like formations within
the slip component 120. Therefore, the slip component 120 may
comprise an interconnecting portion 127 at the top of a slit 124
and at the bottom of the slit 124, having the opening for the slit
124 disposed between the two interconnecting portions 127.
[0052] Further, the slit elements 124 can extend from either end of
the slip component 120, and/or extend thru the inner cylindrical
surface (121) with an axial cut that does not penetrate to the
outer surface of the slip component 120.
[0053] Further, in this view, the insert holes 128 are shown
disposed throughout the outer surface of the slip component 120.
Moreover, although this embodiment only shows two slit elements
124, there may be one slit 124 or more slits disposed around the
circumference of the slip component 120.
[0054] The slits 124 are formed to control breakage of the slip
component 120 during expansion. Therefore, the depth, the length,
the width, and any other characteristics of the slits 124 can be
varied depending on the strength of the composite material used,
the expected forces encountered during expansion, and other
factors. As shown here, the slits 124 are formed on opposite sides
of the cylindrical body 122 and extend from a distal end to almost
a proximal end of the component 120 adjacent the push ring 105. The
slits 124 are defined completely through the thickness of the
cylindrical body 122, although this may not be strictly necessary.
Additionally, more of the slit 124 may be formed on the outside of
the body 122 than the inside so that the interconnecting portions
127 have a triangular cross-section as shown in FIG. 3B. The
interconnecting portions 127 may have many different shapes, but
preferably has a similar triangular cross-sectional area). Overall,
the slits 124 in this arrangement may be configured to control
breakage at about 3,000 to 5,000 lbs.
[0055] FIG. 3D is a detailed view of one of the insert holes 128 of
the disclosed slip component 120. As shown, the insert hole 128 is
disposed within the outer surface of the slip component 120 at a
depth D. As described above, the depth D may extend all the way
through the outer surface of the slip component 120, or may only
extend partially through the slip component 120.
[0056] Also, the insert hole 128 may be disposed within the outer
surface of the slip component 120 at an angle .theta.. The purpose
of disposing inserts 130 at an angle .theta. is so that when the
plug 100 is activated and the slip component 120 is expanded
outward and fractured into halves (125a-b) contacting the casing
(12) of the bore, the inserts 130 within the slip component halves
(125a-b) will engage the casing (12) at an angle to ensure maximum
stability of the plug 100 as it is sealed within the casing
(12).
[0057] FIGS. 4A-4B schematically illustrate the disclosed slip
component 120 in different engagements with the surrounding casing
12 during operation. Depending on the number of slits 124 and the
arrangement of the slits 124 within the slip component 120, there
may be many different ways that the slip component 120, or slip
component halves (125a-b) may engage the casing 12.
[0058] Referring first to FIG. 4A, the slip component 120 is
disposed within casing 12. This end view of the casing 12 shows an
example of how the slip component 120 engages the casing 12 after
the slip component 120 has been compressed over the conical surface
of its adjacent cone (e.g., 106a). As shown, when the slip
component 120 is compressed over the conical surface of the cone
(106a), the outer surface of each slip component halve 125a-b will
engage the casing 12, causing inserts 130 to engage the casing
12.
[0059] As previously described, this engagement of the inserts 130
within the casing 12 provides stability for the plug 100 while in
the bore. Further, as can be seen in FIG. 4A, it is possible that
the slip component halves 125a-b may not fully engage the casing
12. However, FIG. 4A shows that even if the slip component halves
125a-b do not fully engage the casing (12), the majority of the
inserts 130 will still engage the casing 12. However, there may be
many different variations of the engagement of the slip component
120 inserts 130 with the casing 12.
[0060] Referring to FIG. 4B, the slip component halves 125a-b have
fully engaged the casing 12 after the slip component 120 has been
compressed over its adjacent cone 106a. In this example, each of
the inserts 130 have fully engaged the inner surface of the casing
12 in order to provide a flush connection with the casing 12. As
further shown in FIG. 4B, the slip component 120 is fully fractured
and expanded in order to provide adequate separation in order for
the slip component halves 125a-b to fully engage the casing 12.
Again, as described above, after the slip component 120 has shifted
over the conical surface (107a) of the adjacent cone (106a), the
slip component 120 will fracture or separate at the slits 124.
[0061] In the previous embodiment, only the uphole assembly 104a on
the plug 100 included the disclosed slip component 120. This is not
strictly necessary as will be appreciated herein. For example, FIG.
5 illustrates an elevational view of another plug 100 having two
composite slip components 120 according to the present disclosure.
As before, the plug 100 includes a mandrel 102 with the composite
slip components 120 of the present disclosure disposed thereon. In
this embodiment, the slip components 120 are disposed both at the
upper end of plug 100 and at the lower end. In this embodiment,
each of the slip components 120a-b also have slits 124 on either
side. Also, the slip components 120a-b have insert holes 128
disposed around the surface as well as inserts 130 disposed within
these holes 128.
[0062] In operation, the composite slip components 120a-b will
shift over the conical surfaces 107a-b of the adjacent cones 106a-b
until the slip components 120a-b expand, fracture, and fully engage
the casing (12). Further as shown in FIG. 5, the conical surfaces
107a-b may have either a smooth conical surface (e.g., as shown by
surface 107a) or may a series of flat surface (e.g., as shown by
cone 107b). Either way, conical surfaces 107a-b serve similar
purposes, i.e., to allow the slip components 120a-b to transition
smoothly, expand, fracture, and engage the inner surface of the
casing 12. Furthermore, as previously described, when plug 100 is
actuated, the packing element 109 will expand and create a pressure
seal within the casing 12.
[0063] In previous embodiments, the slip component 120 includes at
least two slits 124, although other configurations are possible.
For example, FIGS. 6A-6C illustrate an end view, a cross-sectional
view, and a perspective view of another composite slip component
120 according to the present disclosure. As described above, the
slip component 120 has a cylindrical body 122 with multiple insert
holes 128 defined within its outer surface on a portion of its
inner cylindrical surface 121. In this embodiment, it can be seen
that slip component 120 only has one slit 124.
[0064] FIG. 6B shows a cross-sectional view of the slip component
120. As shown in this view, the slip component 120 includes the
ramp 126 on the inner cylindrical surface 121. Functionality, the
ramp 126 provides the slip component 120 an easier transition over
the cones (106a-b) of plug (100). Further, FIG. 6B shows that the
slip component 120 contains the insert holes 128 within the outer
surface. The insert holes 128 can be disposed throughout the
surface of the slip component 120 in a variety of different
arrangements, depths, and or angles. Also, as described above, the
insert holes 128 can have inserts (130) disposed within.
[0065] In reference to FIG. 6D, the slip component 120 is shown
expanded within the casing 12, and has fully engaged the inner
surface of the casing 12. In this embodiment, the one slit 124 on
the cylindrical body 122 has fractured, allowing the slip component
120 to completely expand within the casing 12. As previously
described, this is the result of the slip component 120 being
compressed over the adjacent cone (106a-b) of plug 100. As seen,
the outer cylindrical surface of the body 122 has fully engaged the
casing 12, and each of the inserts 130 have been disposed against
the casing 12.
[0066] The foregoing description of preferred and other embodiments
is not intended to limit or restrict the scope or applicability of
the inventive concepts conceived of by the Applicants. It will be
appreciated with the benefit of the present disclosure that
features described above in accordance with any embodiment or
aspect of the disclosed subject matter can be utilized, either
alone or in combination, with any other described feature, in any
other embodiment or aspect of the disclosed subject matter.
[0067] In exchange for disclosing the inventive concepts contained
herein, the Applicants desire all patent rights afforded by the
appended claims. Therefore, it is intended that the appended claims
include all modifications and alterations to the full extent that
they come within the scope of the following claims or the
equivalents thereof.
* * * * *