Steel pipe cable connecting device

Abstract

The invention belongs to the technical field of high-temperature submersible steel pipe cable connection, and discloses a steel pipe cable connecting device. The conducting rod is used for connecting wire cores of two steel pipe cables; the high-temperature-resistant insulating material layer is lapped at the connecting position of the two wire cores and on the conducting rod; the high-temperature-resistant insulating tube is sleeved outside the high-temperature-resistant insulating material layer; the shell is arranged outside the high-temperature-resistant insulating tube in a sleeving manner; the first end sealing structure comprises a first plug connected to the inner wall face of the first opening end of the shell in a sealed mode, a first flexible graphite sealing assembly pressed between the first plug and the high-temperature-resistant insulating pipe by the first plug, and at least one modular sealing assembly connected with the outer wall face of the first opening end of the shell in a sealed mode. The second end sealing structure comprises a second plug connected to the inner wall face of the second opening end of the shell in a sealed mode, a metal clamping sleeve pressed between the second plug and the inner wall of the shell by the second plug, and at least one modular sealing assembly connected with the outer wall face of the second opening end of the shell in a sealed mode.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature submersible steel pipe cable connection, and in particular to a steel pipe cable connection device. Background Art

[0002] Currently, steam stimulation is a widely used method for offshore heavy oil production. Also known as periodic steam injection or cyclic steam injection, this involves injecting a certain amount of high-temperature, high-pressure, wet, saturated steam into the oil reservoir, then holding the well for several days to heat the crude oil, and then opening the well for production. This production method primarily uses a two-pass injection and production string. This double-pass string injection and production process has disadvantages such as high string replacement costs, significant heat loss during workovers, and reduced production efficiency. Therefore, a high-temperature electric pump integrated injection and production technology has been developed.

[0003] The high-temperature electric pump integrated injection and production technology utilizes a 350°C high-temperature electric pump unit and a 370°C high-temperature submersible steel pipe cable. The existing connection between the high-temperature electric pump unit's lead cable and the high-temperature submersible steel pipe cable is first crimped with a press-fit copper sleeve, then twisted, and finally wrapped with armored steel tape. This connection method currently cannot meet the high-temperature and high-pressure conditions of steam wells. Furthermore, this connection method has low mechanical strength, with stress points concentrated at the press-fit copper sleeve. During downhole operation, external forces can cause a decrease in insulation and sealing capabilities, and even fracture the joint. Summary of the Invention

[0004] In order to improve the stability of the connection between steel pipe cables, the present invention proposes a steel pipe cable connection device.

[0005] According to the present invention, the steel pipe cable connection device includes: a conductive rod for connecting the cores of two steel pipe cables; a high-temperature resistant insulating material layer wrapped around the connection position of the two cores and the conductive rod; a high-temperature resistant insulating tube, sleeved on the outside of the high-temperature resistant insulating material layer; an outer shell, sleeved on the outside of the high-temperature resistant insulating tube; a first end sealing structure, including a first plug sealedly connected to the inner wall surface of the first open end of the outer shell and a first flexible graphite sealing assembly pressed by the first plug between the first plug and the high-temperature resistant insulating tube, and at least one modular sealing assembly sealedly connected to the outer wall surface of the first open end of the outer shell; and a second end sealing structure: including a second plug sealedly connected to the inner wall surface of the second open end of the outer shell and a metal ferrule pressed by the second plug between the second plug and the inner wall of the outer shell, and at least one modular sealing assembly sealedly connected to the outer wall surface of the second open end of the outer shell.

[0006] Furthermore, the modular sealing assembly includes: a joint, the inner stop of the first end of the joint is provided with a first flexible graphite pad for compression sealing with the step on the outer peripheral wall of the shell, and the interior of the second end is provided with a second flexible graphite sealing assembly, and the second flexible graphite sealing assembly is compressed and sealed by a second plug.

[0007] Furthermore, the second flexible graphite sealing component is replaced by a metal ferrule.

[0008] Furthermore, the first flexible graphite gasket is replaced by a metal O-ring.

[0009] Furthermore, the first end sealing structure includes two modular sealing assemblies connected in series, wherein the inner stop of the first end of the joint is provided with an internal thread and the outer periphery of the second end is provided with an external thread, so that multiple modular sealing assemblies can be connected end to end.

[0010] Furthermore, the inner ends at both ends of the shell are provided with internal threads for threaded connection with the first plug and the second plug with external threads; the outer peripheral walls at both ends of the shell are provided with external threads for threaded connection with the modular sealing assembly.

[0011] Furthermore, the first flexible graphite sealing assembly and the second flexible graphite sealing assembly are both composed of alternately stacked metal gaskets and flexible graphite gaskets.

[0012] Furthermore, the metal gasket is located at the outermost side.

[0013] Furthermore, the high temperature resistant insulating material layer is a self-adhesive polyimide film, which is formed by coating a thermoplastic polyimide adhesive on a thermosetting polyimide film.

[0014] Furthermore, the high temperature resistant insulating tube is made of thermosetting polyimide, and its axial length is greater than that of the high temperature resistant insulating material.

[0015] The steel pipe cable connection device of the present application has significant advantages over the existing technology: in terms of mechanical strength and stability, the design of the metal ferrule transfers the external pulling force to the shell, avoiding force concentration and improving the stability of the connection, and the threaded connection between the components is simple and firm, which is convenient for installation and disassembly; in terms of sealing performance, through multi-channel sealing design (such as flexible graphite sealing components at both ends, metal ferrules, modular sealing components, etc.) and flexibly replaceable and combined sealing components (such as replacement of flexible graphite pads with metal O-rings, flexible graphite sealing components with metal ferrules), a better Reliable and more adaptable to the sealing effect of different working conditions, effectively preventing the intrusion of high-temperature and high-pressure media; in terms of insulation performance, the high-temperature resistant insulating tube is made of high-temperature resistant self-adhesive polyimide film wrapped and combined with thermosetting polyimide, which doubly guarantees the insulation stability in high-temperature environments and avoids corona discharge and arc phenomena. Overall, the steel pipe cable connection device of this application is superior to the existing technology in structural design, material application and function realization, and is more suitable for the steel pipe cable connection needs in harsh environments such as steam throughput method in offshore heavy oil extraction, which greatly improves the reliability, stability and service life of the connection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 2 is a schematic structural diagram of a steel pipe cable connection device according to an embodiment of the present invention;

[0017] Figure 2 for Figure 1 A schematic structural diagram of a modular sealing assembly is shown;

[0018] Figure 3 for Figure 1 The structural diagram of the high-temperature submersible steel pipe cable connector shown in FIG.

[0019] Figure 4 for Figure 1 Schematic diagram of the structure of the flexible graphite sealing assembly shown. DETAILED DESCRIPTION

[0020] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0021] Figure 1 FIG2 shows the structure of a steel pipe cable connection device 100 according to an embodiment of the present invention. Figure 1 and Figure 3 As shown, the steel tube cable connection device 100 may include: a conductive rod 10 for connecting the cores 16 of two steel tube cables 1; a high-temperature resistant insulating material layer 8 wrapped around the connection position of the two cores 16 and the conductive rod 10; a high-temperature resistant insulating tube 9, sleeved on the outside of the high-temperature resistant insulating material layer 8; an outer shell 2, sleeved on the outside of the high-temperature resistant insulating tube 9; a first end sealing structure, including a first plug 3 sealedly connected to the inner wall surface of the first open end of the outer shell 2 and a first flexible graphite sealing component 4 pressed by the first plug 3 between the first plug 3 and the high-temperature resistant insulating tube 9, and at least one modular sealing component 7 sealedly connected to the outer wall surface of the first open end of the outer shell 2; and a second end sealing structure: including a second plug 6 sealedly connected to the inner wall surface of the second open end of the outer shell 2 and a metal ferrule 5 pressed by the second plug 6 between the second plug 6 and the inner wall of the outer shell 2, and at least one modular sealing component 7 sealedly connected to the outer wall surface of the second open end of the outer shell 2.

[0022] Combine Figure 1 and Figure 3 As shown, when two steel tube cables 1 need to be connected, the steel tube sheath layer 14 and the insulation layer 15 at the joint of the two steel tube cables 1 are first peeled off to expose the wire core 16, and then the conductive rod 10 is installed on the wire core 16 to achieve electrical connection of the wire core 16. Next, the outer layer of the high-temperature resistant insulating material layer 8 is wrapped around the connection position, and then the high-temperature resistant insulating tube 9 is put on and placed inside the housing 2.

[0023] At the first open end of the shell 2, the first plug 3 can be threadedly connected to the inner wall of the shell 2, pressing the first flexible graphite sealing component 4 between the shell 2 and the high-temperature resistant insulating tube 9 to form a first seal. At the same time, the modular sealing component 7 can be threadedly connected to the outer wall surface of the first open end of the shell 2, and the first flexible graphite pad 13 in its joint 11 is tightly pressed against the step on the outer peripheral wall of the shell 2 to form an external seal of the first open end of the shell 2. For the second open end of the shell 2, the second plug 6 can be threadedly connected to the inner wall of the shell 2, pressing the metal ferrule 5 between the inner wall of the shell 2 and the steel pipe sheath layer 14 of the steel pipe cable 1 to form a seal. The metal ferrule 5 can transmit the tensile force to the shell 2, avoiding force concentration and improving the stability of the connection. In addition, the modular sealing component 7 can also be threadedly connected to the outer wall surface of the second open end of the shell 2 to achieve an external seal of the second open end.

[0024] Through the close cooperation of the above-mentioned multi-layer sealing structure and various components, the conductive rod 10 realizes the reliable connection of the wire core 16 to ensure electrical performance; the high-temperature resistant insulating material layer 8 and the high-temperature resistant insulating tube 9 provide double insulation protection, enhance insulation and high temperature resistance; the outer shell 2 provides mechanical protection; the first end sealing structure and the second end sealing structure respectively form multiple seals to effectively prevent the invasion of external substances, which together enable the steel pipe cable connection device 100 of the embodiment of the present invention to effectively prevent the invasion of external liquids, gases, impurities, etc. in high temperature and high pressure environments, especially in hot injection well conditions with a temperature resistance of 350°C and a pressure resistance of 21Mpa, thereby ensuring the stability and insulation performance of the connection of the internal wire core 16, successfully solving the problem of poor insulation and sealing performance of existing connection devices in high temperature and high pressure environments, greatly improving the stability and service life of the connection device, reducing the risk of operation interruption due to failure of the connection device, ensuring the reliable operation of the steel pipe cable 1 under complex working conditions, and providing a more reliable solution for cable connections in harsh environments such as offshore heavy oil production.

[0025] In such Figure 2 In the preferred embodiment shown, modular sealing assembly 7 may include a connector 11. A first flexible graphite gasket 13 is provided at the inner end of the first end of connector 11 for compressing and sealing against a step on the outer wall of housing 2. A second flexible graphite sealing assembly 12 is provided within the second end of the connector, which is compressively sealed by a second plug 6. The design of connector 11 in modular sealing assembly 7 further enhances the sealing effect at the open end of housing 2. The modular structure facilitates assembly and allows for adjustment of the number and combination of modular sealing assemblies 7 according to actual needs.

[0026] In a preferred embodiment, the second flexible graphite sealing component 12 can be replaced with a metal ferrule 5. Replacing the second flexible graphite sealing component 12 with a metal ferrule 5 can enhance the reliability and deformation resistance of the seal at this location by utilizing the rigidity and strength of the metal ferrule 5. At the same time, the metal ferrule 5 can better transmit the tensile force to the housing 2, thereby improving the mechanical strength and stability of the connection device and preventing connection failure caused by tensile force.

[0027] In another preferred embodiment, the first flexible graphite pad 13 can be replaced with a metal O-ring. Replacing the first flexible graphite pad 13 with a metal O-ring can leverage the elasticity and high-pressure resistance of the metal O-ring to more effectively seal under high-pressure conditions, enhancing the stability and durability of the seal and adapting to complex downhole pressure fluctuations.

[0028] In such Figure 1 In the preferred embodiment shown, the first-end sealing structure may include two modular sealing assemblies 7 connected in series. The internal stopper at the first end of the connector 11 is internally threaded, while the outer periphery of the second end is externally threaded, enabling end-to-end connection of multiple modular sealing assemblies 7. In this embodiment, the first-end sealing structure utilizes two modular sealing assemblies 7 connected in series, creating a multi-layer sealing barrier that significantly improves sealing performance and reduces the risk of seal failure. The threaded design of the connector 11 enables end-to-end connection of the modular sealing assemblies 7, making the sealing structure more compact and stable, facilitating installation and removal, and improving assembly efficiency.

[0029] like Figure 1 As shown, the inner stoppers at both ends of the housing 2 are each provided with internal threads for threaded connection with the externally threaded first and second plugs 3 and 6. External threads are provided on the outer circumferential walls of the housing 2 at both ends for threaded connection with the modular sealing assembly 7. The internal threads at both ends of the housing 2 are threadedly connected to the plugs, facilitating quick installation and securement of the plugs. Simultaneously, the external threads of the housing 2 are threadedly connected to the modular sealing assembly 7, ensuring a tight connection between the modular sealing assembly 7 and the housing 2, ensuring the reliability of the entire sealing system. The threaded connection structure is simple, making it easy to process and mass-produce.

[0030] According to the present invention, Figure 4In the preferred embodiment shown, both the first flexible graphite sealing assembly 4 and the second flexible graphite sealing assembly 12 are composed of alternating stacks of metal gaskets 17 and flexible graphite gaskets 18. This arrangement allows both the first flexible graphite sealing assembly 4 and the second flexible graphite sealing assembly 12 to combine the high temperature resistance, corrosion resistance, and good sealing properties of the flexible graphite gasket 18 with the high strength and deformation resistance of the metal gasket 17. The metal gasket 17 can limit excessive compression of the flexible graphite gasket 18. The overlapping arrangement of the two can actively mitigate stress concentration caused by different thermal expansion coefficients of the materials, thereby ensuring that the sealing assembly maintains a stable and reliable sealing effect in high-temperature and high-pressure environments, thereby extending its service life.

[0031] Preferably, if Figure 4 As shown, metal gasket 17 is located on the outermost side. This outermost position enhances the mechanical strength and wear resistance of the sealing assembly, resisting the impact and friction of external mechanical forces, protecting the internal flexible graphite gasket 18, further improving the reliability and durability of the sealing system, and ensuring the long-term stability of the sealing performance.

[0032] According to the present invention, in a preferred embodiment, the high-temperature-resistant insulating material 8 can be a self-adhesive polyimide film, formed by coating a thermosetting polyimide film with a thermoplastic polyimide adhesive. This high-temperature-resistant insulating material 8 exhibits both excellent heat resistance and good adhesion and flexibility. It adheres tightly to the wire core and the conductive rod surface, forming a uniform, gap-free insulating layer. This effectively prevents corona discharge and arcing, improves insulation performance and reliability, and facilitates construction operations.

[0033] In another preferred embodiment, the high-temperature-resistant insulating tube 9 can be made of thermosetting polyimide and have an axial length greater than the high-temperature-resistant insulating material layer 8. Such a high-temperature-resistant insulating tube 9 has higher heat resistance and mechanical strength, and can provide long-term and stable protection for the internal high-temperature-resistant insulating material layer 8 and conductive rod 10. The axial length of the high-temperature-resistant insulating tube 9 is greater than the high-temperature-resistant insulating material layer 8, ensuring that the high-temperature-resistant insulating tube 9 completely covers the high-temperature-resistant insulating material layer 8, preventing the high-temperature-resistant insulating material layer 8 from being exposed or damaged in the axial direction, further enhancing the insulation performance and environmental reliability of the entire connecting device.

[0034] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0035] In the description of this application, it should be understood that the terms "length", "axial" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A steel pipe cable connection device, characterized in that: include: A conductive rod (10) for connecting the cores (16) of two steel tube cables (1); a high-temperature resistant insulating material layer (8) wrapped around the connection position of the two wire cores (16) and the conductive rod (10); A high-temperature resistant insulating tube (9) is sleeved on the outside of the high-temperature resistant insulating material layer (8); An outer shell (2) is sleeved on the outside of the high-temperature resistant insulating tube (9); A first end sealing structure comprises a first plug (3) sealingly connected to the inner wall surface of the first open end of the housing (2), a first flexible graphite sealing component (4) compressed by the first plug (3) between the first plug (3) and the high-temperature resistant insulating tube (9), and at least one modular sealing component (7) sealingly connected to the outer wall surface of the first open end of the housing (2); and The second end sealing structure comprises a second plug (6) sealingly connected to the inner wall surface of the second open end of the housing (2), a metal ferrule (5) pressed by the second plug (6) between the second plug (6) and the inner wall of the housing (2), and at least one modular sealing component (7) sealingly connected to the outer wall surface of the second open end of the housing (2).

2. The steel pipe cable connection device according to claim 1, characterized in that: The modular sealing assembly (7) comprises: a joint (11); an inner stopper at a first end of the joint (11) is provided with a first flexible graphite pad (13) for compressing and sealing with a step on an outer peripheral wall of the housing (2); a second flexible graphite sealing assembly (12) is provided inside the second end; the second flexible graphite sealing assembly (12) is compressed and sealed by the second plug (6).

3. The steel pipe cable connection device according to claim 2, characterized in that: The second flexible graphite sealing component (12) is replaced by the metal ferrule (5).

4. The steel pipe cable connection device according to claim 2, characterized in that: The first flexible graphite gasket (13) is replaced by a metal O-ring.

5. The steel pipe cable connection device according to any one of claims 2 to 4, characterized in that: The first end sealing structure comprises two modular sealing assemblies (7) connected in series, wherein the inner stop of the first end of the joint (11) is provided with an internal thread, and the outer periphery of the second end is provided with an external thread, so that a plurality of modular sealing assemblies (7) can be connected end to end.

6. The steel pipe cable connection device according to any one of claims 1 to 4, characterized in that: The inner stoppers at both ends of the housing (2) are provided with internal threads for threaded connection with the first plug (3) and the second plug (6) with external threads; the outer peripheral walls at both ends of the housing (2) are provided with external threads for threaded connection with the modular sealing assembly (7).

7. The steel pipe cable connection device according to any one of claims 2 to 4, characterized in that: The first flexible graphite sealing assembly (4) and the second flexible graphite sealing assembly (12) are both composed of alternately stacked metal gaskets (17) and flexible graphite gaskets (18).

8. The steel pipe cable connection device according to claim 7, characterized in that: The metal gasket (17) is located at the outermost side.

9. The steel pipe cable connection device according to any one of claims 1 to 4, characterized in that: The high-temperature resistant insulating material layer (8) is a self-adhesive polyimide film, which is formed by coating a thermoplastic polyimide adhesive on a thermosetting polyimide film.

10. The steel pipe cable connection device according to any one of claims 1 to 4, characterized in that: The high-temperature resistant insulating tube (9) is made of thermosetting polyimide, and its axial length is greater than that of the high-temperature resistant insulating material (8).

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