Patent Grant
8257103
In a variety of well related applications, electric power is delivered downhole to a submersible component. For example, power cables may be routed down through a wellbore for connection with a submersible motor of an electric submersible pumping system. The lower end of the electric cable is connected with the submersible component by a connector system, often called a pothead system.
Existing pothead systems generally comprise a metal pothead body through which the power cable conductors are routed. Terminal ends of the power cable conductors extend from the pothead body for insertion into corresponding conductor receptacles of the submersible component. Within the metal pothead body, the power cable conductors are surrounded by dielectric insulation, elastomer seals, and compression blocks to protect the functionality of the pothead system. Additional seals can be located between the pothead body and a corresponding housing of the submersible component to further seal and protect the conductive paths. However, such multicomponent pothead systems can be complex, expensive, and susceptible to leaks.
In general, the present application provides a technique for protecting electrical conductors in a submerged environment, such as a wellbore environment. A connector system is deployed at the end of an electric cable to enable connection of the electric cable with a submersible component. The connector system comprises a connector body formed of a moldable material that is molded around at least one conductor. The moldable material insulates and protects the at least one conductor when the connector body is engaged with the submersible component.
Certain embodiments will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
In the following description, numerous details are set forth to provide an understanding of various preferred embodiments. However, it will be understood by those of ordinary skill in the art that the embodiments may be practiced without many of these details and that numerous variations or modifications from the described embodiments may be possible.
The present application generally involves a system and methodology related to submerged connections between electrical cables and submersible components. In one embodiment, a connector system is provided for enabling an electrical connection between a power cable and a submersible component, such as an electric, submersible motor. The connector system utilizes a connector, sometimes referred to as a pothead, which simplifies construction, seals against the one or more internal conductors, and facilitates the formation of a seal with the submersible component.
According to one specific example, the connector system comprises a connector body that is molded around each conductor of the electric cable. For example, the connector body may be molded around three conductors of the type used in various downhole power cables. Moldable material is selected and molded around the one or more conductors to provide a pressure seal around each conductor and to provide dielectric insulation without the need for additional components. The molded connector body also provides great resistance to mechanical damage.
The use of moldable material enables formation of the connector body in a variety of configurations. For example, the connector body can be molded into complex shapes that include various features. In one embodiment, the connector body is molded to form a conductor housing/primary body portion, a mounting flange, and a mating portion to enable sealed engagement with the submersible component. The entire connector body may be formed as a single, unitary, molded component. Also, the unitary connector body may be formed around individual conductors or groups of conductors, such as the three conductors found in various power cables used to power three-phase motors.
The moldable material is selected according to the environment in which the pothead/connector system is to be employed. Depending on the application, the connector body may be formed from a thermoplastic material, a thermoset material, a liquid crystal polymer material, or another suitable moldable material. The use of these moldable materials allows the connector body housing to provide a pressure seal with respect to the conductors that prevents the well environment from entering the submersible component, e.g. submersible motor. The material of choice provides the dielectric insulation strength over conductors, e.g. copper conductors. The material also is compatible with the well environment and provides mechanical strength to enable fastening of, e.g. bolting, the connector body to the submersible component. The use of such materials allows creation of connector systems that do not require any additional elastomeric sealing elements because the sealing function is accomplished by the molded connector body.
Referring generally to
An electric connection system 28 provides an electrical connection between electric, submersible component 26 and an electric cable 30, e.g. an electric power cable. The electric connection system 28 comprises a connector body 32 formed of a moldable material 34. The moldable material 34 enables formation of connector body 32 in a variety of configurations that sealingly enclose one or more internal conductors 36 extending into the connector body 32 from an end of the electric cable 30.
In the embodiment illustrated in
The electric submersible pumping system 38 is deployed to a desired location in wellbore 42 via a conveyance 50 which may be in the form of a tubing 52, e.g. coiled tubing, or other suitable conveyance. The system 38 is connected to conveyance 50 by a connector 54 and may comprise a variety of pumping related components. For example, electric submersible pumping system 38 may comprise a submersible pump 56 connected to a pump intake 58. The pump intake 58 allows well fluid to be drawn into submersible pump 56 when pump 56 is powered by submersible motor 40. In many applications, a motor protector 60 is located between submersible motor 40 and pump 56 to enable pressure equalization while isolating motor fluid from well fluid.
In the embodiment illustrated in
Referring generally to
Flange portion 64 presents an engagement face or surface 68 designed to abut against a corresponding engagement region of submersible component 26. In the particular example illustrated, connector body 32 further comprises a mating portion 70 that extends from engagement surface 68 to ensure a seal between connector body 32 and the submersible component 26. The seal formed by mating portion 70 prevents the influx of harmful downhole constituents and protects one or more terminal ends 72 of conductors 36 when those terminal ends 72 are plugged into corresponding receptacles of submersible component 26. In this embodiment, mating portion 70 comprises a mating face 74 which may be designed to present a tapered sealing surface that forms a secure seal between connector body 32 and submersible component 26 even without separate elastomer seal elements.
The flange portion 64, mating portion 70, and mating face 74 may be constructed in a variety of shapes and configurations. For example, mating portion 70 may be extended, recessed, or a combination of extended and recessed portions. Additionally, the mating face 74 may be formed as a tapered sealing surface or as another type of sealing surface designed to form a protective seal when connector body 32 is fully engaged with submersible component 26. In any of these configurations, the primary body portion 62, flange portion 64, mating portion 70, and mating face 74 can be formed as a unitary component from the moldable material 34. Furthermore, the illustrated embodiment shows terminal ends 72 arranged in a triad configuration, but the conductors 36 and terminal ends can be arranged in a variety of other configurations.
Referring generally to
The creation of various connector systems 28 may be accomplished according to various processes. However, one example of a process for forming connection system 28 is illustrated by the flowchart of
Once the moldable material is selected, conductors 36 are positioned in a mold, as indicated by block 80. The mold is then filled with moldable material, as indicated by block 82. The filling of the mold may be accomplished according to a variety of molding techniques that may vary with the type of moldable material selected. The moldable material is displaced around the internal conductors and forms a seal with those internal conductors when cured, as indicated by block 84. In this particular example, the connector body/pothead 32 is then removed from the mold, as indicated by block 86. Placement of the conductors and construction of the mold are designed to provide extended terminal ends 72 and suitable sealing surfaces, such as mating face 74, to form a lasting and dependable seal with submersible component 26. In some applications, the curing process (or portions of the curing process) may be accomplished after the connector body is removed from the mold.
Depending on the environment and the electric submersible component with which connector body 32 is engaged, the actual materials used and the configuration selected for the connector body may vary. In some applications, for example, individual conductors may be sealed within connector body 32, while in other applications larger numbers of plural conductors, e.g. three conductors, may be sealed in connector body 32. Additionally, the conductors may be formed from copper or other conductive materials and terminate in a variety of terminal ends 72. The flange portion may be constructed in various configurations with different arrangements of openings or other connection features. Additionally, the entire flange portion may be replaced with other types of connection features. In some applications, separate seal elements can be used in cooperation with the connector body; and/or the moldable material may be constructed with a variety of sealing surfaces that enable a desired seal in downhole or other subterranean environments. The conductors, moldable material, and connector body configuration are selected to provide the pressure seal and dielectric strength to carry current to the submersible component, e.g. submersible motor.
Although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Accordingly, such modifications are intended to be included within the scope of this invention as defined in the claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3786397 | Bridges | Jan 1974 | A |
| 4387313 | Yamamoto et al. | Jun 1983 | A |
| 4679875 | Ramsey | Jul 1987 | A |
| 5670747 | Lawer et al. | Sep 1997 | A |
| 6397945 | Manke et al. | Jun 2002 | B1 |
| 6409485 | Ebner | Jun 2002 | B1 |
| 6910870 | Ebner | Jun 2005 | B2 |
| 7611339 | Tetzlaff et al. | Nov 2009 | B2 |
| 7789689 | Frey et al. | Sep 2010 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20110130020 A1 | Jun 2011 | US |
