WO2016089938A1 - Polymeric materials for downhole electric motors - Google Patents

Abstract

An electric submersible pump system can include a shaft; a pump operatively coupled to the shaft; a multiphase power cable connector; and a multiphase electric motor operatively coupled to the multiphase power cable connector and the shaft where the multiphase electric motor includes a terpolymeric material that includes triester units where crosslinks exist across hydrocarbon chains of at least a portion of the triester units.

Description

POLYMERIC MATERIALS FOR DOWNHOLE ELECTRIC MOTORS

RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of a U.S. Provisional Application having Serial No. 62/086,920, filed 3 December 2014, which is incorporated by reference herein.

BACKGROUND

[0002] Polymeric materials can include one or more polymers. A polymer may be considered to be a relatively large molecule or macromolecule composed of subunits. Polymers are created via polymerization of smaller molecules that can include molecules known as monomers. Polymers may be characterized by physical properties such as, for example, toughness, viscoelasticity, tendency to form glasses and semicrystalline structures, melting temperature, etc.

SUMMARY

[0003] An electric submersible pump system can include a shaft; a pump operatively coupled to the shaft; a multiphase power cable connector; and a multiphase electric motor operatively coupled to the multiphase power cable connector and the shaft where the multiphase electric motor includes a terpolymeric material that includes triester units where crosslinks exist across hydrocarbon chains of at least a portion of the triester units. A method can include forming a mixture that includes ENB, DCPD and a functionalized n-ester; contacting the mixture with a portion of an electric motor; and curing the mixture. A downhole tool can include an electric motor that includes a terpolymeric material that includes triester units where crosslinks exist across hydrocarbon chains of at least a portion of the triester units. An electric submersible pump system can include a shaft; a pump operatively coupled to the shaft; a multiphase power cable connector; and a multiphase electric motor operatively coupled to the multiphase power cable connector and the shaft where the multiphase electric motor includes a polymeric composite material that includes inorganic particles that have a thermal conductivity at approximately 25 degrees C greater than or equal to about 30 W-rrr¹ -K^~1. A method can include formulating a mixture of at least one monomer and inorganic particles that have a thermal conductivity at approximately 25 degrees C in excess of about 30 W-rrr¹ - K^~1 ; and curing the mixture to form an encapsulant that encapsulates at least a portion of stator windings of a multiphase electric motor of an electric submersible pump. A downhole tool can include an electric motor that includes a polymeric composite material that includes inorganic particles that have a thermal conductivity at approximately 25 degrees C greater than or equal to about 30 W-rrr¹ - K^~1. Various other apparatuses, systems, methods, etc., are also disclosed.

[0004] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Features and advantages of the described implementations can be more readily understood by reference to the following description taken in

conjunction with the accompanying drawings.

[0006] Fig. 1 illustrates examples of equipment in geologic environments;

[0007] Fig. 2 illustrates an example of an electric submersible pump system;

[0008] Fig. 3 illustrates examples of equipment;

[0009] Fig. 4 illustrates an example of a system that includes a motor;

[0010] Fig. 5 illustrates an example of a cable;

[0011] Fig. 6 illustrates examples of cables;

[0012] Fig. 7 illustrates examples of equipment;

[0013] Fig. 8 illustrates examples of equipment;

[0014] Fig. 9 shows a photograph of a portion of an electric motor;

[0015] Fig. 10 illustrates an example of a method;

[0016] Fig. 1 1 illustrates an example of a method;

[0017] Fig. 12 illustrates an example of a method;

[0018] Fig. 13 illustrates an example of a method;

[0019] Fig. 14 illustrates examples of plots of data;

[0020] Fig. 15 illustrates examples of plots of data;

[0021] Fig. 16 illustrates examples of plots of data;

[0022] Fig. 17 illustrates an example of a polymeric material;

[0023] Fig. 18 illustrates an example of a plot of data; and [0024] Fig. 19 illustrates example components of a system and a networked system.

DETAILED DESCRIPTION

[0025] The following description includes the best mode presently

contemplated for practicing the described implementations. This description is not to be taken in a limiting sense, but rather is made merely for the purpose of describing the general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.

[0026] As an example, a polymeric material can include one or more organic units and/or one or more inorganic units. As an example, a polymeric material may be copolymeric, which can include terpolymeric and higher (e.g., greater than three types of monomeric materials that react to form a copolymer).

[0027] As an example, a polymeric material can be a polymeric composite material. As an example, a polymeric composite material may include more filler than polymer, for example, depending on desired properties. For example, consider a polymeric composite material that includes one or more inorganic fillers where the volume of the one or more inorganic fillers (in total) is greater than about 50 percent of the total volume of the polymeric composite material. As an example, as to mass percentage, consider a polymeric composite material that includes one or more inorganic fillers where the mass of the one or more inorganic fillers (in total) is greater than about 50 percent of the total mass of the polymeric composite material or, for example, greater than about 75 percent of the total mass of the polymeric composite material. As an example, due to density differences between a filler and polymer, a mass fraction as to a filler may be higher than a volume fraction of the filler. For example, as to one or more oxides and/or one or more nitrides as filler material(s), such one or more filler materials will tend to be denser than a polymeric material (e.g., polymeric matrix material); thus, percent mass of a filler material can be higher than percent volume of the filler material.

[0028] As an example, a polymer may be a thermosetting polymer. As an example, a polymer may be a non-thermosetting polymer. As an example, a polymeric material may include a mixture of one or more thermosetting polymers and one or more non-thermosetting polymers. [0029] As an example, a polymeric material may be or include an ethylene propylene diene monomer (M-class) rubber (EPDM), which is a type of synthetic rubber that is an elastomer. As an example, a polymeric material may be or include a nitrile butadiene rubber (NBR), which is a family of unsaturated copolymers of 2- propenenitrile and various butadiene monomers (1 ,2-butadiene and 1 ,3-butadiene). As an example, a polymeric material may be or include polyether ether ketone (PEEK), which is an organic thermoplastic polymer in the polyaryletherketone (PAEK) family. As an example, a polymeric material may be or include

polyvinylidene fluoride, or polyvinylidene difluoride (PVDF), which is a thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. The aforementioned EPDM, NBR (e.g., also consider HNBR), PEEK, PAEK and PVDF materials are given as some examples of types of polymers that may be in a polymeric material.

[0030] Epoxy resins, also known as polyepoxides are a class of reactive prepolymers and polymers which contain epoxide groups.

[0031] Maleimide and its derivatives can be prepared from maleic anhydride, for example, by treatment with amines followed by dehydration. A feature of the reactivity of maleimides is their susceptibility to additions across the double bond either by Michael additions or via Diels-Alder reactions. Bismaleimides are a class of compounds with two maleimide groups connected by the nitrogen atoms via a linker. Bismaleimides can be used as crosslinking reagents (e.g., in polymer chemistry).

[0032] Polybutadiene is a synthetic rubber that is a polymer that can be formed from the polymerization process of the monomer 1 ,3-butadiene.

[0033] Oxazines are heterocyclic compounds that include one oxygen atom and one nitrogen atom. Isomers exist depending on the relative position of the heteroatoms and relative position of the double bonds. Derivatives may also referred to as oxazines; examples include ifosfamide and morpholine (tetrahydro- 1 ,4-oxazine).

[0034] Cyanate esters include an -OCN group. Cyanate esters can be cured and/or postcured by heating. As an example, curing may be alone at elevated temperatures or, for example, at lower temperatures in presence of a suitable catalyst. As an example, a catalyst may be a transition metal complex such as, for example, one that includes cobalt, copper, manganese and/or zinc. As an example, cyanate esters can be used to produce a thermoset material with a relatively high glass-transition temperature (Tg), for example, up to about 400 degrees C with a relatively low dielectric constant. A cyanate ester material may exhibit relatively low moisture uptake and a higher toughness compared to epoxies.

[0035] Silicones are polymers that include repeating units of siloxane.

Silicones can be relatively heat-resistant and/or rubber-like, for example, consider examples such as silicone oil, silicone grease, silicone rubber, silicone resin, and silicone caulk.

[0036] Ring-opening metathesis polymerization (ROMP) is a type of olefin metathesis chain-growth polymerization. Reactions can be driven by relief of ring strain in cyclic olefins (e.g. norbornene, cyclopentene, etc.). A catalyst that may be used in a ROMP reaction can include a metal, for example, consider a RuC /alcohol mixture, a catalyst, etc. As an example, a catalyst can be a transition metal carbene complex. For example, consider benzylidene-bis(tricyclohexylphosphine)- dichlororuthenium, [1 ,3-bis-(2,4,6-trimethylphenyl)-2- imidazolidinylidene]dichloro(phenylmethylene)(tricyclohexylphosphine)ruthenium, Dichloro(o-isopropoxyphenylmethylene)(tricyclohexylphosphine)ruthenium(ll), and [1 ,3-Bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(o- isopropoxyphenylmethylene)ruthenium.

[0037] As an example, a polymer may be formed at least in part via ROMP. For example, as a prepolymer component amenable to forming a polymer via ROMP, consider a carbon backbone with functional groups that include at least one oxygen that provides an amount of hydrophilicity may be present along with a hydrocarbon chain (e.g., carbon backbone) that provides an amount of

hydrophobicity where at least one functional group may be present on the

hydrophobic hydrocarbon chain where such a functional group may participate in ROMP (e.g., via relief of ring stress). In such an example, the prepolymer component may be an ester such as a diester, a triester, etc. (e.g., an n-ester). As an example, consider a triester that includes at least one hydrocarbon chain with a functional group that includes a ring that is amenable to ROMP via relief of ring stress.

[0038] As mentioned, a ROMP process can employ a catalyst that can include a metal (e.g., Ru, etc.). As an example, a ROMP process may be utilized to form a copolymer (e.g., via two monomers, three monomers, etc.). For example, consider a scheme for forming a copolymer utilizing a functionalized triester as one of the monomers. As an example, DILULIN material (Cargill Inc., Minneapolis, MN) may be utilized, which is a mixture of norbornyl-functionalized linseed oil and

cyclopentadiene (CPD) oligomers (e.g., one fraction consisting of modified linseed oil at about 70 percent by weight and another of cyclopentadiene (CPD) oligomers at about 30 percent by weight). In such an example, the norbornene groups are ROMP-reactive. In such a scheme, one or more additional materials can be included such as, for example, one or more of dicyclopentadiene (DCPD) and ethylidenenorbornene (ENB) (e.g., to form a copolymer, which may be a terpolymer, etc.). At room temperature, DCPD is a white crystalline solid. Norbornene is a bridged cyclic hydrocarbon that can be provided as a white solid. Norbornene includes a cyclohexene ring with a methylene bridge between C-3 and C-6; it carries a double bond which induces ring strain. ENB is a bicyclic monomer and

intermediate that includes two double bonds, each with a different reactivity. ENB can be produced from vinyl norbornene, which can be made from butadiene and dicyclopentadiene DCPD.

[0039] As an example, a terpolymer may be a DCPD/ENB/DILULIN

terpolymer (DED terpolymer). Synthesis of such a terpolymer may proceed at least in part via ROMP. For example, DED terpolymer can be cured via ROMP using transition metal chlorides (e.g., WC , hexachloro tungsten) in combination with Lewis-acidic co-catalysts (e.g., EtAIC , ethylaluminum dichloride). As an example, a DED terpolymer can also be cured with transition metal complexes (e.g. titanium, tungsten, molybdenum, ruthenium, osmium, etc.) with organic ligands. As an example, cationic polymerization can be accomplished using one or more cationic catalysts, such as, for example, one or more of BF3O(C2H₅)2 (boron trifluoride ethyl etherate), B(C6Fs)₃ (tris (pentafluorophenyl) borane), MAO (methylalumoxane), VCI₄ (tetrachlorovanadium), and AIBr₃ (tribromoalumane).

[0040] While a terpolymer is mentioned as an example of a copolymer, in general, one or more types of copolymers may be synthesized. For example, consider a DCPD/DILULIN copolymer (DD copolymer) or an ENB/DILULIN copolymer (ED copolymer).

[0041] As mentioned, a copolymer thermosets can be synthesized from DCPD and/or ENB as well as a functionalized oil (e.g., as in the DILULIN material, etc.). Such synthesis can include ring opening metathesis polymerization (ROMP), which may employ a catalyst or catalysts (e.g., 2nd generation Grubbs' catalyst, etc.). The DILULIN material includes norbornyl-functionalized linseed oil synthesized by Diels- Alder reaction of linseed oil and DCPD at high temperatures and pressures. The DILULIN oil component, a triester, has an average of less than one bicyclic moiety per triglyceride. The low reactivity of the DILULIN material due to the low number of bicyclic moiety compared to DCPD and ENB can decrease curing kinetics, which can, for example, provide time for one or more filling and/or impregnation process (e.g., before gelation, a transition from liquid to solid). As an example, the relatively low viscosity of DCPD and/or ENB may be controlled by adding different

concentrations of the DILULIN material.

[0042] As an example, a terpolymer or other copolymer formed via use of a functionalized n-ester and ROMP, may exhibit toughness and adhesion to magnet wire insulation (e.g., via presence of the n-ester structure).

[0043] As an example, a copolymer formed at least in part from a

functionalized n-ester may be utilized as a varnish/encapsulant material for an electric motor (e.g., consider an electric motor of an electric submersible pump (ESP)). For example, the aforementioned DED copolymer thermoset may be utilized. Such DED copolymer thermosets have relatively high toughness at relatively high temperature and pressure, which may extend service time. As an example, due to the relatively low viscosity and ability to manipulate processability and thermal conductivity, a copolymer based at least in part on a functionalized n- ester may be useful as, for example, a potting material, an encapsulation material, etc., particularly for relatively extreme environments.

[0044] As an example, a copolymer material formed at least in part from a functionalized n-ester and ROMP can be utilized where high Tg, high toughness thermoset resins with a very low curing temperature are presently used. As an example, such a copolymer material may replace one or more of phenolic and epoxy materials (e.g., while providing improved properties and processability).

[0045] A pre-ceramic polymer can be a polymer that can be heated to elevated temperature or pyrolyzed to form a ceramic material. For example, consider polycarbosilanes, with a carbon-silicon backbone, that produce silicon carbide on pyrolysis and polysiloxanes, with a silicon-oxygen backbone, that produce silicon oxycarbides on pyrolysis.

[0046] As an example, a polymer composite material can include a polymer matrix that is an organic or inorganic polymer matrix (e.g., one or more of epoxy, bismaleimide, polybutadiene, benzoxazine, cyanate ester, silicone, Ring-Opening Metathesis Polymers (ROMP), preceramic polymers) or a mixture thereof.

[0047] As an example, a polymer composite material can be cured by application of heat and can be used as either a solvent free system or dispersed in solvent to aid in viscosity reduction. As an example, a polymer composite can be obtained through use of a polymer matrix filled with particulate filler. As an example, particulate filler can include one or more of aluminum oxide, aluminum nitride, boron nitride, silicon nitride, and beryllium oxide.

[0048] Examples of some potential filler materials and property comparisons are presented in Table 1 , below.

[0049] Table 1. Examples of thermally conductive/electrically insulative fillers.

[0050] In Table 1 , the example fillers tend to have relatively high levels of thermal conductivity while still having relatively high dielectric strengths. As an example, in a polymer composite material, a filler level may in a range of

approximately 0.1 percent by volume to approximately 60 percent by volume.

[0051] As an example, a method can include selecting one or more particulate sizes and/or one or more morphologies, for example, to obtain a desired property value or combination of values for different properties. As an example, one or more filler may have a modified surface chemistry, for example, to assist in its ability to "bond" to a polymer matrix. In such an example, the ability to bond may improve mechanical properties and reduce thermal expansion.

[0052] As an example, to maintain mechanical robustness of magnet wire wrapped in a stator of an electric motor, insulated motor windings may use an end coil retention system where the motor windings are held in place by a structural composite that includes a fibrous reinforcement material or materials (e.g., glass, quartz, aramid, etc.) and a polymer matrix (e.g., an organic and/or inorganic polymer matrix).

[0053] As an example, stator motor windings of magnet wire may be held in place by a polymer composite material that encapsulates end turns of the windings and, for example, fills slots. As an example, a method can include applying one or more techniques to avoid or otherwise reduce the presence or occurrence of air voids. For example, consider one or more of vacuum impregnation and degassing while a prepolymer is heated to a low viscosity prior to gelation.

[0054] As an example, thermally conductive encapsulant material(s) may be utilized in an ESP system. Such materials may help to reduce motor winding temperatures when compared to other materials. As an example, such materials may be suitable for applications that utilize electric motors as in, for example, SAGD, subsea, geothermal, etc. While ESP systems are mentioned, such materials may be utilized in one or more other types of applications (e.g., drilling and measurement operations, etc.).

[0055] Various polymeric materials and/or polymeric composite materials may find use in the oil and gas industry. For example, such materials may be suitable for use in equipment that can be disposed at least in part in a downhole environment, which may be subject to chemicals, temperatures, pressures, etc. that can impact durability and performance of such equipment.

[0056] Fig. 1 shows examples of geologic environments 120 and 140. In Fig. 1 , the geologic environment 120 may be a sedimentary basin that includes layers (e.g., stratification) that include a reservoir 121 and that may be, for example, intersected by a fault 123 (e.g., or faults). As an example, the geologic environment 120 may be outfitted with any of a variety of sensors, detectors, actuators, etc. For example, equipment 122 may include communication circuitry to receive and to transmit information with respect to one or more networks 125. Such information may include information associated with downhole equipment 124, which may be equipment to acquire information, to assist with resource recovery, etc. Other equipment 126 may be located remote from a well site and include sensing, detecting, emitting or other circuitry. Such equipment may include storage and communication circuitry to store and to communicate data, instructions, etc. As an example, one or more satellites may be provided for purposes of communications, data acquisition, etc. For example, Fig. 1 shows a satellite in communication with the network 125 that may be configured for communications, noting that the satellite may additionally or alternatively include circuitry for imagery (e.g., spatial, spectral, temporal, radiometric, etc.).

[0057] Fig. 1 also shows the geologic environment 120 as optionally including equipment 127 and 128 associated with a well that includes a substantially horizontal portion that may intersect with one or more fractures 129. For example, consider a well in a shale formation that may include natural fractures, artificial fractures (e.g., hydraulic fractures) or a combination of natural and artificial fractures. As an example, a well may be drilled for a reservoir that is laterally extensive. In such an example, lateral variations in properties, stresses, etc. may exist where an

assessment of such variations may assist with planning, operations, etc. to develop the reservoir (e.g., via fracturing, injecting, extracting, etc.). As an example, the equipment 127 and/or 128 may include components, a system, systems, etc. for fracturing, seismic sensing, analysis of seismic data, assessment of one or more fractures, etc.

[0058] As to the geologic environment 140, as shown in Fig. 1 , it includes a well 141 (e.g., a bore) and equipment 147 for artificial lift, which may be an electric submersible pump (e.g., an ESP). In such an example, a cable or cables may extend from surface equipment to the equipment 147, for example, to provide power, to carry information, to sense information, etc.

[0059] Conditions in a geologic environment may be transient and/or persistent. Where equipment is placed within a geologic environment, longevity of the equipment can depend on characteristics of the environment and, for example, duration of use of the equipment as well as function of the equipment. Where equipment is to endure in an environment over an extended period of time, uncertainty may arise in one or more factors that could impact integrity or expected lifetime of the equipment. As an example, where a period of time may be of the order of decades, equipment that is intended to last for such a period of time may be constructed to endure conditions imposed thereon, whether imposed by an environment or environments and/or one or more functions of the equipment itself.

[0060] As an example, an environment may be a harsh environment, for example, an environment that may be classified as being a high-pressure and high- temperature environment (HPHT). A so-called HPHT environment may include pressures up to about 138 MPa (e.g., about 20,000 psi) and temperatures up to about 205 degrees C (e.g., about 400 degrees F and about 480 K), a so-called ultra- HPHT environment may include pressures up to about 241 MPa (e.g., about 35,000 psi) and temperatures up to about 260 degrees C (e.g., about 500 degrees F and about 530 K) and a so-called HPHT-hc environment may include pressures greater than about 241 MPa (e.g., about 35,000 psi) and temperatures greater than about 260 degrees C (e.g., about 500 degrees F and about 530 K). As an example, an environment may be classified based in one of the aforementioned classes based on pressure or temperature alone. As an example, an environment may have its pressure and/or temperature elevated, for example, through use of equipment, techniques, etc. For example, a SAGD operation may elevate temperature of an environment (e.g., by 100 degrees C or more; about 370 K or more).

[0061] Fig. 2 shows an example of an ESP system 200 that includes an ESP 210 as an example of equipment that may be placed in a geologic environment. As an example, an ESP may be expected to function in an environment over an extended period of time (e.g., optionally of the order of years).

[0062] In the example of Fig. 2, the ESP system 200 includes a network 201 , a well 203 disposed in a geologic environment (e.g., with surface equipment, etc.), a power supply 205, the ESP 210, a controller 230, a motor controller 250 and a VSD unit 270. The power supply 205 may receive power from a power grid, an onsite generator (e.g., natural gas driven turbine), or other source. The power supply 205 may supply a voltage, for example, of about 4.16 kV.

[0063] As shown, the well 203 includes a wellhead that can include a choke (e.g., a choke valve). For example, the well 203 can include a choke valve to control various operations such as to reduce pressure of a fluid from high pressure in a closed wellbore to atmospheric pressure. A wellhead may include one or more sensors such as a temperature sensor, a pressure sensor, a solids sensor, etc.

[0064] As to the ESP 210, it is shown as including cables 21 1 (e.g., or a cable), a pump 212, gas handling features 213, a pump intake 214, a motor 215, one or more sensors 216 (e.g., temperature, pressure, strain, current leakage, vibration, etc.) and a protector 217.

[0065] As an example, an ESP may include a REDA™ HOTLINE™ high- temperature ESP motor. Such a motor may be suitable for implementation in a thermal recovery heavy oil production system, such as, for example, SAGD system or other steam-flooding system. [0066] As an example, an ESP motor can include a three-phase squirrel cage with two-pole induction. As an example, an ESP motor may include steel stator laminations that can help focus magnetic forces on rotors, for example, to help reduce energy loss. As an example, stator windings can include copper and insulation.

[0067] As an example, the one or more sensors 216 of the ESP 210 may be part of a digital downhole monitoring system. For example, consider the

commercially available PHOENIX™ MULTISENSOR XT150 system marketed by Schlumberger Limited (Houston, Texas). A monitoring system may include a base unit that operatively couples to an ESP motor (see, e.g., the motor 215), for example, directly, via a motor-base crossover, etc. As an example, such a base unit (e.g., base gauge) may measure intake pressure, intake temperature, motor oil

temperature, motor winding temperature, vibration, currently leakage, etc. As explained with respect to Fig. 4, a base unit may transmit information via a power cable that provides power to an ESP motor and may receive power via such a cable as well.

[0068] As an example, a remote unit may be provided that may be located at a pump discharge (e.g., located at an end opposite the pump intake 214). As an example, a base unit and a remote unit may, in combination, measure intake and discharge pressures across a pump (see, e.g., the pump 212), for example, for analysis of a pump curve. As an example, alarms may be set for one or more parameters (e.g., measurements, parameters based on measurements, etc.).

[0069] Where a system includes a base unit and a remote unit, such as those of the PHOENIX™ MULTISENSOR XT150 system, the units may be linked via wires. Such an arrangement provide power from the base unit to the remote unit and allows for communication between the base unit and the remote unit (e.g., at least transmission of information from the remote unit to the base unit). As an example, a remote unit is powered via a wired interface to a base unit such that one or more sensors of the remote unit can sense physical phenomena. In such an example, the remote unit can then transmit sensed information to the base unit, which, in turn, may transmit such information to a surface unit via a power cable configured to provide power to an ESP motor.

[0070] In the example of Fig. 2, the well 203 may include one or more well sensors 220, for example, such as the commercially available OPTICLINE™ sensors or WELLWATCHER BRITEBLUE™ sensors marketed by Schlumberger Limited (Houston, Texas). Such sensors are fiber-optic based and can provide for real time sensing of temperature, for example, in SAGD or other operations. As shown in the example of Fig. 1 , a well can include a relatively horizontal portion. Such a portion may collect heated heavy oil responsive to steam injection. Measurements of temperature along the length of the well can provide for feedback, for example, to understand conditions downhole of an ESP. Well sensors may extend a

considerable distance into a well and possibly beyond a position of an ESP.

[0071] In the example of Fig. 2, the controller 230 can include one or more interfaces, for example, for receipt, transmission or receipt and transmission of information with the motor controller 250, a VSD unit 270, the power supply 205 (e.g., a gas fueled turbine generator, a power company, etc.), the network 201 , equipment in the well 203, equipment in another well, etc.

[0072] As shown in Fig. 2, the controller 230 may include or provide access to one or more modules or frameworks. Further, the controller 230 may include features of an ESP motor controller and optionally supplant the ESP motor controller 250. For example, the controller 230 may include the UNICONN™ motor controller 282 marketed by Schlumberger Limited (Houston, Texas). In the example of Fig. 2, the controller 230 may access one or more of the PIPESIM™ framework 284, the ECLIPSE™ framework 286 marketed by Schlumberger Limited (Houston, Texas) and the PETREL™ framework 288 marketed by Schlumberger Limited (Houston, Texas) (e.g., and optionally the OCEAN™ framework marketed by Schlumberger Limited (Houston, Texas)).

[0073] In the example of Fig. 2, the motor controller 250 may be a

commercially available motor controller such as the UNICONN™ motor controller. The UN ICONN™ motor controller can connect to a SCADA system, the

ESPWATCHER™ surveillance system, etc. The UNICONN™ motor controller can perform some control and data acquisition tasks for ESPs, surface pumps or other monitored wells. As an example, the UNICONN™ motor controller can interface with the aforementioned PHOENIX™ monitoring system, for example, to access pressure, temperature and vibration data and various protection parameters as well as to provide direct current power to downhole sensors. The UNICONN™ motor controller can interface with fixed speed drive (FSD) controllers or a VSD unit, for example, such as the VSD unit 270. [0074] For FSD controllers, the UNICONN™ motor controller can monitor ESP system three-phase currents, three-phase surface voltage, supply voltage and frequency, ESP spinning frequency and leg ground, power factor and motor load.

[0075] For VSD units, the UNICONN™ motor controller can monitor VSD output current, ESP running current, VSD output voltage, supply voltage, VSD input and VSD output power, VSD output frequency, drive loading, motor load, three- phase ESP running current, three-phase VSD input or output voltage, ESP spinning frequency, and leg-ground.

[0076] In the example of Fig. 2, the ESP motor controller 250 includes various modules to handle, for example, backspin of an ESP, sanding of an ESP, flux of an ESP and gas lock of an ESP. The motor controller 250 may include any of a variety of features, additionally, alternatively, etc.

[0077] In the example of Fig. 2, the VSD unit 270 may be a low voltage drive (LVD) unit, a medium voltage drive (MVD) unit or other type of unit (e.g., a high voltage drive, which may provide a voltage in excess of about 4.16 kV). As an example, the VSD unit 270 may receive power with a voltage of about 4.16 kV and control a motor as a load with a voltage from about 0 V to about 4.16 kV. The VSD unit 270 may include commercially available control circuitry such as the

SPEEDSTAR™ MVD control circuitry marketed by Schlumberger Limited (Houston, Texas).

[0078] Fig. 3 shows cut-away views of examples of equipment such as, for example, a portion of a pump 320, a protector 370 and a motor 350 of an ESP. The pump 320, the protector 370 and the motor 350 are shown with respect to cylindrical coordinate systems (e.g., r, z, Θ). Various features of equipment may be described, defined, etc. with respect to a cylindrical coordinate system. As an example, a lower end of the pump 320 may be coupled to an upper end of the protector 370 and a lower end of the protector 370 may be coupled to an upper end of the motor 350. As shown in Fig. 3, a shaft segment of the pump 320 may be coupled via a connector to a shaft segment of the protector 370 and the shaft segment of the protector 370 may be coupled via a connector to a shaft segment of the motor 350. As an example, an ESP may be oriented in a desired direction, which may be vertical, horizontal or other angle. As shown in Fig. 3, the motor 350 is an electric motor that includes a connector 352, for example, to operatively couple the electric motor to a power cable, for example, optionally via one or more motor lead extensions (see, e.g., Fig. 4).

[0079] Fig. 4 shows a block diagram of an example of a system 400 that includes a power source 401 as well as data 402 (e.g., information). The power source 401 provides power to a VSD block 470 while the data 402 may be provided to a communication block 430. The data 402 may include instructions, for example, to instruct circuitry of the circuitry block 450, one or more sensors of the sensor block 460, etc. The data 402 may be or include data communicated, for example, from the circuitry block 450, the sensor block 460, etc. In the example of Fig. 4, a choke block 440 can provide for transmission of data signals via a power cable 41 1 (e.g., including motor lead extensions "MLEs"). A power cable may be provided in a format such as a round format or a flat format with multiple conductors. MLEs may be spliced onto a power cable to allow each of the conductors to physically connect to an appropriate corresponding connector of an electric motor (see, e.g., the connector 352 of Fig. 3). As an example, MLEs may be bundled within an outer casing (e.g., a layer of armor, etc.).

[0080] As shown, the power cable 41 1 connects to a motor block 415, which may be a motor (or motors) of an ESP and be controllable via the VSD block 470. In the example of Fig. 4, the conductors of the power cable 41 1 electrically connect at a wye point 425. The circuitry block 450 may derive power via the wye point 425 and may optionally transmit, receive or transmit and receive data via the wye point 425. As shown, the circuitry block 450 may be grounded.

[0081] As an example, power cables and MLEs that can resist damaging forces, whether mechanical, electrical or chemical, may help ensure proper operation of a motor, circuitry, sensors, etc.; noting that a faulty power cable (or MLE) can potentially damage a motor, circuitry, sensors, etc. Further, as mentioned, an ESP may be located several kilometers into a wellbore. Accordingly, time and cost to replace a faulty ESP, power cable, MLE, etc., can be substantial (e.g., time to withdraw, downtime for fluid pumping, time to insert, etc.).

[0082] As an example, a cable may allow for extended run life, low cost, and improved manufacturability. For example, a downhole power cable for electrical submersible pumps (ESP) may include various features, materials of construction, etc. that may improve reliability and reduce environmental impact (e.g., during use, after use, etc.). [0083] As an example, a cable may be rated. For example, ESP cables may be rated by voltage such as about 3 kV, about 4 kV or about 5 kV. As to form, a round cable may be implemented in boreholes where sufficient room exists and a so- called "flat" cable may be implemented where less room may be available (e.g., to provide clearance, etc.).

[0084] As an example, a round ESP cable rated to about 5 kV may include a copper conductor(s), oil and heat resistant ethylene propylene diene monomer (M- class) rubber insulation (EPDM insulation), a barrier layer (e.g., lead and/or fluoropolymer or without a barrier layer), a jacket layer (e.g., oil resistant EPDM or nitrile rubber), and armor (e.g., galvanized or stainless steel or alloys that include nickel and copper such as MONEL™ alloys, Huntington Alloys Corporation,

Huntington, West Virginia).

[0085] As an example, a flat ESP cable rated to about 5 kV may include a copper conductor(s), oil and heat resistant EPDM rubber insulation, a barrier layer (e.g., lead and/or fluoropolymer or without a barrier layer), a jacket layer (e.g., oil resistant EPDM or nitrile rubber or without a jacket layer), and armor (e.g., galvanized or stainless steel or alloys that include nickel and copper such as

MONEL™ alloys).

[0086] In the foregoing examples, armor on the outside of a cable acts to protect the cable from damage, for example, from handling during transport, equipment installation, and equipment removal from the wellbore. Additionally, armor can help to prevent an underlying jacket, barrier, and insulation layers from swelling and abrasion during operation. In such examples, as armor is formed out of metallic strips and wrapped around the cable, voids exist between the overlapping armor layers which can collect well fluid after the cable has been installed in a wellbore. In such scenarios, when the cable is removed from the wellbore the well fluid tends to remain trapped in voids and therefore can cause environmental damage as it drips off of the cable during transport and recycling. Further, as an example, if armor is not present, well fluid can become trapped inside a jacket layer and, for example, lead to environmental challenging situations when the cable is removed from a wellbore.

[0087] As an example, a cable can reduce environmental impact via a reduction of features that may pose potential risks for well fluid (e.g., oil, etc.) to be trapped inside the cable. For example, such a cable can include a durable polymeric coating over an armor layer (e.g., or a jacket layer) to help prevent well fluid from becoming trapped between overlapping armor layers (e.g., or inside the jacket if the cable does not have armor). In such an example, the polymeric coating may be an outermost layer that is smooth (e.g., without ridges, etc. as may be formed by overlying metal strips of armor).

[0088] As an example, a layer disposed over an armor layer (e.g., over an outer surface of an armor layer) may be of sufficient robustness to reduce risk of damage, for example, during installation. In such an example, the layer may be resistant to abrasion from well fluid.

[0089] Fig. 5 shows an example of a cable 500 that includes various components. For example, the cable 500 can include conductors 510, conductor shields (e.g., which may be optional), insulation 520, insulation shields (optional), conductive layers (e.g., which may be optional), barrier layers 530 (e.g., which may be optional), a cable jacket 540, cable armor 550 (e.g., which may be optional) and an outer coating 560 (e.g., an outermost coating or layer).

[0090] As an example, insulation material may include EPDM and/or PEEK. As an example, where insulation material is EPDM, a compound formulation for oil and decompression resistance may be used.

[0091] As an example, an insulation layer may adhere to or be bonded to a conductor shield, for example, where a conductor shield is present. As an example, an insulation layer may be continuous with an insulation shield, for example, with complete bonding or without complete bonding thereto. As an example, where PEEK is selected as a material for an insulation layer, mechanical properties thereof may allow for improved damage resistance, for example, to resist damage to a cable during cable install, cable operation, cable repositioning, cable removal, etc. In such an example, PEEK can offer relatively high stiffness, which may allow for greater ease in sealing over a cable (e.g., cable members such as members that each include a conductor), for example, at a cable termination point or points (e.g., motor pothead, well connectors, feed-throughs, etc.). As an example, such an approach may improve cable and system reliability.

[0092] As an example, a cable may include a barrier layer to help protect the cable from corrosive downhole gases and fluids. As an example, one or more additional barrier layers may be used, for example, depending on intended use, environmental conditions, etc. As an example, a barrier may be formed of extruded material, tape, etc. As an example, a barrier layer may include a fluoropolymer or fluoropolymers, lead, and/or other material (e.g., to help protect against well fluids, etc.). As an example, a combination of extruded and taped layers may be used.

[0093] In the example of Fig. 5, the cable 500 is shown as including a contiguous cable jacket 540 that jackets the first, second and third conductors 510 (e.g., including layers of the first, second and third conductors 510).

[0094] As an example, for a flat cable configuration (e.g., and for a round cable configuration where conductors may be twisted together), a fluid, gas and temperature resistant jacket may be used. Such a jacket may help protect a cable from damage, for example, in challenging downhole environments.

[0095] As an example, a cable jacket may include one or more layers of EPDM, nitrile, hydrogenated nitrile butadiene rubber (HNBR), fluoropolymer, chloroprene, and/or other material resistant to constituents, conditions, etc. in a downhole environment.

[0096] As an example, a jacket may be made of a fluid resistant nitrile elastomer, for example, with low swell ratings in water and in hydrocarbon oil and, for example, with appropriate resistance to wellbore gases.

[0097] As an example, low swell property of the jacket may act to reduce (e.g., minimize) an amount of well fluid that may possibly be absorbed into the cable. As an example, an elastomer jacket may help to prevent fluid migration into a cable and help to provide mechanical protection of insulated conductors set within the elastomer jacket (e.g., jacketed by the elastomer jacket).

[0098] As an example, cable armor, which may be optional, may include galvanized steel, stainless steel, alloys that include nickel and copper such as MONEL™ alloys, or other metal, metal alloy, or non-metal resistant to downhole conditions.

[0099] As shown in the example of Fig. 5, the cable 500 includes a cable outer coating 560. Such a coating may optionally be provided over cable armor, if present. As mentioned, a cable outer coating may help to reduce environmental impact, for example, by reducing presence of features that may pose potential risks for well fluid (e.g., oil, etc.) to be trapped inside the cable. For example, a cable outer coating may be a durable polymeric coating over an armor layer (e.g., or other layer such as a jacket layer) to help prevent well fluid from becoming trapped between overlapping armor layers (e.g., or inside the jacket if the cable does not have armor). In such an example, an outermost layer of a cable may be formed in a manner that has reduced surface roughness, reduced undulations, reduced corrugations, etc., for example, which may act to carry and/or entrap fluid, debris, etc. As an example, a cable outer coating may be relatively smooth and be resistant to swell (e.g., via gasses, liquids, etc.).

[00100] As an example, a cable outer coating may be made of polyvinylidene fluoride (PVDF, KYNAR™ polymer (Arkema, Inc., King of Prussia, Pennsylvania), TEDLAR™ polymer (E. I. du Pont de Nemours & Co., Wilmington, Delaware), etc.). As an example, a cable outer coating may be made of PVDF modified with about 0.1 percent to about 10 percent by weight adducted maleic anhydride, for example, to facilitate bonding to a metallic armor or elastomer jacket (e.g. where armor is not employed).

[00101 ] Fig. 6 shows an example of a geometric arrangement of components of a round cable 610 and an example of a geometric arrangement of components of an oblong cable 630. As shown the cable 610 includes three conductors 612, a polymeric layer 614 and an outer layer 616 and the oblong cable 630 includes three conductors 632, a polymeric layer 634 (e.g., optionally a composite material with desirable heat transfer properties) and an optional outer polymeric layer 636 (e.g., outer polymeric coat, which may be a composite material). In the examples of Fig. 6, a conductor may be surrounded by one or more optional layers, as generally illustrated via dashed lines. For example, as to the cable 630, consider three 1 gauge conductors (e.g., a diameter of about 7.35 mm), each with a 2 mm layer and a 1 mm layer. In such an example, the polymeric layer 634 may encapsulate the three 1 gauge conductors and their respective layers where, at ends, the polymeric layer 634 may be about 1 mm thick. In such an example, an optional armor layer may be of a thickness of about 0.5 mm. In such an example, the optional outer polymeric layer 636 (e.g., as covering armor) may be of a thickness of about 1 mm (e.g., a 1 mm layer).

[00102] As shown in Fig. 6, the cable 610 includes a circular cross-sectional shape while the cable 630 includes an oblong cross-sectional shape. In the example of Fig. 6, the cable 610 with the circular cross-sectional shape has an area of unity and the cable 630 with the oblong cross-sectional shape has area of about 0.82. As to perimeter, where the cable 610 has a perimeter of unity, the cable 630 has a perimeter of about 1.05. Thus, the cable 630 has a smaller volume and a larger surface area when compared to the cable 610. A smaller volume can provide for a smaller mass and, for example, less tensile stress on a cable that may be deployed a distance in a downhole environment (e.g., due to mass of the cable itself).

[00103] In the cable 630, the conductors 632 may be about 7.35 mm (e.g., about 1 AWG) in diameter with insulation of about 2 mm thickness, lead (Pb) of about 1 mm thickness, a jacket layer (e.g., the layer 634) over the lead (Pb) of about 1 mm thickness at ends of the cable 630, optional armor of about 0.5 mm thickness and an optional polymeric layer of about 1 mm thickness (e.g., the layer 636 as an outer polymeric coat). As an example, the cable 630 may be of a width of about 20 mm (e.g., about 0.8 inches) and a length of about 50 mm (e.g., about 2 inches), for example, about a 2.5 to 1 width to length ratio).

[00104] As an example, a cable may be formed with phases split out from each other where each phase is encased in solid metallic tubing.

[00105] As an example, a cable can include multiple conductors where each conductor can carry current of a phase of a multiphase power supply for a multiphase electric motor. In such an example, a conductor may be in a range from about 8 AWG (about 3.7 mm) to about 00 AWG (about 9.3 mm).

[00106] Table 2. Examples Components.

[00107] In Table 2, where a cable has an oblong cross-sectional shape, the jacket over lead (Pb) layer may be, for example, of a thickness of about 20 mils to about 85 mils (e.g., about 0.5 mm to about 2.2 mm) at ends of the oblong cross- sectional shape and, for example, at various points along opposing sides of the oblong cross-sectional shape. For example, material forming the jacket over lead (Pb) layer may be thicker in regions between conductors (e.g., consider

approximately triangular shaped regions).

[00108] As an example, a cable may include conductors for delivery of power to a multiphase electric motor with a voltage range of about 3 kV to about 8 kV. As an example, a cable may carry power, at times, for example, with amperage of up to about 200 A or more.

[00109] As to operational conditions, where an electric motor operates a pump, locking of the pump can cause current to increase and, where fluid flow past a cable may decrease, heat may build rapidly within the cable. As an example, locking may occur due to gas in one or more pump stages, bearing issues, particulate matter, etc.

[00110] As an example, a cable may carry current to power a multiphase electric motor or other piece of equipment (e.g., downhole equipment powerable by a cable).

[00111 ] Fig. 7 shows various examples of motor equipment. A pothead unit 701 includes opposing ends 702 and 704 and a through bore, for example, defined by a bore wall 705. As shown, the ends 702 and 704 may include flanges configured for connection to other units (e.g., a protector unit at the end 702 and a motor unit at the end 704). The pothead unit 701 includes cable passages 707-1 , 707-2 and 707- 3 (e.g., cable connector sockets) configured for receipt of cable connectors 716-1 , 716-2 and 716-3 of respective cables 714-1 , 714-2 and 714-3. As an example, the cables 714-1 , 714-2 and 714-3 and/or the cable connectors 716-1 , 716-2 and 716-3 may include one or more polymeric materials. For example, a cable may include polymeric insulation while a cable connector may include polymeric insulation, a polymeric component (e.g., a bushing), etc. As an example, the cables 714-1 , 714-2 and 714-3 may be coupled to a single larger cable. The single larger cable may extend to a connector end for connection to a power source or, for example, equipment intermediate the cable and a power source (e.g., an electrical filter unit, etc.). As an example, a power source may be a VSD unit that provides three-phase power for operation of a motor.

[00112] Fig. 7 also shows a pothead unit 720 that includes a socket 721 . As an example, a cable 722 may include a plug 724 that can couple to the socket 721 of the pothead unit 720. In such an example, the cable 722 may include one or more conductors 726. As an example, a cable may include at least one fiber optic cable or one or more other types of cables. [00113] As explained above, equipment may be placed in a geologic

environment where such equipment may be subject to conditions associated with function or functions of the equipment and/or be subject to conditions associated with the geologic environment. Equipment may experience conditions that are persistent (e.g., relatively constant), transient or a combination of both. As an example, to enhance equipment integrity (e.g., reduction in failures, increased performance, longevity, etc.), equipment may include at least one polymeric material.

[00114] Fig. 8 shows a perspective cut-away view of an example of a motor assembly 800 that includes a power cable 844 (e.g., MLEs, etc.) to supply energy, a shaft 850, a housing 860 that may be made of multiple components (e.g., multiple units joined to form the housing 860), stacked laminations 880, stator windings 870 of wire (e.g., magnet wire) and rotor laminations 890 and rotor windings 895 coupled to the shaft 850 (e.g., rotatably driven by energizing the stator windings 870).

[00115] As shown in Fig. 8, the housing 860 includes an inner surface 861 and an outer surface 865. As an example, the housing 860 can define one or more cavities via its inner surface 861 where one or more of the cavities may be

hermetically sealed. As an example, such a cavity may be filled at least partially with dielectric oil. As an example, dielectric oil may be formulated to have a desired viscosity and/or viscoelastic properties, etc.

[00116] As shown, the shaft 850 may be fitted with a coupling 852 to couple the shaft to another shaft. A coupling may include, for example, splines that engage splines of one or more shafts. The shaft 850 may be supported by bearings 854-1 , 854-2, 854-3, etc. disposed in the housing 860.

[00117] As shown, the housing 860 includes opposing axial ends 862 and 864 with the substantially cylindrical outer surface 865 extending therebetween. The outer surface 865 can include one or more sealable openings for passage of oil (e.g., dielectric oil), for example, to lubricate the bearings and to protect various

components of the motor assembly 800. As an example, the motor assembly 800 may include one or more sealable cavities. For example, a passage 866 allows for passage of one or more conductors of the cable 844 (e.g., or cables) to a motor cavity 867 of the motor assembly 800 where the motor cavity 867 may be a sealable cavity. As shown, the motor cavity 867 houses the stator windings 870 and the stator laminations 880. As an example, an individual winding may include a plurality of conductors (e.g., magnet wires). For example, a cross-section 872 of an individual winding may reveal a plurality of conductors that are disposed in a matrix (e.g., of material or materials) or otherwise bound together (e.g., by a material or materials). In the example of Fig. 8, the motor housing 860 includes an oil reservoir 868, for example, that may include one or more passages (e.g., a sealable external passage and a passage to the motor cavity 867) for passage of oil.

[00118] As an example, a shaft may be reciprocating, for example, where a shaft includes one or more magnets (e.g., permanent magnets) that respond to current that passes through stator windings.

[00119] As to electrically insulating materials that exhibit thermal conductivities that exceed those of various thermosets, consider one or more of aluminum oxide, aluminum nitride, boron nitride, silicon nitride, zinc oxide and beryllium oxide. As an example, a filler or filler material can be or include one or more electrically insulating materials that exhibit thermal conductivities that exceed that of a polymeric matrix.

[00120] Aluminum oxide (AI2O3) is an electrical insulator with a relatively high thermal conductivity (e.g., about 30 W-rrr¹ - K^~1) for a ceramic material.

[00121 ] Aluminum nitride (AIN) is a semiconductor material with a relatively high thermal conductivity for a ceramic material (e.g., about 70 to about 210

W-m^~1 - K^~1 for polycrystalline material, and as high as about 285 W-m^~1 - K^~1 for single crystals).

[00122] As an example, a thermally conductive material may be or include boron nitride (BN). For example, consider hexagonal boron nitride, which may be referred to as h-BN, a-BN, or g-BN (graphitic BN). Hexagonal boron nitride (point group = D6h; space group = P63/mmc) has a layered structure. Within each layer, boron and nitrogen atoms are bound by strong covalent bonds, whereas the layers are held together by weak van der Waals forces. The interlayer registry of these sheets differs, however, from the pattern seen for graphite, because the atoms are eclipsed, with boron atoms lying over and above nitrogen atoms. This registry reflects the polarity of the B-N bonds. The partly ionic structure of BN layers in h-BN reduces covalency and electrical conductivity.

[00123] Thermal conductivity of suspended few-layer hexagonal boron nitride (h-BN) measured for thermal resistance values of 1 1-12 atomic layer h-BN samples with suspended lengths ranging between 3 and 7.5 μιη, provided a room- temperature thermal conductivity of an 1 1 -layer sample at about 360 W-rrr¹ - K^~1, approaching the basal plane value reported for bulk h-BN. As an example, h-BN can have a thermal conductivity in excess of about 360 W-rrr¹ - K^~1 in the basal plane (e.g., about 600 W-m- - K^"1).

[00124] Silicon nitride (Si₃N₄) has a thermal conductivity of about 10 to about 43 W-m- - K-¹.

[00125] Zinc oxide is an inorganic compound with the formula ZnO. Zinc oxide is a white powder that tends to be quite insoluble in water. As an example, zinc oxide may have a density of about 5.6 g/cm³; noting that fully dense zinc oxide crystal can have a thermal conductivity at room temperature of about 40 W-rrr¹ -K^~1; noting that bulk zinc oxide can be of higher thermal conductivity values (e.g., consider doped zinc oxide, etc.).

[00126] Beryllium oxide (BeO) is an electrical insulator with a relatively high thermal conductivity of about 330 W-rrr¹ -K^~1.

[00127] As an example, a polymeric matrix of a polymeric composite material may be formed of organic and/or inorganic monomeric and/or polymeric materials. As an example, one or more of an epoxy, bismaleimide, polybutadiene,

benzoxazine, cyanate ester, silicone, Ring-Opening Metathesis Polymers (ROMP), and preceramic polymers may be utilized.

[00128] As an example, one or more monomers and/or polymers may be amphiphilic, which may facilitate blending in one or more fillers. As an example, the functionalized linseed oil marketed as DILULIN material is amphiphilic and can allow for increasing the content of one or more inorganic fillers.

[00129] As an example, a polymeric material can be thermally conductive and electrically insulative and be utilized to encapsulate windings of an electric motor. Such an approach may provide for lower winding temperatures and end coil temperatures through heat dissipation. As an example, such a polymeric material may be used to achieve encapsulation that protects windings from fluid ingression, for example, without causing heat rises that can result from the use of thermally insulative encapsulants.

[00130] An electric motor may include a coil retention system such as, for example, a full winding encapsulation type, a varnished windings type, or an end coil retention type (e.g., one that does not support wires in slots). As an example, a glass-fiber tape can be included in a coil retention system where, for example, the glass-fiber tape is wrapped around end turns and where the glass-fiber tape is impregnated with a crosslinking resin. [00131 ] As an example, an encapsulation technique can depend on the type of coil retention system employed. For example, the use of a thermosetting polymer can depend on the type of coil retention system. An encapsulated system can involve use of one or more materials and one or more particular processes. As an example, varnished windings approach can include use of a solvent-based polybutadiene system, which tends to be more elastomeric than structural. An end coil retention resin can be a silica-filled epoxy, which has suitable structural properties due in part to the fact that the end coil retention provides coil stabilization while holding the end turns and while not supporting wires in the slots.

[00132] As an example, an encapsulant material can support and protect windings with a limited contribution to heat rise. Such a material can be of a high dielectric strength at low thicknesses (e.g., approximately 0.004 inch to

approximately 0.008 inch; about 0.1 mm to about 0.2 mm). Such a material can exhibit thermal stability to handle motor running temperatures. For example, a SAGD steam injection ESP system or a geothermal ESP system may experience motor temperatures as high as about 300 degrees C. As an example, a high amperage subsea ESP system may see long term operation at temperatures in excess of about 180 degrees C. Such a material can exhibit a relatively low thermal expansion such that it does not expand excessively with temperature, which could place stress on motor windings. Such a material can exhibit suitable toughness, for example, to withstand mechanical and thermal shock without fracturing, which could lead to debris that could interfere with performance of an electric motor. Such a material can be compatible with one or more types of dielectric motor oils (e.g., purified mineral oils, polyalphaolefin (PAO) synthetic oils, PFPE (polyperfluoroether), etc.). Such a material can be relatively resistance to well fluid(s), which can thereby allow an electric motor to function in case of leakage well fluid.

[00133] As to dielectric motor oils, these may be characterized by thermal conductivity. Dielectric motor oils tend to have relatively low thermal conductivities. For example, a PAO oil can have a thermal conductivity of about 0.14 W-rrr¹ -K^~1. As another example, a PFPE oil can have a thermal conductivity that may be less than 0.1 W-rrr¹ -K^~1. Where an electric motor includes dielectric motor oil, such oil may be a relatively poor thermal conductor. Such dielectric motor coil can be in contact with an encapsulant. Where an encapsulant includes one or more fillers, the thermal conductivity of the encapsulant can be increased, for example, in comparison to a polymeric encapsulant that does not include such one or more fillers (e.g., one or more fillers with thermal conductivity greater than about 30 W-rrr¹ - K^~1).

[00134] As mentioned, materials that are thermally insulative such as materials that include a substantial amount of silica filler can cause an electric motor to operate at temperatures higher than those desired or possible through use of less thermally insulative materials. Increase heat retention and/or higher temperatures can impact reliability of an electric motor.

[00135] As an example, a silica filled epoxy may have suitable thermal stability and low thermal expansion; however, it may be limited in terms of processability and thermal conductivity.

[00136] As an example, a polybutadiene varnish can be used to protect against fluid ingression; however, such material tends to have a lower thermal conductivity than a silica filled epoxy. Use of polybutadiene can lead to heat rises in an electric motor. Further, such material can have a relatively high thermal expansion, which can lead to stress being placed on windings (e.g., where used for full encapsulation, etc.).

[00137] As an example, to maintain mechanical robustness of magnet wire wrapped in a stator of an electric motor, insulated motor windings may use a coil retention system where at least ends of coils are held in place by a structural composite that includes fibrous reinforcement (e.g., one or more of glass, quartz, aramid, etc.) and an organic and/or inorganic polymer matrix (e.g., epoxy, bismaleimide, cyanate ester, silicone, Ring-Opening Metathesis Polymers (ROMP), preceramic polymers, etc.).

[00138] Fig. 9 shows a photograph of a portion of an electric motor where resin is applied to glass fabric for the lower portion of the windings shown in the photograph (e.g., upper portion shows the glass fabric without the resin).

[00139] As an example, windings can be held in place by a polymeric composite material that completely encapsulates end turns and that fills slots. In such an example, air voids may be substantially removed through use of vacuum impregnation and degassing while prepolymer is heated to a low viscosity prior to gelation.

[00140] As an example, a polymeric composite material can include a polymer matrix that is an organic and/or inorganic polymer matrix (e.g., epoxy, bismaleimide, polybutadiene, benzoxazine, cyanate ester, silicone, Ring-Opening Metathesis Polymers (ROMP), preceramic polymers, etc.). Such one or more materials may be cured by application of heat and, for example, may be used as either a solvent free system or dispersed in solvent to aid in viscosity reduction. The polymeric composite can be obtained through the use of the polymeric matrix being at least partially filled with one or more types of particulate fillers such as, for example, one or more of aluminum oxide, aluminum nitride, boron nitride, silicon nitride, and beryllium oxide (see, e.g., Table 1 ).

[00141 ] Such fillers can have relatively high levels of thermal conductivity while still having relatively high dielectric strengths. As an example, an amount of filler or fillers can be in a range of about 0.1 percent by volume to about 60 percent by volume. As an example, by mass, filler or fillers may be, for example, in a range from about 0.1 percent to 90 percent or more.

[00142] As mentioned, by varying one or more particulate sizes and/or one or more morphologies, an approach may tailor a material to achieve one or more desired properties (e.g., desired property values, etc.). As an example, particle sizes may be specified as an average particle size, a median particle size, etc. As an example, a particle size distribution may be modal or multimodal. As an example, particles of different size distributions may be mixed, for example, to achieve a desired "packing" structure within a polymeric matrix. As an example, a particle size may be specified as an average, a median, a D value, etc. As an example, a specified particle size may be given in a range from about 100 nanometers to about 100 micrometers. As an example, one or more of D10, D50 and D90 may be used to represent a midpoint and range of particle sizes. As an example, a sieve analysis can generate an S-curve for calculating intercepts of 10%, 50% and 90% mass. As an example, an approach to size may involve one or more laser and imaging technologies.

[00143] As mentioned, a filler or fillers may have modified surface chemistries, for example, to assist in bonding to a polymeric matrix, which may improve mechanical properties and reduce thermal expansion.

[00144] Thermally conductive encapsulants can improve reliability of ESP systems by decreasing motor winding temperatures. Applications can include SAGD, subsea, geothermal, etc. Such materials may be suitable for use in equipment for drilling and measurement operations (e.g., D&M). [00145] Fig. 10 shows an example of a method 1000 that includes various material input blocks 1010, 1020, 1030, 1040 and 1050 for inputting material to form a mixture 1060. As an example, the method 1000 can utilize two or more of the input blocks 1010, 1020, 1030, 1040 and 1050 to form the mixture 1060.

[00146] As shown in the example of Fig. 10, the material input block 1010 is for inputting ENB, the material input block 1020 is for inputting DCPD, the material input block 1030 is for inputting one or more functionalized n-esters, the material input block 1040 is for inputting at least one catalyst, and the material input block 1050 is for inputting one or more fillers (e.g., particles, etc.).

[00147] In the example of Fig. 10, the method 1000 can include forming the mixture 1060 and curing the mixture with respect to time to form a product 1070, which may have properties at time X. As shown in the example of Fig. 10, the method 1000 can include further curing of the product 1070 to form product 1072, which may have properties at time X + Δ where one or more of the properties may differ from one or more of those at time X. For example, where further curing occurs, hardness may increase (e.g., a Shore hardness at one time may differ from a Shore hardness at another, later time).

[00148] Fig. 1 1 shows an example of a method 1 100 that may be applied with respect to a downhole tool such as an electric motor of an ESP. Fig. 11 also shows a photograph 1 180 of an example of a portion of a product (e.g., a portion of an example of a stator).

[00149] In the example of Fig. 1 1 , the method 1 100 includes a formulation block 1 1 10 for forming a mixture (see, e.g., the mixture 1060 of Fig. 10), a contact block 1 120 for contacting the mixture and a formation block 1 170 for forming a product by at least in part curing the mixture.

[00150] In Fig. 1 1 , the photograph 1 180 shows a lamination 1 181 that includes a slot 1 182 where slot liner material 1 183 defines an interior space such that the slot liner material 1 183 surrounds magnet wire 1 192 that includes insulation 1 191. As shown in the photograph 1 180, polymeric material 1 193, which may be polymeric composite material, is disposed exteriorly and interiorly with respect to the slot liner material 1 183. As an example, the insulation 1 191 can be of the order of about 0.1 mm to about 0.3 mm. As an example, the slot liner material 1 183 can be a polymeric film that may be of one or more layers where a layer of the film may be of the order of about 0.1 mm to about 0.3 mm. As shown, the polymeric material 1193 can at least partially fill spaces defined by the slot 1 182 of the lamination 1 181. As an example, an individual plate may be formed of carbon steel with an oxide coating where a plurality of such plates can be stacked to form the laminations.

[00151 ] As an example, heat energy generated during operation of an electric motor that includes the stator of the photograph 1 180 may be transferred to the polymeric material 1 193. For example, current in the magnet wire 1 192 can generate heat due at least in part to resistance of the magnet wire 1 192. As the polymeric material 1 193 is in contact with the magnet wire 1 192 (e.g., via the electrical insulation 1 191 ) it can conduct at least a portion of the heat energy away from the magnet wire 1 192, noting that resistance of the magnet wire 1 192 may depend on temperature (e.g., consider a wire where resistance increases with temperature or, in other words, where the wire becomes less efficient as temperature increases).

[00152] As an example, where laminations are at a temperature that is greater than that of polymeric material, which may be polymeric composite material, heat energy may be transferred to the polymeric material, which may be proximate to fluid, etc. that is of a lesser temperature. In such a manner, polymeric material can help to reduce heat energy build-up in a stator of an electric motor.

[00153] Fig. 12 shows an example of a method 1200 with respect to an example of an electric motor 1210 that may be part of an electric submersible pump (ESP) system. As shown in Fig. 12, the electric motor 1210 includes a housing 1220 with threads 1222. Lead wires (e.g., brush wires) 1232 are shown where a number of such wires can correspond to a number of phases. For example, for a three phase electric motor, there can be three lead wires 1232 (e.g., two being shown in the cutaway view). The lead wires 1232 can be associated with a top or uphole end of an electric submersible pump; whereas, at a bottom or downhole end, a wye point may exist where phases are electrically coupled. As an example, a wye point may be electrically coupled to one or more other components such as, for example, a gauge (e.g., a sensor unit, etc.).

[00154] As shown in the example of Fig. 12, the lead wires 1232 are electrically coupled to phase windings or phase coils where ends of the windings or coils 1234 can extend downward through slots 1227 in laminations 1225. As shown in the example of Fig. 12, a polymeric material 1242, which may optionally be a polymeric composite material (e.g., polymeric material that includes one or more fillers) contacts the ends of the windings or coils 1234 and a portion of the polymeric material 1242 extends downwardly through the slots 1227 in the laminations 1225.

[00155] In the example of Fig. 12, a molding insert 1250 may be utilized to contain the polymeric material 1242 (e.g. encapsulant material) during curing of the polymeric material (e.g., where reactions occur involving at least in part monomers, etc.).

[00156] As to the method 1200, it can include an injection process 1201 for injecting polymeric material 1242 into a cavity of the housing 1220 to contact ends of windings or coils (e.g., of magnet wire), a molding process 1202 for molding the polymeric material 1242 about the ends of the windings or coils in a manner to not interfere with other components of an electric motor (e.g., to create a shaft space and/or rotor space, etc.), an assembly process 1203 for assembling an electric motor 1210 that includes the stator disposed in the housing 1220 and an assembly process 1204 for assembly a downhole tool that can utilize the electric motor 1210 (e.g., an ESP, etc.).

[00157] As an example, a cavity of an electric motor may be characterized at least in part by volume. As an example, a cavity of an electric motor may be characterized at least in part by shape. As an example, an encapsulant may form a relatively contiguous mass within an electric motor. For example, consider a mass of encapsulant that is in contact with ends of windings or coils for a plurality of individual windings (e.g., directly in contact or indirectly in contact via liner material or other material wrapped or otherwise disposed around insulated magnet wire, etc.) where each of the individual windings corresponds to an individual phase of a stator of an electric motor. In such an example, the stator may be formed at least in part by laminations that form a stack where openings in individual plates form slots that pass through the stack (e.g., in a direction substantially parallel to a rotational axis direction of a rotor) and where the windings or coils include portions that pass through the slots. As an example, a mass of encapsulant can include portions that are disposed in such slots.

[00158] As an example, a stator can include a central portion formed by laminations and substantially axially lengths of magnet wire and opposing end portions adjacent to opposing ends of the laminations where the magnet wire loops to form looped ends (e.g., referred to as ends of windings or coils, which may be referred to as winding ends, coil ends, etc.). In an electric motor, an individual winding can include a lead end that is electrically coupled to a respective lead wire and a wye end that is electrically coupled at least in part to one or more other wye ends of one or more other corresponding individual windings. As an example, a mass of substantially contiguous encapsulant may contact first sets of ends of windings and second sets of ends of winding where the substantially contiguous encapsulant passes through slots through which the windings pass. Such a stator can be disposed in a housing.

[00159] As an example, a volume of a substantially contiguous encapsulant may be of the order of liters for an electric motor of an ESP system, for example, consider a volume range from about 1 liter to about 30 liters. As an example, consider an electric motor that has a substantially cylindrical shape with a diameter of about 18 cm and an axial length of about 10 m. In such an example, a volume of encapsulant may be of the order of tens of liters.

[00160] As an example, for an electric motor of another type of downhole tool, the volume may be in a range where a lower limit of the range is of the order of milliliters. As an example, a downhole tool may be a wireline tool. As an example, a downhole tool may be a completions tool. As an example, a downhole tool can include an electric motor that has a substantially cylindrical shape. In such an example, consider, as an example, a total volume of about 350 milliliters, a length of about 12 cm and a diameter of about 5 cm. Of the total volume, a fraction thereof can be encapsulant (e.g., an encapsulant volume of the order of tens of milliliters).

[00161 ] Fig. 13 shows an example of a method 1300 that includes a formation block 1310 for forming a mixture, a degas block 1320 for degassing the mixture and a formation block 1370 for forming a product that includes the mixture in an at least partially cured state. In the example of Fig. 13, the mixture may be of a suitable viscosity that allows for degassing such that entrainment of gas is reduced of the mixture in the at least partially cured state. As an example, after degassing, curing may occur or continue to form a thermoset that is relatively free of gas bubble defects.

[00162] As an example, a mixture may be at a target viscosity that provides for suspending the one or more fillers (e.g., for homogeneous or other distribution of one or more fillers) and that provides for injecting the mixture into a cavity and optionally further degassing of the mixture (e.g., in the cavity, etc.). [00163] As an example, a method can include pulling a vacuum to a stator, heating the stator while pulling the vacuum to reduce moisture, providing a mixture of encapsulant material, and pumping at least a portion of the mixture into the stator (e.g., via a gear pump, a piston pump, etc.). In such an example, the pumping can include flowing the mixture via a bottom location of the stator while at a top location a vacuum may be applied, which may assist with the pumping and/or assist with degassing/avoiding bubble formation/entrainment. As an example, curing may commence at one or more stages and may be accelerated and/or slowed, for example, via control of one or more parameters (e.g., temperature, etc.).

[00164] As an example, where an ecapsulant is a polymeric composite material, during the curing thereof, the presence of one or more fillers (e.g., electrically insulating and thermally conductive with a thermal conductivity of about 30 W-m^~1 - K^~1 or more) can help to provide a more even cure as heat energy may be transferred in a manner that acts to help to avoid temperature inhomogeneity. In such an example, stress in a cured polymeric composite material (e.g., a mass of encapsulant) may be reduced when compared to cured material that does not include the aforementioned one or more fillers. As an example, a reduction in stress inhomogeneity may increase in a manner that depends on size because, as size of an encapsulated mass increases, risk of inhomogeneity of temperature (e.g., curing, etc.) may increase; thus, where one or more fillers are included, heat energy may be more readily conducted and "smoothed" during curing, which can reduce stress inhomogeneity.

[00165] As mentioned, varnish or encapsulation may be applied to various components of an ESP such as motor stator components to provide protection from mechanical damage (e.g., shock and/or vibration), to increase dielectric insulation, to protect magnet wire (tape and adhesive) from thermal and hydrolytic degradation, etc.

[00166] As an example, a varnish and/or encapsulant material for downhole use can include a copolymer of dicyclopentadiene (DCPD) and ethylidene- norbornene (ENB). DCPD/ENB copolymers tend to exhibit suitable mechanical, thermal and electrical properties even after aging at high temperature and pressure, especially when compared to standard polybutadiene (PB) varnish material.

[00167] As an example, a varnish and/or encapsulant material for downhole use can include a terpolymer of DCPD, ENB and DILULIN material. Such a varnish and/or encapsulant material can be a composite material. For example, consider a terpolymeric matrix that includes particles (e.g., filler or fillers, etc.). In such an example, the particles may be thermally conductive and, by their presence in the terpolymeric matrix, increase the thermal conductivity beyond that of the terpolymeric matrix without such particles.

[00168] ENB, 5-ethylidene-2-norborene (e.g., bicyclo(2.2.1 )hept-2-ene,5- ethylidene), has a formula weight of about 120 g/mol (C9H12) with a relatively colorless appearance as a liquid at room temperature (e.g., 25 degrees C) and a boiling point of about 146 degrees C (760 mm Hg). Its density is about 0.89 g/ml at 25 degrees C. As an example, a supply may include a mixture of endo and exo forms and, for example, an amount of BHT as an inhibitor (e.g., order of hundreds of ppm or less). ENB can be used as a diene monomer in the production of ethylene- propylene-diene rubber (EPDM). As a bicyclic monomer and intermediate that contains two double bonds, each with different reactivity, it is possible to react one of the double bonds of ENB, and retain the other double bond of ENB for subsequent reaction. ENB is registered in chemical abstracts under bicyclo(2.2.1 )hept-2-ene,5- ethylidene. The CAS registry number is 16219-75-3.

[00169] As to viscosity of ENB, at 20 degrees C, it has an absolute viscosity of about 1.1 cP, which decreases to about 0.8 cP at about 40 degrees C. For comparison, at about 20 degrees C, water has a viscosity of about 1 cP.

[00170] DCPD, dicyclopentadiene (e.g., tricyclo[5.2.1.0²'⁶]deca-3,8-diene) has a formula weight of about 132 g/mol and a density of about 0.98 g/ml. Its melting point is about 32.5 degrees C and its boiling point is about 170 degrees C. At room temperature, DCPD is a crystalline solid. The CAS registry number is 77-73-6.

[00171 ] ENB (liquid) and DCPD (crystalline) can be mixed at room temperature (e.g., about 25 degrees C). For example, adding about 5 percent by weight of ENB to DCPD can reduce the melting point of DCPD (e.g., to lower than about 0 degrees C). In such an example, the mixture of ENB and DCPD is liquid at room

temperature. Where DCPD is utilized without ENB and where a liquid is desired, the temperature of the DCPD can be raised to above its melting point.

[00172] Curing of DCPD without ENB can be quite fast and, for various purposes, relatively uncontrollable at temperatures just above room temperature (e.g., at about 30 degrees C). By adding ENB to DCPD, a mixture with a relatively low viscosity (e.g., less than water) may be formed at, for example, room temperature. Such a mixture, due to its relatively low viscosity, may be degassed more readily (e.g., to free of bubbles) when compared to a more viscous liquid (e.g., consider a melt of DCPD without ENB). Where a mixture is to be used as a varnish and/or encapsulant, a lower viscosity can help to reduce entrainment/entrapment of gas. Gas within a varnish and/or encapsulant and/or at an interface between the varnish and/or encapsulant and another material or materials can increase risk of defects (e.g., adhesion, cracking, etc.). As an example, a mixture of DCPD and ENB can be formulated to be a liquid with a relatively low viscosity, which may be used to fabricate a varnish/encapsulant thermoset with reduced risk of trapping air, forming bubbles, forming defects, etc.

[00173] ENB is also miscible with DCPD over an entire range of compositions (e.g., from about 0 percent by weight to about 100 percent by weight). DCPD and ENB have similar reactivity and toughness. ENB, when mixed with DCPD, does not, in general, negatively impact reactivity or mechanical properties compared to DCPD without ENB.

[00174] As mentioned, DILULIN material may be utilized to form a terpolymer (e.g., a type of copolymer). As an example, DILULIN material may be utilized with DCPD and ENB to form a terpolymer thermoset.

[00175] As an example, DILULIN material can be added to DCPD and ENB to form a polymeric material with improve toughness when compared to a copolymeric material of DCPD and ENB without DILULIN material.

[00176] At room temperature (e.g., about 25 degrees C), a DILULIN material thermoset tends to be relatively rubbery due its relatively low Tg (e.g., consider a fully cured DILULIN material thermoset).

[00177] As an example, DILULIN material can be utilized with DCPD and ENB to increase elasticity and increase toughness of a resulting DCPD/ENB/DILULIN (DED) terpoymer thermoset.

[00178] As an example, DILULIN material can be utilized with DCPD and ENB to reduce curing kinetics of terpolymer formation, for example, due at least in part to its lower reactivity when compared to DCPD and ENB.

[00179] As an example, DILULIN material may be utilized to adjust curing kinetics of a mixture that includes DCPD and ENB. As an example, curing kinetics may be slowed down to provide time sufficient to introduce a material or materials into a mixture, to transport a mixture, to flow a mixture, to shape a mixture, etc. [00180] As an example, consider a method that includes utilizing DILULIN material in a mixture to retard polymeric reactions to provide sufficient time to fill slots of an electric motor stator (e.g., ESP stator, etc.) before reaching a gel point (e.g., transition from liquid to solid).

[00181 ] As an example, DILULIN material may be utilized in a mixture to provide amphiphilic character. DILULIN material includes portions that tend to be hydrophobic (e.g., lipophilic) and portions that tend to be hydrophilic. As an example, when placed in an immiscible biphasic system that includes aqueous and organic solvents, an amphiphilic material tends to partition the two phases where, for example, the extent of the hydrophobic and hydrophilic portions can determine the extent of partitioning. As an example, an amphiphilic material can be attracted to an interface or interfaces. As an example, an amphiphilic material can be attracted to a material that may be solid. For example, consider a particle that has a surface that is hydrophilic in character or a particle that has a surface that is hydrophobic in character.

[00182] As an example, DILULIN material may be considered to be a surfactant. A surfactant can lower surface tension (e.g., or interfacial tension), for example, between two liquids or between a liquid and a solid. As an example, a liquid may be a mixture. As an example, a liquid may suspend a solid, for example, for some period of time.

[00183] As an example, a mixture may be formulated to achieve a desired viscosity and reaction kinetics to form a terpolymer where the viscosity and/or reaction kinetics provide for suspending particles. As an example, such a mixture can include DILULIN material that makes particles more compatible with monomers in the mixture.

[00184] As an example, DILULIN material may be utilized as an amphiphilic structure that can improve miscibility and dispersibility of particles. For example, consider thermally conductive filler particles in a polymer matrix (e.g., DCPD/ENB).

[00185] As an example, a method can include forming a terpolymeric material from a mixture of DCPD, ENB and DILULIN material and particles. In such an example, the particles can include particles that have a thermal conductivity that is greater than a thermal conductivity of a terpolymeric material formed from a mixture of DCPD, ENB and DILULIN material. As an example, utilization of DILULIN material can increase the weight percentage of particles in a copolymeric material. [00186] A copolymeric material formed with DCPD/ENB and thermally conductive particles exhibited a limit as to the weight percentage of the particles that could be homogeneously mixed with DCPD/ENB (e.g., a maximum concentration of the thermally conductive particles). Through utilization of DILULIN material at about 5 percent by weight in a mixture with DCPD and ENB, the limit was increased by more than about 15 percent by weight (e.g., the maximum concentration of the thermally conductive particles that can be homogenously mixed with the DCPD/ENB polymer matrix increased).

[00187] As an example, a method can include forming a terpolymeric composite material using DCPD, EBN, DILULIN material and particles. In such an example, the formulation may be tailored as to one or more characteristics, which may be processing characteristics prior to or during curing (e.g., via ROMP, etc.) and/or post-process characteristics including, for example, a characteristic ability to further cure in situ, etc. As an example, a terpolymeric material, which may be a terpolymeric composite material, can be a thermoset with one or more of desired mechanical, thermal, and dielectrical properties. As an example, such a thermoset may be utilized as part of an electric motor assembly. For example, such a thermoset may be used as a varnish and/or encapsulant of an ESP motor.

[00188] As an example, in a material formed from ENB, DCPD and DILULIN material, ENB can act to reduce the melting point of DCPD and DILULIN can act as a surfactant that facilitates mixing in thermally conductive filler material (e.g., thermally conductive particles). As an example, a terpolymeric material can be a terpolymeric thermoset that can withstand relatively high temperatures, exhibit suitable toughness and exhibit suitable adhesion, for example, as a varnish and/or encapsulant for an electric motor such as, for example, an ESP motor.

[00189] As an example, a copolymeric material may be tailored as to one or more of its mechanical properties, glass transition temperature (Tg), coefficient of thermal expansion (CTE), thermal stability and dielectric properties, for example, by changing the copolymer composition.

[00190] In hydrocarbon reservoirs where downhole pressure is insufficient to produce fluid to the surface, an ESP system may be employed. ESP operation may expose an ESP to high temperature, pressure, and corrosive fluids and gases (e.g. hydrogen sulfide (H2S) and carbon dioxide (CO2)). A harsh environment can decrease efficiency and service life of an ESP motor, for example, due to an increased probability of insulation breakdown (e.g., mechanically, thermally and/or electrically).

[00191 ] Some high temperature varnishes for industrial motors are polyester, polyurethane, or acrylic based. While these varnishes provide suitable performance in air or at low temperature, they can be inherently poor in fluid that includes even small amounts of moisture at temperatures above about 80 degrees C as they can undergo degradation due to hydrolysis. For an ESP motor that is at risk of being exposed to moisture, such materials, by themselves, may be inadequate.

[00192] Downhole ESP electric motors can utilize polybutadiene (PB) or epoxy based varnishes, which tend to have acceptable processability and fluid resistance. However, they can present some issues at high temperature. For example, PB- based compounds while having good initial electrical properties, they suffer from a substantial decrease in mechanical properties (e.g., they become brittle) after aging at 225 degrees C and 1500 psi. Cracking in the PB material can propagate into polyimide wire insulation and cause premature system failure, particularly because polyimide is susceptible to hydrolytic degradation. Further, a large amount of volatile organic compound (e.g., vinyl toluene) can be evaporated during the curing process of PB. Yet further, a PB thermoset tends to have a relatively large value of CTE and poor thermal conductivity.

[00193] As an example, a copolymeric material may be utilized for electric motors and/or other electric components. For example, consider a copolymeric material that includes DCPD and ENB, which may be simultaneously polymerized via ring-opening metathesis polymerization (ROMP), for example, using Grubbs' catalyst (or other suitable catalyst) to produce copolymer thermosets with suitable mechanical properties (e.g., high rigidity, excellent toughness and impact strength), chemical resistance, and stability against thermal and hydrolytic degradation. As an example, a DCPD/ENB copolymeric material may be used in a reaction injection molding system to fabricate a part or component.

[00194] As an example, a DCPD/ENB copolymer thermoset can be tailored by its composition of at least DCPD to ENB, for example, to control mechanical, thermal, electrical, and/or hydrolytic degradation. As an example, such a thermoset may be utilized as a varnish and/or encapsulation material for an ESP motor. As an example, monomeric materials can be mixed with an amount of Grubbs' catalyst (e.g., as low as about 0.001 weight percent) and injected homogenously into an ESP motor (e.g., into a cavity, etc.).

[00195] As an example, a copolymeric DCPD/ENB material can be cured directly after an injection process, for example, at room temperature for about 1 h. As an example, a more complete curing process can be accomplished by heating at about 80 degrees C for about 1 h, at about 120 degrees C for about 3 h, and at about 170 degrees C for another 2 h.

[00196] As an example, a curing process may be relatively free of evaporation of organic volatile compounds. As an example, a produced thermoset can be formed with a relatively high dimensional stability.

[00197] Fig. 14 shows example plots 1410, 1420 and 1430. The plot 1410 shows temperature dependence of storage modulus and tan δ for different

DCPD/ENB copolymer compositions. Single glass relaxation processes have been observed for each of the different copolymeric composition, which is indicative that the two components are copolymerized simultaneous to form a single phase thermoset structure.

[00198] In the plot 1410, the peak maximum of tan δ systematically shifts to higher temperatures with increasing DCPD content due to the higher Tg of DCPD compared to ENB thermoset.

[00199] In the plot 1420, DSC thermograms for the DCPD/ENB copolymers of different concentrations are shown. The calorimetric Tg of the copolymers increased with increasing the DCPD content in good agreement with the DMA data.

[00200] As shown in Fig. 14, the Tg obtained from the peak maximum of tan δ is higher than that calculated from DSC as shown in the plot 1430 (e.g., due to tan δ in the plot 1410 being related to a cooperative a-relaxation process that is frequency dependent).

[00201 ] As an example, change in Tg with composition can be utilized to tailor materials for one or more specific operation temperature ranges. As illustrated in Fig. 14, the plateau of the storage modulus at high temperature (e.g., temperatures higher than the Tg) and the Tg of the copolymer thermosets can increase after post curing at 250 degrees C. This behavior can make such materials even more mechanically stable at high temperature during the service life of a piece of equipment, an assembly, a system (e.g., an ESP motor, etc.). [00202] Fig. 15 shows plots 1510 and 1520. The plot 1520 shows how the Tg increased for the polymeric materials that were measured twice by DMA. The DMA 2nd run showed about a 60 degree C increase in the Tg of each composition above the first run.

[00203] Fig. 16 shows plots 1610 and 1620. As shown in Fig. 16, DCPD/ENB copolymers can exhibit a relatively high thermal stability under nitrogen atmosphere (see, e.g., the plot 1610).

[00204] The thermal stability increased systematically with an increase in the DCPD composition. The onset of degradation temperatures for pure ENB and DCPD are approximately 400 and 445 degrees C, respectively. These data are also indicative of suitability for use over a wide range of high temperature, for example, without an unacceptable amount of thermal degradation.

[00205] The relatively low value of CTE can be a criterion for a good varnish or encapsulation material. The DCPD/ENB copolymer thermosets tend to have much lower CTE values compared with PB varnish material.

[00206] In Fig. 16, the plot 1620 shows the composition dependence of CTE at 30 and 200 degrees C. As shown, the CTE decreases with increasing concentration of DCPD. The value of CTE is approximately 122 and 181 μΐη/(ιη. degree C) for a PB varnish material at 30 and 200 degrees C, respectively.

[00207] The CTE of the aforementioned PB varnish material is more than three times higher than that of pure DCPD thermoset at 200 degrees C (55 μΐη/(ιη.οΟ)). Therefore, the copolymeric materials can offer mechanical and thermal properties that are more favorable than those of the PB varnish material (e.g., PB resin).

[00208] DCPD/ENB copolymer thermosets can exhibit dielectric permittivity, dissipation factor, and resistivity at 200 degrees C of approximately 2, 0.05, and 5x10¹⁶ Ohm. cm, respectively. The dielectric breakdown of these materials is about 23.7 MV/m compare to 21.3 MV/m for the aforementioned PB varnish (e.g., PB resin).

[00209] As an example, a varnish/encapsulation material for an ESP motor can include one or more DCPD/ENB copolymeric thermosets. DCPD/ENB thermosets can exhibit mechanical, thermal, hydrolytical, and dimensional stability in hot/wet environment under high pressure. Such copolymeric materials can increase one or more of service life, efficiency, and reliability of an electric motor of an ESP. [00210] Materials such as PB-based resin tend to have relatively high values of coefficient of thermal expansion (CTE) compared to metal conductors (e.g., copper). A mismatch between CTE of copper and varnish/encapsulant material can lead to poor adhesion and cracks in a thermoset material.

[00211 ] As an example, low viscosity monomers can be polymerized in-situ to create a high strength, high toughness encapsulant material. As an example, such a material may be a copolymer thermoset that can adhere, for example, to magnet wire and that can also be of sufficient toughness to reduce risk of cracking due to a difference in CTE between the copolymer thermoset and a substrate to which it is adhered or to be adhered.

[00212] As an example, a copolymer thermoset may be synthesized from monomeric materials selected from dicyclopentadiene (DCPD), ethylidene- norbornene (ENB), and functionalized n-ester (e.g., DILULIN material, etc.) via ring opening metathesis polymerization (ROMP) using a suitable catalyst.

[00213] As an example, DILULIN material may be utilized, which is a norbornyl- functionalized linseed oil synthesized by Diels-Alder reaction of linseed oil and DCPD at high temperatures and pressures. DILULIN material can have an average of less than one bicyclic moiety per triglyceride. In such an example, the low reactivity of DILULIN material due to the low number of bicyclic moiety compared to DCPD and ENB can decrease curing kinetics, which can provide time for filling and/or impregnation (e.g., before gelation).

[00214] As an example, the relatively low viscosities of DCPD and ENB can be controlled by adding a selected concentration of a functionalized n-ester (e.g., DILULIN, etc.). A functionalized n-ester as a component in a premix can further provide additional toughness and adhesion, for example, to magnet wire insulation.

[00215] As an example, a copolymer may be a terpolymer. As an example, a terpolymer may be formed through use of DCPD, ENB and a functionalized n-ester such as, for example, DILULIN material, which as functionalized linseed oil, tends to be relatively environmentally-friendly.

[00216] As an example, the relatively rapid ROMP reaction of DCPD and ENB can be decreased via addition of a functionalized n-ester where, for example, the functionalized n-ester has a lower reactivity (e.g., as may be characterized by the number of cyclic moieties per hydrocarbon chain). Such an approach can allow time for filling before gelation (e.g., transition from liquid to solid). [00217] Fig. 17 shows an example of a terpolymer. Such a terpolymer may be formed, for example, via a method that includes providing a functionalized n-ester that can be reacted with DCPD and/or ENB using a catalyst or catalysts to produce a thermoset material, optionally including one or more additives (e.g., fillers, etc.).

[00218] As an example, a terpolymer thermoset can be synthesized at least in part from three monomers with strained ring alkene. For example, consider a norbornene-modified linseed oil (e.g., with approximately one bicyclic strained ring moiety per triglyceride), DCPD and ENB. As an example, an exothermic reaction can be carried out via one or more of ROMP, cationic polymerization, etc. For example, for a ROMP reaction, metallacycles can be formed using a transition metal catalyst to break shared double bond atoms and open the olefin rings and initialize reaction between opened olefin rings with norbornene-modified linseed oil to form a terpolymer three-dimensional interconnected thermoset (see, e.g., the example of Fig. 17).

[00219] As mentioned, a 2nd generation Grubbs' catalyst may be utilized. As an example, one or more of the following catalysts may be utilized: nitro-Grela catalyst (1 ,3-dimesitylimidazolidin-2-ylidene)(2-isopropoxy-5 nitrobenzylidene) ruthenium (VI) chloride (e.g., as marketed by Apeiron Catalysts, Wroclaw, Poland); a LatMet catalyst (1 ,3-Bis(2,4,6-trimethylphenylimidazolidin-2- ylidene)(tricyclohexylphosphine)-(2-oxobenzylidene) ruthenium(VI) dichloride (e.g., as marketed by Apeiron Catalysts, Wroclaw, Poland); and a HeatMet catalyst (1 ,3- dimesitylimidazolidin-2-ylidene)(2-((2-ethoxy-2-oxoethylidene) amino) benzylidene) ruthenium(VI) chloride (e.g., as marketed by Apeiron Catalysts, Wroclaw, Poland); noting that one or more other types of catalysts may be utilized (e.g., additionally or alternatively).

[00220] Various trials were performed to make terpolymer thermosets such as DCPD-co-ENB-co-DILULIN material, with different concentrations. Such trials utilized an amount of 2nd generation Grubbs' catalyst (e.g., about 0.1 weight percent) for ring-opening metathesis polymerization (ROMP). Where DCPD, ENB and the DILULIN material were provided, these three "monomers" reacted simultaneously and produced a relatively homogenous one-phase thermoset.

[00221 ] As an example, a method can be utilized for synthesis of a DCPD-co- ENB-co-DILULIN material terpolymer thermoset such as, for example, the thermoset of Fig. 17. For example, a catalyst can be mixed with the DILULIN material followed by addition of DCPD and then ENB. A curing process can be carried out at room temperature for about 3 h; thereafter, a more complete curing process can be accomplished at about 80 degrees C for about 3 h, about 120 degrees C for about 3 h, and about 170 degrees C for about 7h (e.g., a post curing process).

[00222] Fig. 18 shows a plot 1810. A dynamic mechanical analysis (DMA) data revealed that the glass transition temperature (peak maximum of tan δ) of the terpolymers systematically decreased with increasing DILULIN material content. The value of storage modulus at different temperatures is shown to be composition dependent.

[00223] The numbers of unsaturated or unreacted double bonds in DILULIN material, ENB, and DCPD that remain after the curing process can react during an accelerated aging process and consequently induce yet additional post curing in the terpolymer thermoset. As an example, an environment of use may provide temperature and/or pressure that can cause such unsaturated or unreacted double bonds to react and thereby alter the characteristics of a copolymeric material, for example, in situ.

[00224] Referring again to Fig. 18, the plot 1810 shows temperature

dependence of storage modulus and tan δ for DCPD/ENB/DILULIN material copolymer thermosets of different concentrations and the plot 1820 shows temperature dependence of storage modulus and tan δ for DCPD/ENB/DILULIN material for 80/10/10 weight percent terpolymer thermosets after different aging times.

[00225] Curing kinetics of various thermosets can be influenced by

concentration of the functionalized n-ester. In particular, the higher the concentration of the functionalized n-ester, the slower the kinetics of the crosslinking reactions.

[00226] The gel time of pure DCPD is less than about 2 min compared to about 2 h for the DCPD/ENB/DILULIN material with a composition of 70/10/20 weight percent (e.g., at about room temperature). The increase in gel time (e.g., cure time) can provide an opportunity for processing, introduction of one or more additives, etc. Reduction in kinetics for crosslinking reactions via use of a functionalized n-ester with DCPD and ENB can allow for use of a range of temperatures and/or time windows for procedures such as, for example, filling, impregnating, etc. [00227] As an example, a thermoset formed via copolymerization of monomers that include a functionalized n-ester can be utilized as, for example, a varnish or encapsulant materials for an electric motor or other electronic component, assembly, system, etc. As an example, an ESP motor can include one or more DCPD-co- EENB-co-DILULIN material terpolymer thermosets. In such an example, such one or more thermosets may provide toughness at high temperature and pressure and extend service time. As an example, due to low viscosity and ability to manipulate processability and thermal conductivity, various materials may be employed, for example, as potting and/or encapsulation materials for environments that may be at relatively high temperatures and/or pressures.

[00228] As an example, a copolymeric material as a relatively high Tg, toughness thermoset resin with a low curing temperature may be utilized in various applications where phenolic or epoxy materials may be used. Such a copolymeric material may improve properties and processing.

[00229] As an example, a functionalized n-ester may be a triglyceride (e.g., a triacylglycerol, triacylglyceride, or TAG). As an example, a functionalized n-ester may be a diglyceride (e.g., diacylglycerol, diacylglyceride, or DAG).

[00230] As an example, a functionalized n-ester may be a functionalized vegetable oil or a functionalized animal fat. Mono-, di- and tri-glycerides are related to fatty acids: a monoglyceride is the condensation of one fatty acid and glycerol; a diglyceride is the condensation of two fatty acids and glycerol; and a triglyceride is the condensation of three fatty acids and glycerol.

[00231 ] As an example, a functional group can be a ring. In such an example, the ring may provide a driving force for a polymerization reaction. For example, consider ROMP.

[00232] As an example, an electric submersible pump system can include a shaft; a pump operatively coupled to the shaft; a multiphase power cable connector; and a multiphase electric motor operatively coupled to the multiphase power cable connector and the shaft where the multiphase electric motor includes a terpolymeric material that includes triester units where crosslinks exist across hydrocarbon chains of at least a portion of the triester units. In such an example, the terpolymeric material can include bicyclic units. As an example, consider at least a portion of the crosslinks including at least one bicyclic unit. [00233] As an example, a terpolymehc material can include particles such as, for example, inorganic material. Such particles may include at least one metal oxide. For example, consider at least one metal oxide selected from a group consisting of aluminum oxide, silicon dioxide and zinc oxide.

[00234] As an example, a terpolymehc material can include particles that include include at least one metal nitride, for example, consider one or more of boron nitride and aluminum nitride.

[00235] As an example, a terpolymehc material can include particles that include semiconductor particles.

[00236] As an example, a method can include forming a mixture that includes ENB, DCPD and a functionalized n-ester; contacting the mixture with a portion of an electric motor; and curing the mixture. In such an example, the functionalized n- ester can be or include DILULIN® material.

[00237] As an example, a method can include decreasing the melt point temperature of a mixture by adding additional ENB.

[00238] As an example, a functionalized n-ester can be amphiphilic.

[00239] As an example, a functionalized n-ester can include a functionalized triester.

[00240] As an example, a method can include forming a mixture that includes ENB, DCPD, a functionalized n-ester and an inorganic material. As an example, such an inorganic material may be particles where such particles can include one or more metal oxides (e.g., metal oxide particles, etc.) and/or one or more metal nitrides (e.g., metal nitride particles, etc.).

[00241 ] As an example, a method can include operating an electric motor where operating the electric motor generates heat energy that causes additional curing of a mixture.

[00242] As an example, a downhole tool can include an electric motor that includes a terpolymehc material that includes triester units where crosslinks exist across hydrocarbon chains of at least a portion of the triester units. In such an example, the electric motor may be a multiphase electric motor. As an example, the terpolymehc material may be an ecapsulant such as, for example, a stator encapsulant.

[00243] As an example, an electric submersible pump system can include a shaft; a pump operatively coupled to the shaft; a multiphase power cable connector; and a multiphase electric motor operatively coupled to the multiphase power cable connector and the shaft where the multiphase electric motor includes a polymeric composite material that includes inorganic particles that have a thermal conductivity at approximately 25 degrees C greater than or equal to about 30 W-m-1 - K-1.

[00244] As an example, inorganic particles can include an inorganic nitride. As examples, consider one or more of aluminum nitride, boron nitride, and silicon nitride.

[00245] As an example, inorganic particles can include an inorganic oxide. As examples, consider one or more of aluminum oxide and beryllium oxide.

[00246] As an example, inorganic particles can include an inorganic oxide and an inorganic nitride.

[00247] As an example, a polymeric composite material can include at least one amphiphilic repeating unit. For example, consider at least one amphiphilic repeating unit that includes a functionalized n-ester.

[00248] As an example, a polymeric composite material can include a functionalized n-ester as a repeating unit.

[00249] As an example, a polymeric composite material can include from about 0.1 percent to about 60 percent by volume of inorganic particles that have a thermal conductivity at approximately 25 degrees C greater than or equal to about 30 W-m- - K^"1.

[00250] As an example, a polymeric composite material can be an encapsulant that encapsulates at least a portion of stator windings of an electric motor, which may be, for example, a multiphase electric motor.

[00251 ] As an example, a polymeric composite material can be a varnish that covers at least a portion of stator windings of an electric motor, which may be a multiphase electric motor.

[00252] As an example, a method can include formulating a mixture of at least one monomer and inorganic particles that have a thermal conductivity at

approximately 25 degrees C in excess of about 30 W-m^-1 - K^-1; and curing the mixture to form an encapsulant that encapsulates at least a portion of stator windings of a multiphase electric motor of an electric submersible pump. In such an example, the particles can include an inorganic nitride and/or an inorganic oxide. For example, consider one or more of aluminum nitride, boron nitride, and silicon nitride and/or one or more of aluminum oxide and beryllium oxide. [00253] As an example, in the aforementioned method, at least one monomer can be an amphiphilic monomer. For example, consider an amphiphilic monomer that is a functionalized n-ester. As an example, an amphiphilic monomer can be a functionalized organic oil.

[00254] As an example, a relationship can exist between an amount of amphiphilic monomer and an amount of inorganic particles where a greater amount of the amphiphilic monomer provides for incorporating a greater amount of the inorganic particles. As an example, a mixture can include from about 0.1 percent to about 60 percent by volume of the inorganic particles.

[00255] As an example, a method can include formulating a mixture of at least one monomer and inorganic particles that have a thermal conductivity at

approximately 25 degrees C in excess of about 30 W-rrr¹ - K^~1; and curing the mixture to form an encapsulant that encapsulates at least a portion of stator windings of a multiphase electric motor of an electric submersible pump.

[00256] As an example, a downhole tool can include an electric motor that includes a polymeric composite material that includes inorganic particles that have a thermal conductivity at approximately 25 degrees C greater than or equal to about 30 W-m^~1 - K^~1. In such an example, the electric motor can be a multiphase electric motor.

[00257] As an example, one or more methods described herein may include associated computer-readable storage media (CRM) blocks. Such blocks can include instructions suitable for execution by one or more processors (or cores) to instruct a computing device or system to perform one or more actions.

[00258] According to an embodiment, one or more computer-readable media may include computer-executable instructions to instruct a computing system to output information for controlling a process. For example, such instructions may provide for output to sensing process, an injection process, drilling process, an extraction process, an extrusion process, a pumping process, a heating process, etc.

[00259] Fig. 19 shows components of a computing system 1900 and a networked system 1910. The system 1900 includes one or more processors 1902, memory and/or storage components 1904, one or more input and/or output devices 1906 and a bus 1908. According to an embodiment, instructions may be stored in one or more computer-readable media (e.g., memory/storage components 1904). Such instructions may be read by one or more processors (e.g., the processor(s) 1902) via a communication bus (e.g., the bus 1908), which may be wired or wireless. The one or more processors may execute such instructions to implement (wholly or in part) one or more attributes (e.g., as part of a method). A user may view output from and interact with a process via an I/O device (e.g., the device 1906). According to an embodiment, a computer-readable medium may be a storage component such as a physical memory storage device, for example, a chip, a chip on a package, a memory card, etc.

[00260] According to an embodiment, components may be distributed, such as in the network system 1910. The network system 1910 includes components 1922- 1 , 1922-2, 1922-3, . . ., 1922-N. For example, the components 1922-1 may include the processor(s) 1902 while the component(s) 1922-3 may include memory accessible by the processor(s) 1902. Further, the component(s) 1902-2 may include an I/O device for display and optionally interaction with a method. The network may be or include the Internet, an intranet, a cellular network, a satellite network, etc.

Conclusion

[00261 ] Although only a few examples have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the examples. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means- plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words "means for" together with an associated function.

Claims

CLAIMS What is claimed is:

1. An electric submersible pump system comprising:

a shaft;

a pump operatively coupled to the shaft;

a multiphase power cable connector; and

a multiphase electric motor operatively coupled to the multiphase power cable connector and the shaft wherein the multiphase electric motor comprises a terpolymeric material that comprises triester units wherein crosslinks exist across hydrocarbon chains of at least a portion of the triester units.

2. The electric submersible pump system of claim 1 wherein the terpolymeric material comprises bicyclic units.

3. The electric submersible pump system of claim 1 wherein at least a portion of the crosslinks comprise at least one bicyclic unit.

4. The electric submersible pump system of claim 1 wherein the terpolymeric material comprises particles.

5. The electric submersible pump system of claim 4 wherein the particles comprise inorganic material.

6. The electric submersible pump system of claim 4 wherein the particles comprise at least one metal oxide.

7. The electric submersible pump system of claim 6 wherein the at least one metal oxide comprises at least one member selected from a group consisting of aluminum oxide, silicon dioxide and zinc oxide.

8. The electric submersible pump system of claim 4 wherein the particles comprise at least one metal nitride.

9. The electric submersible pump system of claim 8 wherein the at least one metal nitride comprises at least one member selected from a group consisting of boron nitride and aluminum nitride.

10. A method comprising:

forming a mixture that comprises ENB, DCPD and a functionalized n-ester; contacting the mixture with a portion of an electric motor; and

curing the mixture.

1 1. The method of claim 10 wherein the functionalized n-ester is amphiphilic.

12. The method of claim 10 wherein the functionalized n-ester comprises a functionalized triester.

13. The method of claim 10 wherein the mixture comprises an inorganic material.

14. The method of claim 10 wherein the mixture comprises particles that comprise a metal oxide.

15. The method of claim 10 wherein the mixture comprises particles that comprise a metal nitride.

16. A downhole tool comprising:

an electric motor that comprises a terpolymeric material that comprises triester units wherein crosslinks exist across hydrocarbon chains of at least a portion of the triester units.

17. An electric submersible pump system comprising:

a shaft;

a pump operatively coupled to the shaft;

a multiphase power cable connector; and

a multiphase electric motor operatively coupled to the multiphase power cable connector and the shaft wherein the multiphase electric motor comprises a polymeric composite material that comprises inorganic particles that comprise a thermal conductivity at approximately 25 degrees C greater than or equal to about 30 W-m- - K-¹.

18. The electric submersible pump system of claim 17 wherein the inorganic particles comprise an inorganic nitride.

19. The electric submersible pump system of claim 18 wherein the inorganic nitride comprises a member selected from a group consisting of aluminum nitride, boron nitride, and silicon nitride.

20. The electric submersible pump system of claim 17 wherein the inorganic particles comprise an inorganic oxide.

21. The electric submersible pump system of claim 20 wherein the inorganic oxide comprises a member selected from a group consisting of aluminum oxide and beryllium oxide.

22. The electric submersible pump system of claim 17 wherein the polymeric composite material comprises a functionalized n-ester as a repeating unit.

23. The electric submersible pump system of claim 17 wherein the polymeric composite material comprises from about 0.1 percent to about 60 percent by volume of the inorganic particles.

24. The electric submersible pump system of claim 17 wherein the polymeric composite material comprises an encapsulant that encapsulates at least a portion of stator windings of the multiphase electric motor.

25. The electric submersible pump system of claim 17 wherein the polymeric composite material comprises a varnish that covers at least a portion of stator windings of the multiphase electric motor.

26. A method comprising:

formulating a mixture of at least one monomer and inorganic particles that comprise a thermal conductivity at approximately 25 degrees C in excess of about 30 W-m- - K-¹; and

curing the mixture to form an encapsulant that encapsulates at least a portion of stator windings of a multiphase electric motor of an electric submersible pump.

27. A downhole tool comprising:

an electric motor that comprises a polymeric composite material that comprises inorganic particles that comprise a thermal conductivity at approximately 25 degrees C greater than or equal to about 30 W-m^~1 - K^~1.