Patent ID: 12227995

DESCRIPTION OF EMBODIMENTS

The description that follows includes example systems, methods, techniques, and program flows that embody aspects of the disclosure. However, it is understood that this disclosure may be practiced without these specific details.

Overview

In some embodiments, a slimline connector described herein may streamline the connection process and optimize a sizing of the pump motor of an ESP system. A primary advantage over the conventional tape-in potheads is the enclosed plug-in type of connection, eliminating a need for preparation at the well site, thus reducing assembly time and a potential of contamination and/or damage to various electrical components. At a well site, a field technician may remove a protective cap from the motor head connection and the cap from the pothead/connector. The field technician may position and align the pothead with a connection port on the motor head, slides the pothead to engage and make up the connection. This type of connection may be completed within a short period. Weather conditions may necessitate some preliminary preparation of the work area, although this is the case for the tape-in pothead connections too. The field technician may require minimal training to install the slimline connector to the motor of the ESP, as basic mechanical and electrical knowledge and standard field installation skills are amply sufficient. The motor head connection may consist of a plurality of individual ports (three are shown), circumferentially positioned, and machined parallel with the motor rotational axis. Although the design may introduce some complexity to the motor head geometry, the allowance for larger diameter motor shaft may supersede the machining cost. In some embodiments, an electrical insulation system comprising connector pins and sockets may be preassembled into custom-made electrically insulating components in the motor head and pothead respectively. The material of the insulators may be comprised of organic (PEEK) materials, non-organic (ceramic) materials, or a combination of organic and non-organic materials. The plug-in connection enabled by the enclosed slimline connector (and the connection components tightly installed inside the motor head and the connector housing) may reduce a risk of fatigue failure of the electrical connection because of the vibration over the entire ESP run-life.

Example Slimline Connector

FIG.1depicts an isometric view of an example electric motor of an electric submersible pump (ESP) that includes a slimline connector and MLE, according to some embodiments. A motor100(such as an electric motor) may be utilized in electric submersible pump (ESP) applications. The motor100may be powered from a surface power generation unit such as a gas or diesel generator through a variable speed drive (VSD) and transformer. Power may be conveyed down to the motor100through an electrical cable1910as depicted inFIG.19(main cable, round profile), which crosses over to a motor lead extension (MLE)300(flat cable) above one or more pumps to minimize a radial height of the cable over the length of the electric submersible pump (ESP) system. The motor lead extension (MLE) may terminate in a pot-head connector. The MLE300depicted inFIG.1terminates at a slimline connector200. This slimline connector is shown in greater detail inFIG.2.

FIG.2depicts a more detailed isometric view of the example slimline connector and motor lead extension (MLE) ofFIG.1on a motor head, disconnected from the motor head, according to some embodiments The slimline connector200is depicted as disconnected from the motor100. In this illustration, the slimline connector200may be found in a position before the field connection to the motor100is performed.

Details of this connector are presented inFIG.3andFIG.4. Further details of this embodiment are presented inFIG.9throughFIG.11. InFIG.3, a connector housing201encloses the electrical connection system terminated onto the motor lead extension's (MLE)300individual phases (FIG.3). A plurality of axial cavities220(seeFIG.9) may be positioned at pre-defined radial and angular locations on an end face of the connector housing201which may be configured to accept individual phase connector components. The compression nuts202and lock nuts203and a rear face of the connector housing201may provide the sealing and retention for each individual phase of the motor lead extension (MLE)300.

Similarly, on the motor100, a plurality of through axial holes111(seeFIG.4, three are shown) in the motor head adaptor101may be positioned at the same position as the axial cavities220in the connector housing201(FIG.3). One or more receptacle guide tubes102may protrude from the motor head adaptor101and form the motor connector guiding system. In some embodiments, the connector housing201may include a lug230and a through-hole231on each side of the connector. The lugs230and through-holes231may be used to secure the slimline connector200to the motor head adaptor101through connection holes121in the motor head130by means of threaded fasteners213(not shown inFIG.4, shown inFIG.7). The receptacle guide tubes102may also be mounted parallel to the rotational axis of the motor100.

A front view of the slimline connector200and the motor lead extension (MLE)300is shown inFIG.5, according to some embodiments. Power pins207and concentric power pin insulators208(three are shown) and their locations on the connector housing201are depicted in a radial configuration. The radial configuration of the power pins207may allow the slimline connector200to also maintain a radial shape, allowing for increased motor sizing in the wellbore (i.e., the connector requires less space in the wellbore than would more traditional connectors). The concentric power pin insulators208(which, along with the power pins207as depicted from this front view may be referred to as a “power port”) may also be circumferentially disposed on the slimline connector200. In some implementations, the concentric power pin insulators208and power pins may be adjacently disposed along the radial shape of the slimline connector200. In some embodiments, the lugs230are extensions of the connector housing201body (machined features in the connector housing).

FIG.6depicts a front view of the motor head adaptor, according to some embodiments.FIG.6presents a phase distribution on the motor head adaptor101, with a (receptacle) power socket104in the center, surrounded by a power socket front electrical insulator sleeve106and enclosed by the receptacle guide tube102. The location of the connection holes121on the motor head130is also presented herein.FIGS.3-6may depict the axial orientation of the connection with the motor head which may allow the motor shaft150outer diameter to be maximized. For example, the slimline connector200may be mounted parallel to a rotational axis of the motor100. In contrast, more traditional tape-in type potheads may utilize a connector that is inclined by up to 10° with respect to the motor axis. In designing the slimline connector200to have a compact geometry, to be mounted parallel with the motor axis, and whereby the three individual phases of the connection are positioned in a circumferential orientation, the slimline connector200may contribute to a considerable space saving inside the motor head in its radial direction. This radial space may be utilized to increase the shaft diameter; thus, higher power may be transmitted from the motor to the pump for the same motor frame size (same series). A flat or angular connector, for example, may impede into this radial space and result in a sub-optimal motor sizing. In some embodiments, the slimline connector may be used on any motor series (319 series, 375 series, 400 series, 456 series, etc.).

In some embodiments, the individual phases of the slimline connector200may be positioned at predefined distances from one another, similar to how the three axial cavities220(seeFIG.9) may be positioned at pre-defined radial and angular locations on an end face of the connector housing201. Having the individual phases at predefined distances from each other may largely reduce or eliminate a risk of electrical failure (shorting, arcing, etc.) between the individual phases. Each phase may be protected by the individual insulator sleeve106in single cavities. The distance between phases may be increased many-folds compared to conventional potheads, and this may make it difficult for electrical arcing (discharge) between the phases compared to the tape-in potheads.

FIG.7depicts a side view of the example slimline connector and motor lead extension (MLE) in connected and in disconnected states, according to some embodiments. Just before the connection, the slimline connector200rests within a recess131(refer toFIG.4) on the motor head130and lines up with the receptacle guide tubes102installed in the motor head adaptor101prior to connection. In some embodiments, the mating of the slimline connector200and the receptacle guide tubes102may occur when the connector housing201is pushed over the receptacle guide tubes102. To assist with the connector mating, one or more threaded fasteners213may be used.

Cross-sections showing the internal arrangement of the connector components through various phases of the connection in both the un-mated and mated connections are illustrated inFIG.8,FIG.9, andFIG.10respectively.FIG.8depicts a first cross-sectional view of the example slimline connector un-mated with the motor head through one of the phases of the connection.FIG.9depicts a first cross-sectional view of the example slimline connector mated with the motor head through one of the phases of the connection, according to some embodiments.FIG.10depicts a first cross-sectional view of the example slimline connector through one of the phases of the connection, according to some embodiments.

In some embodiments, the primary seal may be formed between the connector housing201and the receptacle guide tube102by means of the O-ring103. When the slimline connector200is fully engaged with the receptacle guide tubes102, the O-ring103may form a pressure seal between a sealing face214of the connector housing201and the O-ring groove inner diameter of the receptacle guide tube102. Insulators106and208may comprise insulator sleeves and may overlap and increase an insulation thickness and a high voltage arc tracking length over a power pin207and a power socket104connection. Motor oil from the motor internal volume110may transfer from the motor100to the slimline connector200through an annular gap122between the power socket front electrical insulator106outer diameter and the receptacle guide tube102inner diameter. The motor oil may also fill an axial cavity220, an annular area221between the motor lead extension (MLE)300, an insulation jacket302outer diameter, and the connector housing201through the axial cavity220inside diameter, and the annular area between a lead sheath303outer diameter and the compression nut202inside diameter, up to an epoxy resin211.

A detailed description of the slimline connector200components and the connector system inside the motor100are now described.FIG.10depicts a first cross-sectional view of the example slimline connector disconnected from the motor head, according to some embodiments. The slimline connector200may comprise: the connector housing201, the power pin207, the concentric power pin insulator208, a sealing grommet209, a compression collar210, the compression nut202, a split retaining collar212, a lead washer204, and the lock nut203. In some embodiments, the concentric power pin insulator208may be made from polyetheretherketone (PEEK) or a similar electrically insulating material. The connector housing201may comprise the plurality of axial cavities220as described previously. In some embodiments, the concentric power pin insulators208may be secured in the axial cavity220by means of a threaded connection224. In some embodiments, the power pin207may be terminated onto a solid copper conductor301of the motor lead extension (MLE)300. In some embodiments, the power pins207may be soldered onto the solid copper conductor301. In other embodiments, the power pins may be threaded and crimped onto the solid copper conductor301.

In some embodiments, the lock nut203, lead washer204, and the split retaining collar212may be installed over the lead sheath303of the motor lead extension's (MLE300) individual phases, in the order listed above. The compression nut202, the lead washer204, the compression collar210and the sealing grommet209may be installed over the insulation jacket302of the motor lead extension (MLE)300individual phases, in the order listed above. After all components are installed on the individual phases of the motor lead extension (MLE)300, the plurality of phases may be inserted into the connector housing201simultaneously. The power pins207may locate firmly inside the concentric power pin insulators208. The sealing grommet209may stop against a tapered sealing face225of the axial cavity220. The compression collar210may stop against the end face of the sealing grommet209. By threading in the compression nut202into a tapped hole226in the connector housing201, the compression collar210may be compressed against the sealing grommet209which slides axially along the insulation jacket302. Due to the tapered sealing face225, the sealing grommet209may be compressed radially onto the insulation jacket302. A seal may be formed between the tapered sealing face225and the sealing grommet209outer diameter and between the sealing grommet209inner diameter and the insulation jacket302outer diameter. The compression of the sealing grommet209may stop when the compression nut202touches the end face of the connector housing201. At the same time, the lead washer204may also be compressed into its location on the connector housing201, forming a pressure tight seal between the compression nut202and the connector housing201. An epoxy resin211may be injected into the annular area222between the compression nut202inner diameter and the insulation jacket302outer diameter to form a fluid barrier. The epoxy resin may also enclose the cable lead sheath303up to the split retaining collar212.

By axially compressing the split retaining collar212while threading the lock nut203into the tapped hole227in the compression nut202, the split retaining collar212may clamp down onto the lead sheath303. A similar tapered face to225in the compression nut202assists with the retaining collar212compression onto the lead sheath303. The rate of compression of the retaining collar212onto the lead sheath303may be limited by the axial travel of the lock nut203when it stops against the end face of the compression nut202. A second lead washer204may be compressed into its location in the compression nut202, forming a pressure tight seal between the lock nut203and the compression nut202. In some embodiments, a secondary fluid barrier205(seeFIG.10) may be formed between the lock nut203and the cable lead sheath303by means of a low temperature lead-based solder. In some embodiments, the exposed lead sheath303outside the slimline connector200and up to the metal jacket (not depicted) may be surrounded by a few layers of high modulus tape206which may provide structural support for the motor lead extension (MLE)300conductors at the location where the metal jacket has been removed.

FIG.11depicts a first cross-sectional view of an example connection receptacle in the motor head, according to some embodiments. An electrical connector system inside the motor head adaptor101shown inFIG.11, may comprise: the power socket104, one or more electrical contacts105, the power socket front electrical insulator (insulator sleeve)106, a power socket rear electrical insulator107, the receptacle guide tube102and the O-rings103. As shown inFIG.6, the power socket front electrical insulator106may be visible as an insulator sleeve on the face of the motor head adaptor101, while the power socket rear electrical insulator107may reside within the motor head adaptor101. The receptacle guide tube102may be secured into the motor head adaptor101by means of the threaded connection125. The power socket104may terminate onto a motor lead140. In some embodiments, the power socket104may be crimped onto the stranded core of the motor lead140. In some embodiments, the power socket104may include the electrical contacts105. The power socket104may be surrounded by the power socket front electrical insulator (insulator sleeve)106and the power socket rear electrical insulator107. The power socket rear electrical insulator107may also enclose part of the motor lead140. In some embodiments, the power socket front electrical insulator106and the power socket rear electrical insulator107may be comprised of PEEK or a similar electrically insulating material. In some embodiments, to prevent fluid migration between the well bore and the motor internal volume110, elastomeric seals may be utilized. An O-Ring109may provide the seal between the motor head adaptor101and the motor head130. The O-ring103may provide the seal between the motor head adaptor101and the receptacle guide tubes102.

In some embodiments, each receptacle guide tube102may enclose each power socket104and corresponding insulating cover inside the motor head. In some embodiments, the receptacle guide tubes102may be formed from steel or an alloy of similar strength and performance properties. The receptacle guide tubes102may serve multiple functions including: guarding the insulators107-106and the power socket104from mechanical damage during the connector installation, providing a sealing surface for the elastomeric O-Ring (such as elastomeric O-ring103) or a metallic C-Ring (described inFIG.13), and assisting with slimline connector200assembly during the field connection, protruding out from the motor head and forming a guide for the slimline connector200.

Traditional tape-in and plug-in potheads may comprise of a common insulator in both motor head and connector housings, forming a round connector. In the slimline connector200, each power lead, pin and socket may be housed in individual axial holes, such as the axial cavities220. Instead of a round insulator, the slimline connector200may utilize circumferentially distributed insulators in the individual axial cavities220. This arrangement of the individual phases within the MLE connector housing and motor head may enable the slimline connector200to have a smaller height compared to the conventional potheads.

In some embodiments, when servicing the motor in the shop and the electric submersible pump (ESP) in the field, motor oil from the motor inside the motor internal volume110may escape through the annular gap122between the power socket front electrical insulator106outer diameter and the receptacle guide tube102internal diameter. In some embodiments, customized protective caps and O-rings (not shown) may be installed over the receptacle guide tubes102to prevent motor oil leak during the motor or ESP servicing.

In some embodiments, O-rings may be utilized in a different configuration to prevent motor oil leakage.FIG.12depicts a second cross-sectional view of the example connection receptacle in the motor head, according to some embodiments. In these embodiments, the connector arrangement in the motor head adaptor101may include the O-Ring112and O-Ring113may be introduced to prevent motor fluid leakage from the motor100during servicing. The O-Ring112may create the sealing between the power socket front electrical insulator106and the receptacle guide tube102, whereas the O-Ring113may stop the motor fluid leak between the power pin207and the power socket front electrical insulator106. There may not be a need for a customized protective cap during servicing. In some embodiments, dielectric grease may be used in the axial cavity220of the slimline connector200. The grease may fill all the voids inside the slimline connector200, as oil will not reach these voids when the slimline connector200is connected to terminals in the motor head adaptor101. The voids may damage the slimline connector200if not filled. For example, the grease may be used to eliminate the voids from the connector, as these voids at atmospheric pressure may cause significant differential pressure between the well bore and the interior of the slimline connector200across the sealing grommet209and the epoxy resin211when the slimline connector200is deployed in a wellbore.

In some embodiments, the slimline connector200may be configured with components for use in various temperature applications.FIG.13depicts a second cross-sectional view of the example slimline connector mated with the motor head, according to some embodiments. In some embodiments, the slimline connector200may be configured for use in high-temperature applications such as Steam Assisted Gravity Drainage (SAGD). In some embodiments, the seal may be formed between the connector housing215and the receptacle guide tube114by means of one or more metallic C-Rings115. When the slimline connector200is fully engaged with the receptacle guide tubes114, the metallic C-Ring115may form the seal between the sealing face214of the connector housing215and the sealing surface120(shown inFIG.15) on the receptacle guide tube114. The retaining ring219may provide a retention method for the metallic C-Ring115during the slimline connector200dis-engagement. When the slimline connector200is fully engaged with the receptacle guide tubes114, the insulators218and117may overlap and increase the insulation thickness and the high voltage arc tracking length over the power pin207and the power socket104connection. Motor oil from the motor internal volume110may transfer from the motor100to the slimline connector200through the annular gap122between the power socket front electrical insulator117outer diameter and the bore in the motor head adaptor101and the receptacle guide tube114inner diameters. The motor oil may fill the axial cavity220, the annular area221between the motor lead extension (MLE)300and insulation jacket312outer diameter, and between the connector housing215and the axial cavity220internal diameter. The motor oil may additionally fill the annular area between the tubing313outer diameter and compression fitting sealing glands217. In some embodiments, the annular area223between the insulation jacket312outer diameter and the tube313inside diameter may be pre-filled with grease.

In some embodiments, the elastomeric seals such as the elastomeric O-ring103may fail in the above-described high-temperature scenarios. For high temperature application, where the standard elastomer type of sealing may not be successfully employed, a method of metal-to-metal sealing system using the metallic C-ring115may be used when connecting into to motor head interface. Typical elastomeric seals may fail at or above temperatures approaching 400 degrees Fahrenheit. However, the metallic C-ring115may overcome this challenge and withstand higher temperatures. Further, the metallic C-rings115may be designed to deflect but not permanently deform under a high compressive stress. The seals formed using the metallic C-rings115(C-Seals) may perform well in applications where temperature becomes an issue for elastomeric seals. The C-rings may be customized to fit into smaller cross-section sealing profiles than a standard O-Ring (such as the elastomeric O-ring103). The metallic C-rings115may also provide benefits such as corrosion resistance, robustness in the subsurface, and the C-rings may be easy to install by an operator.

Other configurations of the electrical connector system inside the motor100may be utilized.FIG.14depicts a second cross-sectional view of the example slimline connector through one of the phases of the connection, according to some embodiments. In some embodiments, the slimline connector200may comprise: the connector housing215, the metallic C-Ring115, the retaining ring219, the power pin207, the power pin electrical insulator218, the compression fitting216, and the compression fitting sealing glands217. The connector housing215may include the plurality of axial cavities220as described earlier. The power pin electrical insulators218may be secured in the connector housing215and axial cavity220by means of a threaded connection224. In some embodiments, the material of the power pin electrical insulator218may comprise ceramic or a material of similar qualities. The power pin207may terminate onto the solid copper conductor310of the motor lead extension (MLE)300. In some embodiments, the power pins207may be threaded and crimped onto the copper conductor310.

In some embodiments, the motor lead extension (MLE)300may consist of a tubing cladded high temperature power cable. This cable may comprise: the solid copper conductor310, a high dielectric insulation311, a high temperature electrical insulation jacket312, and a tubing313. The compression fitting216and the compression fitting sealing glands217may be installed over the tubing313of the motor lead extension (MLE)300individual phases in the order listed above. After the components are installed on each individual phase of the motor lead extension (MLE)300, the three phases may be inserted into the connector housing215simultaneously. The power pins207may locate firmly inside the power pin electrical insulators218. By threading in the compression fitting216into a tapped hole228in the connector housing215, the compression fitting sealing glands217may become compressed against the tapered sealing face229of the connector housing215and the axial cavity220. The compression fitting sealing glands217may slide axially along the insulation jacket312and, due to the tapered sealing face229, may be compressed radially onto the tubing313. A metal-to-metal seal may be formed between the tapered sealing face229and the compression fitting sealing glands217outer diameter and between the compression fitting sealing glands217inner diameter and the tubing313outer diameter. The rate of compression of the compression fitting sealing glands217onto the tubing313may be determined by a pre-defined torque value applied to the compression fitting216.

FIG.15depicts a third cross-sectional view of the example connection receptacle in the motor head, according to some embodiments. InFIG.15, the electrical connector inside the motor head adaptor101may comprise: the power socket104, the electrical contact105, a power socket front electrical insulator117, a power socket rear electrical insulator118, the receptacle guide tube114, the metallic C-rings115and the retaining ring116. In some embodiments, the receptacle guide tube114may be secured into the motor head adaptor101by means of the threaded connection125. The power socket104may be terminated onto the motor lead140. The power socket104may be crimped or soldered onto the stranded core of the motor lead140. In some embodiments, the electrical receptacle may comprise of the power socket104and lamella contacts105. In some embodiments, the electrical contacts105may be comprised of lamella contacts. The lamella contacts105and the power socket104may be made from a copper alloy or a nickel alloy to maintain their mechanical strength and electrical performance at high temperatures. The lamella contacts105and the power socket104(made from a copper alloy) may also be plated with various materials (nickel, gold) to ensure electrical performance of the contact faces at high temperatures and to avoid corrosion.

The power socket104may be surrounded by the power socket front electrical insulator117and the power socket rear electrical insulator118. The power socket rear electrical insulator118may also enclose part of the motor lead140. In some embodiments, the insulators may be comprised of ceramic or other suitable material.

In some embodiments, to prevent fluid migration between the well bore and the motor internal volume110, metal sealing rings may be utilized. The metallic C-Ring119may provide the sealing between the motor head adaptor101and the motor head130by metal-to-metal contact. The metallic C-Ring115may additionally provide the sealing between the motor head adaptor101and the receptacle guide tubes114when the metallic C-Ring115is inserted into the annular gap123between sealing surface120of the receptacle guide tube114and the counter bore sealing surface124in the motor head adaptor101. The retaining ring116may locate the metallic C-Ring115inside the counter bore in the motor head adaptor101and prevent the axial movement of the C-Ring seal formed by the metallic C-ring115. In some embodiments, when servicing the motor in the shop and the electric submersible pump (ESP) in the field, motor oil from the motor inside the motor internal volume110may escape through the annular gap122between the power socket front electrical insulator117outer diameter and the receptacle guide tube114internal diameter. One or more customized protective caps with O-Rings (not shown in this embodiment) may be installed over the receptacle guide tubes114to prevent motor oil leakage during the motor or ESP servicing.

In some embodiments, the motor connector arrangement for high temperature applications, like Steam Assisted Gravity Drainage (SAGD), as depicted inFIG.13may use an alternate sealing method.FIG.16depicts a cross-sectional view through one of the phases of the connection, showing the slimline connector mated with the motor head using an alternative sealing method, according to some embodiments. In this embodiment, the seal may be formed between the connector housing232and the receptacle guide tube126by means of a graphite sealing gasket127. When the slimline connector200is fully engaged with the receptacle guide tubes126, the graphite sealing gasket127may be compressed into the cavity formed by connector-housing bore faces233aand233band receptacle guide tube faces134aand134b. The graphite sealing gasket127may be designed and sized such that when compressed into the formed cavity, the gasket may expand to fill the cavity produced by the faces mentioned above, thus creating a pressure tight seal.

When the slimline connector200is fully engaged with the receptacle guide tubes126, the insulators218and117may overlap and increase the insulation thickness and the high voltage arc tracking length over the power pin207and the power socket104connection. Motor oil from the motor internal volume110may transfer from the motor100to the slimline connector200through the annular gap122between the power socket front electrical insulator117outer diameter and the bore in the motor head adaptor101. The motor oil may additionally transfer between the receptacle guide tube126inner diameters and fill the axial cavity220, as well as the annular area221between the motor lead extension (MLE)300and the insulation jacket312outer diameter, and between the connector housing232and the axial cavity220internal diameter. The motor oil may also fill the annular area between the tubing313outer diameter and compression fitting sealing glands217. In some embodiments, the annular area223between the insulation jacket312outer diameter and the tube313inside diameter may be pre-filled with grease.

FIGS.17and18depict alternate embodiments of the example slimline connector.FIG.17depicts a third cross-sectional view of the example slimline connector through one of the phases of the connection, according to some embodiments. In this alternate embodiment, the slimline connector200may comprise: the connector housing232, the power pin207, the power pin electrical insulator218, the compression fitting216and the compression fitting sealing glands217. The connector housing may include the plurality of axial cavities220(machined holes) as described earlier. In some embodiments, the power pin electrical insulators218may be secured in the connector housing232within the axial cavity220by means of a threaded connection224. In some embodiments, the material of the power pin electrical insulator218may comprise ceramic or other suitable material. The power pin207may be terminated onto the solid copper conductor310of the motor lead extension (MLE)300. In some embodiments, the power pins207may be threaded and crimped onto the copper conductor310.

In some embodiments, the motor lead extension (MLE)300may consist of a tubing-cladded high temperature power cable. This cable may comprise: a solid copper conductor310, a high dielectric insulation311, a high temperature electrical insulation jacket312and a tubing313. The compression fitting216and the compression fitting sealing gland217may be installed over the tubing313of the motor lead extension (MLE)300individual phases in the order listed above. After the components are installed on each individual phase of the motor lead extension (MLE)300, the three phases may be inserted into the connector housing232on the motor simultaneously. The power pins207may be located firmly inside the power pin electrical insulators218. By threading in the compression fitting216into the tapped hole228in the connector housing232, the compression fitting sealing glands217may become compressed against the tapered sealing face229of the connector housing232within the axial cavity220. The compression fitting sealing glands217may slide axially along the insulation jacket312and, due to the tapered sealing face229, may be compressed radially onto the tubing313. A metal-to-metal seal may form between the tapered sealing face229and the compression fitting sealing glands217outer diameter and between the compression fitting sealing glands217inner diameter and the tubing313outer diameter. The rate of compression of the compression fitting sealing glands217onto the tubing313may be determined by a pre-defined torque value applied to the compression fitting216.

FIG.18depicts a fourth cross-sectional view of the example connection receptacle in the motor head, according to some embodiments. In this embodiment, the electrical connector inside the motor head adaptor101may comprise: the power socket104, the electrical contact105, the power socket front electrical insulator117, the power socket rear electrical insulator118, the receptacle guide tube126and the graphite sealing gaskets127.

In some embodiments, the lamella contacts105and the power socket104may be made from a copper alloy or a nickel alloy to maintain their mechanical strength and electrical performance at high temperatures. The lamella contacts105and the power socket104made from a copper alloy may also be plated with various materials (nickel, gold) to ensure electrical performance of the contact faces at high temperatures and to avoid corrosion.

The receptacle guide tube126may be secured into the motor head adaptor101by means of the threaded connection125. The power socket104may be terminated onto the motor lead140. In some embodiments, the power socket may be crimped or soldered onto the stranded core of the motor lead140. In some embodiments, the electrical receptacle comprises of the power socket104and lamella contacts105. The power socket104may be surrounded by the power socket front electrical insulator117and the power socket rear electrical insulator118. The power socket rear electrical insulator118may also enclose part of the motor lead140. In some embodiments, the insulators may be comprised of ceramic or a similar material which may tolerate the subsurface environment of the ESP.

In this embodiment, to prevent fluid migration between the well bore and the motor internal volume110, graphite sealing gaskets may be utilized. The sealing between the motor head adaptor101and the motor head130may be achieved by compressing the graphite sealing gasket128into the cavity formed by faces133aand133bon the motor head adaptor101and faces132aand132bon the motor head130, when the motor head130is fully engaged inside the motor head adaptor101. A graphite sealing gasket128may be designed and sized such that when compressed into the formed cavity, it expands and fills the cavity produced by the faces mentioned above, thus creating the pressure tight seal.

In some embodiments, a graphite sealing gasket127may provide the seal between the motor head adaptor101and the receptacle guide tubes126when the graphite sealing gasket127is compressed into the cavity formed by the motor head adaptor101faces135aand135band the receptacle guide tube126faces129aand129b. The graphite sealing gasket127may be designed and sized such that when compressed into the formed cavity, the graphite sealing gasket127may expand and fill the cavity produced by the faces mentioned above, thus creating the pressure tight seal. In some embodiments, when servicing the motor in the shop and the electric submersible pump (ESP) in the field, motor oil from the motor inside the motor internal volume110may escape through the annular gap122between the power socket front electrical insulator117outer diameter and the receptacle guide tube114internal diameter. A customized protective cap with O-Rings (not shown in this embodiment) may be installed over the receptacle guide tubes114and may be used to prevent motor oil leak during the motor or ESP servicing.

Example ESP System

An example ESP system (application) in which a conductive cable (as described herein) may be used is now described.FIG.19depicts an example well system having an ESP, according to some embodiments.FIG.19depicts a well system1900. While the well system1900illustrates a land-based subterranean environment, example implementations contemplate any well site environment including a subsea environment. In one or more embodiments, any one or more components or elements may be used with subterranean operations equipment located on offshore platforms, drill ships, semi-submersibles, drilling barges and land-based rigs.

In some embodiments, the well system1900may be positioned (at least partially) in a wellbore1904below a surface1902in a formation1924. The wellbore1904may comprise a vertical, deviated, horizontal, or any other type of wellbore. The wellbore1904may be defined in part by a casing1906that may extend from the surface1902to a selected downhole location. Portions of the wellbore1904that do not comprise the casing1906may be referred to as open hole.

Various types of hydrocarbons or fluids may be pumped from the wellbore1904to the surface1902using a pump system1950disposed or positioned downhole, for example, within, partially within, or outside the casing1906of the wellbore1904. In some implementations, the pump system1950may comprise an electric submersible pump (ESP) system. The well system1900may include an electrical cable1910(round cable) and a motor lead extension (MLE)1911(flat cable).

The pump system1950may comprise a pump1908, a pump flow control system1912, a seal or equalizer1914, a motor1916, and a downhole sensor1918. The pump1908may be an ESP, including but not limited to, a multi-stage centrifugal pump, a rod pump, a progressive cavity pump, any other suitable pump system or combination thereof. The pump1908may transfer pressure to the fluid1926or any other type of downhole fluid to propel the fluid from downhole to the surface1902at a desired or selected pumping rate. The pump1908may be coupled to a pump flow control system1912comprising a housing1913. The motor1916may, in some embodiments, be a permanent magnet motor (PMM) or a comparable motor to drive the pump1908and may be coupled to at least the downhole sensor1918. The MLE1911may be coupled to the motor1916. In some embodiments, the MLE1911may connect into the slimline connector200at the motor1916. The slimline connector200may be coupled to the motor1916at the surface by an operator prior to deployment in the wellbore1904. The electrical cable1910may provide power to the motor1916via the MLE1911, transmit one or more control or operation instructions from the controller1920to the motor1916, or both. The electrical cable1910may be communicatively coupled to the controller1920and also to a flowmeter1921disposed at the surface1902. The flowmeter1921may be replaced with any suitable sensor utilized to measure a parameter of the fluid1926.

The fluid1926may be a multi-phase wellbore fluid comprising one or more hydrocarbons. For example, the fluid1926may be a two-phase fluid that comprises a gas phase and a liquid phase from a wellbore or reservoir in the formation1924. The fluid1926may enter the wellbore1904, the casing1906or both through one or more perforations1930in the formation1924and flow uphole to one or more intake ports1927of the pump system1950, wherein the one or more intake ports1927may be disposed at a distal end of the pump1908. The pump1908may transfer pressure to the fluid1926by adding kinetic energy to the fluid1926via centrifugal force and converting the kinetic energy to potential energy in the form of pressure. The pump1908may lift the fluid1926to the surface1902.

The motor1916may include an electric submersible motor configured or operated to turn the pump1908and may, for example, be a two or more-pole, three-phase squirrel cage induction motor or a permanent magnet motor (PMM). However, other motor configurations may be possible. A production tubing section1922may couple to the pump1908using one or more connectors1928or may couple directly to the pump1908. Any one or more production tubing sections1922may be coupled together to extend the pump system1950into the wellbore1904to a desired or specified location.

Example Flowchart

FIG.20depicts a flowchart of example operations, according to some embodiments. The operations inFIG.20are described with reference to the slimline connector and multiple components of the connection with the motor head adaptor as described inFIGS.1-19. These names are for reading convenience and the operations inFIG.20may be performed by any component with the functionality described below. Operations of a flowchart2000begin at block2002.

At block2002, multiple power ports circumferentially disposed on the slimline connector200are aligned with power sockets104circumferentially disposed on a motor head adaptor101coupled with the motor100attached to an electric submersible pump (ESP) system, according to some embodiments. Each power port (also known as phases of the connection) may comprise a power pin207and the concentric power pin insulator208disposed within an axial cavity220behind a sealing face214of the slimline connector200. The slimline connector200comprises three phases, and these phases may be aligned with three power sockets104on the motor head adaptor101by a user or operator at the surface. In some embodiments, prior to aligning the multiple power ports, protective caps may be removed from the sealing face214of the slimline connector200and from one or more receptacle guide tubes102on the motor head adaptor101. These protective caps may provide protection against weather (rain, snow, etc.) or dust during transport until the slimline connector200is prepared for connection to the motor head adaptor101. Flow progresses to block2004.

At block2004, the slimline connector200is engaged via a plug-in connection to the motor head adaptor101, according to some embodiments. The power pins207may be guided by a user or operator into the receptacle guide tubes102(one per power socket) simultaneously until the power pin207is engaged with the electrical contact105of the motor head adaptor101. The design of the slimline connector200(and may enable this connection to be a quick, plug-in connection into the motor head adaptor101. Flow progresses to block2006.

At block2006, the ESP system comprising at least the slimline connector200, motor lead extension (MLE)300, the motor100, and the motor head adaptor101is lowered into a wellbore at a well site. Once the plug-in connection between the power ports of the slimline connector200and the power sockets104of the motor head adaptor101is engaged, the ESP coupled to the motor100may be conveyed downhole. Power may be supplied through the slimline connector200to the motor100, and the ESP may pump fluid to the surface. Flow of flowchart2000ceases.

Example Embodiments

Use of the phrase “at least one of” preceding a list with the conjunction “and” should not be treated as an exclusive list and should not be construed as a list of categories with one item from each category, unless specifically stated otherwise. A clause that recites “at least one of A, B, and C” can be infringed with only one of the listed items, multiple of the listed items, and one or more of the items in the list and another item not listed.

As used herein, the term “or” is inclusive unless otherwise explicitly noted. Thus, the phrase “at least one of A, B, or C” is satisfied by any element from the set {A, B, C} or any combination thereof, including multiples of any element.

Embodiment #1: An apparatus comprising: a slimline connector to connect a motor lead extension (MLE) to an electric motor of an electric submersible pump (ESP) to be positioned in a wellbore, the electric motor having a rotational axis, and wherein the slimline connector comprises: multiple power ports positioned circumferentially around an axis of the slimline connector, wherein the axis of the slimline connector is parallel with the rotational axis of the electric motor, and wherein each port of the multiple power ports is associated with a different electrical phase.

Embodiment #2: The apparatus of Embodiment 1, wherein the multiple power ports are placed at a predefined distance from one another to avoid an electrical failure between phases.

Embodiment #3: The apparatus of any one of Embodiments 1-2, further comprising a plurality of axial cavities, wherein each axial cavity is positioned at pre-defined radial and angular location on an end face of the slimline connector.

Embodiment #4: The apparatus of Embodiment 3, wherein each axial cavity comprises a power pin, wherein the power pin is connected to a copper conductor, and wherein the power pin is to be inserted into a corresponding power socket on a motor head adaptor.

Embodiment #5: The apparatus of Embodiment 4, wherein each power pin of the slimline connector includes a concentric power pin insulator.

Embodiment #6: The apparatus of any one of Embodiments 4-5, further comprising: one or more axial holes on either side of the slimline connector; and for each axial hole, a lug used to secure the slimline connector to the motor head adaptor.

Embodiment #7: A connector and motor head adaptor system configured to form a plug-in connection to provide power to an electric motor of an electric submersible pump (ESP) to be positioned in a wellbore, the connector and motor head adaptor system comprising: a slimline connector comprising multiple power ports positioned circumferentially around an axis of the slimline connector, wherein each port of the multiple power ports is associated with a different electrical phase; a motor lead extension coupled to the slimline connector; a motor head adaptor comprising multiple circumferentially disposed power sockets; and the electric motor, wherein the electric motor has a rotational axis, and wherein the axis of the slimline connector is parallel with the rotational axis of the electric motor.

Embodiment #8: The connector and motor head adaptor system of Embodiment 7, wherein the multiple power ports are placed at a predefined distance from one another to avoid an electrical failure between phases.

Embodiment #9: The connector and motor head adaptor system of any one of Embodiments 7-8, further comprising a plurality of axial cavities, wherein each axial cavity is positioned at pre-defined radial and angular location on an end face of the slimline connector, and wherein each axial cavity comprises a power pin.

Embodiment #10: The connector and motor head adaptor system of Embodiment 9, wherein each power pin of the slimline connector is connected to a copper conductor, and wherein each power pin includes a concentric power pin insulator.

Embodiment #11: The connector and motor head adaptor system of any one of Embodiments 7-10, further comprising: one or more axial holes on either side of the slimline connector; and for each axial hole, a lug used to secure the slimline connector to the motor head adaptor.

Embodiment #12: The connector and motor head adaptor system of any one of Embodiments 10-11, wherein the motor head adaptor further comprises: for each power socket, a receptacle guide tube to guard each concentric power pin insulator and to guide the slimline connector during assembly, wherein the receptacle guide tubes are parallel with the rotational axis of the electric motor, and wherein the receptacle guide tubes are comprised of steel.

Embodiment #13: The connector and motor head adaptor system of Embodiment 12, further comprising: one or more graphite sealing gaskets, wherein the one or more graphite sealing gaskets are to form a seal between a connector housing of the slimline connector and each of the receptacle guide tubes.

Embodiment #14: The connector and motor head adaptor system of any one of Embodiments 12-13, further comprising: one or more elastomeric O-rings, wherein the one or more elastomeric O-rings are to form a seal between a connector housing of the slimline connector and each of the receptacle guide tubes.

Embodiment #15: The connector and motor head adaptor system of Embodiment 14, wherein the one or more elastomeric O-rings are to form a seal between each concentric power pin insulator and each of the receptacle guide tubes.

Embodiment #16: The connector and motor head adaptor system of any one of Embodiments 12-15, further comprising: one or more metallic C-rings for use in high-temperature applications, wherein the one or more metallic C-rings form a seal between each receptacle guide tube and the connector housing of the slimline connector.

Embodiment #17: A method comprising: aligning, power ports circumferentially disposed in a slimline connector with power sockets circumferentially disposed on a motor head adaptor coupled with a motor attached to an electric submersible pump (ESP) system; engaging a plug-in connection between the power ports of the slimline connector and the power sockets of the motor head adaptor; and conveying the ESP system into a wellbore.

Embodiment #18: The method of Embodiment 17, further comprising: removing protective caps from the power ports and the power sockets, wherein removing the protective caps is completed by a user at a surface of the wellbore.

Embodiment #19: The method of any one of Embodiments 17-18, wherein engaging the plug-in connection comprises: for each power socket, inserting a power pin into the power socket until a seal between a connector housing and a receptacle guide tube is formed.

Embodiment #20: The method of Embodiment 19, further comprising: supplying power to the ESP through the plug-in connection via a surface power generation unit.