Submersible electric pump plug-in cable head structure

Abstract

The utility model relates to a submersible electric pump plug-in cable head structure belongs to submersible electric pump connecting component technical field. The one end of joint body is fixedly connected with submersible electric pump junction box, and the other end of joint body is fixedly connected with one end of plug-in pipe, the inner wall of plug-in pipe is equipped with internal thread, plug-in core subassembly passes through joint body and is threadedly connected with plug-in pipe, and the sealing element is equipped between plug-in core subassembly and joint body, the other end of plug-in pipe is fixedly connected with locking mechanism, the cable conductor of cable after stripping is inserted into locking mechanism and reaches plug-in core subassembly, and locking sleeve is sleeved on the cable, locking sleeve is threadedly connected with locking mechanism and fixes cable. The structure of the utility model is through the synergistic optimization of'mechanical fixing - electric connection - sealed isolation', comprehensively solves the installation damage, sealing failure, vibration loosening, maintenance cumbersome and other problems of the existing cable head, significantly improves the reliability, safety and economy in the harsh environment of downhole, provides key support for the efficient operation of submersible electric pump.

Description

Technical Field

[0001] This utility model belongs to the technical field of submersible electric pump connection components, specifically a submersible electric pump insert-type cable head structure. Background Technology

[0002] Submersible electric pumps (SAPs) are key equipment in oilfield development, used to lift crude oil from downhole to the surface. Their operating environment is characterized by high temperature, high pressure, strong corrosion, and intense vibration. The cable head, as the connection between the SSP and the power cable, directly affects the stability and safety of the pump's operation; its sealing performance, structural reliability, and ease of installation and maintenance are crucial.

[0003] Existing submersible electric pump cable heads mostly use a threaded connection structure, which requires rotating the cable or connector body during installation to achieve a tight fit. This can easily lead to twisting and damage to the cable insulation layer, reducing insulation performance. The sealing structure is mostly a single sealing ring design, which is prone to aging and failure under long-term high temperature and high pressure conditions downhole, allowing well fluid to enter and cause conductor short circuits. At the same time, threaded connections are prone to loosening under severe vibration, further increasing the risk of failure. Moreover, maintenance requires complete disassembly, which is cumbersome and significantly increases the maintenance cost and downtime of oilfield operations. Summary of the Invention

[0004] To address the problems existing in the background technology, this utility model provides a submersible electric pump insertable cable head structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a submersible electric pump insert cable head structure, comprising a connector body, a plug tube, a plug core assembly, a seal, a locking mechanism, a locking sleeve, a cable conductor, and a cable; One end of the connector body is fixedly connected to the submersible electric pump junction box, and the other end of the connector body is fixedly connected to one end of the plug tube. The inner wall of the plug tube is provided with internal threads. The plug core assembly passes through the connector body and is threadedly connected to the plug tube. A sealing element is provided between the plug core assembly and the connector body. The other end of the plug tube is fixedly connected to the locking mechanism. The exposed cable conductor is inserted into the locking mechanism and into the plug core assembly. A locking sleeve is fitted on the cable. The locking sleeve is threadedly connected to the locking mechanism and fixes the cable.

[0006] The ferrule assembly includes a ferrule, a conductive core, an insulating layer, an electrical slot, and multiple sector-shaped rubber plates; One end of the conductive core is fixedly connected to the plug, and the other end of the conductive core is provided with an electrical slot. The inner wall of the electrical slot is provided with multiple fan-shaped rubber plates evenly distributed and inclined in the circumferential direction. The outer wall of the conductive core is provided with an insulating layer. The insulating layer is made of polytetrafluoroethylene material that is resistant to high temperature and high pressure, and is used to achieve insulation isolation between the conductive core and the connector body. The insulating layer is provided with external threads and is threadedly connected to the internal threads on the plug tube.

[0007] The inner wall of the seal is provided with two annular ridges, and the insulating layer is provided with two annular grooves that correspond one-to-one with the annular ridges, with each annular ridge inserted into the corresponding annular groove.

[0008] Both the insert and the conductive core are made of copper alloy, which has excellent electrical conductivity and mechanical strength. The outer walls of the insert and the conductive core are plated with silver, which can reduce contact resistance, reduce heat loss during current transmission, and improve corrosion resistance.

[0009] The locking mechanism includes a rubber snap ring and multiple sector-shaped posts; The other end of the insertion tube is provided with a plurality of fan-shaped posts evenly distributed circumferentially. The outer walls of the plurality of fan-shaped posts are provided with threads. The plurality of fan-shaped posts are inclined towards the center. The locking sleeve is conical and has internal threads on its inner wall that cooperate with the plurality of fan-shaped posts. The plurality of fan-shaped posts are threadedly connected to the locking sleeve. The inner walls of the plurality of fan-shaped posts are provided with rubber retaining rings. A sealing ring is provided between the ends of the plurality of fan-shaped posts and the inner bottom surface of the locking sleeve.

[0010] A flange is fixedly fitted on the connector body. The flange is connected to the submersible electric pump junction box by bolts. A sealing ring is provided at the connection between the flange and the submersible electric pump junction box.

[0011] Compared with the prior art, the beneficial effects of this utility model are: 1. No insulation damage during installation, ensuring cable insulation reliability: The locking mechanism of "conical locking sleeve + sector column" is adopted. During installation, only the locking sleeve needs to be tightened. The conical surface squeezes and forces the sector column to shrink and fix the cable in the center. There is no need to rotate the cable or the connector body. This fundamentally avoids the cable insulation layer distortion and cracking problems caused by traditional threaded connection, ensuring long-term stable insulation performance and reducing the risk of leakage.

[0012] 2. Triple sealing for coordinated protection, preventing downhole media intrusion: Integrating axial, radial, and inlet triple seals; the sealing rings of the flange and junction box form the first axial barrier, the interlocking of the sealing ring ridge and the insulating layer groove forms a radial seal, and the sealing rings of the fan-shaped column end and the locking sleeve block the cable inlet gap. The triple seals work together to resist downhole high temperature, high pressure and corrosive media, solving the problem of easy aging and failure of traditional single seals, and greatly reducing the risk of conductor short circuits caused by well fluid intrusion.

[0013] 3. Vibration-resistant and anti-loosening design, adaptable to severe vibration conditions: The locking mechanism achieves double fixation through "rigid contraction of the fan-shaped column + elastic clamping of the rubber spring". Combined with the pre-tightening force of the threaded connection of each component, it can not only firmly lock the cable and internal components, but also absorb vibration energy through the elastic deformation of the rubber parts, offset the impact stress generated by severe vibration downhole, avoid the loosening problem of traditional threaded connection under vibration, and ensure the long-term stability of electrical contact and sealing.

[0014] 4. Highly efficient and stable electrical connection, balancing corrosion resistance and conductivity: The inclined fan-shaped rubber plate inside the electrical slot tightly wraps the cable conductor through radial elastic force, ensuring continuous and stable electrical contact; the plug and conductive core are made of highly conductive copper alloy and silver-plated. The copper alloy ensures mechanical strength and basic conductivity, while the silver layer reduces contact resistance and improves corrosion resistance in corrosive media such as hydrogen sulfide, extending the service life of the electrical connection components.

[0015] 5. Modular and detachable structure simplifies installation and maintenance: Core components (insert assembly and connector, locking sleeve and sector post, flange and junction box, etc.) are all connected by threads or bolts. No special tools are required for installation. During maintenance, the corresponding components can be disassembled individually (e.g., the cable can be removed by loosening the locking sleeve, and the conductive structure can be inspected by unscrewing the insert assembly). This solves the cumbersome problem of traditional integral structures requiring complete disassembly, shortens maintenance time, and reduces oilfield downtime losses and maintenance costs.

[0016] 6. The insulation layer is suitable for harsh environments and ensures electrical safety: The insulation layer is made of polytetrafluoroethylene, which is resistant to high temperature and high pressure. It can stably isolate the conductive core from the metal parts such as the connector body, avoid insulation breakdown or short circuit in extreme downhole environments, and provide electrical protection for the long-term safe operation of the submersible pump.

[0017] In summary, the structure of this utility model, through the synergistic optimization of "mechanical fixing - electrical connection - sealing isolation", comprehensively solves the problems of installation damage, sealing failure, vibration loosening, and cumbersome maintenance of existing cable heads, significantly improving the reliability, safety and economy in harsh downhole environments, and providing key support for the efficient operation of submersible electric pumps. Attached Figure Description

[0018] Figure 1 This is a front view of the present invention; Figure 2 This is a schematic diagram of the electrical slot and the connection relationship of multiple sector-shaped rubber plates of this utility model; Figure 3 This is a schematic diagram of the locking mechanism of this utility model. Detailed Implementation

[0019] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.

[0020] This embodiment describes a submersible electric pump insert cable head structure, including a connector body 1, a plug tube 2, a plug core assembly 3, a sealing element 4, a locking mechanism 5, a locking sleeve 6, a cable conductor 8, and a cable 9. One end of the connector body 1 is fixedly connected to the submersible electric pump junction box, and the other end of the connector body 1 is fixedly connected to one end of the plug tube 2. The inner wall of the plug tube 2 is provided with internal threads. The core assembly 3 passes through the connector body 1 and is threadedly connected to the plug tube 2. A sealing element 4 is provided between the core assembly 3 and the connector body 1. The other end of the plug tube 2 is fixedly connected to the locking mechanism 5. The exposed cable conductor 8 of the cable 9 is inserted into the locking mechanism 5 and into the core assembly 3. A locking sleeve 6 is fitted on the cable 9. The locking sleeve 6 is threadedly connected to the locking mechanism 5 and fixes the cable 9.

[0021] The insert assembly 3 includes an insert post 31, a conductive core 32, an insulating layer 33, an electrical slot 34, and multiple fan-shaped rubber plates 35. One end of the conductive core 32 is fixedly connected to the plug 31, and the other end of the conductive core 32 is provided with an electrical slot 34. The inner wall of the electrical slot 34 is provided with a plurality of fan-shaped rubber plates 35 evenly distributed and inclined in the circumferential direction. The outer wall of the conductive core 32 is provided with an insulating layer 33. The insulating layer 33 is made of polytetrafluoroethylene material that is resistant to high temperature and high pressure, and is used to achieve insulation isolation between the conductive core 32 and the connector body 1. The insulating layer 33 is provided with external threads and is threadedly connected to the internal threads on the plug tube 2.

[0022] The inner wall of the sealing element 4 is provided with two annular ridges, and the insulating layer 33 is provided with two annular grooves that correspond one-to-one with the annular ridges, with each annular ridge inserted into the corresponding annular groove.

[0023] Both the insert 31 and the conductive core 32 are made of copper alloy, which has excellent electrical conductivity and mechanical strength. The outer walls of both the insert 31 and the conductive core 32 are plated with silver, which can reduce contact resistance, reduce heat loss during current transmission, and improve corrosion resistance.

[0024] The locking mechanism 5 includes a rubber snap ring 52 and multiple sector-shaped posts 51; The other end of the insertion tube 2 is provided with a plurality of fan-shaped posts 51 evenly distributed circumferentially. The outer walls of the plurality of fan-shaped posts 51 are all provided with threads. The plurality of fan-shaped posts 51 are all inclined towards the center (the inclination angle is adapted to the taper of the locking sleeve 6). The locking sleeve 6 is tapered and has internal threads on its inner wall that cooperate with the plurality of fan-shaped posts 51. The plurality of fan-shaped posts 51 are threadedly connected to the locking sleeve 6. The inner walls of the plurality of fan-shaped posts 51 are provided with rubber snap rings 52. A sealing ring is provided between the ends of the plurality of fan-shaped posts 51 and the inner bottom surface of the locking sleeve 6.

[0025] A flange 7 is fixedly fitted on the connector body 1. The flange 7 is connected to the submersible electric pump junction box by bolts. A sealing ring is provided at the connection between the flange 7 and the submersible electric pump junction box.

[0026] The core of this submersible electric pump insert cable head structure is to achieve a reliable connection between the cable and the submersible electric pump junction box through a coordinated design of "mechanical fixation - electrical connection - sealed isolation," in the harsh environment of high temperature, high pressure, and multiple media downhole. Its operation revolves around the structural coordination of each component: The connector body 1, as the core load-bearing component, is rigidly connected to the submersible pump junction box via bolts at one end through a fixed flange 7. The sealing ring at the connection between the flange 7 and the junction box forms an axial seal under pre-tightening force. The other end is fixedly connected to the insertion tube 2, forming a through channel from the junction box to the cable. The insert assembly 3 penetrates the connector body 1 and is tightly connected to the internal thread of the insertion tube 2 through the external thread of the insulation layer 33. The insulation layer 33 is made of high-temperature and high-pressure resistant polytetrafluoroethylene (PTFE), which not only provides insulation and isolation between the conductive core 32 and the metal components such as the connector body 1, but also, through cooperation with the sealing element 4, ensures... 4. The annular ridge of the inner wall is embedded in the annular groove of the insulation layer to form a radial seal; after the cable 9 exposes the cable conductor 8, it passes through the locking sleeve 6 and is inserted into the locking mechanism 5. Multiple sector-shaped columns 51 of the locking mechanism 5 are evenly distributed circumferentially along the end of the insertion tube 2 and inclined towards the center. The outer wall thread matches the inner wall thread of the tapered locking sleeve 6. When the locking sleeve is tightened, the tapered surface squeezes and forces the sector-shaped columns 51 to shrink towards the center. The rubber snap ring 52 on the inner wall tightly fits the outer wall of the cable with the shrinkage, realizing the dual mechanical fixation of "rigid shrinkage + elastic clamping". At the same time, the sealing ring between the end of the sector-shaped column 51 and the inner bottom surface of the locking sleeve 6 prevents the medium from entering from the gap. After the cable conductor 8 is inserted into the electrical slot 34 of the insert assembly 3, the inclined fan-shaped rubber plates 35 evenly distributed along the circumference inside the slot are stretched open and generate radial elastic force, tightly wrapping the conductor to maintain stable electrical contact. The insert 31 and the conductive core 32 are made of high-conductivity copper alloy and the outer wall is silver-plated, which not only ensures mechanical strength and conductivity, but also reduces contact resistance, reduces heat generation and improves corrosion resistance through the silver layer, ultimately forming a reliable current path from the cable conductor 8 to the submersible pump junction box. In the overall structure, the rigid fixing of the flange 7 and the threaded connection of each component, combined with the elastic buffer of the rubber parts, not only ensure the structural stability to adapt to downhole vibration and impact, but also block the intrusion of downhole media through multiple sealing designs (radial sealing, axial sealing and cable inlet sealing), thereby meeting the reliability requirements of long-term downhole operation of the submersible pump.

[0027] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A plug-in cable head structure for a submersible electric pump, characterized in that: Includes connector body (1), insertion tube (2), ferrule assembly (3), seal (4), locking mechanism (5), locking sleeve (6), cable conductor (8) and cable (9); One end of the connector body (1) is fixedly connected to the submersible electric pump junction box, and the other end of the connector body (1) is fixedly connected to one end of the plug tube (2). The inner wall of the plug tube (2) is provided with internal threads. The core assembly (3) passes through the connector body (1) and is threadedly connected to the plug tube (2). A sealing element (4) is provided between the core assembly (3) and the connector body (1). The other end of the plug tube (2) is fixedly connected to the locking mechanism (5). The exposed cable conductor (8) of the cable (9) is inserted into the locking mechanism (5) and into the core assembly (3). A locking sleeve (6) is fitted on the cable (9). The locking sleeve (6) is threadedly connected to the locking mechanism (5) and fixes the cable (9).

2. The submersible electric pump insert-type cable head structure according to claim 1, characterized in that: The ferrule assembly (3) includes a ferrule (31), a conductive core (32), an insulating layer (33), an electrical slot (34), and multiple fan-shaped rubber plates (35). One end of the conductive core (32) is fixedly connected to the plug (31), and the other end of the conductive core (32) is provided with an electrical slot (34). The inner wall of the electrical slot (34) is provided with a plurality of fan-shaped rubber plates (35) evenly distributed in the circumferential direction. The outer wall of the conductive core (32) is provided with an insulating layer (33). The insulating layer (33) is made of polytetrafluoroethylene material that is resistant to high temperature and high pressure, and is used to achieve insulation isolation between the conductive core (32) and the connector body (1). The insulating layer (33) is provided with an external thread and is threadedly connected to the internal thread on the plug tube (2).

3. The submersible electric pump insert-type cable head structure according to claim 2, characterized in that: The inner wall of the sealing element (4) is provided with two annular ridges, and the insulating layer (33) is provided with two annular grooves that correspond one-to-one with the annular ridges, with each annular ridge inserted into the corresponding annular groove.

4. The submersible electric pump insert-type cable head structure according to claim 2, characterized in that: The insert (31) and conductive core (32) are both made of copper alloy. Copper alloy has excellent conductivity and mechanical strength. The outer walls of the insert (31) and conductive core (32) are plated with silver, which can reduce contact resistance, reduce heat loss during current transmission, and improve corrosion resistance.

5. The submersible electric pump insert-type cable head structure according to claim 1, characterized in that: The locking mechanism (5) includes a rubber snap ring (52) and multiple sector-shaped posts (51); The other end of the insertion tube (2) is provided with a plurality of fan-shaped columns (51) evenly distributed around the circumference. The outer walls of the plurality of fan-shaped columns (51) are provided with threads. The plurality of fan-shaped columns (51) are inclined towards the center. The locking sleeve (6) is conical and has internal threads on its inner wall that cooperate with the plurality of fan-shaped columns (51). The plurality of fan-shaped columns (51) are threadedly connected to the locking sleeve (6). The inner walls of the plurality of fan-shaped columns (51) are provided with rubber snap rings (52). A sealing ring is provided between the ends of the plurality of fan-shaped columns (51) and the inner bottom surface of the locking sleeve (6).

6. The submersible electric pump plug-in cable head structure according to claim 1, characterized in that: A flange (7) is fixedly fitted on the connector body (1). The flange (7) is connected to the submersible electric pump junction box by bolts. A sealing ring is provided at the connection between the flange (7) and the submersible electric pump junction box.

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