U.S. patent application number 13/818787 was filed with the patent office on 2013-09-26 for high pressure tie back receptacle and seal assembly.
This patent application is currently assigned to HALLIBURTON ENERGY SERVICES, INC.. The applicant listed for this patent is Brock Watson. Invention is credited to Brock Watson.
Application Number | 20130248209 13/818787 |
Document ID | / |
Family ID | 47558743 |
Filed Date | 2013-09-26 |
United States Patent
Application |
20130248209 |
Kind Code |
A1 |
Watson; Brock |
September 26, 2013 |
HIGH PRESSURE TIE BACK RECEPTACLE AND SEAL ASSEMBLY
Abstract
A tie back assembly and method of use is presented. In one
method, a tie back seal mandrel is inserted into a tie back
receptacle. Both the inner surface of the tie back receptacle and
the outer surface of the seal mandrel are tapered to cooperate when
mated. A seal assembly forms an annular seal between the tapered
surfaces when the mandrel is inserted into the receptacle.
Preferably the seal assembly has a burst seal and a collapse seal
carried on one of the tapered surfaces, where the seals are spaced
apart longitudinally. The seals are positioned at locations along
the tapered surfaces to provide adequate wall thickness for support
at pressure. Hydrostatic fluid in the wellbore increases the force
necessary to withdraw the seal mandrel dues to creation of a lower
pressure zone between the spaced apart seals.
Inventors: |
Watson; Brock; (Oklahoma
City, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Watson; Brock |
Oklahoma City |
OK |
US |
|
|
Assignee: |
HALLIBURTON ENERGY SERVICES,
INC.
Houston
TX
|
Family ID: |
47558743 |
Appl. No.: |
13/818787 |
Filed: |
July 20, 2012 |
PCT Filed: |
July 20, 2012 |
PCT NO: |
PCT/US2012/047594 |
371 Date: |
May 30, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61510395 |
Jul 21, 2011 |
|
|
|
Current U.S.
Class: |
166/387 ;
166/242.6 |
Current CPC
Class: |
E21B 43/106 20130101;
E21B 33/10 20130101; E21B 43/103 20130101; E21B 17/02 20130101 |
Class at
Publication: |
166/387 ;
166/242.6 |
International
Class: |
E21B 33/10 20060101
E21B033/10; E21B 17/02 20060101 E21B017/02 |
Claims
1-3. (canceled)
4. A method of assembling together a tie back receptacle member and
a tie back seal member in a wellbore extending through a
subterranean formation, the method comprising the steps of:
positioning the tie back receptacle member in the wellbore at a
downhole location where the wellbore comprises a casing; hanging
the tie back receptacle member in the wellbore and supported by the
casing; running the tie back seal member into the wellbore, the tie
back seal member having a seal mandrel at its lower end, the seal
mandrel having a tapered outer surface; positioning the seal
mandrel into the tie back receptacle member, the tie back
receptacle member defining a tie back receptacle having a tapered
inner surface; and sealing the tapered surfaces against one another
by moving at least a burst seal and a collapse seal carried on one
of the tapered surfaces into sealing engagement with the other
tapered surface; and wherein the burst and collapse seals are
spaced apart from one another.
5. The method according to claim 4, further comprising the step of
moving the burst seal into sealing engagement between the tapered
surfaces and moving the collapse seal into sealing engagement
between the tapered surfaces.
6. The method according to claim 5, wherein an annular space is
defined between the burst and collapse seals and the tapered
surfaces, and further comprising the step of flowing wellbore fluid
out of the annular space.
7. The method according to claim 6, wherein the step of flowing
wellbore fluid out of the annular space further comprises flowing
wellbore fluid over at least one of the collapse and burst
seals.
8. The method according to claim 6, further comprising the step of
creating a lower pressure in the annular space than the hydrostatic
pressure in the wellbore.
9. The method according to claim 6, wherein the step of flowing
wellbore fluid out of the annular space further comprises, flowing
wellbore fluid out of the annular space after the seal mandrel is
positioned in sealing engagement with the tie back receptacle.
10. The method according to claim 8, wherein the lower pressure in
the annular space is created during a further step of withdrawing
the seal mandrel from the tie back receptacle.
11. The method according to claim 10, further comprising the step
of expanding the seal mandrel in response to creating the lower
pressure in the annular space.
12. The method according to claim 11, further comprising the step
of contracting the tie back receptacle in response to creating the
lower pressure in the annular space.
13. The method according to claim 4, further comprising the step of
fastening the tie back receptacle member and the seal member
together.
14. The method according 13, further comprising the step of
interlocking coordinating grooves and ridges on the tapered
surfaces of the seal mandrel and tie back receptacle.
15. The method according to claim 14, wherein the grooves and
ridges are positioned between the burst and collapse seals.
16. (canceled)
17. A tie back assembly for use in a subterranean wellbore, the
assembly comprising: a seal mandrel having a tapered outer surface;
a tie back receptacle of a size to receive the seal mandrel
therein, the tie back receptacle having a tapered inner surface
corresponding to the tapered surface of the seal mandrel; and an
annular seal assembly positioned between the outer surface of the
seal mandrel and the inner surface of the tie back receptacle; and
wherein the seal assembly comprises two longitudinally spaced
apart, annular seals.
18. The assembly according to claim 17, wherein an annular space is
defined between the annular seals, the inner surface of the tie
back receptacle and the outer surface of the seal mandrel, the
seals designed to hold against less pressure from fluid trapped in
the annular space than pressure from fluid exterior to the annular
space.
19. The assembly according to claim 17, further comprising a
plurality of surface structures formed on the outer surface of the
seal mandrel and a corresponding plurality of surface structures
formed on the inner surface of the tie back receptacle, the surface
structures cooperating to produce an increase in drag force when
the seal mandrel is removed from the tie back receptacle.
20. The method according to claim 17, wherein the two
longitudinally spaced apart seals act to produce a relatively lower
pressure area defined by the annular space when the seal mandrel is
removed from the tie back receptacle.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application for patent claims priority to U.S.
Provisional Application Ser. No. 61/510,395, to Watson, filed Jul.
21, 2011, which application is incorporated herein in its entirety
for all purposes.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to equipment and methods used
in subterranean wells, and more particularly to a tie back seal and
tie back seal receptacle assembly and method.
[0004] 2. Background Art
[0005] Wellbores are typically formed by drilling and thereafter
lining a borehole with steel pipe called casing. The casing
provides support to the wellbore and facilitates the isolation of
certain areas of the wellbore adjacent hydrocarbon bearing
formations. The casing typically extends down the wellbore from the
surface of the well and the annular area between the outside of the
casing and the borehole in the earth is filled with cement to
permanently set the casing in the wellbore.
[0006] As the wellbore is drilled to a new depth, additional
strings of pipe are run into the well to that depth whereby the
upper portion of the string of pipe, or liner, is overlapping the
lower portion of the casing. The liner string is then fixed or hung
in the wellbore, usually by some mechanical means such as a setting
sleeve hanger, expandable hanger, or other means well known in the
art.
[0007] In some instances wells are completed with the remote
perforating of liner to provide a fluid path for hydrocarbons to
enter the wellbore where they flow into a screened portion of
another smaller tubular or production tubing. In these instances,
the wellbore around the tubing is isolated with packers to close
the annular area and urge the hydrocarbons into the production
tubing. In other completions, the last string of liner extending
into the wellbore is itself pre-slotted or perforated to receive
and carry hydrocarbons upwards in the wellbore. In these instances,
production tubing is usually connected to the top of the liner to
serve as a conduit to the surface of the well. In this manner, the
liner is "tied back" to the surface of the well.
[0008] In order to complete these types of wells, the production
tubing is inserted in the top of a liner in a sealing relationship
usually accomplished by utilization of a polished bore receptacle
in the liner top. A polish bore receptacle has a smooth cylindrical
inner bore designed to receive and seal a tubular having a seal
assembly on its lower end. The polished bore receptacle and seal
assembly combination allows the production tubing to be "stung"
into the liner in a sealing relationship and be selectively removed
therefrom. As herein, the term "polished bore receptacle" refers to
a device used to locate and seal a first tubular in a second
tubular. The term "smooth bore receptacle" is also used in the
industry. For disclosure regarding tie back receptacles and tie
back seal mandrels consider the following U.S. patents and U.S.
Patent Application Publications, each of which are incorporated
herein by reference for all purposes: U.S. Patent Application
Publication 2009/0200041 A1, to Watson, filed Feb. 7, 2008; U.S.
Patent Application Publication 2006/0269360 to Rowley, published
November, 2006; U.S. Patent Application Publication 2005/0217866 to
Watson, published October 2005; U.S. Patent Application Publication
2006/0065403 to Watson, published March 2006; U.S. Pat. No.
7,195,073 to Fraser, filed May 1, 2003; U.S. Pat. No. 7,854,266 to
Watson; U.S. Pat. No. 7,779,910 issued Aug. 24, 2010 to Watson;
U.S. Pat. No. 6,056,061 to Ross. For further disclosure, see SPE
106757, Expandable Liner Hanger Resolves Sealing Problems and
Improves Integrity in Liner Completion Scenarios, James Willford
and Pete Smith (2007), which is incorporated herein by reference
for all purposes.
[0009] Mechanical mechanisms, such as latches, are also used in the
industry to hold tie back seal mandrels in position in relation to
tie back receptacles. For example, commercial latches are available
from Halliburton Energy Services, Inc., under the trade names Ratch
Latch and Versalatch.
[0010] One common type of tie back assembly is a mono-diameter tie
back assembly. The typical mono-diameter tie back receptacle (TBR)
and seal mandrel for a liner generally have a pressure rating about
half the liner pressure rating because geometric limitations
require the TBR and the seal mandrel to each be approximately half
the liner thickness. The assembly has a relatively low pressure
rating, which limits the use of the tie back assembly and makes it
unworkable in some wells.
[0011] Consequently, there exists a need for a tie back assembly
with an increased pressure rating for the tie back seal and the
TBR. Improvement of the pressure rating should allow use of such
tie back assemblies in, for example, deep water wells. Deep water
wells require higher pressure ratings for liners. Further, new
government and industry regulations may require higher pressure
ratings. The disclosed invention has higher pressure ratings than
prior art assemblies.
SUMMARY OF THE INVENTIONS
[0012] Embodiments of the present invention generally relate to
methods and apparatus for completing a well. Exemplary methods and
apparatus for assembling a tie back receptacle member and a tie
back seal member in a wellbore extending through a subterranean
formation is provided. In one method, the tie back receptacle
member having a tie back receptacle is positioned and hung on a
casing along the wellbore. A tie back seal member having a seal
mandrel is run into the wellbore and positioned so the seal mandrel
fits into the tie back receptacle. Both the inner surface of the
tie back receptacle and the outer surface of the seal mandrel are
tapered to cooperate when mated. A seal assembly forms an annular
seal between the tapered surfaces when the mandrel is inserted into
the receptacle. The tie back receptacle member can further include
a hanger body, an expandable hanger body, hanger seals, and setting
sleeve. Preferably the seal assembly has a burst seal and a
collapse seal carried on one of the tapered surfaces, where the
seals are spaced apart longitudinally. The seals are positioned at
locations along the tapered surfaces to provide adequate wall
thickness for support at pressure. Hydrostatic fluid in the
wellbore preferably assists in maintaining the seal mandrel and
receptacle in position. Wellbore fluid flows from an annular space
defined between the spaced apart seals, thereby creating a lower
pressure zone. Upon disconnect, the lower pressure zone acts to
enlarge the seal mandrel and shrink the tie back receptacle,
thereby increasing the friction between the mandrel and receptacle.
Additional features can be added, such as cooperating grooves and
ridges on the mating tapered surfaces, latches, etc. A tie back
assembly and methods of use are disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The drawing is incorporated into and forms a part of the
specification to illustrate at least one embodiment and example of
the present invention. Together with the written description, the
drawing serves to explain the principles of the invention. The
drawing is only for the purpose of illustrating at least one
preferred example of at least one embodiment of the invention and
is not to be construed as limiting the invention to only the
illustrated and described example or examples. The various
advantages and features of the various embodiments of the present
invention will be apparent from a consideration of the drawing in
which:
[0014] FIG. 1, a schematic illustration is shown of a preferred
embodiment of a tie back assembly according to an aspect of the
invention;
[0015] FIG. 2 is a schematic detail of FIG. 1 showing an exemplary
tie back receptacle and seal mandrel according to an aspect of the
invention; and
[0016] FIG. 3 is a detail schematic view of an exemplary ridge and
groove mating assembly according to an aspect of the invention
DETAILED DESCRIPTION
[0017] Embodiments of the present invention generally relate to
methods and apparatus for completing a well. The invention relates
more particularly to a tie back assembly having a tie back seal and
tie back seal receptacle and a method of use thereof. Referring
more particularly to the drawings, wherein like reference
characters are used throughout the various figures to refer to like
or corresponding parts, there is shown in the figures, an exemplary
embodiment of a tieback seal system of the present invention.
[0018] Turning first to FIG. 1, a schematic illustration is shown
of a preferred embodiment of a tie back assembly according to an
aspect of the invention. A wellbore 10 extends through a formation
12. At least a portion of the wellbore has a casing 14 positioned
therein and held in place by cement 16. An exemplary tie back
assembly 18 includes a tie back member 20 having a tie back seal
mandrel 22 at its lower end 24, and a tie back receptacle member
26. The exemplary tie back receptacle member 26 includes a hanger
body 28, a setting sleeve 30, and a tie back receptacle 32 formed
at its upper end 34. The tie back assembly is used to form a
pressure tight seal assembly 36 between the tie back member 20 and
tie back receptacle member 26.
[0019] It is understood that the tubular members can be other
tubing or tubulars as are used in the industry, such as part of a
work string, production string, liner, hanger, etc. Further, the
tie back assembly can be positioned in the well by a tubing string,
wireline or coiled tubing.
[0020] In this embodiment, the telescoped or overlapping portion of
tie back member 20 comprises a tie back seal mandrel 22. The
telescoped or overlapping portion of tie back receptacle member 26
comprises a tie back seal receptacle 32. The outer surface 38 of
the seal mandrel 22 is positioned interior and adjacent to, and
longitudinally overlapping with, the inner surface 40 of the tie
back seal receptacle 32. The seal assembly 36 includes, in a
preferred embodiment, a collapse seal 42 and a burst seal 44
positioned between the seal mandrel outer surface 38 and the tie
back receptacle inner surface 40. The seals can be carried on
either member, although preferably on the seal mandrel, and are
designed to seal the annular space between the mandrel and tie back
receptacle. Such seals are commercially available and are known in
the art. The seals are typically elastomer, plastic, nylon, a
relatively soft metal or other deformable material capable of
withstanding a corrosive, high temperature or otherwise damaging
downhole environment.
[0021] Well known technology permits wellbore tubulars to be
expanded in situ. In addition to simply enlarging a tubular, the
technology permits the physical attachment of a smaller tubular to
a larger tubular by increasing the outer diameter of a smaller
tubular with radial force from within. The expansion can be
accomplished by a mandrel or a cone-shaped member urged through the
tubular to be expanded or by an expander tool run in on a tubular
string. For an example of an expander tool see: U.S. Pat. No.
7,779,910 issued Aug. 24, 2010 to Watson entitled Expansion Cone
For Expandable Liner Hanger, which is incorporated herein by
reference for all purposes. The term "expander tool" is used herein
to refer to any member that used to expand a tubular, such as the
roller expander tool, a cone member, hydraulic pressure or any
other type of expansion member used in the oil and gas industry.
The hanger assembly 28 and setting sleeve assembly 30 are not
described in detail herein as they are well known in the art. The
hanger assembly 28 includes a plurality of seals 29 for sealing
between the casing 14 and the tubing member 26. The hanger shown is
an expandable hanger and the annular seals 29 are moved into
sealing contact with the casing during expansion.
[0022] FIG. 2 is a schematic detail of FIG. 1 showing an exemplary
tie back receptacle and seal mandrel according to an aspect of the
invention. The inner diameters of the tie back receptacle member 26
and seal member 20 are substantially identical, forming a
mono-diameter assembly, in the preferred embodiment, as indicated
by the dotted line. The figure is designed to provide a clearer
understanding of the apparatus and method although the assembly
elements are shown spaced apart in the figure, items and spaces are
not to scale, etc. The seal mandrel and tie back receptacle are
shown as not contacting one another, for example, except at the
burst and collapse seals. In use, it is understood that the tapered
surfaces of the seal mandrel and tie back receptacle would, in
fact, touch. The hanger body 28 is here shown expanded.
[0023] The seal mandrel outer surface 38 is tapered from a
relatively larger diameter at its upper end 46 to a relatively
smaller diameter at its lower end 48. Consequently, the seal
mandrel 22 has a relatively thicker cross-section of material at
its upper end 46 and a relatively thinner cross-section of material
at its lower end 48. Similarly, the tie back receptacle inner
surface 40 is tapered from a relatively larger diameter at its
lower end 50 to a relatively smaller diameter at its upper end 52.
Consequently, the tie back receptacle 32 has a relatively thinner
cross-section of material at its upper end 52 and a relatively
thicker cross-section of material at its lower end 50. The tapered
surfaces 38 and 40 cooperate, when the seal mandrel is inserted
into the tie back receptacle, and enable sealing between the
mandrel and receptacle. Thus, the invention provides an increase in
the thickness of the TBR at the lower end and thins the TBR at the
upper end in comparison to prior art assemblies. It also increases
the thickness of the seal mandrel at the upper end and decreases
the thickness at the lower end in comparison to prior art
assemblies. In a preferred embodiment, the tapered surfaces are
conical, however, the tapered surfaces can take other designs, such
as a plurality of generally trapezoidal flat surfaces, etc. The
collapse seal is positioned along a portion of the seal mandrel
where the mandrel wall is thick enough to support the collapse seal
at a targeted collapse pressure, such as at upper end 46. In a
preferred embodiment, the same pressure would not be successfully
held if the collapse seal was placed along the seal mandrel at a
location having a thinner wall, such as at lower end 48. Similarly,
the burst seal is positioned along a portion of the tie back
receptacle where the wall is thick enough to support the burst seal
at a targeted burst pressure, such as at lower end 50. In a
preferred embodiment, the same burst pressure would not be
successfully held if the burst seal was placed along the tie back
receptacle at a location having a thinner wall, such as at upper
end 52.
[0024] Preferably the collapse seal 42 and burst seal 44 are spaced
apart, as shown, although other arrangements are possible. The
collapse seal 42 is seen positioned at a location along the upper
end 46 where the seal mandrel 22 is relatively thicker. This
arrangement results in higher burst and collapse ratings due to the
relatively thicker material between the burst seal and hanger body
and between the collapse seal and tie back body. The member
material between the burst and collapse seals is supported because
of the two nested cylinders.
[0025] In a preferred embodiment, the seal is self-locking in
response to hydrostatic pressure. The self-locking seal works
something like a suction cup. As the seal is moved into a sealed
position, and/or when in the sealed position, liquid trapped
between the burst and collapse seals and between the tapered
surfaces will be forced out over one or both seals, such as along
flow path F. The seals will typically be unable to hold significant
fluid pressure between the seals due to the thin section. Further,
the seals can be designed to purposely allow fluid to escape from
the area between the seals. When the tie back seal mandrel is
withdrawn from the tie back receptacle, a lower pressure area is
formed between the seals since the volume between the seals is
increasing. The lower pressure will cause the seal mandrel to
expand and the tie back receptacle to shrink. This relative
expansion and shrinkage will cause a substantial increase in
friction between the tie back receptacle and the seal mandrel.
[0026] FIG. 2 also shows an optional latching assembly having
circumferential grooves 54 formed in the outer surface 38 of the
seal mandrel 22 and corresponding and cooperating circumferential
ridges 56 formed on the inner surface 40 of the tie back receptacle
32. The grooves increase the pullout drag force when the seal
mandrel is withdrawn from the tie back receptacle. The grooves and
ridges are designed such that they will snap together elastically
during insertion of the seal mandrel into the tie back receptacle.
The locking grooves and ridges are preferably positioned along the
seal mandrel and tie back receptacle in the area between the burst
and collapse seals.
[0027] FIG. 3 is a detail schematic view of an exemplary ridge and
groove mating or latching assembly according to an aspect of the
invention. The tie back seal mandrel 22 has a plurality of
circumferential grooves 54 formed in its tapered surface 38. The
tie back receptacle 32 has a corresponding and cooperating
plurality of circumferential ridges 56 extending from its tapered
surface 40. As can be seen, the grooves 54 are preferably
acme-style grooves, that is, defined by flat angled walls 60 and 62
and a flat bottom surface 64. The ridges 56 similarly have flat
angular walls 66 and 68 and a flat top surface 70. When the seal
mandrel is inserted into the tie back receptacle, the ridges and
grooves lock into cooperating positions, as seen in FIG. 3. The
grooves increase the pullout drag force when the seal mandrel is
withdrawn from the tie back receptacle. The grooves and ridges are
designed such that they will snap together elastically during
insertion of the seal mandrel into the tie back receptacle. The
locking grooves and ridges are preferably positioned along the seal
mandrel and tie back receptacle in the area between the burst and
collapse seals. The grooves and ridges can be substituted with
alternative structures as are known in the art.
[0028] In use, a preferred method includes at least some of the
following steps for assembling together a tie back receptacle
member and a tie back seal member in a wellbore extending through a
subterranean formation: positioning the tie back receptacle member
in the wellbore at a downhole location where the wellbore comprises
a casing; hanging the tie back receptacle member in the wellbore
and supported by the casing; running the tie back seal member into
the wellbore, the tie back seal member having a seal mandrel at its
lower end, the seal mandrel having a tapered outer surface;
positioning the seal mandrel into the tie back receptacle member,
the tie back receptacle member defining a tie back receptacle
having a tapered inner surface; and sealing the tapered surfaces
against one another by moving at least one seal carried on one of
the tapered surfaces into sealing engagement with the other tapered
surface. Additional potential steps and features include: wherein
the tie back receptacle member further comprises a hanger body, and
further comprising the step of expanding the hanger body into
sealing engagement with the casing; wherein at least one seal is
carried on the tapered surface of the seal mandrel; wherein the at
least one seal comprises a burst seal and a collapse seal, the
burst and collapse seals spaced apart from one another; moving the
burst seal into sealing engagement between the tapered surfaces and
moving the collapse seal into sealing engagement between the
tapered surfaces; wherein an annular space is defined between the
burst and collapse seals and the tapered surfaces, and further
comprising the step of flowing wellbore fluid out of the annular
space; wherein the step of flowing wellbore fluid out of the
annular space further comprises flowing wellbore fluid over at
least one of the collapse and burst seals; creating a lower
pressure in the annular space than the hydrostatic pressure in the
wellbore; wherein the step of flowing wellbore fluid out of the
annular space further comprises, flowing wellbore fluid out of the
annular space after the seal mandrel is positioned in sealing
engagement with the tie back receptacle; wherein the lower pressure
in the annular space is created during a further step of
withdrawing the seal mandrel from the tie back receptacle;
expanding the seal mandrel in response to creating the lower
pressure in the annular space; contracting the tie back receptacle
in response to creating the lower pressure in the annular space;
fastening the tie back receptacle member and the seal member
together; interlocking coordinating grooves and ridges on the
tapered surfaces of the seal mandrel and tie back receptacle; and
wherein the grooves and ridges are positioned between the burst and
collapse seals.
[0029] While compositions and methods are described in terms of
"comprising," "containing," or "including" various components or
steps, the compositions and methods also can "consist essentially
of" or "consist of" the various components and steps. As used
herein, the words "comprise," "have," "include," and all
grammatical variations thereof are each intended to have an open,
non-limiting meaning that does not exclude additional elements or
steps.
[0030] Therefore, the present inventions are well adapted to carry
out the objects and attain the ends and advantages mentioned as
well as those which are inherent therein. While the invention has
been depicted, described, and is defined by reference to exemplary
embodiments of the inventions, such a reference does not imply a
limitation on the inventions, and no such limitation is to be
inferred. The inventions are capable of considerable modification,
alteration, and equivalents in form and function, as will occur to
those ordinarily skilled in the pertinent arts and having the
benefit of this disclosure. The depicted and described embodiments
of the inventions are exemplary only, and are not exhaustive of the
scope of the inventions. Consequently, the inventions are intended
to be limited only by the spirit and scope of the appended claims,
giving full cognizance to equivalents in all respects.
[0031] Also, the terms in the claims have their plain, ordinary
meaning unless otherwise explicitly and clearly defined by the
patentee. Moreover, the indefinite articles "a" or "an", as used in
the claims, are defined herein to mean one or more than one of the
element that it introduces. If there is any conflict in the usages
of a word or term in this specification and one or more patent(s)
or other documents that may be incorporated herein by reference,
the definitions that are consistent with this specification should
be adopted.
* * * * *