Cable penetrating device suitable for airtight wellhead

Abstract

The utility model belongs to the technical field of cable penetrating devices, and discloses a cable penetrating device suitable for an airtight wellhead, which comprises an oil pipe four-way joint, an oil pipe hanger and a cable penetrating device which are sequentially arranged from outside to inside, an upper flange is arranged at the top of the oil pipe four-way joint, and the cable penetrating device comprises a penetrating device shell. Sealing assemblies are arranged on the peripheral side of the cable penetrating device in the height direction and comprise the first sealing assembly, the second sealing assembly, the third sealing assembly and the fourth sealing assembly which are sequentially arranged from bottom to top, and the first sealing assembly and the second sealing assembly are used for achieving sealing between the cable penetrating device and the tubing hanger. The third sealing assembly and the fourth sealing assembly are used for achieving sealing between the cable penetrating device and the upper flange, the second sealing assembly and the fourth sealing assembly are used in a combined mode, and the service life of the sealing assemblies can be effectively prolonged while the sealing effect is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of cable crossing devices, and in particular relates to a cable crossing device suitable for an airtight wellhead. Background Art

[0002] In an era of increasing energy scarcity, oil production is intensifying, and corresponding oil extraction technologies are developing rapidly. Currently, electric submersible pumps (ESPs) are the most widely used technology. Their operating principle is as follows: The ESP is lowered into the well along with the oil pipeline. A surface power source transmits electrical energy to a submersible motor downhole via a transformer, a control panel, and a submersible cable. The motor drives a multi-stage centrifugal pump, converting the electrical energy into mechanical energy, lifting the well fluid to the surface. The cable requires a cable pass-through to ensure its safety and sealing.

[0003] However, oil production is an ongoing process; interruptions can result in immeasurable losses. In the event of maintenance or other emergencies such as power outages, gas injection (gas lift) is required to lift the oil from the well to the surface. When using gas lift, the cable pass-through must be sealed to prevent gas leaks from causing a drop in downhole pressure or other safety incidents. During installation, the cable pass-through must pass through the upper flange, tubing hanger, and tubing spool, inevitably reducing the consistency of the seal. To address this, prior art typically installs multiple sealing rings, primarily O-rings, inside the tubing hanger and upper flange, creating a seal.

[0004] As can be seen from the above, the following technical problems usually exist in the existing technology: under the action of gas pressure, the O-ring is very easy to deform, resulting in a reduction in the sealing effect. In addition, as the deformation time increases, part of the elastic deformation of the O-ring will gradually transform into plastic deformation, which cannot be restored to its original state and is difficult to replace. Overall, the sealing method of the O-ring is not conducive to long-term use. Summary of the Invention

[0005] In view of this, the present invention is intended to provide a cable passing device suitable for an airtight wellhead, so as to solve the technical problems of large deformation and short service life of the sealing ring in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions:

[0007] A cable crossing device suitable for an airtight wellhead comprises, arranged in sequence from outside to inside, a tubing spool, a tubing hanger, and a cable crossing device. The tubing spool is provided with an upper flange on top. The cable crossing device comprises a crossing device housing. Sealing assemblies are provided along the height direction on the circumference of the cable crossing device. The sealing assemblies comprise, arranged in sequence from bottom to top, a first sealing assembly, a second sealing assembly, a third sealing assembly, and a fourth sealing assembly. The first and second sealing assemblies are used to achieve a seal between the cable crossing device and the tubing hanger. The third and fourth sealing assemblies are used to achieve a seal between the cable crossing device and the upper flange.

[0008] Furthermore, a second sleeve screw-in groove is formed on the top surface of the upper flange, the cable passer penetrates the second sleeve screw-in groove in a vertical direction and is located at the center of the second sleeve screw-in groove, the fourth sealing assembly falls into the bottom of the second sleeve screw-in groove, and a second sleeve is provided above the fourth sealing assembly, the second sleeve is sleeved on the outer periphery of the passer housing and the two are threadedly connected;

[0009] Furthermore, the fourth sealing assembly is composed of multiple sealing parts, including an upper retaining ring and a lower retaining ring arranged opposite to each other at the upper and lower ends, the outer end surfaces of the two retaining rings are both horizontal planes and the opposing surfaces of the two retaining rings are concave, a V-ring is arranged between the upper retaining ring and the lower retaining ring, the V-ring includes multiple first V-rings, the first V-ring opening faces downward, and its top surface fits with the concave surface of the upper retaining ring, a second V-ring of the same size is arranged between adjacent first V-rings, and a second O-ring for transition is provided between the first V-ring at the end and the lower retaining ring;

[0010] Furthermore, the number of the first V-shaped rings is 3, the number of the second V-shaped rings is 2, the material of the first V-shaped rings is polytetrafluoroethylene, and the material of the second V-shaped rings is hydrogenated nitrile rubber;

[0011] Furthermore, the top of the tubing hanger is provided with a first sleeve screw-in groove and a metal sealing ring installation groove which are connected and coaxial from top to bottom. The cable passer penetrates the first sleeve screw-in groove and the metal sealing ring installation groove in a central direction. The second sealing assembly includes a metal sealing ring and a first sleeve located above the metal sealing ring. The metal sealing ring falls into the metal sealing ring installation groove. The first sleeve is located in the first sleeve screw-in groove. The first sleeve is sleeved on the outer periphery of the passer housing and the two are threadedly connected.

[0012] Furthermore, the diameter of the metal sealing ring installation groove gradually decreases from top to bottom, forming an inwardly inclined slope, and the diameter of the portion of the through-device housing corresponding to the metal sealing ring installation groove gradually increases from top to bottom, forming an outwardly inclined slope. The above two together form a sealed space that is wide at the top and narrow at the bottom.

[0013] Furthermore, a first mounting groove adapted for the first sealing assembly is formed on the housing of the transit device, the first sealing assembly includes a first O-ring located in the first mounting groove, and an anti-deformation retaining ring is provided above the first O-ring in the first sealing assembly;

[0014] Furthermore, a second mounting groove adapted to the third sealing assembly is formed on the housing of the transmitter. The third sealing assembly includes a first O-ring located in the second mounting groove. Anti-deformation retaining rings are provided on both the upper and lower sides of the first O-ring in the third sealing assembly.

[0015] The beneficial effects of the present invention are:

[0016] (1) Compared with the prior art, by setting up the second sealing component, the first sleeve presses down the metal sealing ring, causing the metal sealing ring to deform laterally. At the same time, the inclined surfaces on both sides of the metal sealing ring limit the lateral deformation of the metal sealing ring to a certain extent, making the metal sealing ring fit more closely with the inclined surfaces on both sides, thereby ensuring the stability of the metal seal;

[0017] (2) The fourth sealing assembly is composed of multiple sealing parts. A sandwich structure is formed by arranging a second V-ring between adjacent first V-rings. The first V-ring and the second V-ring are made of two materials with different hardnesses. While ensuring that the sealing assembly has good wear resistance, it can also enable the sealing assembly to have a large deformation amount, thereby ensuring the sealing effect.

[0018] (3) The fourth sealing component is mainly made of flexible materials such as rubber, which is easy to install and will not cause the housing of the transmitter to deform during the installation process. In addition, by arranging the fourth sealing component on the top of the oil pipe four-way body, the high temperature and high pressure environment below can effectively prevent the fourth sealing component from being corroded, thereby ensuring that the fourth sealing component maintains good sealing performance and extends its service life; the second sealing component is mainly made of metal materials, which has good high temperature resistance, corrosion resistance and other properties, and the part of the transmitter housing corresponding to the metal sealing ring installation groove is thickened to prevent the transmitter housing from being deformed while further improving the sealing effect.

[0019] (4) By combining the second sealing component with the fourth sealing component, the service life of the sealing component can be effectively improved while ensuring the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention is described with the following drawings:

[0021] Figure 1 This is a cross-sectional view of a cable passing device suitable for an airtight wellhead in Example 1 of the present utility model;

[0022] Figure 2 for Figure 1 A magnified view of point A1 in the middle;

[0023] Figure 3 for Figure 2 A magnified view of point A2 in the middle;

[0024] Figure 4 for Figure 2 A magnified view of A3 in the middle;

[0025] Figure 5 for Figure 2 A magnified view of the A4 position in the middle;

[0026] Figure 6 for Figure 2 A magnified view of A5 in the middle;

[0027] Figure 7 Schematic diagram of the structure of the fourth sealing component in the first embodiment of the present invention.

[0028] The following are marked in the accompanying drawings:

[0029] Oil pipe spool 1, oil pipe spool body 11, accommodating chamber 111, upper flange 12, second sleeve screw-in groove 121, top screw assembly 13, second pressure test hole 14, third pressure test hole 15, oil pipe hanger 2, square sealing ring 21, first sleeve screw-in groove 22, metal sealing ring mounting groove 23, first pressure test hole 24, cable passer 3, passer housing 31, first mounting groove 311, second mounting groove 312, oil pipe 4, sealing assembly 5, first sealing assembly 51, first O-ring 511, anti-deformation retaining ring 512, second sealing assembly 52, metal sealing ring 521, first sleeve 522, third sealing assembly 53, fourth sealing assembly 54, upper retaining ring 541, lower retaining ring 542, V-ring 543, first V-ring 5431, second V-ring 5432, second O-ring 544, second sleeve 545. DETAILED DESCRIPTION

[0030] Example 1, see Figure 1-Figure 7 .

[0031] A cable crossing device suitable for an airtight wellhead comprises an oil pipe spool 1, an oil pipe hanger 2 and a cable crossing device 3 arranged in sequence from outside to inside. A sealing component 5 is arranged on the circumference of the cable crossing device 3 along the height direction.

[0032] like Figure 1As shown, the tubing spool 1 comprises a tubing spool body 11 and an upper flange 12 located at the top of the tubing spool body 11, which are detachably connected via threads. The tubing spool body 11 defines an interior cavity 111 for mounting a tubing hanger 2. A cable pass-through 3 and tubing 4 are threaded through the tubing hanger 2, which is inserted into the cavity 111 within the tubing spool body 11 and secured by the upper flange 12. Multiple square sealing rings 21 are provided around the tubing hanger 2, ensuring a seal between the tubing hanger 2 and the tubing spool body 11. Furthermore, the top of the tubing spool body 11 is equipped with multiple jackscrew assemblies 13, each with a conical inner end. The outer surface of the tubing hanger 2 is provided with retaining grooves that mate with the jackscrew assemblies 13. The jackscrew assemblies 13 are pushed inward to create close contact with the retaining grooves, further enhancing the seal between the tubing hanger 2 and the tubing spool body 11.

[0033] The cable passing device 3 is provided with a sealing component 5 on its peripheral side. Figure 1 As shown, the sealing assembly 5 includes a first sealing assembly 51, a second sealing assembly 52, a third sealing assembly 53 and a fourth sealing assembly 54 arranged in sequence from bottom to top. It should be explained in detail that the first sealing assembly 51 and the second sealing assembly 52 are used to achieve sealing between the cable passer 3 and the oil pipe hanger 2, and the third sealing assembly 53 and the fourth sealing assembly 54 are used to achieve sealing between the cable passer 3 and the upper flange 12.

[0034] like Figure 1 As shown, the cable passer 3 includes an external passer housing 31 with a circular cross-section. A first mounting groove 311 is formed on the passer housing 31, which is compatible with a first sealing assembly 51. The first sealing assembly 51 includes a first O-ring 511 positioned within the first mounting groove 311. The first O-ring 511 is deformed within the first mounting groove 311 by compression, thereby achieving a seal. In this embodiment, the passer housing 31 has three spaced-apart first mounting grooves 311, and the number of first sealing assemblies 51 is also three. It should be noted that when there are fewer than three first sealing assemblies 51, the sealing performance is insufficient and poor. When there are more than three first sealing assemblies 51, the installation process becomes more complicated and the number of first mounting grooves 311 on the passer housing 31 increases, reducing the structural strength of the passer housing 31. Therefore, by limiting the number of first sealing assemblies 51 to three, installation convenience is improved while ensuring sealing performance and maintaining the structural strength of the passer housing 31.

[0035] like Figure 2 、 Figure 4As shown, the top of the tubing hanger 2 is formed from top to bottom with a first sleeve screw-in groove 22 and a metal sealing ring installation groove 23, which are interconnected and coaxial. The cable passer 3 penetrates the first sleeve screw-in groove 22 and the metal sealing ring installation groove 23 in the central direction. The second sealing assembly 52 includes a metal sealing ring 521 and a first sleeve 522 located above the metal sealing ring 521. The metal sealing ring 521 is positioned within the metal sealing ring installation groove 23. The first sleeve 522 is located within the first sleeve screw-in groove 22. The first sleeve 522 is sleeved around the periphery of the passer housing 31 and the two are threadedly connected. When an external force is applied to screw the first sleeve 522 downward, the first sleeve 522 squeezes the metal sealing ring 521 during the downward movement, causing the metal sealing ring 521 to deform and fill the metal sealing ring installation groove 23, thereby achieving a metal seal.

[0036] It is worth emphasizing that in this embodiment, the diameter of the metal sealing ring installation groove 23 gradually decreases from top to bottom, forming an inwardly inclined slope, and the diameter of the portion of the through-hole housing 31 corresponding to the metal sealing ring installation groove 23 gradually increases from top to bottom, forming an outwardly inclined slope. The above two together form a sealed space that is wide at the top and narrow at the bottom. Figure 4 As shown, the cross section of the metal sealing ring 521 is wedge-shaped, and the inner and outer side surfaces of the lower end of the metal sealing ring 521 are respectively in contact with the housing 31 of the penetrator and the oil pipe hanger 2.

[0037] The first sleeve 522 presses down on the metal sealing ring 521, causing it to deform laterally. Simultaneously, the inclined surfaces on either side of the metal sealing ring 521 limit this lateral deformation to a certain extent, allowing the metal sealing ring 521 to fit more closely with the inclined surfaces, thereby ensuring the stability of the metal seal. It should be further emphasized that the portion of the cable pass-through housing 31 corresponding to the metal sealing ring mounting groove 23 is thickened to resist the extrusion force exerted on the cable pass-through housing 31 during the metal sealing process, thereby preventing deformation of the cable pass-through 3 and ensuring a stable sealing effect.

[0038] A first pressure test hole 24 is opened on the side wall of the tubing hanger 2 and is located between the first sealing assembly 51 and the second sealing assembly 52 . The sealing performance of the first sealing assembly 51 and the second sealing assembly 52 is tested through the first pressure test hole 24 .

[0039] After completing the relevant tests of the first pressure test hole 24, the entire oil pipe hanger 2 is placed into the accommodating cavity 111 inside the oil pipe spool body 11, and then the upper flange 12 is installed. A third sealing component 53 and a fourth sealing component 54 are provided between the cable pass-through 3 and the upper flange 12. Figure 5As shown, in this embodiment, the third sealing assembly 53 is constructed identically to the first sealing assembly 51. Specifically, a second mounting groove 312 is formed on the cable entry housing 31, adapted for the third sealing assembly 53. The third sealing assembly 53 includes a first O-ring 511 positioned within the second mounting groove 312. Extrusion causes the first O-ring 511 to deform within the second mounting groove 312, thereby achieving a seal between the cable entry 3 and the upper flange 12. Similarly, similar to the first sealing assembly 51, the third sealing assembly 53 is also provided in three sections. The reason for this has been explained in connection with the first sealing assembly 51 and will not be repeated here.

[0040] A second pressure test hole 14 is provided on the upper flange 12 . The second pressure test hole 14 is located between the second sealing assembly 52 and the third sealing assembly 53 and is communicated with the accommodating cavity 111 . The sealing performance of the second sealing assembly 52 and the third sealing assembly 53 is tested through the second pressure test hole 14 .

[0041] The top surface of the upper flange 12 defines a second sleeve threading slot 121. The cable passer 3 vertically penetrates this slot and is positioned at its center. The fourth sealing assembly 54 rests at the bottom of the second sleeve threading slot 121, above which is a second sleeve 545. This second sleeve 545 fits over the periphery of the passer housing 31 and is threadedly connected. By applying an external force to thread the second sleeve 545 downward, the second sleeve 545 compresses the fourth sealing assembly 54 during its downward movement, causing it to deform laterally, thereby filling the second sleeve threading slot 121 and achieving a seal.

[0042] like Figure 7 As shown, the fourth sealing assembly 54 is composed of multiple sealing components, including an upper retaining ring 541 and a lower retaining ring 542, which are arranged at opposite ends. The outer end surfaces of the two retaining rings are both horizontal, and the opposing surfaces of the two retaining rings are concave. A V-ring 543 is disposed between the upper retaining ring 541 and the lower retaining ring 542. The V-ring 543 includes multiple first V-rings 5431. The first V-rings 5431 open downward, and their top surfaces mate with the concave surface of the upper retaining ring 541. Second V-rings 5432 of the same size are disposed between adjacent first V-rings 5431. The openings of the first V-rings 5431 and the second V-rings 5432 face the same direction and are in close contact with each other. A second O-ring 544 is disposed between the first V-ring 5431 at the end and the lower retaining ring 542 for transition.

[0043] It's important to emphasize that, after comprehensive consideration of multiple factors, including the axial dimension, frictional resistance, and lip wear of the fourth seal 54, the number of first V-rings 5431 was determined to be three, while the number of second V-rings 5432 was determined to be two, to ensure optimal performance. Furthermore, the first V-ring 5431 is made of polytetrafluoroethylene (PTFE), while the second V-ring 5432 is made of hydrogenated nitrile butadiene rubber (HNBR). This indicates that the first V-ring 5431 has a higher hardness than the second V-ring 5432, meaning it is more wear-resistant than the second V-ring 5432. However, the second V-ring 5432 is more susceptible to deformation than the first V-ring 5431. Therefore, by placing the second V-ring 5432 between adjacent first V-rings 5431 to form a sandwich structure, the seal assembly not only possesses excellent wear resistance but also allows for greater deformation, thus ensuring effective sealing. In addition, the material of the second O-ring 544 is also hydrogenated nitrile rubber (HNBR), and the second O-ring 544 is easy to deform, thereby achieving a better transition effect.

[0044] A third pressure test hole 15 is formed on the top of the upper flange 12 . The third pressure test hole 15 is located between the third sealing assembly 53 and the fourth sealing assembly 54 . The sealing performance of the third sealing assembly 53 and the fourth sealing assembly 54 is tested through the third pressure test hole 15 .

[0045] During gas lift production, the cable pass-through 3 tends to slide upward under the influence of gas pressure. Consequently, the first O-ring 511 in the first sealing assembly 51 and the first O-ring 511 in the third sealing assembly 53 are susceptible to excessive deformation or even being squeezed out of the groove, causing damage to the first O-ring 511. Therefore, in this embodiment, firstly, an anti-deformation retaining ring 512 is provided above the first O-ring 511 in the first sealing assembly 51, and secondly, anti-deformation retaining rings 512 are provided on both the upper and lower sides of the first O-ring 511 in the third sealing assembly 53. The addition of the anti-deformation retaining rings 512 improves the seal's pressure-bearing capacity while preventing the first O-ring 511 from being squeezed out of the groove, thereby avoiding damage to the first O-ring 511.

[0046] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A cable crossing device suitable for an airtight wellhead, characterized in that: It includes an oil pipe spool, an oil pipe hanger and a cable passer which are arranged in sequence from the outside to the inside. An upper flange is provided on the top of the oil pipe spool. The cable passer includes a passer shell. A sealing assembly is provided on the circumference of the cable passer along the height direction. The sealing assembly includes a first sealing assembly, a second sealing assembly, a third sealing assembly and a fourth sealing assembly which are arranged in sequence from bottom to top. The first sealing assembly and the second sealing assembly are used to achieve sealing between the cable passer and the oil pipe hanger. The third sealing assembly and the fourth sealing assembly are used to achieve sealing between the cable passer and the upper flange.

2. The cable passing device suitable for an airtight wellhead according to claim 1, characterized in that: A second sleeve screw-in groove is provided on the top surface of the upper flange, the cable passer penetrates the second sleeve screw-in groove in the vertical direction and the cable passer is located at the center of the second sleeve screw-in groove, the fourth sealing assembly falls into the bottom of the second sleeve screw-in groove, and a second sleeve is provided above it. The second sleeve is sleeved on the outer periphery of the passer housing and the two are threadedly connected.

3. The cable passing device suitable for an airtight wellhead according to claim 2, characterized in that: The fourth sealing assembly is composed of multiple sealing parts, including an upper retaining ring and a lower retaining ring arranged opposite to each other at the upper and lower ends. The outer end surfaces of the above two retaining rings are both horizontal planes and the relative surfaces of the two retaining rings are concave. A V-ring is arranged between the upper retaining ring and the lower retaining ring. The V-ring includes multiple first V-rings, the opening of the first V-ring faces downward, and its top surface fits with the concave surface of the upper retaining ring. A second V-ring of the same size is arranged between adjacent first V-rings, and a second O-ring for transition is provided between the first V-ring at the end and the lower retaining ring.

4. The cable passing device suitable for an airtight wellhead according to claim 3, characterized in that: The number of the first V-shaped rings is 3, the number of the second V-shaped rings is 2, the material of the first V-shaped rings is polytetrafluoroethylene, and the material of the second V-shaped rings is hydrogenated nitrile rubber.

5. The cable passing device suitable for an airtight wellhead according to claim 1 or 4, characterized in that: The top of the oil pipe hanger is provided with a first sleeve screw-in groove and a metal sealing ring installation groove which are connected and coaxial from top to bottom. The cable passer penetrates the first sleeve screw-in groove and the metal sealing ring installation groove along the center direction. The second sealing assembly includes a metal sealing ring and a first sleeve located above the metal sealing ring, wherein the metal sealing ring falls into the metal sealing ring installation groove, the first sleeve is located in the first sleeve screw-in groove, and the first sleeve is sleeved on the outer periphery of the passer housing and the two are threadedly connected.

6. The cable passing device suitable for an airtight wellhead according to claim 5, characterized in that: The diameter of the metal sealing ring installation groove gradually decreases from top to bottom, forming an inward-inclined slope. The diameter of the part of the through-device shell corresponding to the metal sealing ring installation groove gradually increases from top to bottom, forming an outward-inclined slope. The above two together form a sealed space that is wide at the top and narrow at the bottom.

7. The cable passing device suitable for an airtight wellhead according to claim 1, characterized in that: A first mounting groove adapted to the first sealing assembly is formed on the housing of the transmitter. The first sealing assembly includes a first O-ring located in the first mounting groove. An anti-deformation retaining ring is provided above the first O-ring in the first sealing assembly.

8. The cable passing device suitable for an airtight wellhead according to claim 7, characterized in that: A second mounting groove adapted to the third sealing assembly is formed on the housing of the transmitter. The third sealing assembly includes a first O-ring located in the second mounting groove. Anti-deformation retaining rings are provided on both the upper and lower sides of the first O-ring in the third sealing assembly.

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