U.S. patent application number 15/175336 was filed with the patent office on 2016-12-22 for rotating backup system for packer elements used in non-retrievable applications.
The applicant listed for this patent is Parker-Hannifin Corporation. Invention is credited to Mason Dane Morehead, Philip Thomas.
Application Number | 20160369586 15/175336 |
Document ID | / |
Family ID | 57575352 |
Filed Date | 2016-12-22 |
United States Patent
Application |
20160369586 |
Kind Code |
A1 |
Morehead; Mason Dane ; et
al. |
December 22, 2016 |
ROTATING BACKUP SYSTEM FOR PACKER ELEMENTS USED IN NON-RETRIEVABLE
APPLICATIONS
Abstract
A packer element assembly includes an annular sealing element
having inner and outer sides, wherein the sealing element is
axially compressible from a first position to a set position, and
first and second backup rings located on opposite ends of the
sealing element. When the sealing element is axially compressed to
the set position, the sealing element expands radially, and the
backup rings rotate relative to the sealing element. A setting
method may include locating the packer element assembly within a
well casing bore, and axially compressing the packer element
assembly to the set position. The sealing element expands radially
such that the outer side of the sealing element expands against the
well casing bore and the backup rings are rotated relative to the
sealing element to eliminate a gap between a mandrel and the
sealing element, thereby preventing extrusion of the sealing
element along both inner and outer sides.
Inventors: |
Morehead; Mason Dane;
(Spartanburg, SC) ; Thomas; Philip; (Greenville,
SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Parker-Hannifin Corporation |
Cleveland |
OH |
US |
|
|
Family ID: |
57575352 |
Appl. No.: |
15/175336 |
Filed: |
June 7, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62181566 |
Jun 18, 2015 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 33/1216 20130101;
E21B 33/128 20130101; E21B 43/26 20130101 |
International
Class: |
E21B 33/128 20060101
E21B033/128 |
Claims
1. A packer element assembly comprising: an annular sealing element
having an inner side and an outer side, and the sealing element is
axially compressible from a first position to a set position; and
first and second backup rings located on opposite ends of the
sealing element; wherein, when the sealing element is axially
compressed from the first position to the set position, the sealing
element expands radially, and the backup rings rotate relative to
the sealing element to prevent axial extrusion of the sealing
element at both the inner side and the outer side in the set
position.
2. The packer element assembly of claim 1, wherein each backup ring
has a cross-sectional face such that when the first and second
backup rings rotate to the set position, the cross-sectional face
is configured to prevent axial extrusion of the sealing element at
both the inner side and the outer side.
3. The packer element assembly of claim 2, wherein the
cross-sectional face comprises an upper side, a first slope that is
sloped with a first angle relative to the upper side, a second
slope that is sloped with a second angle relative to the upper
side, and a chamfered end opposite the upper side.
4. The packer element assembly of claim 3, wherein the first angle
of the first slope is greater than the second angle of the second
slope.
5. The packer element assembly of claim 3, wherein in the set
position, a chamfer of each chamfered end compresses against the
sealing element adjacent the inner side of the sealing element.
6. The packer element assembly of claim 1, wherein the backup rings
are made of a thermoplastic material.
7. The packer element assembly of claim 6, wherein the backup rings
are made of one of a polyaryletherketone, polytetrafluoroethylne,
or polyamide-imide material.
8. The packer element assembly of claim 1, wherein the backup rings
are made of one of brass, bronze, or aluminum.
9. The packer element assembly of claim 1, wherein the sealing
element is made of an elastomeric material.
10. The packer element assembly of claim 1, further comprising a
mandrel positioned on the inner side of the sealing element.
11. The packer element assembly of claims 10, further comprising a
first setting cone located around the mandrel on a down hole side
of the sealing element, and a second setting cone located around
the mandrel on an up hole side of the setting element, wherein the
second setting cone is moveable from the up hole side toward the
down hole side to axially compress the sealing element from the
first position to the set position.
12. A method of setting a packer element assembly comprising the
steps of: locating a packer element assembly at a desired position
within a well casing bore, the packer element assembly comprising
an annular sealing element having an inner side and an outer side,
and first and second backup rings located on opposite ends of the
sealing element; axially compressing the packer element assembly to
a set position, wherein the sealing element expands radially such
that the outer side of the sealing element expands against the well
casing bore; and wherein upon axially compressing the sealing
element to the set position, the backup rings rotate relative to
the sealing element to eliminate a first gap between the well
casing and the outer side of the sealing element, thereby
preventing extrusion of the sealing element along the well
casing.
13. The setting method of claim 12, wherein the packer element
assembly further comprises a mandrel positioned on the inner side
of the sealing element, wherein upon axially compressing the
sealing element, the rotating of the backup rings relative to the
sealing element further eliminates a second gap between the mandrel
and the inner side of the sealing element, thereby preventing
extrusion of the sealing element along the mandrel.
14. The setting method of claim 13, wherein the packer element
assembly further comprises a first setting cone located around the
mandrel on a down hole side of the sealing element, and a second
setting cone located around the mandrel on an up hole side of the
setting element; and the setting method further comprising moving
the second setting cone from the up hole side toward the down hole
side to axially compress the sealing element from the first
position to the set position.
15. The setting method of claim 12, wherein the packer element
assembly is compressed from an up hole side of the well casing
toward a down hole side of the well casing.
16. The setting method of claim 12, wherein the backup rings each
has a chamfered end, and when the backup rings rotate a chamfer of
each chamfered end compresses against the sealing element adjacent
the inner side of sealing element.
Description
FIELD OF INVENTION
[0001] The present invention relates to packer elements used in
sealing segments of drilling operations, such as down hole seals
used in oil and gas hydraulic fracturing systems, and more
particularly to backup components for such sealing assemblies.
BACKGROUND OF THE INVENTION
[0002] In oil and gas drilling operations, a variety of down hole
tools are used for the manufacturing, operation, and maintenance of
such drilling systems. One example of a down hole tool is a plug
seal or packer element assembly, which can be used to seal and
isolate certain portions of a drilled well from other portions of
the well. A sealing plug that fully isolates one well portion
(e.g., a down hole portion) from another well portion (e.g., an up
hole portion), wholly blocking flow between the two portions, is
commonly referred to as a bridge plug. Other types of plug seals
may allow flow in a particular direction (e.g., downstream), but
block flow in other directions (e.g., upstream). Plug seals may be
permanent, or may be non-permanent dissolving or otherwise
removable plug seals.
[0003] Hydraulic fracturing (commonly referred to as "fraccing" or
"Tracking") is becoming a common method of oil and gas drilling,
which may employ packer element assemblies or plug seals to isolate
different portions of a well. For example, a plug seal or packer
element assembly may be located within an outer well casing so as
to isolate a down hole portion of a well from an up hole portion of
the well. In the up hole portion, the well casing may include a
plurality of transverse holes that open into a surrounding rock
formation. In the hydraulic fracturing process, pressurized fluid
is pumped down into the well. At the packer element assembly, flow
is blocked from proceeding from the up hole portion into the down
hole portion, pressurizing the well. Under such pressure, the fluid
is forced through the holes in the up hole well casing into the
adjacent rock formation. The pressurized flow into the rock
formation in turn creates cracks through which oil and gas may be
extracted.
[0004] Conventional packer element assemblies, however, have proven
to be deficient in certain respects. In typical assembly
configurations, an inner mandrel operates to isolate segments of
the drilling operation within a bore defined by an outer well
casing. A packer element assembly includes a rubber-type sealing
element, which expands under an axial setting pressure to provide a
seal between the mandrel and the well casing. Under the high
pressure, the sealing material of the packer element assembly can
extrude along the well casing, and/or along the mandrel, which can
damage the seal material and undermine the sealing efficacy.
Accordingly, backup systems are provided to prevent extrusion of
the sealing material. It has proven difficult, however, to provide
a backup system that functions effectively under the extreme
conditions of high pressure drilling operations.
SUMMARY OF THE INVENTION
[0005] The present invention generally is directed to a backup
system to resist extrusion of a packer element assembly. Packer
element assemblies typically may be configured as cylindrical
assemblies that are used for down hole isolation, and typically
include one or multiple rubber elements that expand to seal the
annulus between the packer mandrel and the well bore of the well
casing. This expansion occurs during the axial setting of the
packer element assembly. Pressure from hydraulic fracturing can
then occur. For higher pressure applications, backup rings may be
installed on both ends of the sealing element to resist rubber
extrusion due to high pressures. The ultimate goal of a backup ring
is to fully close the annulus gap between the mandrel and the well
bore so that no rubber of the sealing element can extrude through
the annulus. The present invention thus provides a continuous,
semi-rigid backup ring system that is able to rotate during the
packer setting process, and once set substantially precludes
extrusion of the sealing element.
[0006] More particularly, once set, the backup system will
completely fill the annulus gap between the mandrel and the well
bore, including gap portions of the annulus both along the well
casing and along the mandrel. This is performed via a specifically
configured geometry that once rotated, prevents sealing element
extrusion both over and under the backup ring, thus completely
encasing the sealing element. The backup ring material generally
should be relatively soft enough to fully rotate, yet sufficiently
rigid and strong enough to hold and perform the backup function
under high temperatures and pressures. To achieve such
characteristics, the backup ring may be manufactured from numerous
thermoplastsic materials including polyaryletherketones (e.g., PEEK
or PAEK), polytetrafluoroethylne (PTFE), polyamide-imide (PAI), and
like materials. Softer metals may also be used, including brass,
bronze, aluminum, and like materials.
[0007] An aspect of the invention is a packer element assembly. In
exemplary embodiments, the packer element assembly may include an
annular sealing element having an inner side and an outer side,
wherein the sealing element is axially compressible from a first
position to a set position, and first and second backup rings
located on opposite ends of the sealing element. When the sealing
element is axially compressed from the first position to the set
position, the sealing element expands radially, and the backup
rings rotate relative to the sealing element to prevent axial
extrusion of the sealing element at both the inner side and the
outer side in the set position. Each backup ring may have a
cross-sectional face such that when the first and second backup
rings rotate to the set position, the cross-sectional face is
configured to prevent axial extrusion of the sealing element at
both the inner side and the outer side.
[0008] Another aspect of the invention is a method of setting a
packer element assembly. In exemplary embodiments, the setting
method may include the steps of: locating a packer element assembly
at a desired position within a well casing bore, the packer element
assembly comprising an annular sealing element having an inner side
and an outer side, and first and second backup rings located on
opposite ends of the sealing element; axially compressing the
packer element assembly to a set position, wherein the sealing
element expands radially such that the outer side of the sealing
element expands against the well casing bore; and wherein upon
axially compressing the sealing element to the set position, the
backup rings rotate relative to the sealing element to eliminate a
first gap between the well casing and the outer side of the sealing
element and a second gap between the mandrel and the inner side of
the sealing element, thereby preventing extrusion of the sealing
element along the well casing and mandrel.
[0009] These and further features of the present invention will be
apparent with reference to the following description and attached
drawings. In the description and drawings, particular embodiments
of the invention have been disclosed in detail as being indicative
of some of the ways in which the principles of the invention may be
employed, but it is understood that the invention is not limited
correspondingly in scope. Rather, the invention includes all
changes, modifications and equivalents coming within the spirit and
terms of the claims appended hereto. Features that are described
and/or illustrated with respect to one embodiment may be used in
the same way or in a similar way in one or more other embodiments
and/or in combination with or instead of the features of the other
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a drawing depicting a side view of a packer
element assembly in accordance with embodiments of the present
invention.
[0011] FIG. 2 is a drawing depicting a cross-sectional view of the
packer element assembly of FIG. 1.
[0012] FIGS. 3 is a drawing depicting a top view of one of the
backup rings for use in a packer element assembly in accordance
with embodiments of the present invention.
[0013] FIG. 4 is a drawing depicting a cross-sectional view of the
backup ring of FIG. 3.
[0014] FIG. 5 is a drawing depicting a close-up view of the
cross-section of the backup ring of FIGS. 3 and 4.
[0015] FIG. 6 is a drawing depicting a side view of an exemplary
packer element assembly in the unset position relative to a well
casing and mandrel in accordance with embodiments of the present
position.
[0016] FIG. 7 is a drawing depicting a side view of the packer
element assembly of FIG. 6 in the set position.
[0017] FIG. 8 is a drawing depicting an isometric view of an
exemplary packer element assembly in the unset position.
[0018] FIG. 9 is a drawing depicting an isometric view of the
packer element assembly of FIG. 8 in the set position.
DETAILED DESCRIPTION
[0019] Embodiments of the present invention will now be described
with reference to the drawings, wherein like reference numerals are
used to refer to like elements throughout. It will be understood
that the figures are not necessarily to scale.
[0020] FIG. 1 is a drawing depicting a packer element assembly 10
in accordance with embodiments of the present invention, and FIG. 2
is a cross-sectional view of the packer element assembly 10 of FIG.
1. In these figures, the packer element assembly 10 is depicted in
the unset configuration. The packer element assembly may have a
generally cylindrical configuration so as to act as a plug seal to
isolate different portions of an oil or gas well, and thus the
packer element assembly may be positioned within commensurately
cylindrical portions of a well casing. Generally, the packer
element assembly may include an annular sealing element having an
inner side and an outer side, and the sealing element is axially
compressible from a first (unset) position to a set position, and
first and second backup rings located on opposite ends of the
sealing element. As further detailed below, when the sealing
element is axially compressed from the first position to the set
position, the sealing element expands radially, and the backup
rings rotate relative to the sealing element to prevent axial
extrusion of the sealing element at both the inner side and the
outer side in the set position.
[0021] Referring to the example of FIGS. 1 and 2, the packer
element assembly 10 may include an annular packer sealing element
12 that acts as an elastomeric sealing element between a mandrel
and a well casing bore (not shown in these figures), and thus is
made of a rubber-like, elastomeric material as are known in the art
for sealing in down hole drilling operations. The sealing element
has an inner side 11, which is the inner surface shown in the
cross-sectional view of FIG. 2, that interfaces with an outer
diameter of a mandrel. The sealing element further has an outer
side 13, which is the outer surface shown in the side view of FIG.
1, that interfaces with the inner diameter of a well casing. The
packer element assembly 10 further includes opposing backup rings
14 and 15 on opposite ends of the sealing element, which provide
the backup function that prevents the packer element sealing
material from extruding along the well casing or along the mandrel
when the packer element assembly is in the set position.
[0022] FIGS. 3-5 are schematic diagrams depicting various views of
one of the backup rings 14 (or 15) in accordance with embodiments
of the present invention. FIG. 3 is a drawing depicting a top view
of one of such backup rings. As seen in the view of FIG. 3, the
backup ring 14 has a ring configuration so as to encircle an end of
the sealing element as seen in FIGS. 1 and 2. It will be
appreciated that the second backup ring 15 would be configured with
a comparable ring structure as the first backup ring 14.
[0023] FIG. 4 is a drawing depicting a cross-sectional view of the
backup ring 14 of FIG. 3, and FIG. 5 is a drawing depicting a
close-up view of an end portion of the backup ring. FIG. 4, and
more particularly the close-up view of FIG. 5, illustrate the
geometry of an exemplary backup ring cross-section 16. It similarly
will be appreciated that the second backup ring 15 would be
configured with a comparable cross-sectional configuration as the
first backup ring 14. Generally, each backup ring may have a
cross-sectional face such that when the first and second backup
rings rotate to the set position, the cross-sectional face is
configured to prevent axial extrusion of the sealing element at
both the inner side and the outer side. The backup ring material
generally should be relatively soft enough to fully rotate, yet
sufficiently rigid and strong enough to hold and perform the backup
function under high temperatures and pressures. To achieve such
characteristics, the backup ring may be manufactured from any of
numerous thermoplastsic materials including polyaryletherketones
(e.g., PEEK or PAEK), polytetrafluoroethylne (PTFE),
polyamide-imide (PAI), and like materials. Softer metals may also
be used, including brass, bronze, aluminum, and like materials.
[0024] Referring most readily to FIG. 5, the geometry of the
cross-section 16 may include an upper side 18, and a first slope 20
that is sloped with a first angle A relative to the upper side 18,
and a second slope 22 that is sloped with a second angle B relative
to the upper side 18. In exemplary embodiments, the first angle A
of the first slope is greater than the second angle B of the second
slope. The slopes are configured to define a chamfered end 24
opposite from the upper side 18, and specifically having a chamfer
26. As further explained below, the geometry of the backup ring
cross-section is configured to permit the backup ring 14 to rotate
relative to the packer sealing element 12 during setting to provide
an effective backup function to enhance the efficacy of the seal.
In the set position, the chamfer 26 of each chamfered end 24 of the
backup rings compresses against the sealing element adjacent the
inner side of the sealing element. The direction of rotation of
opposing backup rings is shown in the arrows of FIGS. 4 and 5.
[0025] FIG. 6 is a drawing depicting a side view of an exemplary
packer element assembly 10 in a first or unset position relative to
a well casing 28 in accordance with embodiments of the present
position. Reference numeral 30 represents the inner surface of the
well casing 28 that defines the bore in which the packer element
assembly 10 is utilized. Opposite to the well casing 28, the packer
assembly 10 interacts against a mandrel 31. Reference numeral 32
represents an outer face of the mandrel 31 used with the packer
element assembly 10.
[0026] Elements 34 and 36 represent opposing setting tool elements,
such as opposing first and second setting cones that may be used to
set the packer element assembly 10. The first setting cone 34 and
the second setting cone 36 are generally ring structures that are
located in the space 37 between the mandrel and the well casing
comparably as the packer element assembly, and the setting cones
particularly may be located around and against the mandrel spaced
inwardly from the inner surface of the well casing. For example the
first setting cone 34 may be located around the mandrel on a down
hole side of the sealing element, and the second setting cone nay
be located around the mandrel on an up hole side of the setting
element. As further detailed below, the second setting cone may be
moveable from the up hole side toward the down hole side to axially
compress the sealing element from the first or unset position to
the set position. In addition, as seen in FIG. 5, in the
first/unset position there is a first annulus or gap 38 between the
packer sealing element 12 and the well casing inner surface 30, and
a second annulus or gap 40 between the backup rings 14 and 15 and
the mandrel outer surface 32. During setting, the backup rings 14
and 15 rotate in the direction of the arrows depicted in FIG. 6.
The rotation of the backup rings closes the gaps 38 and 40 as shown
in FIG. 7.
[0027] FIG. 7 is a drawing thus depicting a side view of the packer
element assembly 10 in the set position relative to the well casing
28 and mandrel 31. As indicated in FIG. 7, in exemplary embodiments
the packer element assembly 10 is set from the up hole side 42 (the
right side in the depiction of FIGS. 6 and 7 as oriented) by
compression of the packer assembly towards the down hole side 44
(the left side in the depiction of FIGS. 6 and 7 as oriented). In
other words, the setting cone 36 is moved down hole towards setting
cone 34, which compresses the packer element assembly 10 in the
axial direction. The axial compression causes the packer sealing
element 12 to expand radially against the well casing. In addition,
the backup rings 14 and 15 rotate in the directions shown by the
arrows in FIG. 6 relative to the sealing element to the set
position shown in FIG. 7, which prevents axial extrusion of the
sealing material at either the inner side or outer side of the
sealing element 12. In particular, as a result of the rotation, the
closing of the gap 38 includes elimination of such gap between the
well casing and the backup rings. In addition, the rotation at the
chamfered ends 24 results in the chamfer 26 pressing against and
compressing the sealing element 12. The result is a further closing
of the gap 40 between the backup rings and the mandrel. With such a
gapless configuration upon setting on both sides of the sealing
element, an effective seal is maintained with enhanced backup
functioning that prevents the material of the sealing element 12
from extruding along either the well casing or the mandrel. More
specifically, such axial extrusion is precluded both along the well
casing at the outer side of the sealing element, and along the
mandrel at the inner side of the sealing element, as the rings 14
and 15 have rotated to close both gaps as between the backup rings
and the mandrel and well casing.
[0028] FIGS. 8 and 9 are drawings that depict additional isometric
views of the packer element assembly 10 in the unset (FIG. 8) and
set (FIG. 9) positions. The well casing has been removed from FIGS.
8 and 9 for an enhanced view of the packer assembly as the packer
assembly is moved between the set and unset positions. FIGS. 8 and
9 further illustrate a method of setting a packer element assembly
in accordance with embodiments of the present invention. The
setting method generally may include locating the packer element
assembly within a well casing bore, and axially compressing the
packer element assembly from the first/unset position to the set
position. During such compression, the sealing element expands
radially such that the outer side of the sealing element expands
against the well casing bore to eliminate the first gap between the
sealing element and the well casing bore, and the backup rings are
rotated relative to the sealing element to eliminate the second gap
between the mandrel and the sealing element. In this manner, the
setting of the packer element assembly prevents extrusion of the
sealing element along both the inner side against the mandrel and
the outer side against the well casing bore.
[0029] The progression of FIG. 8 to FIG. 9 shows the setting of the
packer element assembly 10 between the first and second setting
cones 34 and 36. As referenced above, setting typically is
performed by axial compression from the up hole side (the top in
the depiction of FIGS. 8 and 9 as oriented) by compression of the
packer assembly towards the down hole side 44 (the bottom in the
depiction of FIGS. 8 and 9 as oriented). FIG. 9 further shows how
the backup rings 14 and 15 have rotated relative to the sealing
element 12. Once the packer element assembly is set, the setting
cones typically will remain down hole in such set positions. An
optional ratchet mechanism may be employed to prevent the setting
cones from sliding out from the set position.
[0030] With the configuration of the present invention, the backup
rings may be singular, continuous, and homogeneous. There is no
need to provide notches, segments, grooves, or like structures in
the backup rings as are typical in conventional backup systems, and
thus the backup rings of the present invention are less complex to
manufacture. In addition, the thermoplastic materials of the backup
rings are less costly and easier to manufacture as compared to
conventional backup rings, and the materials are highly millable as
compared to conventional backup ring materials which can provide
for easier removal should removal become necessary. The backup ring
positioning once set is highly stable and gapless on both the well
casing and mandrel sides to prevent any axial extrusion of the
sealing element material. In addition, the rotation provides
effective backup performance, but the slight nature of the rotation
is such that the seal is energized with less stress on the assembly
components as compared to conventional configurations. This
reduction of stress may prolong the useful life the sealing element
material.
[0031] An aspect of the invention, therefore, is a packer element
assembly. In exemplary embodiments, the packer element assembly
includes an annular sealing element having an inner side and an
outer side, and the sealing element is axially compressible from a
first position to a set position, and first and second backup rings
located on opposite ends of the sealing element. When the sealing
element is axially compressed from the first position to the set
position, the sealing element expands radially, and the backup
rings rotate relative to the sealing element to prevent axial
extrusion of the sealing element at both the inner side and the
outer side in the set position. The packer element assembly may
include one or more of the following features, either individually
or in combination.
[0032] In an exemplary embodiment of the packer element assembly,
each backup ring has a cross-sectional face such that when the
first and second backup rings rotate to the set position, the
cross-sectional face is configured to prevent axial extrusion of
the sealing element at both the inner side and the outer side.
[0033] In an exemplary embodiment of the packer element assembly,
the cross-sectional face comprises an upper side, a first slope
that is sloped with a first angle relative to the upper side, a
second slope that is sloped with a second angle relative to the
upper side, and a chamfered end opposite the upper side.
[0034] In an exemplary embodiment of the packer element assembly,
the first angle of the first slope is greater than the second angle
of the second slope.
[0035] In an exemplary embodiment of the packer element assembly,
in the set position, a chamfer of each chamfered end compresses
against the sealing element adjacent the inner side of the sealing
element.
[0036] In an exemplary embodiment of the packer element assembly,
the backup rings are made of a thermoplastic material.
[0037] In an exemplary embodiment of the packer element assembly,
the backup rings are made of one of a polyaryletherketone,
polytetrafluoroethylne, or polyamide-imide material.
[0038] In an exemplary embodiment of the packer element assembly,
the backup rings are made of one of brass, bronze, or aluminum.
[0039] In an exemplary embodiment of the packer element assembly,
the sealing element is made of an elastomeric material.
[0040] In an exemplary embodiment of the packer element assembly,
the assembly further includes a mandrel positioned on the inner
side of the sealing element.
[0041] In an exemplary embodiment of the packer element assembly,
the assembly further includes a first setting cone located around
the mandrel on a down hole side of the sealing element, and a
second setting cone located around the mandrel on an up hole side
of the setting element, wherein the second setting cone is moveable
from the up hole side toward the down hole side to axially compress
the sealing element from the first position to the set
position.
[0042] Another aspect of the invention is a method of setting a
packer element assembly. In exemplary embodiments, the setting
method includes the steps of: locating a packer element assembly at
a desired position within a well casing bore, the packer element
assembly comprising an annular sealing element having an inner side
and an outer side, and first and second backup rings located on
opposite ends of the sealing element; axially compressing the
packer element assembly to a set position, wherein the sealing
element expands radially such that the outer side of the sealing
element expands against the well casing bore; and wherein upon
axially compressing the sealing element to the set position, the
backup rings rotate relative to the sealing element to eliminate a
first gap between the well casing and the outer side of the sealing
element, thereby preventing extrusion of the sealing element along
the well casing. The setting method may include one or more of the
following features, either individually or in combination.
[0043] In an exemplary embodiment of the setting method, the packer
element assembly further comprises a mandrel positioned on the
inner side of the sealing element, wherein upon axially compressing
the sealing element, the rotating of the backup rings relative to
the sealing element further eliminates a second gap between the
mandrel and the inner side of the sealing element, thereby
preventing extrusion of the sealing element along the mandrel.
[0044] In an exemplary embodiment of the setting method, the packer
element assembly further comprises a first setting cone located
around the mandrel on a down hole side of the sealing element, and
a second setting cone located around the mandrel on an up hole side
of the setting element; and the setting method further comprising
moving the second setting cone from the up hole side toward the
down hole side to axially compress the sealing element from the
first position to the set position.
[0045] In an exemplary embodiment of the setting method, the packer
element assembly is compressed from an up hole side of the well
casing toward a down hole side of the well casing.
[0046] In an exemplary embodiment of the setting method, the backup
rings each has a chamfered end, and when the backup rings rotate a
chamfer of each chamfered end compresses against the sealing
element adjacent the inner side of sealing element.
[0047] Although the invention has been shown and described with
respect to a certain embodiment or embodiments, it is obvious that
equivalent alterations and modifications will occur to others
skilled in the art upon the reading and understanding of this
specification and the annexed drawings. In particular regard to the
various functions performed by the above described elements
(components, assemblies, devices, compositions, etc.), the terms
(including a reference to a "means") used to describe such elements
are intended to correspond, unless otherwise indicated, to any
element which performs the specified function of the described
element (i.e., that is functionally equivalent), even though not
structurally equivalent to the disclosed structure which performs
the function in the herein illustrated exemplary embodiment or
embodiments of the invention. In addition, while a particular
feature of the invention may have been described above with respect
to only one or more of several illustrated embodiments, such
feature may be combined with one or more other features of the
other embodiments, as may be desired and advantageous for any given
or particular application.
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