U.S. patent application number 14/330479 was filed with the patent office on 2014-11-06 for motor winding wire for a hydrocarbon application.
The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Peterson V. Howard, Byong Jun Kim, Joseph Varkey.
Application Number | 20140326464 14/330479 |
Document ID | / |
Family ID | 39685237 |
Filed Date | 2014-11-06 |
United States Patent
Application |
20140326464 |
Kind Code |
A1 |
Varkey; Joseph ; et
al. |
November 6, 2014 |
MOTOR WINDING WIRE FOR A HYDROCARBON APPLICATION
Abstract
A motor winding wire. The motor winding wire may be configured
for use in, and direct exposure to, a hydrocarbon environment. The
motor winding wire may be electrically insulated by one polymer
layer, whereas another, outer, polymer layer is employed to provide
moisture resistance as well as other contaminant and hydrocarbon
environment shielding to the underlying layer. Additionally, this
manner of polymer layering over the motor winding wire is achieved
in a manner cognizant of the limited dimension of the motor winding
wire.
Inventors: |
Varkey; Joseph; (Sugar Land,
TX) ; Kim; Byong Jun; (Sugar Land, TX) ;
Howard; Peterson V.; (Bellville, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Family ID: |
39685237 |
Appl. No.: |
14/330479 |
Filed: |
July 14, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12748393 |
Mar 27, 2010 |
8776359 |
|
|
14330479 |
|
|
|
|
11951818 |
Dec 6, 2007 |
7714231 |
|
|
12748393 |
|
|
|
|
60889650 |
Feb 13, 2007 |
|
|
|
Current U.S.
Class: |
166/369 |
Current CPC
Class: |
H02K 3/32 20130101; Y10T
428/31529 20150401; H01B 7/282 20130101; Y10T 29/49071 20150115;
Y10T 29/4902 20150115; Y10T 29/49002 20150115; B32B 7/02 20130101;
Y10T 428/3154 20150401; H02K 3/44 20130101; Y10T 428/31699
20150401; Y10T 428/31681 20150401; B32B 27/06 20130101; Y10T
428/31692 20150401; E21B 43/128 20130101; H01B 7/2806 20130101;
H01B 3/18 20130101; Y10T 29/49073 20150115 |
Class at
Publication: |
166/369 |
International
Class: |
E21B 43/12 20060101
E21B043/12; H02K 3/32 20060101 H02K003/32; H02K 3/44 20060101
H02K003/44 |
Claims
1. A method of pumping a fluid from a hydrocarbon well, the method
comprising: positioning an electric submersible pump downhole in
the well; and employing a motor of the electric submersible pump to
drive the pumping substantially continuously for at least about the
productive life of the well, the motor having motor winding wire
with a conductive core surrounded by an electrically insulating
polymer layer, the insulating polymer layer surrounded by a
contaminant resistant outer polymer layer.
2. The method of claim 1 wherein the productive life of the well
exceeds about two years.
3. The method of claim 1 wherein the conductive core is greater
than about 18 gauge and the insulating polymer layer has a
thickness of at least about 1 mil.
4. The method of claim 1 wherein the conductive core is less than
about 18 gauge and the insulating polymer layer has a thickness
less than about 2 mils.
4. The method of claim 1 wherein the motor winding wire
additionally comprises a tie layer between the insulating polymer
layer and the outer polymer layer.
5. The method of claim 1 wherein the conductive core of the motor
winding wire comprises a diameter less than approximately 0.01 inch
(30 AWG) and wherein the motor winding wire comprises a breakdown
voltage in a five percent salt in water solution of approximately
1000 V AC.
6. The method of claim 1 wherein the insulating polymer layer
comprises a polyimide.
7. The method of claim 1 wherein the insulating polymer layer
comprises a polyimide and wherein the outer polymer layer comprises
expanded PTFE.
8. The method of claim 1 wherein the conductive core of the motor
winding wire comprises a diameter less than approximately 0.01 inch
(30 AWG) and further comprising conducting electricity in the motor
winding wire in a five percent salt in water solution up to a
voltage of approximately 10000 V AC.
9. The method of claim 1 wherein the conductive core is less than
about 30 gauge, and wherein the insulting polymer layer comprises a
thickness of approximately 0.001 inch and wherein the outer polymer
layer comprises a thickness of approximately 0.0005 inch.
10. The method of claim 1 wherein the conductive core is less than
about 30 gauge.
Description
[0001] CROSS REFERENCE TO RELATED APPLICATION(S)
[0002] This application is a Divisional of U.S. application Ser.
No. 12/748,393, filed Mar. 27, 2010, now pending, which is a
Divisional of U.S. application Ser. No. 11/951,818 filed Dec. 6,
2007, now U.S. Pat. No. 7,714,231, and also claims priority under
35 U.S.C. .sctn. 119(e) to U.S. Provisional Application Ser. No.
60/889,650, entitled Motor Winding Wires for Oilfield Application,
filed Feb. 13, 2007. Each of the foregoing applications are
incorporated herein by reference.
FIELD
[0003] Embodiments described relate to equipment for placement
within a hydrocarbon well. In particular, embodiments of equipment
employing magnetized motor winding wires are described wherein the
equipment may be configured for placement and relatively continuous
use within the well over an extended period of time, perhaps
between about 1 1/2 and 5 years.
BACKGROUND
[0004] A variety of hydrocarbon applications involve the use of
electrically powered equipment disposed within a hydrocarbon well
for extended periods of time. For example, an electric submersible
pump (ESP) may be positioned within a hydrocarbon well to promote
the extraction of hydrocarbons from the well. In such circumstances
it may be preferable to leave the pump in place and operating
throughout the hydrocarbon production from the well. Thus,
depending on the hydrocarbon reservoir itself and the parameters of
the operation, the pump may be left operating and in place for up
to about 5 years or longer.
[0005] Equipment such as the indicated ESP may include several
components susceptible to damage upon exposure to the downhole
conditions of the well. For example, the moisture content, chemical
makeup, and pressure or temperature extremes of the downhole
environment may tend to degrade certain components of the ESP over
time. Components of the ESP susceptible to such exposure may
include a power cable and motor parts such as motor windings or
conductors. However, measures may be taken to help shield such
components from the downhole environment. For example, in the case
of the power cable, thick and robust, moisture resistant polymer
layers may be extruded over an electrically conductive core. In
this manner the core may remain substantially unaffected by
downhole conditions so as to help ensure that the cable remains
operation for an extended period. Alternatively, in the case of the
motor and windings, they may be housed within an oil-filled and
hermetically sealed casing isolated from the environment of the
well.
[0006] Unfortunately, the oil filled casing noted above invariably
fails to maintain complete isolation from the conditions in the
surrounding downhole environment. For example, when left within the
well for an extended period, moisture and chemical contaminants
from the downhole environment are eventually able to seep through
and penetrate the casing to some degree. Nevertheless, in the case
of some parts of the motor, the fact that the casing remains
predominantly oil-filled may be enough to avoid failure. For
example, the moving parts of the motor may remain in the presence
of sufficient lubrication to remain operational in spite of a
degree of moisture and chemical contaminants. However, as described
below, the direct exposure of the motor windings to the well
contaminants, especially moisture, may be enough to render them
ineffective, leading to malfunction of the entire ESP.
[0007] Unlike other parts of the motor, motor winding wires are not
dependent upon the presence of sufficient oil concentration within
the casing in order to remain operational. Rather, like the power
cable, it is the substantial shielding of the motor winding wires
from direct contact with downhole contaminants, especially
moisture, which may be key to ensuring continued functionality of
the wires. However, as indicated above, given enough time downhole,
the casing is likely to be penetrated by such downhole contaminants
leaving the wires directly exposed to contaminants.
[0008] In order to further shield the motor winding wires from
direct exposure to downhole contaminants, polymer layers may be
provided about the conductive core of the motor winding wires.
Thus, in theory, the polymer layers may provide a degree of
shielding to the motor winding wires similar to the power cable
configuration noted above. Unfortunately, however, the dimensions
and properties of the motor winding wires themselves render
conventional polymer layering and shielding ineffective for
prolonged protection of the wires from exposure to downhole
contaminants. For example, a conventional motor winding wire may be
magnetized wire core of no more than about 5 gauge copper wire,
generally between about 16 and 50 gauge. Furthermore, the motor
winding wire may be configured for relatively tight windings. As
such, no more than between about 0.25 to 20 mil polymer layers may
be effectively provided over the wires. In fact, for 30 gauge or so
windings and smaller, as a matter of practicality it may be more
effective to bypass extruding the polymer layer altogether and
simply varnish the polymer over the wound wires to provide the
shielding from downhole contaminants. Regardless, the polymer layer
may be of limited thickness and effectiveness.
[0009] In addition to the limited thickness, the effectiveness of
the polymer layer as a shield from downhole contaminants may be
further limited by the particular types of polymers available for
use with motor winding wires. That is, given the small dimension
and the conductive nature of motor winding wire, materials disposed
thereabout may be of an electrically insulating character to ensure
proper wire operation. These materials may include polyimide,
polyester, polyamide, poly-ether-ether-ketone and other
conventional electrical insulators. Unfortunately, however, such
insulators are prone to hydrolytic degradation or moisture
absorption upon prolonged direct exposure to even a small degree of
moisture and other downhole contaminants. As a result, the motor
winding wire as well as the entire ESP or other equipment employing
such winding wire is prone to fail, generally well in advance of
about 5 years. In fact, smaller ESP motors positioned downhole for
continued use often display a lifespan of no more than about 1
year. Furthermore, efforts to overcome polymer shielding
limitations via over-wrapping or enamel layer configurations remain
insufficient to prevent such hydrolytic degradation and moisture
absorption.
SUMMARY
[0010] A motor winding wire is provided for an application in a
hydrocarbon environment such as the downhole environment of a well.
The wire includes a conductive core with an electrically insulating
polymer layer thereabout. A moisture resistant outer polymer layer
is provided about the electrically insulating polymer layer for
shielding it from moisture in the environment.
[0011] In one embodiment, a tie layer may be disposed between the
electrically insulating polymer layer and the moisture resistant
outer polymer layer. The tie layer may include a polymer of one of
the outer polymer layer and the electrically insulating polymer
layer along with an adhesive functional group to provide bonding
between the outer and electrically insulating polymer layers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a side cross-sectional view of a well with an
embodiment of an electrically driven assembly disposed therein.
[0013] FIG. 2 is an enlarged cross-sectional view of an electric
motor of the assembly and the well of FIG. 1.
[0014] FIG. 3 is an enlarged cross-sectional view of an embodiment
of a motor winding wire of the electric motor of FIG. 2.
[0015] FIG. 4 is cross-sectional view of an alternate embodiment of
a motor winding wire.
[0016] FIG. 5 is an enlarged view of the motor winding wire of FIG.
4 taken from 5-5.
[0017] FIG. 6 is a partially cross-sectional overview of an
embodiment of an electrically driven assembly within a well at an
oilfield.
DETAILED DESCRIPTION
[0018] Embodiments are described with reference to certain types of
motor winding wires for use with electrical equipment for
hydrocarbon applications. In particular, focus is drawn to
equipment in the form of electric submersible pumps employed within
hydrocarbon wells. However, a variety of electrical equipment may
employ embodiments described herein, particularly where the
equipment is intended for long term and/or continuous use while
exposed to a harsh or moisture rich hydrocarbon environment.
[0019] Referring now to FIGS. 1 and 2, an embodiment of an
electrically driven assembly 100 is depicted disposed within a
hydrocarbon well 180. The well 180 is defined by a casing 150
through a formation 190 at an oilfield. In the embodiment shown,
the assembly 100 is electronically driven equipment in the form of
an electric submersible pump (ESP). However, other types of
electrically driven equipment may be employed within such a well
180. As shown, the ESP assembly 100 includes an extraction line
160, a pump 140, and an intake region 130, as well as a motor 125
powered by a cable 175. The ESP assembly 100 may operate by
rotation of a motor assembly 200 within a casing 225 of the motor
125. The motor 125 may be employed to power the pump 140 to draw in
hydrocarbon fluids from the environment of the well 180. Such
fluids may then be driven up the extraction line 160 to the well
surface.
[0020] The above-noted assembly 100 may be disposed within the well
180 for continuous operation over an extended period of time. For
example, an ESP assembly 100 may be disposed within the well 180 as
shown for substantially continuous use throughout the productive
life of the well 180. In most cases, this may be between about 2
and 5 years, or longer. For this period, the assembly 100 may be
subjected to harsh well conditions such as extreme temperatures or
pressures, and exposed to contaminants 110 such as moisture and
corrosive chemicals. Nevertheless, the assembly 100 may remain
functional throughout the substantial duration of the productive
life of the well 180. In particular, as detailed below, motor
winding spools 210 of the assembly 100 may be sufficiently shielded
from contaminants 110 of the well 180 so as to avoid operational
failure of the assembly 100 during the productive life of the well
180.
[0021] Continuing with reference to FIGS. 1 and 2, the assembly 100
is directly exposed to the environment of the well 180 which
includes the above-noted contaminants 110. With reference to FIG.
2, a casing 225 of the motor 125 may be hermetically sealed to
provide a degree of protection from the indicated contaminants 110.
Nevertheless, at some point during the life of the well 180,
contaminants 110 may reach an oil-filled space 250 within the
casing 225. Thus, the rotatable motor assembly 200 being located
within the oil-filled space 250 may be directly exposed to such
contaminants 110. Of particular note, motor winding wire 201 of
motor winding spools 210 may come into direct contact with
contaminants 110 such as moisture. However, as detailed below, the
electrical conductivity of the motor winding wire 201 may remain
substantially unaffected by contact with moisture contaminants 110.
Thus, failure of the motor 125 and thus, the entire ESP assembly
100 may be avoided. Furthermore, while the spools 210 are shown
disposed within an ESP assembly 100, other motorized assemblies may
employ motor winding wire 201 as noted below. Such assemblies may
include downhole tractor assemblies, powered centralizers,
perforation guns, sampling tools and a host of other assemblies
that may be motorized.
[0022] Referring now to FIG. 3, with added reference to FIG. 2,
embodiments of motor winding wire 201 may be configured and
constructed so as to avoid contaminant 110 contact with a
conductive core 300 of the wire 201. In this manner, the conductive
nature of the core 300, generally magnetized copper, may remain
unaffected by contaminants 110 otherwise prone to diminish
conductivity. In particular, the conductive core 300 may be
shielded by a tailored combination of polymer layers 350, 375 as
described below.
[0023] In order to provide corona discharge resistance and
electrically isolate the conductive core 300, an insulating polymer
layer 350 may be provided thereabout. The insulating polymer layer
350 may be of a variety of polymer types conventionally used for
electrically insulating winding or magnet wires and provided in a
variety of manners. For example, where the motor winding wire 201
is larger than about 18 gauge, the insulating polymer may be
extruded to more than about 2 mils in thickness over the core 300
to form the layer 350. Alternatively, for smaller winding wire 201,
an enamel coating or varnishing process may be employed to provide
less than about 2 mils of insulating polymer over the core 300,
thereby forming the insulating polymer layer 350. Additionally,
other techniques for providing the layer 350 may be employed such
as use of an adhesive tape form of the insulating polymer, with the
adhesive type selected based on downhole temperature extremes
likely to be encountered within the well 180.
[0024] Materials for the insulating polymer layer 350 when provided
by extrusion or in the form of a polymer tape may include a
polyimide, polyester, polyesterimide, polyamide-imide, polyamide,
poly-ether-ether-ketone, polyethylene terephthalate, polyphenylene
sulfide, and a self-reinforced polyphenylene. Alternatively, where
the above described technique of varnishing is employed, the
insulating polymer layer 350 may more preferably be a polymeric
imide, ester, ester-imide, ester-amide, amide-imide, urethane or an
epoxy. Additionally, the polymeric or epoxy material may be filled
with nano-scale particles configured to improve durability and/or
insulating characteristics of the insulating polymer layer 350.
[0025] Continuing with reference to FIG. 3, with added reference to
FIGS. 1 and 2, the insulating polymer layer 350 may provide
sufficient electrical insulation and corona discharge protection.
However, an additional moisture resistant outer polymer layer 375
may be provided over the insulating polymer layer 350 so as to
prevent contaminants 110 such as moisture from reaching the
insulating polymer layer 350. In this manner, an insulating polymer
may be selected for the underlying insulating polymer layer 350
without significant concern over contaminants 110 within the well
180. In particular, the material for the insulating polymer layer
350 may be selected without significant concern over hydrolytic
degradation thereof. That is, the outer polymer layer 375 may be
configured to shield the insulating polymer layer 350 from moisture
within the well 180. Thus, electrically insulating polymers,
perhaps even those otherwise susceptible to hydrolytic degradation
upon exposure to moisture, may nevertheless be employed in forming
the insulating polymer layer 350. As a result, a greater degree of
flexibility may be exercised in selecting the proper insulating
polymer for electrical isolation of the underlying core 300.
[0026] In addition to shielding the underlying insulating polymer
layer 350, the outer polymer layer 375 may be configured without
significant regard to providing electrical insulation to the core
300. Thus, polymers for the outer polymer layer 375 may be selected
with focus on moisture resistance, corrosive chemical resistance or
other contaminant shielding characteristics.
[0027] In one embodiment, the outer polymer layer 375 may be
particularly configured based on downhole temperatures within a
well 180 such as that of FIGS. 1 and 2. For example, the outer
polymer layer 375 may be configured to withstand high temperature
downhole conditions exceeding about 300.degree. C. In such an
embodiment, the outer polymer layer 375 may be configured of a
fluoropolymer. For example, an ethylene-tetrafluoroethylene
copolymer may be employed, perhaps amended with an adhesive
functional group to promote adhesion to the insulating polymer
layer 350 may be employed. Maleic anhydride, acrylic acid, carboxyl
acid, or silane, may serve as such an adhesive group. Other
suitable high temperature resistant materials for the outer polymer
layer 375 may include polychlorotrifluoroethylene or ethylene
chlorotrifluoroethlyene which may similarly be amended with an
adhesive group as described. Additionally, perfluoroalkoxy resin,
fluorinated ethylene propylene copolymer, polytetrafluoroethylene,
expanded-polytetrafluoroethylene (ePTFE), and any improved
fluoropolymers may be employed to form the outer polymer layer
375.
[0028] In another embodiment, the outer polymer layer 375 may be
configured for lower temperature applications at below about
300.degree. C. and of a polyolefin such as polyethylene,
polypropylene, ethylene-propylene copolymer,
poly(4-methyl-1pentene), and a polyolefin elastomer. Again, these
materials may be amended with maleic anhydride, acrylic acid,
carboxyl acid, silane or other suitable material to promote
adhesion to the underlying electrically insulating polymer layer
350.
[0029] As with the insulating polymer layer 350, a variety of
techniques may also be employed to deliver the outer polymer layer
375. That is, depending on wire sizing, the outer polymer layer 375
may be extruded, perhaps even co-extruded with the insulating
polymer layer 350. In one embodiment the outer polymer layer 375 is
processed down to about 1 mil following the extrusion.
Alternatively, the outer polymer layer 375 may be sintered over the
insulating polymer layer 350 by conventional techniques.
Additionally, an adhesive tape form of the outer polymer may be
employed to provide the outer polymer layer 375 over the insulating
polymer layer 350.
[0030] Referring now to FIG. 4, an alternate embodiment of a motor
winding wire 400 is depicted. Of particular note is the fact that
the wire 400 includes an additional tie layer 465 disposed between
its outer polymer layer 480 and its insulating polymer layer 450.
The tie layer 465 may be employed to serve as an adhesive layer
between the outer polymer layer 480 and underlying insulating
polymer layer 450 so as to ensure adequate bonding therebetween. As
detailed below, the tie layer 465 may be particularly advantageous
in maintaining such a bond given the different types of materials
employed for the outer polymer layer 480 versus the underlying
insulating polymer layer 450. Ensuring adequate bonding in this
manner may be beneficial to the performance and life of an electric
motor 125 in a harsh downhole environment such as that of FIG.
1.
[0031] Continuing with reference to FIG. 4, the insulating polymer
layer 450 may be configured for electrically insulating a
conductive core 425 of the wire 400. Thus, the insulating polymer
layer 450 may be made of materials such as those detailed above for
the insulating polymer layer 350 of the motor wire 201 of FIGS. 2
and 3. Additionally, the outer polymer layer 480 may be configured
to provide contaminant resistance to the underlying portions of the
wire 400, for example, to moisture. Thus, again, the materials
employed for the outer polymer layer 480 may be those detailed
above with reference to the outer polymer layer 375 of the wire 201
of FIGS. 2 and 3. However, given the generally different purposes
of the insulating polymer layer 450 as compared to the outer
polymer layer 480, the tie layer 465 may be provided to ensure
adequate bonding of the layers 450, 465, 480 to one another.
[0032] Continuing with reference to FIG. 5, an enlarged view of
section 5-5 of FIG. 4 is depicted. In particular, the tie layer 465
is shown between the outer polymer layer 480 and the insulating
polymer layer 450 as described above. So as to ensure compatibility
and bonding to both the other layers 450, 480, the tie layer 465 is
made up of a main chain or base polymer of one of the adjacent
layers 450, 480 with a functional group 500 disbursed therein
having an adhesive character relative to the other of the layers
450, 480. In this manner, the base polymer of the tie layer 465 may
provide for adhesion of one adjacent layer 450, 480 to the tie
layer 465 while the functional group 500 provides adhesion to the
other.
[0033] A variety of base polymers may be employed for the tie layer
465 depending on the materials of the adjacent insulating polymer
layer 450 and outer polymer layer 480. For example, polyethylene,
polypropylene, ethylene-propylene copolymer,
poly(4-methyl-1-pentene), ethylene-tetrafluoroethylene copolymer,
ethylene fluorinated ethylene-propylene terpolymers,
polychlorotrifluoroethylene, ethylene chlorotrifluoroethlyene, as
well as a host of other fluoropolymers may be employed as the base
polymer of the tie layer 465. Maleic anhydride, acrylic acid,
carboxyl acid, silane or other suitable functional group 500 may
similarly be employed to serve as an adhesive relative to one of
the layers 450, 480 adjacent the tie layer 465.
[0034] By way of example, with reference to the above listed
material choices for the tie layer 465, one embodiment of a motor
winding wire 400 as depicted in FIG. 4 may include an electrically
insulating polymer layer 450 of polyamide material whereas the
contaminant resistant outer polymer layer 480 may be of
ethylene-tetrafluoroethylene copolymer. In such an embodiment, the
tie layer 465 may be made up of ethylene-tetrafluoroethylene
copolymer as its base polymer for adhesion to the outer polymer
layer 480. In this example a functional group 500 of, for example,
maleic anhydride may be present throughout the tie layer 565 as
depicted in FIG. 5 to provide adhesion to the underlying insulating
polymer layer 450.
[0035] Continuing with reference to FIGS. 4 and 5, manufacture of
the depicted motor winding wire 400 may be according to techniques
described above relative to the insulating polymer layer 450 and
the outer polymer layer 480. Providing of the intervening tie layer
465 is preferably achieved by extrusion. In fact, in one embodiment
each of the layers 450, 465, 480 is simultaneously co-extruded
about the conductive core 425 to form the wire 400.
[0036] Referring now to FIG. 6, an embodiment of a contaminant
resistant electrically driven assembly 600 in the form of an ESP is
depicted within a well 680 at an oilfield 645. The well 680 is
positioned below conventional surface equipment 625 at the oilfield
645 and equipped with a casing 650 traversing various portions 655,
660 of a formation. The well 680 ultimately provides access to a
production region 675 where the ESP assembly 600 may be positioned
for long term operation exceeding about 2 years and perhaps
throughout the productive life of the well 680.
[0037] Resistance to moisture, harsh chemicals, and other potential
contaminants 610 is provided to motor winding wires of the ESP
assembly 600 according to configurations and techniques detailed
above. Thus, in spite of the potentially harsh moisture rich
downhole conditions, embodiments of the ESP assembly 600 may be
left in place without undue concern over the possibility of pump
failure. In this manner, expenses associated with well shut down
and pump replacement may generally be avoided.
[0038] Embodiments described hereinabove include motor winding
wires, which, in spite of limited dimension, may be provided with
adequate electrical insulating along with sufficient polymer
shielding so as to allow for their direct exposure to moisture and
other hydrocarbon contaminants without undue risk of premature
failure. In fact, equipment employing such motor winding wires may
be positioned downhole in a hydrocarbon well and operated
continuously for the substantial life of the well without serious
concern over equipment breakdown due to motor winding wire
failure.
[0039] The preceding description has been presented with reference
to presently preferred embodiments. However, other embodiments not
detailed hereinabove may be employed. For example, a motor winding
wire constructed of materials and according to techniques detailed
hereinabove may be employed in conjunction with powering of a
downhole tractor, powered centralizer, perforation gun, sampling or
other oilfield tools aside from an ESP. Persons skilled in the art
and technology to which these embodiments pertain will appreciate
that still other alterations and changes in the described
structures and methods of operation may be practiced without
meaningfully departing from the principle, and scope of these
embodiments. Furthermore, the foregoing description should not be
read as pertaining only to the precise structures described and
shown in the accompanying drawings, but rather should be read as
consistent with and as support for the following claims, which are
to have their fullest and fairest scope.
* * * * *