U.S. patent application number 12/255176 was filed with the patent office on 2010-04-22 for well systems and associated methods incorporating fluid loss control.
This patent application is currently assigned to HALLIBURTON ENERGY SERVICES, INC.. Invention is credited to Shane M. Adams, Darren R. Barlow, Justin A. Dowden, William D. Henderson, Thomas Roane, Jimmie R. Williamson.
Application Number | 20100096134 12/255176 |
Document ID | / |
Family ID | 42107710 |
Filed Date | 2010-04-22 |
United States Patent
Application |
20100096134 |
Kind Code |
A1 |
Barlow; Darren R. ; et
al. |
April 22, 2010 |
Well Systems and Associated Methods Incorporating Fluid Loss
Control
Abstract
A method of controlling fluid loss from a wellbore comprises the
steps of: installing a completion string including a well screen
and a fluid loss control device in the wellbore; then installing a
production string in the wellbore; then engaging the production
string with the completion string; and then operating the fluid
loss control device by varying pressure in a fluid passage. A well
system comprises a completion string including a fluid loss control
device, a packer and a well screen, the packer being positioned
between the fluid loss control device and the screen; and a
production string including another packer and engaged with the
completion string, the fluid loss control device being positioned
longitudinally between the packers, and the fluid loss control
device being operable in response to variation of pressure in a
fluid passage.
Inventors: |
Barlow; Darren R.; (Houston,
TX) ; Dowden; Justin A.; (Houma, LA) ; Adams;
Shane M.; (Houma, LA) ; Henderson; William D.;
(Tioga, TX) ; Williamson; Jimmie R.; (Carrollton,
TX) ; Roane; Thomas; (Alvord, TX) |
Correspondence
Address: |
SMITH IP SERVICES, P.C.
P.O. Box 997
Rockwall
TX
75087
US
|
Assignee: |
HALLIBURTON ENERGY SERVICES,
INC.
Carrollton
TX
|
Family ID: |
42107710 |
Appl. No.: |
12/255176 |
Filed: |
October 21, 2008 |
Current U.S.
Class: |
166/292 ;
166/374 |
Current CPC
Class: |
E21B 43/04 20130101;
E21B 2200/04 20200501; E21B 34/10 20130101 |
Class at
Publication: |
166/292 ;
166/374 |
International
Class: |
E21B 34/10 20060101
E21B034/10; E21B 33/13 20060101 E21B033/13 |
Claims
1. A method of controlling fluid loss from a wellbore, the method
comprising the steps of: installing a completion string in the
wellbore, the completion string including a well screen and a fluid
loss control device; then installing a production string in the
wellbore; then engaging the production string with the completion
string; and then operating the fluid loss control device by varying
pressure in a fluid passage.
2. The method of claim 1, wherein in the operating step, the fluid
passage comprises a first annulus formed between the wellbore and
the production string.
3. The method of claim 2, wherein the operating step further
comprises increasing pressure in the first annulus to thereby close
the fluid loss control device.
4. The method of claim 2, wherein the engaging step further
comprises inserting the production string within the completion
string, thereby placing an actuator of the fluid loss control
device in fluid communication with the first annulus via a second
annulus formed between the production string and the completion
string.
5. The method of claim 2, wherein in the engaging step, a packer of
the completion string is positioned longitudinally between the
fluid loss control device and the screen.
6. The method of claim 5, wherein the production string includes a
packer, and wherein the engaging step further comprises making a
hydraulic wet connect connection between the fluid loss control
device on a first side of the production string packer and the
first annulus on an opposite second side of the production string
packer.
7. The method of claim 1, wherein the operating step further
comprises closing the fluid loss control device after the fluid
loss control device is opened.
8. The method of claim 1, wherein in the operating step, the fluid
passage comprises a conduit.
9. A well system for use in a wellbore, the system comprising: a
completion string including a fluid loss control device, a first
packer and a well screen, the first packer being positioned
longitudinally between the fluid loss control device and the well
screen; and a production string engaged with the completion string,
the production string including a second packer, wherein the fluid
loss control device is positioned longitudinally between the first
and second packers, and wherein the fluid loss control device is
operable in response to variation of pressure in a fluid
passage.
10. The system of claim 9, wherein the passage comprises a
conduit.
11. The system of claim 9, wherein the passage comprises an annulus
formed between the wellbore and the production string.
12. The system of claim 9, wherein the second packer is positioned
longitudinally between the annulus and the hydraulic wet
connect.
13. The system of claim 9, further comprising a latching device
which releasably secures the production and completion strings, the
latching device being positioned longitudinally between the fluid
loss control device and the second packer.
14. The system of claim 9, further comprising a latching device
which releasably secures the production and completion strings, the
latching device being positioned longitudinally between the fluid
loss control device and the first packer.
15. The system of claim 9, wherein the fluid loss control device is
closable in response to variation of pressure in the passage.
16. The system of claim 15, wherein the fluid loss control device
is openable in response to variation of pressure in an interior
flow passage of the production string.
17. The system of claim 9, wherein the wellbore is gravel packed
about the well screen.
18. The system of claim 9, wherein pressure is transmitted between
the passage and the fluid loss control device via a hydraulic wet
connect.
19. A method of controlling fluid loss from a wellbore, the method
comprising the steps of: installing a completion string in the
wellbore, the completion string including a well screen and a fluid
loss control device; then installing a production string in the
wellbore; then engaging the production string with the completion
string; then opening the fluid loss control device; and then
closing the fluid loss control device without intervention into the
production string.
20. The method of claim 19, wherein the closing step further
comprises varying pressure in an annulus formed between the
production string and the wellbore.
21. The method of claim 19, wherein the opening step further
comprises varying pressure in an interior flow passage of the
production string.
22. The method of claim 19, wherein in the engaging step, the fluid
loss control device is positioned longitudinally between a packer
of the completion string and a packer of the production string.
23. The method of claim 19, wherein in the engaging step, the fluid
loss control device is positioned between a packer of the
completion string and a packer of the production string.
24. The method of claim 19, further comprising the step of gravel
packing the wellbore about the well screen prior to the production
string installing step.
Description
BACKGROUND
[0001] The present disclosure relates generally to equipment
utilized and operations performed in conjunction with a
subterranean well and, in an embodiment described herein, more
particularly provides well systems and methods incorporating fluid
loss control.
[0002] A gravel pack assembly typically includes a packer, a
closing sleeve, a fluid loss device and a well screen, with a work
string and a multi-position tool engaged within the assembly. A
flowpath is provided in the gravel pack assembly for delivery of
stimulation fluids and a gravel slurry into a wellbore external to
the assembly, and another flowpath is provided for circulating
fluids back to surface. Once the operation is completed, the
multi-position tool and work string are retrieved.
[0003] The fluid loss control device is usually closed upon
retrieval of the work string and multi-position tool, in order to
prevent loss of fluid from the wellbore. The fluid loss control
device is usually opened upon installation of a production string,
to thereby allow for production of fluid to the surface via the
production string.
[0004] Unfortunately, the fluid loss control device cannot be
conveniently closed again if there is a need to retrieve the
production string, or to carry out other operations, such as
chemical washouts for hydrate remediation. In some circumstances, a
wireline- or coiled tubing-conveyed shifting tool can be used to
close the fluid loss control device, but this requires intervention
into the production string, and is costly and inconvenient
(particularly if the production string needs to be urgently
retrieved, such as during an emergency, or if production is via a
floating production storage and offloading (FPSO) facility).
[0005] Therefore, it will be appreciated that improvements are
needed in the art of fluid loss control. These improvements may be
useful in operations other than those discussed above.
SUMMARY
[0006] In the present specification, well systems and methods are
provided which solve at least one problem in the art. One example
is described below in which a fluid loss control device is operable
multiple times without physical intervention. Another example is
described below in which annulus pressure or conduit pressure can
be used to close a fluid loss control device after it has been
opened.
[0007] In one aspect, a method of controlling fluid loss from a
wellbore is provided. The method includes the steps of: installing
a completion string in the wellbore, the completion string
including a well screen and a fluid loss control device; then
installing a production string in the wellbore; then engaging the
production string with the completion string; and then operating
the fluid loss control device by varying pressure in a fluid
passage (such as a conduit and/or an annulus formed between the
wellbore and the production string).
[0008] In another aspect, a well system for use in a wellbore is
provided which includes a completion string including a fluid loss
control device, a packer and a well screen. The packer is
positioned longitudinally between the fluid loss control device and
the well screen. A production string is engaged with the completion
string, and the production string includes another packer. The
fluid loss control device is positioned longitudinally between the
packers, and the fluid loss control device is operable in response
to variation of pressure in a fluid passage (such as a conduit
and/or an annulus formed between the wellbore and the production
string).
[0009] In yet another aspect, a method of controlling fluid loss
from a wellbore includes the steps of: installing a completion
string in the wellbore, the completion string including a well
screen and a fluid loss control device; then installing a
production string in the wellbore; then engaging the production
string with the completion string; then opening the fluid loss
control device; and then closing the fluid loss control device
without intervention into the production string.
[0010] These and other features, advantages and benefits will
become apparent to one of ordinary skill in the art upon careful
consideration of the detailed description of representative
embodiments below and the accompanying drawings, in which similar
elements are indicated in the various figures using the same
reference numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic partially cross-sectional view of a
well system and associated method embodying principles of the
present disclosure;
[0012] FIG. 2 is a schematic partially cross-sectional view of the
well system after further steps in the method have been
performed;
[0013] FIG. 3 is an enlarged scale schematic cross-sectional view
of a fluid loss control device usable in the well system and
method;
[0014] FIG. 4 is a schematic partially cross-sectional view of
another configuration of the well system and its associated
method;
[0015] FIG. 5 is a schematic partially cross-sectional view of
another configuration of the well system and its associated
method;
[0016] FIG. 6 is a schematic partially cross-sectional view of
another configuration of the well system and its associated
method;
[0017] FIG. 7 is a schematic partially cross-sectional view of
another configuration of the well system and its associated
method;
[0018] FIG. 8 is a schematic partially cross-sectional view of
another configuration of the well system and its associated
method;
[0019] FIG. 9 is a schematic partially cross-sectional view of
another configuration of the well system and its associated method;
and
[0020] FIG. 10 is a schematic partially cross-sectional view of
another configuration of the well system and its associated
method.
DETAILED DESCRIPTION
[0021] It is to be understood that the various embodiments
described herein may be utilized in various orientations, such as
inclined, inverted, horizontal, vertical, etc., and in various
configurations, without departing from the principles of the
present disclosure. The embodiments are described merely as
examples of useful applications of the principles of the
disclosure, which are not limited to any specific details of these
embodiments.
[0022] In the following description of the representative
embodiments of the disclosure, directional terms, such as "above",
"below", "upper", "lower", etc., are used for convenience in
referring to the accompanying drawings. In general, "above",
"upper", "upward" and similar terms refer to a direction toward the
earth's surface along a wellbore, and "below", "lower", "downward"
and similar terms refer to a direction away from the earth's
surface along the wellbore.
[0023] Representatively illustrated in FIG. 1 is a well system 10
and associated method which embody principles of the present
disclosure. In the system 10, a completion string 12 has been
installed in a wellbore 14, and a gravel packing operation has been
performed. The wellbore 14 is depicted in FIG. 1 as being cased,
but it is not necessary for the wellbore to be cased, or for a
gravel packing operation to be performed in keeping with the
principles of this disclosure.
[0024] The completion string 12 preferably includes a specialized
gravel packing or frac-pack packer 16, a closing sleeve 18, a fluid
loss control device 20 and a well screen 22. A work string 24 is
engaged with the completion string 12 during installation and
subsequent stimulation/gravel packing operations. The work string
24 includes a multi-position tool 26, seals 28 and washpipe 30.
Many additional components, other components and combinations of
components can be included in the completion and work strings 12,
24 in keeping with the principles of this disclosure.
[0025] After the wellbore 14 has been gravel packed about the
screen 22, the work string 24 is retrieved from the well and the
fluid loss control device 20 is closed to prevent loss of fluid
from the wellbore 14 (or the interior of the casing if the wellbore
is cased) during retrieval of the work string and installation of a
production string 32 (not shown in FIG. 1, see FIG. 2). Except for
the fluid loss control device 20, all or any of the components
depicted in FIG. 1 may be conventional components of the type well
known to those skilled in the art.
[0026] Referring additionally now to FIG. 2, the well system 10 is
depicted after installation of the production string 32. The
production string 32 is inserted into the completion string 12 and
is sealingly engaged therein with seals 34 The production string 32
is also sealed and secured in the wellbore 14 using a packer
36.
[0027] An annulus 38 is formed radially between the production
string 32 and the wellbore 14 (or the interior surface of the
casing if the wellbore is cased), and another annulus 40 is formed
radially between the completion string 12 and tubing 42 of the
production string 32. The annulus 38 is in fluid communication with
the annulus 40 via an opening 44 in the completion string 12 above
the packer 16, an opening through the packer 36, and another
annulus 48 between the packers.
[0028] In one unique feature of the system 10, the fluid loss
control device 20 can be operated by varying pressure in the
annulus 38 (for example, using a pump or other pressurized fluid
source at the surface or mudline), which pressure is communicated
to the fluid loss control device via the openings 44, 46 and annuli
40, 48. In this manner, the fluid loss control device 20 can be
operated even after the work string 24 has been retrieved, and can
be operated multiple times after the production string 32 is
installed, as desired.
[0029] The fluid loss control device 20 may also be operable
multiple times by varying pressure in an interior flow passage 50
of the production string 32. For example, the fluid loss control
device 20 may be opened by increasing pressure in the flow passage
50, and the fluid loss control device may be closed by increasing
pressure in the annulus 38.
[0030] Referring additionally now to FIG. 3, an example of a fluid
loss control device 20 which may be used in the system 10 and
associated method is representatively illustrated. As depicted in
FIG. 3, the device 20 includes a ball valve 52 and an actuator
54.
[0031] When interconnected in the completion string 12, and with
the production string 32 sealingly engaged therein, the flow
passage 50 extends through the device 20. A piston 56 of the
actuator 54 has one side exposed to pressure in the passage 50 via
an opening 58, and an opposite side exposed to pressure in the
annulus 40 via an opening 60. A seal bore 62 is provided for
sealing engagement with the seal 34 at the lower end of the tubing
42.
[0032] It will be readily appreciated that when pressure in the
passage 50 is increased until it is greater than pressure in the
annulus 40, the piston 56 will displace upward and open the ball
valve 52. When pressure in the annulus 40 is subsequently increased
until it is greater than pressure in the passage 50, the piston 56
will displace downwardly to close the ball valve 52, as depicted in
FIG. 3.
[0033] Of course, the device 20 as depicted in FIG. 3 is merely one
simplified example of a fluid loss control device which may be used
in the system 10. Additional features may be incorporated into the
device 20 (such as, shear pins, latches, ratchets, pressurized gas
chambers, etc.) to control how and when the device operates,
different types of valves may be used (such as flappers, etc.), and
other variations may be used in keeping with the principles of this
disclosure.
[0034] Referring additionally now to FIG. 4, another configuration
of the system 10 is representatively illustrated. This
configuration is similar in many respects to the system 10 of FIG.
2, but differs at least in part in that the production string 32
includes a fluid loss control device 20 interconnected below the
packer 36.
[0035] In addition, the production string 32 includes a latching
device 64 for releasably securing the production string to the
packer 16 of the completion string 12, a latching device 66 for
releasably securing the production string to the upper fluid loss
control device 20, a telescoping travel joint 68 positioned between
the packer 36 and the latching device 66, and a conduit 70 for
providing fluid communication between the opening 46 and the
latching device 66. The latching device 66 includes a flowpath (not
visible in FIG. 4) for providing fluid communication between the
conduit 70 and the opening 60 in the upper device 20, so that
pressure in the annulus 38 is communicated to the actuator 54 of
the upper device.
[0036] Thus, the upper device 20 is operable in response to varying
pressure in the annulus 38, and is operable in response to varying
pressure in the passage 50, as in the description above relating to
FIG. 3. However, in the system 10 of FIG. 4, the upper device 20 is
positioned longitudinally between the packers 16, 36.
[0037] Preferably, the upper fluid loss control device 20 is
installed with the production string 32, with the latching device
64 being used to secure the production string (including the
device) to the completion string 12. However, if it should become
necessary to retrieve the production string 32, the upper device 20
can be closed (for example, by pressurizing the annulus 38), and
the production string can be disconnected from the upper device 20
at the latching device 66.
[0038] Closing of the upper device 20 will, thus, conveniently
prevent loss of fluid from the wellbore 14. The latching device 66
will also permit convenient reconnection of the production string
32 to the upper device 20, with pressure in the passage 50 being
used to reopen the valve 52 when desired. This process can be
repeated any number of times.
[0039] Note that the latching device 66 also serves as a hydraulic
wet connect between the upper device 20 and the conduit 70. Fluid
communication between the upper device 20 and the conduit 70 can be
connected or disconnected using the latching device 66 any number
of times.
[0040] Alternatively, the travel joint 68 may be used for
disconnecting the production string 32. For example, the travel
joint 68 could be shear pinned open during installation, with set
down weight being used to shear the pins and activate the travel
joint when in position.
[0041] The production string 32 could then separate at the latching
device 66 when it is necessary to retrieve the production string. A
wet connect 72 (described below) could be used to reconnect the
conduit 70 to the upper device 20 when the production string 32 is
again installed. The latching device 64 may be used to retrieve and
reinstall the upper device 20, if desired.
[0042] Referring additionally now to FIG. 5, another configuration
of the system 10 is representatively illustrated. This
configuration is similar in many respects to the system 10 of FIG.
4, but differs at least in part in that the latching device 64 is
not used to releasably secure the production string 32 to the
completion string 12. Instead, the upper fluid loss control device
20 is preferably installed as part of the completion string 12, and
the production string is releasably secured to the completion
string using the latching device 66 when it is installed.
[0043] Preferably, the upper device 20 is constructed as part of
the packer 16, or at least is connected thereto when the completion
string 12 is installed. The lower device 20 may be used as in
conventional stimulating/gravel packing operations to prevent fluid
loss, while the upper device 20 remains open. However, after the
production string 32 is installed, the upper device 20 is then
operable as needed to prevent fluid loss.
[0044] Alternatively, the lower device 20 may not be used, in which
case the upper device 20 could be closed by the multi-position tool
26 when the work string 24 is retrieved from the well. In this
manner, the additional lower device 20 would not be needed.
[0045] As described above, the upper device 20 is operable by
varying pressure in the annulus 38 and passage 50 to selectively
open and close the device. However, in the configuration of FIG. 5,
a separate hydraulic wet connect 72 is used between the conduit 70
and the upper device 20. Such a wet connect 72 may be used in the
configuration of FIG. 4, if desired.
[0046] Thus, in the event that the production string 32 needs to be
retrieved from the well, the upper device 20 will be closed (for
example, by pressurizing the annulus 38), the production string
will be disconnected from the completion string 12 at the latching
device 66, and the wet connect 72 will be disconnected. When the
production string 32 is installed again, the wet connect 72 will
again provide fluid communication between the upper device 20 and
the annulus 38.
[0047] Referring additionally now to FIG. 6, another configuration
of the system 10 is representatively illustrated. This
configuration is similar in most respects to the configuration of
FIG. 4, but differs at least in that the upper packer 36 is not
used on the production string 32, and the conduit 70 extends to a
remote location (such as the earth's surface, the mudline in a
subsea application, or another location in the well).
[0048] In the configuration of FIG. 6, pressure is applied to the
valve device 20 via the conduit 70 from the remote location,
instead of being applied via the annulus 38. Otherwise, this
configuration of the system 10 operates in the same manner as the
configuration of FIG. 4.
[0049] Referring additionally now to FIG. 7, another configuration
of the system 10 is representatively illustrated. This
configuration is similar in most respects to the configuration of
FIG. 5, but differs at least in that the upper packer 36 is not
used on the production string 32, and the conduit 70 extends to a
remote location (such as the earth's surface, the mudline in a
subsea application, or another location in the well).
[0050] In the configuration of FIG. 7, pressure is applied to the
valve device 20 via the conduit 70 from the remote location,
instead of being applied via the annulus 38. Otherwise, this
configuration of the system 10 operates in the same manner as the
configuration of FIG. 5.
[0051] Referring additionally now to FIGS. 8-10, the well system 10
is representatively illustrated in additional configurations in
which the conduit 70 extends to a remote location, as in FIGS. 6
& 7, but the packer 36 is utilized on the production string 32.
Pressure is applied to operate the valve device 20 via the conduit
70 from the remote location, instead of being applied via the
annulus 38, but otherwise the configurations of FIGS. 8, 9 & 10
operate in the same manner as the configurations of respective
FIGS. 2, 4 & 5 described above.
[0052] It may now be fully appreciated that the above description
provides several advancements to the art of fluid loss control in
wells. For example, the system 10 permits the fluid loss control
device 20 to be operated multiple times, and it can be closed after
being opened, without intervention into the well. Pressure applied
via the annulus 38 can be used to close the device 20 after the
production string 32 has been installed, for example, prior to
retrieving the production string from the well.
[0053] The above disclosure provides a method of controlling fluid
loss from a wellbore 14, with the method including the steps of:
installing a completion string 12 in the wellbore 14, the
completion string 12 including a well screen 22 and a fluid loss
control device 20; then installing a production string 32 in the
wellbore 14; then engaging the production string 32 with the
completion string 12; and then operating the fluid loss control
device 20 by varying pressure in a fluid passage (such as the
conduit and/or an annulus 38 formed between the wellbore 14 and the
production string 32).
[0054] The operating step may include increasing pressure in the
annulus 38 to thereby close the fluid loss control device 20. The
operating step may include closing the fluid loss control device 20
after the fluid loss control device is opened.
[0055] The production string 32 engaging step may include inserting
the production string within the completion string 12, thereby
placing an actuator 54 of the fluid loss control device 20 in fluid
communication with the annulus 38 via another annulus 40 formed
between the production string 32 and the completion string 12.
[0056] In the production string 32 engaging step, a packer 16 of
the completion string 12 may be positioned longitudinally between
the fluid loss control device 20 and the screen 22. The production
string 32 may include a packer 36, and the engaging step may
further include making a hydraulic wet connect connection between
the fluid loss control device 20 on one side of the production
string packer 36 and the annulus 38 on an opposite side of the
production string packer 36.
[0057] Also provided by the above disclosure is a well system 10
for use in a wellbore 14. The system 10 comprises a completion
string 12 including a fluid loss control device 20, a packer 16 and
a well screen 22, with the packer 16 being positioned
longitudinally between the fluid loss control device 20 and the
well screen 22. A production string 32 is engaged with the
completion string 12, with the production string including another
packer 36. The fluid loss control device 20 is positioned
longitudinally between the packers 16, 36, and the fluid loss
control device 20 is operable in response to variation of pressure
in a fluid passage (such as the conduit 70 and/or an annulus 38
formed between the wellbore 14 and the production string 12).
[0058] The wellbore 14 may be gravel packed about the well screen
22.
[0059] Pressure may be transmitted between the annulus 38 and the
fluid loss control device 20 via a hydraulic wet connect 72. The
packer 36 may be positioned longitudinally between the annulus 38
and the hydraulic wet connect 72.
[0060] The system 10 may also include a latching device 66 which
releasably secures the production and completion strings 32, 12,
with the latching device 66 being positioned longitudinally between
the fluid loss control device 20 and the packer 36.
[0061] The system 10 may also include a latching device 64 which
releasably secures the production and completion strings 32, 12,
with the latching device 64 being positioned longitudinally between
the fluid loss control device 20 and the packer 16.
[0062] The fluid loss control device 20 may be closable in response
to variation of pressure in the annulus 38. The fluid loss control
device 20 may be openable in response to variation of pressure in
an interior flow passage 50 of the production string 32.
[0063] The above disclosure also provides a method of controlling
fluid loss from a wellbore 14, which method includes the steps of:
installing a completion string 12 in the wellbore 14, the
completion string 12 including a well screen 22 and a fluid loss
control device 20; then installing a production string 32 in the
wellbore 14; then engaging the production string 32 with the
completion string 12; then opening the fluid loss control device
20; and then closing the fluid loss control device 20 without
intervention into the production string 32.
[0064] The closing step may include varying pressure in an annulus
38 formed between the production string 32 and the wellbore 14. The
opening step may include varying pressure in an interior flow
passage 50 of the production string 32.
[0065] In the production string engaging step, the fluid loss
control device 20 may be positioned longitudinally between a packer
16 of the completion string 12 and a packer 36 of the production
string 32.
[0066] The fluid loss control device 20 may be positioned between a
packer 16 of the completion string 12 and a packer 36 of the
production string 32 in the production string engaging step.
[0067] The method may include the step of gravel packing the
wellbore 14 about the well screen 22 prior to the production string
32 installing step.
[0068] Of course, a person skilled in the art would, upon a careful
consideration of the above description of representative
embodiments, readily appreciate that many modifications, additions,
substitutions, deletions, and other changes may be made to these
specific embodiments, and such changes are within the scope of the
principles of the present disclosure. Accordingly, the foregoing
detailed description is to be clearly understood as being given by
way of illustration and example only, the spirit and scope of the
present invention being limited solely by the appended claims and
their equivalents.
* * * * *