U.S. patent application number 11/380325 was filed with the patent office on 2007-01-04 for bimetallic materials for oilfield applications.
Invention is credited to Anthony Collins, Wayne Fulin, Garud Sridhar, Joseph P. Varkey.
Application Number | 20070003780 11/380325 |
Document ID | / |
Family ID | 37072407 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070003780 |
Kind Code |
A1 |
Varkey; Joseph P. ; et
al. |
January 4, 2007 |
BIMETALLIC MATERIALS FOR OILFIELD APPLICATIONS
Abstract
Corrosion resistant and/or lightweight bimetallic cylinders used
in tools and electric cables, including core surrounded by
corrosion resistant alloy outer cladding materials, where the alloy
clad may include such alloys as beryllium-copper based alloys,
nickel-chromium based alloys, superaustenitic stainless steel
alloys, nickel-cobalt based alloys, nickel-molybdenum-chromium
based alloys, and the like. The core may be a low density core
based substantially upon titanium or titanium alloys.
Inventors: |
Varkey; Joseph P.; (Missouri
City, TX) ; Sridhar; Garud; (Stafford, TX) ;
Collins; Anthony; (Houston, TX) ; Fulin; Wayne;
(Sugar Land, TX) |
Correspondence
Address: |
SCHLUMBERGER IPC;ATTN: TIM CURINGTON
555 INDUSTRIAL BOULEVARD, MD-21
SUGAR LAND
TX
77478
US
|
Family ID: |
37072407 |
Appl. No.: |
11/380325 |
Filed: |
April 26, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11153835 |
Jun 15, 2005 |
7119283 |
|
|
11380325 |
Apr 26, 2006 |
|
|
|
Current U.S.
Class: |
428/586 ; 29/895;
29/895.3; 29/895.32; 428/544 |
Current CPC
Class: |
D07B 2401/2025 20130101;
D07B 2205/3085 20130101; D07B 2201/2013 20130101; D07B 2205/3089
20130101; Y10T 29/49563 20150115; Y10T 29/49544 20150115; Y10T
29/4956 20150115; D07B 2801/18 20130101; H01B 7/046 20130101; D07B
2801/18 20130101; Y10T 428/12292 20150115; Y10T 428/12 20150115;
D07B 2205/3089 20130101; H01B 7/2806 20130101; D07B 2201/2011
20130101; D07B 2205/3085 20130101 |
Class at
Publication: |
428/586 ;
029/895; 029/895.3; 029/895.32; 428/544 |
International
Class: |
F01D 5/18 20060101
F01D005/18; B21D 53/00 20060101 B21D053/00; B22D 7/00 20060101
B22D007/00 |
Claims
1. A bimetallic corrosion resistant cylinder comprising a corrosion
resistant alloy outer clad and a core, wherein the cylinder is used
in wellbore equipment.
2. The cylinder according to claim 1 wherein the core is a low
density core.
3. The cylinder according to claim 2 wherein the low density core
is substantially titanium or titanium alloy.
4. The cylinder according to claim 1 wherein a bonding layer is
placed between the core and the corrosion resistant alloy outer
clad.
5. The cylinder according to claim 1 wherein the cylinder is a
solid body.
6. The cylinder according to claim 1 wherein the cylinder is a
hollow body.
7. The cylinder according to claim 6 wherein the inner surface of
the hollow body has a corrosion resistant alloy inner clad disposed
thereon.
8. The cylinder according to claim 1 as used to form a WHE-pressure
control device, a chain, a marine termination, a tool housing, a
tractor housing, a riser, a casing tube, a pipe, a coil tubing, a
spring, a fastener, a coupler, a centralizer, surface production
facilities, wellhead equipment, dowhhole completion hardware,
control lines, or BHA assemblies.
9. The cylinder according to claim 2 wherein the low density core
is titanium or a titanium alloy, and the corrosion resistant alloy
outer clad is an alloy comprising nickel in an amount from about
10% to about 60% by weight of total alloy weight, chromium in an
amount from about 15% to about 30% by weight of total alloy weight,
molybdenum in an amount from about 2%f to about 20% by weight of
total alloy weight, and cobalt in an amount up to about 50% by
weight of total alloy weight.
10. The cylinder according to claim 1 comprising no greater than
one corrosion resistant alloy outer clad, wherein the corrosion
resistant alloy outer clad comprises an alloy selected from the
group consisting of beryllium-copper based alloys,
copper-nickel-tin based alloys, superaustenitic stainless steel
alloys, nickel-cobalt based alloys, nickel-chromium based alloys,
nickel-molybdenum-chromium based alloys, and any mixtures
thereof.
11. The cylinder according to claim 1 comprising no greater than
one corrosion resistant alloy outer clad, wherein the corrosion
resistant alloy outer clad comprises a nickel-chromium based alloy
or a nickel-cobalt based alloy.
12. The cylinder according to claim 1 comprising no greater than
one corrosion resistant alloy outer clad, wherein the corrosion
resistant alloy outer clad is extruded over the low density core,
and the clad and core are drawn to a desired diameter.
13. The cylinder according to claim 1 comprising no greater than
one corrosion resistant alloy outer clad, wherein the corrosion
resistant alloy outer clad is at least one sheath of corrosion
resistant alloy, and the clad is formed over the low density core,
and wherein the clad and core are drawn to a desired diameter.
14. The cylinder according to claim 2 wherein the low density core
has a density up to about 4.8 g/cm.sup.3.
15. An electric cable according to claim 14 wherein the low density
core has a density from about 4.2 g/cm.sup.3 to about 4.8
g/cm.sup.3.
16. The cylinder according to claim 2 wherein the cylinder is used
to form armor wires for electrical cables.
17. The cylinder according to claim 1 in which the cylinder is
abrasion and corrosion resistant, galling and corrosion resistant,
or abrasion, galling and corrosion resistant,
18. A method of forming bimetallic corrosion resistant cylinder
comprising: a. providing a core, b. bringing the core into contact
with at least one sheath of corrosion resistant alloy material, c.
forming the sheet of corrosion resistant alloy material around the
core, and drawing the combination of the alloy material and core to
a final diameter to form the cylinder.
19. The method according to claim 18 wherein the core is a low
density core.
20. The cylinder according to claim 19 wherein the low density core
is substantially titanium or titanium alloy.
21. The method according to claim 18 wherein a bonding layer is
placed between the core and the corrosion resistant material.
22. The method according to claim 18 wherein the cylinder is a
solid body.
23. The method according to claim 18 wherein the cylinder is a
hollow body.
24. A method according to claim 18 further comprising coating the
low density core with a bonding layer before forming the sheath of
corrosion resistant alloy material around the low density core.
25. The method according to claim 18 wherein the corrosion
resistant alloy material is extruded over the core, and the clad
and core are drawn to a desired diameter.
Description
RELATED APPLICATION DATA
[0001] This patent application is a Continuation-In-Part of and
also claims the benefit of U.S. patent application Ser. No.
11/330,957, filed Jan. 11, 2006.
BACKGROUND OF THE INVENTION
[0002] This invention relates to equipment used in wellbores, and
methods of manufacturing and using such equipment. In one aspect,
the invention relates to wellbore tools and electric cables
constructed in part from corrosion resistant and/or lightweight
bimetallic cylinders.
[0003] Generally, geologic formations within the earth that contain
oil and/or petroleum gas have properties that may be linked with
the ability of the formations to contain such products. For
example, formations that contain oil or petroleum gas have higher
electrical resistivity than those that contain water. Formations
generally comprising sandstone or limestone may contain oil or
petroleum gas. Formations generally comprising shale, which may
also encapsulate oil-bearing formations, may have porosities much
greater than that of sandstone or limestone, but, because the grain
size of shale is very small, it may be very difficult to remove the
oil or gas trapped therein. Accordingly, it may be desirable to
measure various characteristics of the geologic formations adjacent
to a well before completion to help in determining the location of
an oil- and/or petroleum gas-bearing formation as well as the
amount of oil and/or petroleum gas trapped within the formation.
The zones to be analyzed can be vertically underneath the well bore
surface opening or at angles deviated up to 90 degrees or more from
the main well bore.
[0004] Logging tools, which are generally long, pipe-shaped
devices, may be lowered into the well to measure such
characteristics at different depths along the well. These logging
tools may include gamma-ray emitters/receivers, caliper devices,
resistivity-measuring devices, neutron emitters/receivers, and the
like, which are used to sense characteristics of the formations
adjacent the well. A wireline cable connects the logging tool with
one or more electrical power sources and data analysis equipment at
the earth's surface, as well as providing structural support to the
logging tools as they are lowered and raised through the well.
Generally, the wireline cable is spooled out of a truck or an
offshore platform unit, over a pulley, and down into the well.
[0005] Wireline cables are typically formed from a combination of
metallic conductors, insulative materials, filler materials,
jackets, and metallic armor wires. Armor wires typically perform
many functions in wireline cables, including protecting the
electrical core from the mechanical abuse seen in typical downhole
environment, and providing mechanical strength to the cable to
carry the load of the tool string and the cable itself. Armor wire
performance may also be dependent on corrosion protection. Harmful
fluids in the downhole environment may cause armor wire corrosion,
and once the armor wire begins to corrode, strength and pliability
may be quickly compromised. Although the cable core may still
remain functional, it is not economically feasible to replace the
armor wire(s), and the entire cable must typically be discarded.
Tools used in wellbore operations are also vulnerable to excessive
corrosion in sour environments.
[0006] Conventionally, wellbore electrical cables utilize
galvanized steel armor wires (typically plain carbon steels in the
range AISI 1065 and 1085), known in the art as Galvanized Improved
Plow Steel (GIPS) armor wires, which do provide high strength. Such
armor wires are typically constructed of cold-drawn pearlitic steel
coated with zinc for moderate corrosion protection. The GIPS armor
wires are protected by a zinc hot-dip or electrolytic coating that
acts as a sacrificial layer when the wires are exposed to moderate
environments.
[0007] Commonly, sour well cables constructed completely of
corrosion resistant alloys are used in sour well downhole
conditions. While such alloys are well suited for forming armor
wires used in cables for such wells, it is commonly known that the
strength of such alloys may be limited. In the case of tools, to
prevent corrosion, expensive alloys are commonly used. These alloys
include but not limited to the families encompassing super
austenitic stainless steels, cobalt based alloys, stainless steels,
Ni-alloys etc. These alloys are extremely expensive and the cost
involved in some cases does not permit their use in the certain
oilfield environments.
[0008] As deviations in the well bores are increasing, the zones to
be reached for evaluation or production may be at large angles
relative to the well bore opening. To reach these zones, the cable
and tools must be tractored, but the reach may be limited as cables
and tools may not be sufficiently light. Furthermore, deviated well
bores are typically sour as higher concentrations of corrosive
agents are typically present.
[0009] Thus, a need exists for equipment used in wellbores which
may be lower in weight and/or have improved corrosion resistance.
Materials which may be useful to form wellbore tools and cables
that can overcome one or more of the problems detailed above would
be highly desirable, and the need is met at least in part by the
following invention.
SUMMARY OF THE INVENTION
[0010] The invention relates to corrosion resistant and/or
lightweight bimetallic cylinders, such as solid billets or tubes,
useful in equipment for seismic or wellbore operations. The
cylinders are composed of a corrosion resistant alloy-clad material
with an optional low density core. The clad is designed to be
resistant to corrosion as well as possibly resistant to galling
and/or abrasion. When used, a low density core provides a lighter
weight cylinder. The cylinder may be a solid body or a hollowed
body. Cladding the cylinder core may be achieved by forming or
extrusion techniques, for example. Also, the cylinder may be drawn
or machined to a desired diameter.
[0011] Any suitable material may be used as the core. Examples of
some suitable materials useful as the core material include, but
are not necessarily limited to, steel, titanium (.alpha.-phase,
.beta.-phase, .alpha./.beta.-phase), titanium alloys, low alloy
steels (e.g. 4000 series), stainless steels (e.g. 400 series, 300
series, 17-4PH, etc.), and the like. Any appropriate metal or alloy
may be used for the corrosion resistant clad including, but are not
necessarily limited to beryllium-copper based alloys,
nickel-chromium based alloys, superaustenitic stainless steel
alloys, nickel-cobalt based alloys, copper-nickel-tin based alloys,
or even nickel-molybdenum-chromium based alloys. The corrosion
resistant clad may also be an alloy comprising nickel in an amount
from about 10% to about 60% by weight of total alloy weight,
chromium in an amount from about 15% to about 30% by weight of
total alloy weight, molybdenum in an amount from about 2% to about
20% by weight of total alloy weight, cobalt in an amount up to
about 50% by weight of total alloy weight, as well as relatively
minor amounts of other elements such as carbon, nitrogen, titanium,
vanadium, or even iron.
[0012] The cylinders of the invention are useful as components in
oil and gas exploration and production related equipment such as
WHE-pressure control equipment, chains, marine terminations, tool
housings, tractor housings, risers, casing tubings, pipes, coil
tubings, springs, fasteners and couplers, centralizers, surface
production facilities, wellhead equipment, dowhhole completion
hardware, control lines, BHA assemblies, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention may be understood by reference to the
following description taken in conjunction with the accompanying
drawings:
[0014] FIG. 1 is a cross-sectional view of a typical prior art
cable design.
[0015] FIG. 2 is a stylized cross-sectional representation of an
armor wire design useful in some cables of the invention.
[0016] FIG. 3 is a cross-sectional representation of a general
cable design according to the invention using two layers of armor
wires
[0017] FIG. 4 is a cross-sectional representation of a heptacable
design according to the invention, including two layers of armor
wires.
[0018] FIG. 5 represents, by stylized cross-section, a monocable
design according to the invention.
[0019] FIG. 6 illustrates a method of preparing armor wires useful
in cables according to the invention.
[0020] FIG. 7 illustrates another method of preparing some armor
wires useful in cables according to the invention.
[0021] FIG. 8 illustrates yet another method of preparing some
armor wires.
[0022] FIG. 9 is a cross-sectional representation of cables of the
invention which include a polymeric material disposed upon the
armor wires.
[0023] FIGS. 10A and 10B illustrate one corrosion resistant
cylinder embodiment of the invention in both. FIG. 10A is an
isometric three dimensional rendering. FIG. 10B is a
cross-sectional illustration.
[0024] FIGS. 11A and 11B represent a corrosion resistant hollow
body cylinder embodiment of the invention.
[0025] FIG. 12 is an isometric three dimensional rendering of a
cylinder according to invention which is a tubular with an O-ring
groove.
DETAILED DESCRIPTION
[0026] Illustrative embodiments of the invention are described
below. In the interest of clarity, not all features of an actual
implementation are described in this specification. It will of
course be appreciated that in the development of any such actual
embodiment, numerous implementation- specific decisions must be
made to achieve the developer's specific goals, such as compliance
with system related and business related constraints, which will
vary from one implementation to another. Moreover, it will be
appreciated that such a development effort might be complex and
time consuming but would nevertheless be a routine undertaking for
those of ordinary skill in the art having the benefit of this
disclosure.
[0027] This invention relates to equipment used in wellbores, and
methods of manufacturing and using such equipment. In particular,
the invention relates to wellbore tools and electric cables
constructed in part from corrosion resistant and/or lightweight
bimetallic cylinders, such as solid billets or tubes, for example,
as well as methods of using the equipment in seismic and wellbore
operations. Designs for oilfield equipment must often strike a
balance between weight, strength, corrosion resistance and
materials and manufacturing resources. In the case of wireline
cables, the cables must support their own weights plus the weights
of downhole tool strings. Tools should be designed and constructed
in such way to maximize reach and resistance to corrosive material,
while remaining reliable and functional. The use of a corrosion
resistant alloy outer cladding material with an optional low
density core addresses these needs. The outer clad is designed to
be resistant to corrosion, abrasion, and galling. When used, the
low density core provides a lighter weight material thus extending
the potential reach of the tool string, for example.
[0028] While this invention and its claims are not bound by any
particular mechanism of operation or theory, it has been discovered
that using certain alloys to form an alloy outer clad upon a core
to provide a bimetallic cylinder, provides components useful for
forming wellbore cables and tools with resistance to corrosion,
which possess reasonably high strength properties. Preferably, no
greater than one corrosion resistant alloy outer clad is formed
upon the core. In addition to corrosion resistance, the outer clad
may also provide resistance to galling and/or abrasion. When the
outer clad is formed on a low density core, lighter weight cables
and tools may be produced. By low density core it is meant the core
is form substantially from a material with a density up to about
4.8 g/cm.sup.3, for example, from about 4.2 g/cm.sup.3 to about 4.8
g/cm.sup.3. In the case of titanium and its alloys when used as a
core, as it has a lower density material than steel, the resulting
weights are significantly less.
[0029] The term "cylinder" as use herein means a cylindrical body
which is solid, or a cylindrical hollowed body. When the cylinder
is a hollowed body, such as a tube, the outer and inner surfaces
both may have a corrosion resistant outer clad upon the core. The
core used to form the cylinder may be a tube or a solid billet. The
corrosion resistant material is clad onto the core, either upon the
outer periphery of the core, the inner surface in the case of
hollowed body cores, or both. Cladding the cylinder core may be
achieved by forming or extrusion techniques, for example. The
surface roughness of the core and/or the clad material can be
controlled for bonding strength purposes. If a corrosion resistant
clad is not required in the inside of a tube, then a solid
bimetallic billet can be co-extruded and barrel drilled to obtain a
tube, which may be acceptable in cases of short lengths.
[0030] Examples of suitable materials useful as the core material
include, but are not necessarily limited to, steel (i.e.
hypoeutectoid, eutectoid, hypereutectoid), titanium (.alpha.-phase,
.beta.-phase, .alpha./.beta.-phase), titanium alloys, low alloy
steels (e.g. 4000 series), stainless steels (e.g. 400 series, 300
series, 17-4PH, etc.), and the like. Titanium has up to about 45%
lower density than that of steel, stainless steels,
super-austenitic stainless steels, cobalt based alloys, and the
like. As described above, titanium can enable lower weight oilfield
equipment. Some advantages of having lower weight are lower size
transportation equipment, or the possibility to carry an increased
number of similar equipment. The lighter weight may also allow
simplified installation operations and improved safety.
[0031] While there are advantages as a lightweight material,
titanium or titanium alloys, when used alone, is known to be
somewhat unsuitable for oilfield equipment applications,
particularly as titanium is subject to galling (damage caused by
adhesive friction) when titanium parts rub against each other. As
such, galling renders titanium difficult for an application such as
cable armor wires or the outer surface of tools, where the tools
and/or cable may be in contact with each other under high tensions.
Galling resistance for titanium in cables can be mitigated by
expensive alloying also and by creating an impurity layer on the
surface of the wire. The impurities that can be created on the wire
surface cannot be exposed to excessive torsional loading that the
wire and the cable is exposed to during manufacturing and
deployment, and the impurities can lead to potential fracture
initiation sites. However, inventors have discovered that placing a
outer cladding over a lightweight titanium or titanium alloy core
can overcome the problems described above, or at least in part. The
clad material also offers a significant increase in the corrosion
resistance. This is typically useful when the equipment is used in
highly corrosive environments such as sour and highly deviated
wellbores.
[0032] While any suitable alloy may be used as a corrosion
resistant alloy outer clad to form cylinders of the invention, some
examples include, but are not necessarily limited to:
beryllium-copper based alloys; nickel-chromium based alloys (such
as Inconel.RTM. available from Reade Advanced Materials,
Providence, R.I. USA 02915-0039); superaustenitic stainless steel
alloys (such as 20Mo6.RTM. of Carpenter Technology Corp.,
Wyomissing, Pa. 19610-1339 U.S.A., INCOLOY.RTM. alloy 27-7MO and
INCOLOY.RTM. alloy 25-6MO from Special Metals Corporation of New
Hartford, N.Y., U.S.A., or Sandvik 13RM19 from Sandvik Materials
Technology of Clarks Summit, Pa. 18411, U.S.A.); nickel-cobalt
based alloys (such as MP35N from Alloy Wire International, Warwick,
R.I., 02886 U.S.A.); copper-nickel-tin based alloys (such as
ToughMet.RTM. available from Brush Wellman, Fairfield, N.J., USA);
or, nickel-molybdenum-chromium based alloys (such as HASTELLOY.RTM.
C276 from Alloy Wire International). The corrosion resistant alloy
outer clad may also be an alloy comprising nickel in an amount from
about 10% to about 60% by weight of total alloy weight, chromium in
an amount from about 15% to about 30% by weight of total alloy
weight, molybdenum in an amount from about 2% to about 20% by
weight of total alloy weight, cobalt in an amount up to about 50%
by weight of total alloy weight, as well as relatively minor
amounts of other elements such as carbon, nitrogen, titanium,
vanadium, or even iron. The preferred alloys are nickel-chromium
based alloys, and nickel-cobalt based alloys.
[0033] The bimetallic cylinders of the invention are useful as
components in oil and gas exploration and production related
equipment including, but not necessarily limited to, armor wire for
cables, or tools/equipment such as WHE-pressure control equipment
(i.e. BOPs etc.), chains, marine terminations, tool housings,
tractor housings, lubricators/risers, casing tubings, pipes (i.e.
drill pipes etc.), coil tubings, springs, fasteners and couplers,
centralizers for tractors and oil field tools, surface production
facilities, wellhead equipment, dowhhole completion hardware,
control lines, BHA assemblies, and the like.
[0034] In some embodiments of the invention, lightweight armor
wires are used in cables, where the armor wires are prepared from a
metal billet made of low density titanium or its alloy core and a
outer clad made of a corrosion resistant metal, such as austenitic
stainless steel, Inconel.RTM., and the like. The clad may be
extruded over the titanium core or may be formed over the core and
then seam-welded. The billet is drawn to a smaller diameter to form
armor wire stock. The ratio of clad thickness to core width or
diameter remains constant as the billet is drawn to a smaller
diameter. The completed armor wire density or weight per length can
be as much as about 40% less than standard GIPS armor wire, with
significant gains in strength to weight ratios.
[0035] Cables using armor wires of the invention generally include
at least one insulated conductor, and at least one layer of high
strength corrosion resistant armor wires surrounding the insulated
conductor(s). Insulated conductors useful in the embodiments of the
invention include metallic conductors, or even one or more optical
fibers. Such conductors or optical fibers may be encased in an
insulated jacket. Any suitable metallic conductors may be used.
Examples of metallic conductors include, but are not necessarily
limited to, copper, nickel coated copper, or aluminum. Preferred
metallic conductors are nickel coated copper conductors. While any
suitable number of metallic conductors may be used in forming the
insulated conductor, preferably from 1 to about 60 metallic
conductors are used, more preferably 7, 19, or 37 metallic
conductors. Components, such as conductors, armor wires, filler,
optical fibers, and the like, used in cables according to the
invention may be positioned at zero helix angle or any suitable
helix angle relative to the center axis of the cable. Generally, a
central insulated conductor is positioned at zero helix angle,
while those components a surrounding the central insulated
conductor are helically positioned around the central insulated
conductor at desired helix angles. A pair of layered armor wire
layers may be contra-helically wound, or positioned at opposite
helix angles.
[0036] Insulating materials useful to form the insulation for the
conductors and insulated jackets may be any suitable insulating
materials known in the art. Non-limiting examples of insulating
materials include polyolefins,
polytetrafluoroethylene-perfluoromethylvinylether polymer (MFA),
perfluoro-alkoxyalkane polymer (PFA), polytetrafluoroethylene
polymers (PTFE), ethylene-tetrafluoroethylene polymers (ETFE),
ethylene-propylene copolymers (EPC), poly(4-methyl-1-pentene)
(TPX.RTM. available from Mitsui Chemicals, Inc.), other
fluoropolymers, polyaryletherether ketone polymers (PEEK),
polyphenylene sulfide polymers (PPS), modified polyphenylene
sulfide polymers, polyether ketone polymers (PEK), maleic anhydride
modified polymers, perfluoroalkoxy polymers, fluorinated ethylene
propylene polymers,
polytetrafluoroethylene-perfluoromethylvinylether polymers,
polyamide polymers, polyurethane, thermoplastic polyurethane,
ethylene chloro-trifluoroethylene polymers (such as Halar.RTM.),
chlorinated ethylene propylene polymers, Parmax.RTM. SRP polymers
(self-reinforcing polymers manufactured by Mississippi Polymer
Technologies, Inc. based on a substituted poly (1,4-phenylene)
structure where each phenylene ring has a substituent R group
derived from a wide variety of organic groups), or the like, and
any mixtures thereof.
[0037] The insulated conductors may be stacked dielectric insulated
conductors, with electric field suppressing characteristics, such
as those described in U.S. Pat. No. 6,600,108 (Mydur, et al.),
incorporated herein by reference. Such stacked dielectric insulated
conductors generally include a first insulating jacket layer
disposed around the metallic conductors wherein the first
insulating jacket layer has a first relative permittivity, and, a
second insulating jacket layer disposed around the first insulating
jacket layer and having a second relative permittivity that is less
than the first relative permittivity. The first relative
permittivity is within a range of about 2.5 to about 10.0, and the
second relative permittivity is within a range of about 1.8 to
about 5.0.
[0038] Electrical cables using armor wires of the invention may be
of any practical design. The cables may be wellbore cables,
including monocables, coaxial cables, quadcables, heptacables,
seismic cables, slickline cables, multi-line cables, and the like.
In coaxial cable designs of the invention, a plurality of metallic
conductors surrounds the insulated conductor, and is positioned
about the same axis as the insulated conductor. In addition, for
any cables of the invention, the insulated conductors may be
further encased in a tape. All materials, including the tape
disposed around the insulated conductors, may be selected so that
they will bond chemically and/or mechanically with each other.
Armor wires used in the invention make possible lightweight, lower
modulus wireline cables, especially desirable for downhole tractor
applications. Cables of the invention may have an outer diameter
from about 0.5 mm to about 400 mm, preferably, a diameter from
about 1 mm to about 100 mm, more preferably from about 2 mm to
about 15 mm.
[0039] Armor wires may have titanium or its alloys placed at the
core of the armor wires, as described hereinabove. An alloy with
resistance to corrosion and reduction of galling is then clad over
the core. The corrosion resistant alloy layer may be outer clad
over the low-density core by extrusion or by forming over the core.
The corrosion and improved galling resistant outer clad may be from
about 50 microns to about 600 microns in thickness. The material
used for the corrosion and improved galling resistant outer clad
may be any suitable alloy that provides sufficient corrosion
resistance and abrasion resistance when used as a clad. The alloys
used to form the clad may also have tribological properties
adequate to improve the abrasion resistance and lubricating of
interacting surfaces in relative motion, or improved corrosion
resistant properties that minimize gradual wearing by chemical
action, or even both properties.
[0040] Cables include at least one layer of armor wires surrounding
the insulated conductor. The armor wires comprising a low density
core and a corrosion resistant alloy outer clad may be used alone,
or may be combined with other types of armor wires, such as
galvanized improved plow steel wires, superaustenitic stainless
steel armor wires, or even wire rope armor wires, to form the armor
wire layers. Preferably, two layers of armor wires are used to form
preferred electrical cables of the invention.
[0041] Referring now to FIG. 1, a cross-sectional view of a typical
heptacable design. FIG. 1 depicts a cross-section of a typical
armored cable design used for downhole applications. The cable 100
includes a central conductor bundle 102 having multiple conductors
and an outer polymeric insulating material. The cable 100 further
includes a plurality of outer conductor bundles 104, each having
several metallic conductors 106 (only one indicated), and a
polymeric insulating material 108 surrounding the outer metallic
conductors 106. Preferably, the metallic conductor 106 may be a
copper conductor. The central conductor bundle 102 of typical prior
art cables, although need not be, is typically the same design as
the outer conductor bundles 104. An optional tape and/or tape
jacket 110 made of a material that may be either electrically
conductive or electrically non-conductive and that is capable of
withstanding high temperatures encircles the outer conductor
bundles 104. The volume within the tape and/or tape jacket 110 not
taken by the central conductor bundle 102 and the outer conductors
104 is filled with a filler 112, which may be made of either an
electrically conductive or an electrically non-conductive material.
A first armor layer 114 and a second armor layer 116, generally
made of a high tensile strength galvanized improved plow steel
(GIPS) armor wires, surround and protect the tape and/or tape
jacket 110, the filler 112, the outer conductor bundles 104, and
the central conductor bundle 102.
[0042] FIG. 2 is a stylized cross-sectional representation of a
lightweight cylindrical armor wire design. The armor wire 200
includes a low density core 202, surrounded by a corrosion
resistant alloy outer clad 204. An optional bonding layer 206 may
be placed between the core 202 and alloy outer clad 204. The core
202 may be generally made of any low density material such as, by
non-limiting example, titanium and its alloys. Examples of suitable
alloys which may be used as core strength members include, but are
not necessarily limited to CP Grades 1, 2, 3, etc., Beta-C,
Ti-6Al-4V. The core strength member 202 can include a titanium core
for low density, or even plated or coated wires. When used, the
bonding layer 206 may be any material useful in promoting a strong
bond between the high strength core 202 and corrosion resistant
alloy outer clad 204. The microstructure phase of the low density
core can be alpha, alpha-beta or beta.
[0043] Referring now to FIG. 3, a cross-sectional representation of
a general cable design according to the invention that incorporates
two layers of armor wires. The cable 300 includes at least one
insulated conductor 302 and two layers of armor wires, 304 and 306.
The insulated conductor 302 may be a heptacable, quadcable,
monocable, or even coaxial cable design. The armor wire layers, 304
and 306, surrounding the insulated conductor(s) 302 include armor
wires, such as armor wire 200 in FIG. 2, comprising a low density
core and a corrosion resistant alloy outer clad. Optionally, in the
interstitial spaces 308, formed between armor wires, as well as
formed between armor wires and insulated conductor(s) 302, a
polymeric material may be disposed.
[0044] Polymeric materials disposed in the interstitial spaces 308
may be any suitable material. Some useful polymeric materials
include, by nonlimiting example, polyolefins (such as EPC or
polypropylene), other polyolefins, polyaryletherether ketone
(PEEK), polyaryl ether ketone (PEK), polyphenylene sulfide (PPS),
modified polyphenylene sulfide, polymers of
ethylene-tetrafluoroethylene (ETFE), polymers of
poly(1,4-phenylene), polytetrafluoroethylene (PTFE),
perfluoroalkoxy (PFA) polymers, fluorinated ethylene propylene
(FEP) polymers, polytetrafluoroethylene-perfluoromethylvinylether
(MFA) polymers, Parmax.RTM., and any mixtures thereof. Preferred
polymeric materials are ethylene-tetrafluoroethylene polymers,
perfluoroalkoxy polymers, fluorinated ethylene propylene polymers,
and polytetrafluoroethylene-perfluoromethylvinylether polymers. The
polymeric materials may be disposed contiguously from the insulated
conductor to the outermost layer of armor wires, or may even extend
beyond the outer periphery thus forming a polymeric jacket that
completely encases the armor wires. The polymeric material may or
may not be fiber reinforced.
[0045] A protective polymeric coating may be applied to strands of
armor wire for additional protection, or even to promote bonding
between the armor wires and any polymeric material disposed in the
interstitial spaces. As used herein, the term bonding is meant to
include chemical bonding, mechanical bonding, or any combination
thereof. Examples of coating materials which may be used include,
but are not necessarily limited to, fluoropolymers, fluorinated
ethylene propylene (FEP) polymers, ethylene-tetrafluoroethylene
polymers (Tefzel.RTM.), perfluoro-alkoxyalkane polymer (PFA),
polytetrafluoroethylene polymer (PTFE),
polytetrafluoroethylene-perfluoromethylvinylether polymer (MFA),
polyaryletherether ketone polymer (PEEK), or polyether ketone
polymer (PEK) with fluoropolymer combination, polyphenylene sulfide
polymer (PPS), PPS and PTFE combination, latex or rubber coatings,
and the like. Each armor wire may also be plated with materials for
corrosion protection or even to promote bonding between the armor
wires and polymeric material. Nonlimiting examples of suitable
plating materials include copper alloys, and the like. Plated armor
wires may even be cords such as tire cords. While any effective
thickness of plating or coating material may be used, a thickness
from about 10 microns to about 100 microns is preferred.
[0046] FIG. 4 is a cross-sectional representation of a heptacable
design including two layers of armor wires. The cable 400 includes
two layers of armor wires, 402 and 404, surrounding a tape and/or
tape jacket 406. The armor wire layers, 402 and 404, include armor
wires, such as armor wire 200 in FIG. 2, comprising a low density
core and a corrosion resistant alloy outer clad. The interstitial
space within the tape and/or jacket 406 comprises a central
insulated conductor 408 and six outer insulated conductors 410
(only one indicated). The interstitial space within the tape and/or
jacket 406, not occupied by the central insulated conductor 408 and
six outer insulated conductors 410 may be filled with a suitable
filler material, which may be made of either an electrically
conductive or an electrically non-conductive material. The central
insulated conductor 408 and six outer insulated conductors 410,
each have a plurality of conductors 412 (only one indicated), and
insulating material 414 surrounding the conductors 412. Preferably,
the conductor 412 is a nickel coated copper conductor. Optionally,
a polymeric material may be disposed in the interstitial spaces
416, formed between armor wires, as well as formed between armor
wires and tape jacket 406.
[0047] FIG. 5 represents, by stylized cross-section, a monocable
design using armor wires of the invention. The cable 500 includes
two layers of armor wires, 502 and 504, surrounding a tape and/or
tape jacket 506. The armor wire layers, 502 and 504, include armor
wires, such as armor wire 200 in FIG. 2, comprising a high strength
core and a corrosion resistant alloy outer clad. The central
conductor 508 and six outer conductors 510 (only one indicated) are
surrounded by tape and/ or jacket 506 and layers of armor wires 502
and 504. Preferably, the conductors 508 and 510 are nickel coated
copper conductors. The interstitial space formed between the tape
and/or jacket 506 and six outer conductors 510, as well as
interstitial spaces formed between the six outer conductors 510 and
central conductor 508 the may be filled with an insulating material
512 to form an insulated conductor. Optionally, a polymeric
material may be disposed in the interstitial spaces 516, formed
between armor wires, as well as formed between armor wires and tape
jacket 506.
[0048] FIG. 6 illustrates one method of preparing cylinders of the
invention, which may be used as armor wires, among other equipment.
Accordingly, a core A, which may be low density titanium or its
alloys, is provided. At point 602, the core A may optionally be
coated with a bonding layer B, such as brass using a hot dip or
electrolytic deposition process. At point 604 the optional bonding
layer coated core A is brought into contact with a sheet of
corrosion resistant alloy material C, such as, by nonlimiting
example, Inconel.RTM. nickel-chromium based alloy. The alloy
material C is used to prepare the corrosion resistant alloy outer
clad. At points 606, 608, and 610, the alloy material is formed
around the optional bonding layer core A, using, for example,
rollers. Such forming of the alloy material is done at temperatures
ranging between ambient temperature and about 850.degree. C.
Additionally, the optional bonding layer B may flow and to
sufficiently provide a slipping interface between the high strength
core A and the corrosion resistant alloy outer clad comprised of
alloy material C.
[0049] At point 612, the cylinder may be further drawn down (not
necessarily to scale as illustrated) to a final diameter to form an
armor wire D for example. The drawn thicknesses of the optional
bonding layer coated core A alloy clad C may be proportional to the
pre-drawn thickness.
[0050] FIG. 7 illustrates another method of preparing cylinders of
the invention. According to this method, a core A is provided, and
at point 702, the high strength core A is optionally coated with a
bonding layer B. At point 704 the optional bonding layer coated
core A is brought into contact with two separate sheets of
corrosion resistant alloy material, D and E, to form the corrosion
resistant alloy outer clad. At points 706 and 708, the sheets of
alloy material are formed around the optional bonding layer coated
core A. At point 710, the cylinder may be drawn down to a desired
diameter to form cylinder F which may be an armor wire, for
example.
[0051] FIG. 8 illustrates yet another method of preparing cylinders
of the invention, in an extrusion and drawing technique.
Accordingly, a core A is provided, and at point 802, a corrosion
resistant alloy outer clad B is extruded over core A. The material
forming the corrosion resistant alloy outer clad B may be hot or
cold extruded onto the core A. At 804, the cylinder may be drawn
down (not necessarily to scale as illustrated) to a final diameter
to form C. Further, the core A may be optionally coated with a
bonding layer prior to extruding the corrosion resistant alloy
outer clad B.
[0052] Referring now to FIG. 9, a cross-sectional generic
representation of some cables using armor wires of the invention
that include a polymeric material disposed about the armor wires.
The cables include an insulated conductor core 902 which comprises
insulated conductors in such configurations as heptacables,
monocables, coaxial cables, slickline cables, or even quadcables. A
polymeric material 908 is contiguously disposed in the interstitial
spaces formed between layers of armor wires 904 and 906, and
interstitial spaces formed between the armor wires 904 and core
902. The layers of armor wires 904 and 906 are composed of armor
wires comprising a low density core and a corrosion resistant alloy
outer clad. The polymeric material 908 may further include short
fibers. The inner armor wires 904 are evenly spaced when cabled
around the core 902. The polymeric material 908 may extend beyond
the periphery of outer armor wire layer 906 to form a polymeric
jacket thus forming a polymeric encased cable 900.
[0053] The materials forming the insulating layers and the
polymeric materials used in the cables may further include a
fluoropolymer additive, or fluoropolymer additives, in the material
admixture used to form the cable. Such additive(s) may be useful to
produce long cable lengths of high quality at high manufacturing
speeds. Suitable fluoropolymer additives include, but are not
necessarily limited to, polytetrafluoroethylene, perfluoroalkoxy
polymer, ethylene tetrafluoroethylene copolymer, fluorinated
ethylene propylene, perfluorinated poly(ethylene-propylene), and
any mixture thereof. The fluoropolymers may also be copolymers of
tetrafluoroethylene and ethylene and optionally a third co-monomer,
copolymers of tetrafluoroethylene and vinylidene fluoride and
optionally a third co-monomer, copolymers of
chlorotrifluoroethylene and ethylene and optionally a third
co-monomer, copolymers of hexafluoropropylene and ethylene and
optionally third co-monomer, and copolymers of hexafluoropropylene
and vinylidene fluoride and optionally a third co-monomer. The
fluoropolymer additive should have a melting peak temperature below
the extrusion processing temperature, and preferably in the range
from about 200.degree. C. to about 350.degree. C. To prepare the
admixture, the fluoropolymer additive is mixed with the insulating
jacket or polymeric material. The fluoropolymer additive may be
incorporated into the admixture in the amount of about 5% or less
by weight based upon total weight of admixture, preferably about 1%
by weight based or less based upon total weight of admixture, more
preferably about 0.75% or less based upon total weight of
admixture.
[0054] Armor wires of the invention may also serve as electrical
current return or supply wires that provide paths to ground for
downhole equipment or tools. The invention enables the use of armor
wires for current return while minimizing electric shock hazard. In
some embodiments, a polymeric material isolates at least one armor
wire in the first layer of armor wires thus enabling their use as
electric current return wires. Optical fibers may be used in cables
in to transmit optical data signals to and from the device or
devices attached thereto, which may result in higher transmission
speeds, lower data loss, and higher bandwidth.
[0055] FIGS. 10A and 10B illustrate some corrosion resistant
cylinder embodiments of the invention. Referring to FIG. 10A, an
isometric three dimensional rendering, cylinder 1002 is composed of
a core 1004 and corrosion resistant outer clad 1006. FIG. 10B is a
cross-sectional illustration of the same cylinder 1002 to further
illustrate the embodiment. Cylinder 1002, as well as any cylinder
according to the invention, may be sized, drawn, machined, and/or
worked by any means known to those with skill in the art, to form
wires and tools useful for wellbore applications.
[0056] Referring now to FIG. 11A, an isometric three dimensional
rendering of other cylinders, cylinder 1102 is defined by core 1104
and corrosion resistant outer clad 1106. In addition, cylinder 1102
is a hollowed body, such as a tube, the outer surface having
corrosion resistant outer clad 1006 and the inner surface,
corrosion resistant inner surface clad 1108 core 1104. FIG. 11B is
a cross-sectional illustration of cylinder 1102 for further
illustration. Now referring to FIG. 12, an isometric three
dimensional rendering of a cylinder that is a tubular with an
O-ring groove, tubular 1202 has core 1204 and outer clad 1206 on
the outer periphery of the core 1204. Tubular 1202 also has inner
surface clad 1208 lining the hollowed inner portion of tubular
1202. As an additional feature, tubular 1202 has groove 1210 on the
outer surface to accommodate a sealing ring, such as an O-ring. In
some instances, tubular 1202 may be formed over a mandrel and drawn
to form flow tube or other WHE, in such way as maintaining the
relative thicknesses of original layers are maintained.
[0057] The particular embodiments disclosed above are illustrative
only, as the invention may be modified and practiced in different
but equivalent manners apparent to those skilled in the art having
the benefit of the teachings herein. Furthermore, no limitations
are intended to the details of construction or design herein shown,
other than as described in the claims below. It is therefore
evident that the particular embodiments disclosed above may be
altered or modified and all such variations are considered within
the scope and spirit of the invention. In particular, every range
of values (of the form, "from about a to about b," or,
equivalently, "from approximately a to b," or, equivalently, "from
approximately a-b") disclosed herein is to be understood as
referring to the power set (the set of all subsets) of the
respective range of values. Accordingly, the protection sought
herein is as set forth in the claims below.
* * * * *