U.S. patent application number 17/059493 was filed with the patent office on 2021-07-08 for conductive outer jacket for wireline cable.
The applicant listed for this patent is Schlumberger Technology Corporation. Invention is credited to Qingdi Huang, Serko Sarian, Tam Tran, Joseph Varkey.
Application Number | 20210210252 17/059493 |
Document ID | / |
Family ID | 1000005521121 |
Filed Date | 2021-07-08 |
United States Patent
Application |
20210210252 |
Kind Code |
A1 |
Varkey; Joseph ; et
al. |
July 8, 2021 |
Conductive Outer Jacket for Wireline Cable
Abstract
A cable containing a conductive outer layer and methods for
manufacturing the conductive outer layer and the cable are
provided. A cable may include a cable core and a plurality of armor
wire strength members that surround the cable core. The cable may
also include a conductive outer layer disposed about the plurality
of armor wire strength members that physically contacts at least
one armor wire strength member of the plurality of armor wire
strength members.
Inventors: |
Varkey; Joseph; (Richmond,
TX) ; Sarian; Serko; (Houston, TX) ; Huang;
Qingdi; (Sugar Land, TX) ; Tran; Tam; (Sugar
Land, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schlumberger Technology Corporation |
Sugar Land |
TX |
US |
|
|
Family ID: |
1000005521121 |
Appl. No.: |
17/059493 |
Filed: |
May 29, 2019 |
PCT Filed: |
May 29, 2019 |
PCT NO: |
PCT/US2019/034352 |
371 Date: |
November 30, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62678659 |
May 31, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01B 9/00 20130101; H01B
7/1895 20130101; H01B 1/20 20130101; H01B 7/22 20130101 |
International
Class: |
H01B 7/22 20060101
H01B007/22; H01B 7/18 20060101 H01B007/18; H01B 1/20 20060101
H01B001/20; H01B 9/00 20060101 H01B009/00 |
Claims
1. A cable comprising: a cable core; a plurality of armor wire
strength members that surround the cable core; and a conductive
outer layer disposed about the plurality of armor wire strength
members, wherein the conductive outer layer physically contacts at
least one armor wire strength member of the plurality of armor wire
strength members.
2. The cable of claim 1, wherein the conductive outer layer
comprises a polymer jacket doped with a conductive material.
3. The cable of claim 2, wherein the plurality of armor wire
strength members are embedded within the polymer jacket.
4. The cable of claim 2, wherein a doping concentration of the
conductive material is less than 30%.
5. The cable of claim 2, wherein the conductive material comprises
conductive carbon black, metallic fibers, metallic powder,
conductive Nano particles, or any combination thereof.
6. The cable of claim 5, wherein the metallic powder comprises
zinc, copper, or both.
Description
CROSS REFERENCE PARAGRAPH
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/678,659, entitled "CONDUCTIVE OUTER JACKET FOR
WIRELINE CABLE," filed May 31, 2018, the disclosure of which is
hereby incorporated herein by reference.
BACKGROUND
[0002] This disclosure relates to a system and method for
electrically grounding outer strength member layers of a wellbore
cable.
[0003] This section is intended to introduce the reader to various
aspects of art that may be related to various aspects of the
present techniques, which are described and/or claimed below. This
discussion is believed to be helpful in providing the reader with
background information to facilitate a better understanding of the
various aspects of the present disclosure. Accordingly, it should
be understood that these statements are to be read in this light,
and not as an admission of any kind.
[0004] Producing hydrocarbons from a wellbore drilled into a
geological formation is a remarkably complex endeavor. In many
cases, decisions involved in hydrocarbon exploration and production
may be informed by measurements from downhole well-logging tools
that are conveyed deep into the wellbore. The measurements may be
used to infer properties and characteristics of the geological
formation surrounding the wellbore. Thus, when a wellbore is
investigated to determine the physical condition of a fluid within
the wellbore, a gas within the wellbore, or the wellbore itself, it
may be desirable to place downhole device with associated
measurement tools and/or sensors within the wellbore.
[0005] A cable may be used to raise or lower the downhole device
within a casing of the wellbore. The cable may be formed from a
combination of conductors, insulative materials, filler materials,
polymer jackets, and armor wire strength members that extend along
a length of the cable. In many cases, certain of the conductors are
disposed within a protected cable core near a center of the cable.
These conductors may transmit electrical energy, such as an
electrical current, from a power supply disposed near the surface
of the wellbore to the downhole device. As such, the conductors may
facilitate remote operation of the downhole device. In certain
cases, the armor wire strength members circumferentially surround
the cable core and transmit a return electrical current from the
downhole device to the power supply. Many cables may include an
insulative polymer jacket disposed about the armor wire strength
members to smooth an exterior of the cable and facilitate
traversing the cable along the wellbore. Yet, as a result, the
armor wire strength members could carry an undesirable voltage
potential.
SUMMARY
[0006] A summary of certain embodiments disclosed herein is set
forth below. It should be understood that these aspects are
presented merely to provide the reader with a brief summary of
these certain embodiments and that these aspects are not intended
to limit the scope of this disclosure. Indeed, this disclosure may
encompass a variety of aspects that may not be set forth below.
[0007] In one example, a cable includes a cable core and a
plurality of armor wire strength members that surround the cable
core. The cable also includes a conductive outer layer disposed
about the plurality of armor wire strength members that physically
contacts at least one armor wire strength member of the plurality
of armor wire strength members.
[0008] Various refinements of the features noted above may be
undertaken in relation to various aspects of the present
disclosure. Further features may also be incorporated in these
various aspects as well. These refinements and additional features
may exist individually or in any combination. For instance, various
features discussed below in relation to one or more of the
illustrated embodiments may be incorporated into any of the
above-described aspects of the present disclosure alone or in any
combination. The brief summary presented above is intended to
familiarize the reader with certain aspects and contexts of
embodiments of the present disclosure without limitation to the
claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various aspects of this disclosure may be better understood
upon reading the following detailed description and upon reference
to the drawings in which:
[0010] FIG. 1 is a schematic diagram of a wellbore logging system
and downhole device that may obtain data measurements along the
length of the wellbore, in accordance with an embodiment of the
present disclosure;
[0011] FIG. 2 is a schematic diagram of the downhole device and a
cable having a conductive outer layer, in accordance with an
embodiment of the present disclosure;
[0012] FIG. 3 is a perspective view of the cable having the
conductive outer layer, in accordance with an embodiment of the
present disclosure;
[0013] FIG. 4 is a cross-sectional view of the cable, which
illustrates a conductive polymer jacket disposed about armor wire
strength members of the cable, in accordance with an embodiment of
the present disclosure;
[0014] FIG. 5 is a cross-sectional view of the cable, which
illustrates the armor wire strength members embedded within the
conductive polymer jacket; in accordance with an embodiment of the
present disclosure;
[0015] FIG. 6 is a cross-sectional view of the cable, which
illustrates a conductive flat wire array disposed about the armor
wire strength members, in accordance with an embodiment of the
present disclosure;
[0016] FIG. 7 is a cross-sectional view of the cable, which
illustrates a conductive round wire array disposed about the armor
wire strength members, in accordance with an embodiment of the
present disclosure;
[0017] FIG. 8 is a cross-sectional view of the cable, which
illustrates the conductive round wire array disposed about the
conductive polymer jacket, in accordance with an embodiment of the
present disclosure;
[0018] FIG. 9 is a cross-sectional view of the cable, which
illustrates a multi-layered conductive flat wire array disposed
about the armor wire strength members, in accordance with an
embodiment of the present disclosure;
[0019] FIG. 10 is a cross-sectional view of the cable, which
illustrates a multi-layered conductive round wire array disposed
about the armor wire strength members, in accordance with an
embodiment of the present disclosure;
[0020] FIG. 11 is a cross-sectional view of the cable, which
illustrates the multi-layered conductive round wire array disposed
about the conductive polymer jacket, in accordance with an
embodiment of the present disclosure;
[0021] FIG. 12 is a cross-sectional view of the cable, which
illustrates a conductive tape disposed about the armor wire
strength members, in accordance with an embodiment of the present
disclosure; and
[0022] FIG. 13 is a cross-sectional view of the cable, which
illustrates the armor wire strength members embedded within the
conductive tape, in accordance with an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0023] One or more specific embodiments of the present disclosure
will be described below.
[0024] These described embodiments are only examples of the
presently disclosed techniques. Additionally, in an effort to
provide a concise description of these embodiments, all features of
an actual implementation may not be described in the specification.
It should be appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation-specific decisions must be made to achieve the
developers' specific goals, such as compliance with system-related
and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure.
[0025] When introducing elements of various embodiments of the
present disclosure, the articles "a," "an," and "the" are intended
to mean that there are one or more of the elements. The terms
"comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements. Additionally, it should be understood that
references to "one embodiment" or "an embodiment" of the present
disclosure are not intended to be interpreted as excluding the
existence of additional embodiments that also incorporate the
recited features.
[0026] As discussed above, some wellbore cables may include an
insulative polymer jacket that encompasses armor wire strength
members extending along a length of the cable. Accordingly, the
insulative polymer jacket may inhibit grounding the armor wire
strength members to a surrounding environment, such as a casing or
an adjacent geological formation, and thus, enable an accumulation
of electrical charge within the armor wire strength members. The
systems and methods of this disclosure allow for grounding of the
armor wire strength members of jacketed wireline cables which may
reduce, or substantially eliminate, undesirable buildup of
electrical charge and/or undesirable electrical discharge between
the cable and the surrounding environment.
[0027] With this in mind, FIG. 1 illustrates a well-logging system
10 that may employ the systems and methods of this disclosure. The
well-logging system 10 may be used to convey a downhole device 12
or a dummy weight through a geological formation 14 via a wellbore
16. In some embodiments, a casing 17 may be disposed within the
wellbore 16, such that the downhole device 12 may traverse the
wellbore 16 within the casing 17. The downhole device 12 may be
conveyed on a cable 18 via a logging winch system 20. Although the
logging winch system 20 is schematically shown in FIG. 1 as a
mobile logging winch system carried by a truck, the logging winch
system 20 may be substantially fixed (e.g., a long-term
installation that is substantially permanent or modular). Any cable
18 suitable for well logging may be used. The cable 18 may be
spooled and unspooled on a drum 22 and an auxiliary power source 24
may provide energy to the logging winch system 20 and/or the
downhole device 12.
[0028] The downhole device 12 may provide logging measurements 26
to a data processing system 28 via any suitable telemetry (e.g.,
via electrical or optical signals pulsed through the geological
formation 14 or via mud pulse telemetry). The data processing
system 28 may process the logging measurements. The logging
measurements 26 may indicate certain properties of the wellbore 16
(e.g., pressure, temperature, strain, vibration, or other) that
might otherwise be indiscernible by a human operator.
[0029] To this end, the data processing system 28 thus may be any
electronic data processing system that can be used to carry out the
systems and methods of this disclosure. For example, the data
processing system 28 may include a processor 30, which may execute
instructions stored in memory 32 and/or storage 34. As such, the
memory 32 and/or the storage 34 of the data processing system 28
may be any suitable article of manufacture that can store the
instructions. The memory 32 and/or the storage 34 may be ROM
memory, random-access memory (RAM), flash memory, an optical
storage medium, or a hard disk drive, to name a few examples. A
display 36, which may be any suitable electronic display, may
provide a visualization, a well log, or other indication of
properties in the geological formation 14 or the wellbore 16 using
the logging measurements 26.
[0030] FIG. 2 is a schematic diagram of the cable 18 disposed
within the wellbore 16. The cable 18 includes a cable core 40 that
extends along a length of the cable 18. The cable core 40 may
include several insulated conductors that direct an electrical
current 42, or an electrical signal, from a power source, such as
the auxiliary power source 24, to the downhole device 12. The
insulated conductors may be disposed in configurations such as
monocables, coaxial cables, quad cables, heptacables, or any other
suitable cable configuration. As described in greater detail
herein, the cable 18 includes one or more armor wire strength
members that are disposed about the insulated conductors and
transmit a return electrical current from the downhole device 12 to
the auxiliary power source 24. The cable 18 includes a conductive
outer layer 44, which is disposed about and physically contacts the
armor wire strength members, thus forming a conductive connection
there between. Accordingly, the conductive outer layer 44 forms an
exterior surface 46 of the cable 18, which is electrically coupled
to the armor wire strength members.
[0031] The conductive outer layer 44 physically contacts the casing
17 along one or more points of contact, referred to herein as
engagement points 47, which ground the armor wire strength members
of the cable 18 to the surrounding casing 17. As described in
greater detail herein, the conductive outer layer 44 may thus
reduce, or substantially eliminate, a potential difference (e.g., a
voltage differential) between the armor wire strength members and a
surrounding environment, such as the casing 17, components of the
well-logging system 10, and/or the geological formation 14. As
such, undesirable electrical discharge between the armor wire
strength members and such surrounding structures may be
mitigated.
[0032] Although the cable 18 is shown as disposed within the casing
17 in the illustrative embodiment of FIG. 2, it should be noted
that in other embodiments, the cable 18 may be used in a wellbore
that does not include an outer casing, such as the casing 17. In
such embodiments, the conductive outer layer 44 of the cable 18 may
physically contact the geological formation 14 encompassing the
wellbore 16. Accordingly, the engagement points 47 may directly
ground the exterior surface 46 of the cable 18 to the geological
formation 14, and thus, similar to the discussion above,
substantially reduce or eliminate a potential difference between
the armor wire strength members and the environment surrounding the
cable 18.
[0033] FIG. 3 illustrates a perspective view of the cable 18. As
noted above, the conductive outer layer 44 grounds one or more
armor wire strength members 48 disposed within the cable 18 to the
surrounding environment, and thus, ensures that a potential
difference between the armor wire strength members 48 and the
surrounding environment is negligible. For example, in certain
cases, the cable 18 may incur wear during operation of the cable
18, such that a puncture 49 is formed within the conductive outer
layer 44. The puncture 49 may reveal an exposed portion 51 of the
armor wire strength members 48, which is uncovered from the
conductive outer layer 44. However, because the armor wire strength
members 48 and the conductive outer layer 44 are both grounded via
the physical contact between the conductive outer layer 44 and the
engagement points 47, a potential difference between the exposed
portion 51 and the surrounding environment is substantially small.
Accordingly, the conductive outer layer 44 may mitigate, or
substantially eliminate undesirable electrical discharge between
the exposed portion 49 of the armor wire strength members 48 and
the surrounding environment, such as the casing 17, the logging
winch system 20, the drum 22, or any other component of the
well-logging system 10. Further, the conductive outer layer 44 may
ensure that a voltage differential between a first end portion 53
of the cable 18 and a second end portion 55 of the cable 18 is
substantially similar. Accordingly, the conductive outer layer 44
may substantially reduce or eliminate the buildup of electrical
charge between the first and second end portion 53, 55 of the cable
18.
[0034] FIG. 4 is a cross-sectional view of one embodiment of the
cable 18. As noted above, the cable core 40 may include several
conductors 50, which are circumferentially encompassed by an
insulative layer 52. Accordingly, the insulative layer 52 may
substantially block undesirable electrical current flow between the
conductors 50 and other portions of the cable 18. The cable core 40
may be encompassed by a pair of concentric of armor wire strength
member arrays, which collectively form the armor wire strength
members 48. For example, the cable core 40 may be circumferentially
surrounded by one or more inner armor wire strength members 54,
which are circumferentially surrounded by one or more outer armor
wire strength members 56.
[0035] The armor wire strength members 48 may be served (e.g.,
coiled helically) around the cable core 40, extend longitudinally
along the length of the cable core 40, or be disposed about the
cable core 40 in any fashion suitable to surround the cable core
40. The armor wire strength members 48 may physically protect the
cable core 40 and may provide additional rigidity to the cable 18.
In addition, the armor wire strength members 48 may support the
weight of the cable 18 and alleviate strain on the cable core 40.
Further, as noted above, the armor wire strength members 48 may
conduct an electrical current, for example, between the downhole
device 12 and the auxiliary power source 24. For example, the
conductors 50 may direct a primary electrical current, such as the
electrical current 42, from the axillary power source 24 to the
downhole device 12, while the armor wire strength members 48 direct
a return electrical current from the downhole device 12 toward the
auxiliary power source 24. It should be noted that in other
embodiments, the armor wire strength members 48 may include only a
single layer of armor wire strength members that circumferentially
surround the cable core 40, rather a pair of concentric layers,
such as the inner armor wire strength members 54 and the outer
armor wire strength members 56 shown in the illustrative embodiment
of FIG. 4.
[0036] A first layer of polymeric material 60 is contiguously
disposed within interstitial spaces formed between the inner armor
wire strength members 54 and the insulative layer 52 of the cable
core 40. Similarly, a second layer of polymeric material 62 is
contiguously disposed within interstitial spaces formed between the
outer armor wire strength members 56 and the first layer of
polymeric material 60. However, it should be noted that in other
embodiments, the first layer of polymeric material 60 and the
second layer of polymeric material 62 may include a single layer of
polymeric material that extends between the interstitial spaces of
both the inner armor wire strength members 54 and the outer armor
wire strength members 56. In some embodiments, the first and second
layers of polymeric material 60, 62 may include an insulating
material, such as, for example,
polytetrafluoroethylene-perfluoromethylvinylether polymer (MFA),
perfluoro-alkoxyalkane polymer (PFA), polytetrafluoroethylene
polymer (PTFE), ethylene-tetrafluoroethylene polymer (ETFE),
ethylene-propylene copolymer (EPC), poly(4-methyl-1-pentene), other
polyolefins, other fluoropolymers, polyaryletherether ketone
polymer (PEEK), polyphenylene sulfide polymer (PPS), modified
polyphenylene sulfide polymer, polyether ketone polymer (PEK),
maleic anhydride modified polymers, and any mixtures thereof
[0037] A conductive polymer jacket 68 is disposed about the second
layer of polymeric material 62 and forms the conductive outer layer
44 of the cable 18. The conductive polymer jacket 68 includes
conductive materials embedded therein, which enhance an electrical
conductivity of the conductive polymer jacket 68. As a non-limiting
example, materials embedded in the conductive polymer jacket 68 may
include conductive carbon black, chopped or milled carbon fiber,
chopped metallic fibers, and/or conductive Nano-particles. In other
embodiments, a metallic powder may be doped into the conductive
polymer jacket 68. The metallic powder may include, but is not
limited to, materials such zinc, copper, iron, or any suitable
other conductive metallic particles. Further, it should be noted
that in some embodiments, the conductive polymer jacket 68 may
include a combination of any of the materials listed above. A
doping concentration of the above listed materials within the
conductive polymer jacket 68 may be between approximately 0.1% to
30% of a total volume of the conductive polymer jacket 68. However,
in other embodiments, the concentration of conductive materials
embedded within the conductive polymer jacket 68 may be greater
than 30% of the total volume of the conductive polymer jacket
68.
[0038] In any case, the conductive polymer jacket 68 may, for
example, be extruded about the outer armor wire strength members
56. The conductive polymer jacket 68 may physically contact the
outer armor wire strength members 56, and thus, establish an
electrical connection there between. As such, the conductive
polymer jacket 68 may facilitate grounding the outer armor wire
strength members 56 via the engagement points 47 between the
exterior surface 46 of the cable 18 and the casing 17. Accordingly,
the conductive polymer jacket 68 may substantially reduce or
eliminate a buildup of undesirable electric charge within the outer
armor wire strength members 56.
[0039] Turning now to FIG. 5, in certain embodiments, the conducive
polymer jacket 68 may be used in lieu of the second layer of
polymeric material 62. In such cases, the outer armor wire strength
members 56 are embedded within the conductive polymer jacket 68,
such that the conductive polymer jacket 68 may fill interstitial
spaces between the outer armor wire strength members 56. For
example, the conductive polymer jacket 68 may be heated and melted
during assembly of the cable 18, such that the outer armor wire
strength members 56 may be rolled into the conductive polymer
jacket 68. As such, the conductive polymer jacket 68 may also
physically contact the inner armor wire strength members 54.
Accordingly, both the inner armor wire strength members 54 and the
outer armor wire strength members 56 may be grounded to the casing
17 and/or the geological formation 14 via the conductive polymer
jacket 68. In yet further embodiments, the conductive polymer
jacket 68 may extend between the exterior surface 46 of the cable
18 and the insulating layer 52 of the conductors 50, thus rending
the first layer of polymeric material 60 obsolete. In such cases,
the conductive polymer jacket 68 may fill any interstitial spaces
between both the inner and outer armor wire strength members 54,
56.
[0040] Turning now to FIGS. 6 and 7, which illustrate a
cross-sectional view of the cable 18 in which the conductive outer
layer 44 is formed from a conductive wire array 70. The wire array
70 may be served (e.g., coiled helically) around the second layer
of polymeric material 62, extend longitudinally along the length of
the second layer of polymeric material 62, or be disposed about the
second layer of polymeric material 62 in any fashion suitable to
surround second layer of polymeric material 62. Each wire of the
wire array 70 may include flat steel or alloy wire 72, as shown in
FIG. 6, or a round steel or alloy wire 74, as shown in FIG. 6.
Additionally or otherwise, each wire of the wire array 70 may
include a key stone shaped wire, or any other suitable
cross-section of wire. In some embodiments, the wire array 70 may
include a combination of two or more of the wire types listed
above. For example, the wire array 70 may include a combination of
both the flat steel or alloy wire 72 and the round steel or alloy
wire 74. An interstitial space formed between individual wires of
the wire array 70 may be occupied by a pack-off material 76, such
as rubber, polymer, epoxy resin, or the like. Accordingly, the
pack-off material 76 may smoothen an exterior surface of the wire
array 70 or, in other words, the exterior surface 46 of the cable
18, which may facilitate traversing the cable 18 along the wellbore
16. However, it is important to note that the pack-off material 76
does not extend over a radially outermost surface of the wire array
70. In other words, an outer surface of each wire of the wire array
70 remains exposed, such that the wire array 70 may physically
contact the casing 17 at the engagement points 47.
[0041] In some embodiments, the wire array 70 may cover
approximately 5% to 90% of the exterior surface 46 of the cable 18.
The wire array 70 may physically contact one or more armor wires of
the outer armor wire strength members 56, and thus, establish an
electrical connection there between. For example, in certain
embodiments, the wire array 70 may be embedded within the second
layer of polymeric material 62 during manufacturing of the cable
18, and thus, physically contact the outer armor wire strength
members 56. In other embodiments, the outer armor wire strength
members 56 may radially extend beyond the second layer of polymeric
material 62, and thus, facilitate conductive contact with the wire
array 70 disposed circumferentially thereabout. In any case, the
wire array 70 may ground the outer armor wire strength members 56
via the engagement points 46 between the wire array 70 and the
casing 17 and/or the geological formation 14.
[0042] It should be noted that in some embodiments, the wire array
70 may be used in conjunction to the conductive polymer jacket 68
discussed above. For example, as illustrated in FIG. 8, the inner
and outer armor wire strength members 54, 56 may be embedded, or
partially embedded within the conductive polymer jacket 68, and
thus, establish and conductive connection there between. The wire
array 70 may be circumferentially disposed about the conductive
polymer jacket 68. Accordingly, the wire array 70 conductively
engages with both the outer armor wire strength members 56 and the
inner armor wire strength members 54 via the conductive polymer
jacket 68. In further embodiments, the wire array 70 may be
embedded with the conductive polymer jacket 68 and provide
additional support or protection to the conductive polymer jacket
68. In such embodiments, the conductive polymer jacket 68 may fill
interstitial gaps between each wire of the wire array 70, and thus,
smoothen the exterior surface 46 of the cable 18. In other words,
the conductive polymer jacket 68 may be used in lieu of the
pack-off material 76 in such embodiments.
[0043] In some embodiments, the cable 18 may include multiple
concentric layers of wire array disposed about the exterior surface
46 of the cable 18. For example, FIGS. 9, 10, and 11 illustrate
FIGS. 6, 7, and 8, respectively, having an additional wire array 80
disposed about the wire array 70. The additional wire array 80 may
be configured similar to the wire array 70 discussed above, and
provide further protect the cable 18 from wear and/or abrasion,
such as when the cable 18 traverses the wellbore 16 or is unspooled
or spooled from the drum 22. It is important to note that one of
ordinary skill in the art would appreciate that the exterior
surface 46 of the cable 18 is not limited to two layers of wire
arrays, such the wire array 70 and the additional wire array 80.
For example, the cable 18 may include 1, 2, 3, 4, 5, 6, or more
layers of wire array that form the exterior surface 46 of the cable
18, and thus, for the conductive outer layer 44.
[0044] FIG. 12 illustrates a cross-sectional view of the cable 18
in which the conductive outer layer 44 of the cable 18 is formed
from a metallic tape 82 (e.g., a metallic mesh). For example, in
some embodiments, a pack-off material, such as the pack-off
material 76, is disposed between interstitial gaps of the outer
armor wire strength members 56 and the second layer of polymeric
material 62. Accordingly, the pack-off material 76 may provide a
smooth circumferential surface onto which the metallic tape 82 may
adhere. It is important to note that a contact patch 84 of the
outer armor wire strength members 56 remains uncovered by the
pack-off material 76. The contact patch 84 may include a surface
area located near the radially outmost point of each of the outer
armor wire strength members 56, relative to a center of the cable
18. The metallic tape 82 is disposed about the outer armor wire
strength members 56 of the cable 18, such that a conductive
connection is established between the contact patch 84 and the
metallic tape 82. The metallic tape 82 may be served (e.g., coiled
helically) around the outer armor wire strength members 56, extend
longitudinally along the outer armor wire strength members 56, or
be disposed about the outer armor wire strength members 56 in any
fashion suitable to surround the outer armor wire strength members
56.
[0045] Turning now to FIG. 13, in other embodiments, the outer
armor wire strength members 56 may be embedded within the metallic
tape 82. For example, the metallic tape 82 may be applied about
each wire of the outer armor wire strength members 56 in layers
during assembly of the cable 18 and, as such, embed each of the
outer armor wire strength members 56 within the metallic tape 82.
In such embodiments, the metallic tape 82 may replace the second
layer of polymeric material 62, such that the metallic tape 82 may
physically contact the inner armor wire strength members 54.
Accordingly, the metallic tape 82 may conductively couple both the
inner and outer armor wires strength members 54, 56 to the exterior
surface 46 of the cable 18. The metallic tape 82 may thus ground
the inner and outer armor wire strength members 54, 56 during
operation of the cable 18 within the wellbore 16 and/or while
spooling or unspooling from the drum 22.
[0046] In certain cases, the metallic tape 82 may extend from the
exterior surface 46 of the cable 18 to the insulating layer 52 of
the conductors 50, and thus, render the first layer of polymeric
material 60 obsolete. For example, in such cases, the metallic tape
82 may be wrapped about each wire of the inner armor wire strength
members 54 in addition to each wire of the outer armor wire
strength members 56 during assembly of the cable 18. Still further,
the metallic tape 82 may be heated to melt, and thus, for a
continuous layer of metallic tape extending between the
interstitial gaps of the inner and outer armor wire strength
members 54, 56.
[0047] It is important to note that the embodiments of the cable 18
discussed above need not include the conductive outer layer 44
along an entire length of the cable 18. For example, the conductive
outer layer 44 may be disposed along certain portions of the cable
18, while other portions of the cable 18 include a conventional
polymeric outer jacket. Additionally or otherwise, a composition of
the conductive outer layer 44 may change along the length of the
cable 18. For example, certain portions of the cable 18 may include
the conductive polymer jacket 68, while other portions of the cable
18 include the wire array 70, the metallic tape 82, or a
combination thereof
[0048] The specific embodiments described above have been shown by
way of example, and it should be understood that these embodiments
may be susceptible to various modifications and alternative forms.
The disclosed embodiments are suitable for any cable application
requiring an electrically conductive surface disposed about and
outer circumference a cable, such as wireline cables, wireline
cables with embedded strength members, marine cables, or any other
suitable cables. It should be further understood that the claims
are not intended to be limited to the particular forms disclosed,
but rather to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of this
disclosure.
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