Note: Descriptions are shown in the official language in which they were submitted.
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IDENTIFICATION SYSTEM FOR DRILL PIPES AND THE LIKE
BACKGROUND OF THE INVENTION
The present invention is directed to a system and method for marking
components so that they can be identified and tracked. In particular, the
invention is directed to a system and method which comprises an identification
disk having identifying markings disposed thereon which are unique to the
particular component to which the disk is or will be mounted. One component
with which the identification system and method of the present invention may
be
employed is a drill pipe.
Drill pipes are commonly used to drill and service oil and gas wells. Such
drill pipes are exposed to extreme conditions of temperature, pressure, and
abrasion. Failure of a drill pipe during use can create significant problems
for the
drilling operator by imposing both delays and recovery expenses. Because of
the
extreme conditions to which they are subjected and the consequences of
failure,
drill pipes are typically constructed of high grade, costly materials.
Consequently,
the inventory of drill pipe used to drill a typical oil or gas well represents
a
significant investment. Accordingly, it has become a relatively common
practice
=
to mark each section of the drill pipe with an identifying number to allow
information about the drill pipe, including its location and service life, to
be
monitored and maintained.
Various approaches to identifying sections of drill pipe exist. In one
approach an identifying number is engraved into the surface of the pipe. This
approach is reasonably effective so long as the identifying number remains
visible. However, because drill pipes are subject to abrasion, the surface of
the
drill pipe is worn away during use, and over a period of time the identifying
number may disappear.
In another approach to identifying sections of drill pipe, a small electronic
module which can be read with a reader or scanner unit is inserted into a
cavity
formed in the wall of the drill pipe and the cavity is filled with a potting
material or
the like to seal the module in place. Although recessing the electronic module
in
a closed cavity effectively protects it from abrasion, the module is not
protected
from the high temperatures and temperature variations to which the drill pipe
is
subjected, and the failure rate of the electronic tags is therefore relatively
high.
The abrasion to which drill pipes are subjected eventually erodes the pipe
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sections to the point where they can no longer be used because of the
increased
risk of failure. Accordingly, drilling operators typically monitor the wear of
each
section of drill pipe and retire a section when the wear reaches a preselected
limit, which is often referred to the wear allowance. This monitoring is
typically
done by measuring the diameter of the pipe section, which requires a worker to
manually apply a measuring tool or gauge to the pipe.
It can be understood then that a need exists for an effective means of
individually marking sections of drill pipe so that each section can be
identified
and tracked. A need also exists for a more effective and less labor intensive
means of monitoring the degree of wear to individual sections of drill pipe
and
determining when a section should be taken out of service.
SUMMARY OF THE INVENTION
In accordance with the present invention, these and other limitations in the
prior art are addressed by providing an identification system for a component
which comprises a body having an outer surface which in use is subject to
wear.
The system includes an identification disk which comprises generally parallel
upper and lower faces and a thickness which is defined between the upper and
lower faces; a unique identifying marking which is provided on at least the
upper
face, the identifying marking corresponding to the identity of the component;
a
cavity which is formed in the body and extends from the outer surface to a
depth
that is greater than the thickness of the disk; wherein in use of the
identification
system the disk is positioned in the cavity such that the upper face is
directed
toward and disposed below the outer surface; and a lip which is formed from a
portion of the body adjacent the cavity and which, when the disk is positioned
in
the cavity, overlaps an outer peripheral portion of the upper face to thereby
secure the disk in the cavity without obscuring the identifying marking.
In accordance with one embodiment of the invention, the cavity comprises
an inner portion within which the disk is positioned; an outer portion which
extends between the inner portion and the outer surface; and a shoulder which
is
located between the inner and outer portions; wherein the lip is formed from
the
shoulder. In this embodiment, the inner portion may comprise a depth which is
greater than the thickness of the disk.
In accordance with yet another embodiment of the invention, the inner
portion comprises a first diameter, the outer portion comprises a second
diameter
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which is greater than the first diameter, and the shoulder comprises a
generally
square profile. In this embodiment, the inner portion may comprise a depth
which
is greater than the thickness of the disk.
In accordance with a further embodiment of the invention, the inner portion
comprises a first diameter, the outer portion comprises a second diameter
which
is greater than the first diameter, and the shoulder comprises a radially
inner
portion which is located a first distance from the outer surface and a
radially outer
portion which is located a second distance from the outer surface. In this
embodiment, the first distance is less than the second distance and the
shoulder
may comprise, e.g., a generally triangular profile, a concave profile, or a
convex
profile, among other configurations.
In any of the above embodiments, the lip may comprise an upper portion
which is located proximate the bottom of a wear allowance zone of the
component.
The present invention is also directed to a method for providing a
component with a unique identifying marking. The method includes providing an
identification disk which comprises generally parallel upper and lower faces
and a
thickness which is defined between the upper and lower faces; disposing the
identifying marking on at least the upper face; forming a cavity in the body
which
extends from the outer surface to a depth which is greater than the thickness
of
the disk; positioning the disk in the cavity such that the upper face is
directed
toward and disposed below the outer surface; and forming a lip from a portion
of
the body adjacent the cavity such that, when the disk is positioned in the
cavity,
the lip overlaps an outer peripheral portion of the upper face to thereby
secure
the disk in the cavity without obscuring the identifying marking.
Thus, the identification system and method of the present invention
provides a simple yet effective means for marking components such as sections
of drill pipe so that they can be identified and tracked. The identification
disk is
preferably made of a durable material, such as stainless steel. Consequently,
the
disk is relatively impervious to extreme temperatures and pressures. In
addition,
the disk is retained in the cavity by a lip which is formed integrally with
the body
of the component. Thus, little to no risk exists that the disk will be
dislodged
during use of the component. Also, the cavity may be configured and the lip
formed such that an upper portion of the lip is located proximate the wear
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= allowance zone of the component. Thus, as the surface of the component is
worn down during use, exposure of the upper portion of the lip will provide a
visual indication that the component has reached its wear allowance and should
be replaced.
These and other objects and advantages of the present invention will be
made apparent from the following detailed description, with reference to the
accompanying drawings. In the drawings, the same reference numbers may be
used to denote similar components in the various embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a top plan view of one embodiment of an identification disk
which is suitable for use in the identification system and method of the
present
invention;
Figure 2 is a side elevation view of the identification disk shown in Figure
1;
Figure 3 is an illustrative example of a two dimensional code marking
which is suitable for use in the identification system and method of the
present
invention;
Figure 4 is a top plan view of the identification disk of Figure 1 shown
mounted in a representative section of drill pipe;
Figure 5 is a cross sectional view of the drill pipe and identification disk
of
Figure 4 taken along line 5 ¨ 5;
Figure 6 is a cross sectional view similar to Figure 5, but illustrating the
drill pipe having been worn down to the point requiring that it be removed
from
service;
Figure 7 is a top plan view of an alternative embodiment of an
identification disk which is suitable for use in the identification system and
method
of the present invention;
Figure 8 is a top plan view of the identification disk of Figure 1 shown
mounted to a representative section of drill pipe in accordance with another
embodiment of the present invention;
Figure 9 is an enlarged cross sectional view of the drill pipe and
identification disk of Figure 8 taken along line 9 ¨ 9;
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Figure 10 is a cross sectional representation of the drill pipe of Figure 8
showing one embodiment of a cavity within which the identification disk of
Figure
1 may be mounted;
Figure 10a is an enlarged view of the cavity shown in Figure 10;
Figure 11 is a cross sectional representation of the drill pipe of Figure 8
showing another embodiment of a cavity within which the identification disk of
Figure 1 may be mounted;
Figure lla is an enlarged view of the cavity shown in Figure 11;
Figure 12 is an enlarged view similar to Figure 11a but showing a further
embodiment of a cavity within which the identification disk of Figure 1 may be
mounted;
Figure 13 is an enlarged view similar to Figure lla but showing still
another embodiment of a cavity within which the identification disk of Figure
1
may be mounted;
Figures 14a ¨ 14c are cross sectional representations showing the
sequence of mounting the identification disk of Figure 1 into a representative
section of drill pipe in accordance with one embodiment of the method of the
present invention;
Figure 15 is an enlarged cross sectional view of another embodiment of an
identification disk which is suitable for use with the identification system
and
method of the present invention; and
Figure 16 is an enlarged cross sectional view of yet another embodiment
of an identification disk which is suitable for use with the identification
system and
method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a system and method for affixing a
component with unique identifying markings to enable the component to be
identified and tracked throughout its life. The invention involves mounting an
identification disk comprising the unique identifying markings within a cavity
formed in the body of the component. Although the invention has wide
application to various types of components, it will be described herein in the
context of a section of drill pipe. In this context, the wall of the drill
pipe is
analogous to the body of the component.
Referring to Figures 1 and 2, the identification system of one embodiment
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of the present invention comprises an identification disk 10 having generally
parallel upper and lower faces 11, 12. At least the upper face 11 and
preferably
also the lower face 12 are provided with one or more unique identifying
markings
or indicia which correspond to the identity of a distinct section of drill
pipe or the
like to which the disk 10 is or will be mounted. The identifying markings may
comprise, for example, a machine readable code marking 13. Alternatively or in
addition to the code marking 13, the identifying markings may comprise an
alpha-
numeric identification number 14 which can be directly read by a human.
In an exemplary embodiment of the invention, the disk 10 is a planar body
formed of 316 stainless steel. In addition, the disk 10 ideally comprises a
circular
configuration having a diameter of approximately one inch and a thickness
between the upper and lower faces 11, 12 of about one-tenth inch. However, it
should be recognized that the disk 10 may be formed of other suitably durable
materials and may comprise other configurations and/or dimensions.
As shown in Figure 3, the machine readable code marking 13 is ideally
comprised of a two dimensional matrix code. Two dimensional codes have
several advantages over traditional one dimensional bar codes, including
permitting significantly more information or data to be stored in a given
area. For
example, a typical one dimensional bar code is limited to fourteen characters
of
data, whereas a two dimensional code can represent up to several hundred
characters of data. In an exemplary embodiment of the invention, approximately
sixty characters of data are stored in the two dimensional code marking 13.
Two dimensional codes also allow for data redundancy. Thus, if a portion
of the two dimensional code marking 13 is damaged, the data represented by the
code may be read from an undamaged portion of the code marking. The data
redundancy provided by the two dimensional code marking 13 is particularly
significant when the coded article, such as a section of drill pipe, is
subject to
conditions that increase the risk of damage to the code marking.
Although the code marking 13 is described herein as comprising a two
dimensional code, it should be understood that the system of the present
invention is not so limited and that the code marking may comprise any
available
code, including but not limited to a traditional one dimensional bar code.
The code marking 13 and the identification number 14, if used, are
preferably laser engraved on the disk 10. Although other means of applying
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these markings to the disk 10 could be used without deviating from the
principles
of the invention, laser engraving is preferred because it results in the
markings
being slightly cut into the material of the disk, and this provides improved
durability and readability to the markings. Markings formed by laser engraving
are also highly resistant to degradation from chemicals encountered in typical
drilling operations and are not affected by the high temperatures and
pressures to
which the drill pipe may be subjected during use. The specific placement of
the
code marking 13 and the optional identification number 14 on at least the
upper
face 11 of the disk 10 is not critical, although it is preferred that the code
marking
13 not be disposed at the outer peripheral portion of the disk.
The identifying markings comprising the code marking 13 and the optional
identification number 14 represent a discrete and unique code which can be
used
to identify each individual section of drill pipe or the like to which the
disk 10 is or
will be mounted. Each user of the system of the present invention may
determine
the specific data to be represented by the identifying markings. As noted
above,
the data storage capability of the two dimensional code employed for the code
marking 13 allows for the storage of a significant volume of data, and that
capability may be utilized in any desired manner.
In a preferred embodiment of the invention, at least a portion of the
identifying markings comprising the code marking 13 and the optional
identification number 14 represents a unique serial number for each section of
drill pipe or the like to which the disk 10 is or will be mounted. In this
manner, a
comprehensive database may be established and maintained for recording the
complete history of a section of drill pipe, and this history may be accessed
by
the serial number. Thus, when the serial number is read from a section of
drill
pipe, the desired information about the drill pipe can be readily accessed
from the
database. The data storage capability of the two dimensional code marking 13
also allows information about a section of drill pipe to be stored directly on
the
drill pipe so that it may be immediately available from a scanner read-out
without
having to access, e.g., a remotely maintained database.
As generally illustrated in Figures 4 and 5, in one embodiment of the
invention each disk 10 is associated with a section of drill pipe 15 by
embedding
the disk within a cavity 16 which extends into the body or Wall of the drill
pipe
from the outer surface thereof. As shown in Figure 5, the depth of the cavity
16 is
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preferably greater than the thickness of the disk 10 so that the upper face 11
of
the disk will be countersunk below the outer surface. The disposition of the
upper
face 11 below the outer surface protects the identifying markings from
abrasion
and erosion and thereby contributes to the continued readability of the
identifying
markings over the useful life of the drill pipe.
In one embodiment of the invention, the disk 10 is secured in the cavity 16
by means of an adhesive material 17 which is disposed between the bottom of
the cavity and the lower face 12 of the disk. Alternatively, other means of
securing the disk 10 in the cavity 16 may be employed, so long as the
identifying
markings on the upper face 11 are not obscured. Also, it is preferred that the
disk 10 be removable from the cavity so that, in the event the identifying
markings
on the upper face 11 become unreadable, the disk may be removed from the
cavity 16 and the same markings on the lower face 12 of the disk may be read.
A
replacement disk 10 may then be secured in the cavity 16 to assure continued
tracking of the drill pipe 15.
In a preferred embodiment of the invention, the cavity 16 is left open
above the upper face 11 of disk 10. Although some debris may accumulate in
this portion of the cavity 16 during use of the drill pipe, such debris may be
easily
removed before scanning the code marking 13 or reading the identification
number 14. Moreover, the presence of debris may actually serve to protect the
upper face 11 of the disk 10. Although not preferred, the cavity 16 may be
filled
above the disk 10 with, e.g., a transparent material or a removable plug.
It should be noted that boring or otherwise forming the relatively small
cavity 16 into the wall of the drill pipe will not compromise the strength or
durability of the drill pipe or reduce its utility. The location of the cavity
16 is
subject to some variation and is within the discretion of the user or
manufacturer;
however, the cavity is ideally disposed in a location which is subject to wear
and
erosion in order to take full advantage of the features of the present
invention.
For example, the cavity 16 may be disposed in a collar or tool joint of the
drill
pipe.
In addition to providing a secure and protected identification system for
sections of drill pipe and the like, the system of the present invention also
affords
a simple and reliable means for monitoring the wear experienced by a section
of
drill pipe so that a determination can be made as to whether that section
should
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be removed from service. During use, the surface of a section of drill pipe is
abraded away, and when the diameter of the monitored area of the drill pipe is
reduced to a predetermined minimum dimension, the section of drill pipe may no
longer be used.
Thus, in accordance with one embodiment of the invention, the cavity 16 is
bored to a depth approximately equal to the thickness of the disk 10 plus the
wear allowance zone of the drill pipe. In this manner, the distance between
the
outer surface of the drill pipe and the upper face 11 of the disk will be
equal to the
depth of the wear allowance zone. During use of the drill pipe, the wear
allowance zone will gradually decrease as the pipe wears and the diameter of
the
pipe is reduced. As shown in Figure 6, since the cross-sectional configuration
of
the drill pipe is circular and the upper face 11 of the disk 10 is flat,
erosion of the
drill pipe will expose the peripheral edge of the disk before the central
portion of
the upper face 11 is exposed to abrasion. Therefore, the identifying markings
will
still be readable when the section of drill pipe has worn to the point at
which it
must be removed from service. Thus, with the system of the present invention,
monitoring the wear of sections of drill pipe may be reliably performed
visually,
without the need to actually measure the diameter of the pipe.
A number of variations and alternative embodiments are within the scope
of the present invention. In one variation, the identifying indicia could be
omitted
from the lower face 12 of the disk 10. In another variation, the identifying
indicia
may be engraved or otherwise applied to a thin, preferably metal tag 18 which
is
attached to the upper face 11 of the disk 10, as illustrated in Figure 7.
Another embodiment of the identification system of the present invention is
shown in Figures 8 and 9. In this embodiment, the disk 10 is retained in the
cavity 16 by an annular lip 20. The lip 20 is formed after the disk 10 has
been
positioned in the cavity 16. In addition, the lip 20 is configured to overlap
only the
periphery of the disk 10 so that it will securely retain the disk in the
cavity 16
without obscuring the identifying markings located on the top surface 11.
Furthermore, the lip 20 may be formed so that an upper portion of the lip is
located proximate the bottom of the wear allowance zone W of the drill pipe
15.
Thus, as the surface of the drill pipe 15 is worn down through use, exposure
of
the upper portion of the lip 20 will provide a visual indication that the
drill pipe has
reached its wear allowance and should be replaced.
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In accordance with the present invention, the cavity 16 is specifically
configured to facilitate the formation of the lip 20 from a portion of the
wall of the
drill pipe adjacent the cavity. Referring to Figures 10 and 10a, for example,
in
one embodiment of the invention the cavity 16 comprises an inner portion 16a
within which the disk 10 is positioned, an outer portion 16b which extends
between the inner portion and the surface of the drill pipe 15, and an annular
shoulder 22 which is located between the inner and outer portions. In this
embodiment, the inner and outer portions 16a, 16b comprise generally
cylindrical
configurations, the diameter D1 of the inner portion is less than the diameter
D2 of
the outer portion, and the shoulder 22 comprises a generally square profile.
As
will be discussed more fully below, the lip 20 is formed by compressing the
shoulder 22 over the outer periphery of the disk 10, for example using a press
forging process. Thus, the lip 22 comprises an integral part of the drill pipe
15
which will securely retain the disk 10 within the cavity 16 without obscuring
the
identifying markings on the upper face 11 of the disk.
In the embodiment of the invention shown in Figures 10 and 10a, the
diameter D1 of the inner portion 16a of the cavity is about the same as or
slightly
larger than the diameter of the disk 10. In addition, the depth d1 of the
inner
portion 16a of the cavity, which also corresponds to the height of the
shoulder 22
from the bottom of the cavity, is designed to be greater than the thickness of
the
disk 10 by an amount which is sufficient to provide the shoulder with adequate
material above the disk from which to form a lip 20 having a desired thickness
and radial width. Furthermore, the depth d2 of the outer portion 16b of the
cavity
may be chosen to result in an upper portion of the lip 20 being located
proximate
the bottom of the wear allowance zone W of the drill pipe 15. In an exemplary
and non-limiting embodiment of the invention, where the disk 10 comprises a
diameter of 1.00" and a thickness of 0.10", the cavity 16 may comprise the
following dimensions: D1 = 1.000"; d1 = 0.200"; D2 = 1.250"; and d2 = 0.200".
These dimensions would be appropriate, for example, when the cavity 16 is
formed in a drill pipe tool joint which comprises a new outer diameter of
6.625"
and a wear allowance zone of 0.3125" (i.e. a minimum outer diameter of
6.3125").
Another embodiment of the present invention is shown in Figures 11 and
11a. Similar to the embodiment described immediately above, the cavity 16' of
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this embodiment of the invention comprises an inner portion 16a' within which
the
disk 10 is positioned, an outer portion 16b' which extends between the inner
portion and the surface of the drill pipe, and an annular shoulder 22' which
is
located between the inner and outer portions. In addition, the diameter D1 of
the
inner portion 16a' is less than the diameter D2 of the outer portion 16b'. In
contrast with the shoulder 22 of the previous embodiment, however, the
shoulder
22' comprises an inclined profile. In particular, the shoulder 22' comprises a
radially inner portion S1 which is located a first distance h1 from the outer
surface
of the drill pipe and a radially outer portion S2 which is located a second
distance
h2 from the outer surface of the drill pipe that is greater than the first
distance.
Thus, the shoulder 22' comprises a generally triangular profile which forms an
angle a with the outer portion 16b' of the cavity and comprises a height Ah of
h2¨
h1. However, the shoulder 22' could comprise other configurations, including
but
not limited to a concave profile as shown in Figure 12 or a convex profile as
shown in Figure 13.
As in the previous embodiment, the lip 20 is formed by compressing the
shoulder 22' over the outer periphery of the disk 10 using, for example, a
press
forging process. Since the shoulder 22' is inclined rather than square, the
radially
outer surface, or hypotenuse, of the shoulder is not connected to the wall of
the
drill pipe. Consequently, much less force is required to compress the shoulder
into the shape of the lip 20. In addition, the inclined shape of the shoulder
22'
allows better control to be maintained over the shape of the lip 20 during the
forming process.
In the embodiment of the invention shown in Figures 11 and 11a, the
diameter D1 of the inner portion 16a' of the cavity is about the same as or
slightly
larger than the diameter of the disk 10. In addition, the depth d1 of the
inner
portion 16a' of the cavity, which also corresponds to the height of the
shoulder
22' above the bottom of the cavity, is designed to be greater than the
thickness of
the disk 10 by an amount which is sufficient to provide the shoulder with
adequate material above the disk from which to form a lip 20 having a desired
thickness and radial width. Furthermore, the depth d2 of the outer portion
16b' of
the cavity may be chosen to result in an upper portion of the lip 20 being
located
proximate the bottom of the wear allowance zone W of the drill pipe 15. In an
exemplary and non-limiting embodiment of the invention, where the disk 10 =
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comprises a diameter of 1.00" and a thickness of 0.10", the cavity 16' may
comprise the following dimensions: D1 = 1.000"; d1 = 0.200"; D2 = 1.250"; d2 =
h2
= 0.200"; a = 60'; and Ah = 0.045". These dimensions would be appropriate, for
example, when the cavity 16 is formed in a drill pipe tool joint which
comprises a
The method of mounting the disk 10 to a section of drill pipe 15 in
accordance with the present invention will now be described with reference to
Figures 14a ¨ 14c. The first step of the method involves forming the cavity,
such
After the cavity 16a' is formed in the drill pipe 15, the disk 10 is placed in
the inner portion 16a' of the cavity, as shown in Figure 14b. The lip 20 is
then
formed over the disk 10 using, for example, a press forging process. The press
If a need arises to remove the disk 10, the lip 20 may be cut away from the
wall of the drill pipe 15 using a suitable hole saw. This will leave the disk
10
unrestrained and thereby allow the disk to be easily removed from the cavity
16'.
Although the disk 10 has been described above as having parallel upper
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face 12. As a result, the peripheral edge 28 of the disk 10' is inclined
radially
inwardly from the lower face 12 to the upper face 11. This inclined peripheral
edge 28 presents a suitable outer peripheral portion of the disk 10' over
which the
lip 20 may be formed to thereby secure the disk within the cavity 16. In
another
exemplary embodiment of the invention, which is shown in Figure 16, the disk
10"
comprises an outer peripheral edge in which a circumferential, generally V-
shaped groove 30 is formed. As with the inclined peripheral edge 28, the
groove
30 presents a suitable outer peripheral portion of the disk 10' over which the
lip
20 may be formed to thereby secure the disk within the cavity 16.
The cavity has been described herein as being circular since such cavities
can be easily bored and minimize structural stress on the drill pipe. However,
it
should be understood that the scope of the present invention encompasses the
use of non-circular cavities and non-circular disks 10. For example, the
present
invention may be used with rectangular cavities and disks. Thus, unless
otherwise indicated, the terms "cavity" and "disk" in the foregoing
description are
to be understood to include non-circular configurations.
It is also to be understood that although the system and method of the
invention are particularly useful in the context of identifying, tracking, and
monitoring drill pipe, the invention may be effectively utilized for
identifying,
tracking, and/or monitoring other components. The system of the invention is
particularly advantageous for use with components that are subject to ablative
wear and/or extreme environments.
It should be recognized that, while the present invention has been
described in relation to the preferred embodiments thereof, those skilled in
the art
may develop a wide variation of structural and operational details without
departing from the principles of the invention. Therefore, the appended claims
are to be construed to cover all equivalents falling within the true scope and
spirit
of the invention.
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