Cable penetrating device suitable for airtight wellhead

Abstract

The invention 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 invention 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 shortage, oil extraction has become more intense, and the corresponding oil extraction technology has also developed rapidly. At present, the electric submersible pump is the most commonly used technology. Its working principle is as follows: the electric submersible pump is lowered into the well together with the oil pipe, and the ground power supply transmits electrical energy to the submersible motor downhole through the transformer, control panel and submersible cable, so that the motor drives the multi-stage centrifugal pump to rotate, converting electrical energy into mechanical energy, and lifting the well fluid in the oil well to the ground. Among them, the cable needs to be used with a cable crosser to ensure the safety and sealing of the cable.

[0003] However, oil production is a continuous process. If it is interrupted, it will cause immeasurable losses. When encountering maintenance or other emergencies such as power outages, it is necessary to inject gas (gas lift oil production) to lift the underground oil to the ground. When using the gas lift oil production method, it is necessary to ensure the sealing of the cable pass-through around the side to prevent gas leakage from causing a decrease in downhole pressure or causing other safety accidents. During the actual installation process, the cable pass-through needs to pass through the upper flange, the oil pipe hanger and the oil pipe four-way, which inevitably reduces the continuity of the seal. In this regard, in the prior art, multiple sealing rings are usually set inside the oil pipe hanger and the upper flange. The sealing ring is mainly an O-ring, and sealing is performed through multiple sealing rings.

[0004] From the above, it can be seen that the prior art usually has the following technical problems: under the action of gas pressure, the O-ring is very easy to deform, resulting in reduced sealing effect. In addition, as the deformation time increases, part of the elastic deformation of the O-ring will gradually turn 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 intends to provide a cable crossing 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 object, the present invention provides the following technical solutions: A cable crossing device suitable for an airtight wellhead comprises an oil pipe spool, an oil pipe hanger and a cable crossing device arranged in sequence from outside to inside, an upper flange is arranged on the top of the oil pipe spool, the cable crossing device comprises a crossing device housing, a sealing assembly is arranged on the circumference of the cable crossing device along the height direction, the sealing assembly comprises a first sealing assembly, a second sealing assembly, a third sealing assembly and a fourth sealing assembly arranged in sequence from bottom to top, the first sealing assembly and the second sealing assembly are used to achieve sealing between the cable crossing device and the oil pipe hanger, and the third sealing assembly and the fourth sealing assembly are used to achieve sealing between the cable crossing device and the upper flange; Furthermore, 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, a second sleeve is provided above the fourth sealing assembly, the second sleeve is sleeved on the periphery of the passer housing and the two are threadedly connected; Further, the fourth sealing assembly is composed of a plurality of sealing members, including an upper retaining ring and a lower retaining ring which are 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 opposite surfaces of the two retaining rings are concave, a V-shaped ring is arranged between the upper retaining ring and the lower retaining ring, the V-shaped ring includes a plurality of first V-shaped rings, the first V-shaped ring opening is downward, and the top surface thereof is in contact with the concave surface of the upper retaining ring, a second V-shaped ring of the same size is arranged between adjacent first V-shaped rings, and a second O-shaped ring for transition is arranged between the first V-shaped ring at the end and the lower retaining ring; Further, 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; Furthermore, 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, the first sleeve is sleeved on the periphery of the passer housing and the two are threadedly connected; Furthermore, the diameter of the metal sealing ring installation groove decreases gradually from top to bottom, forming an inwardly inclined slope, and the diameter of the portion of the traverser housing corresponding to the metal sealing ring installation groove increases gradually from top to bottom, forming an outwardly inclined slope, and the above two together form a sealing space that is wide at the top and narrow at the bottom; Furthermore, a first installation groove adapted to the first sealing assembly is formed on the housing of the traverser, the first sealing assembly includes a first O-ring located in the first installation groove, and an anti-deformation retaining ring is arranged above the first O-ring in the first sealing assembly; Furthermore, a second installation groove adapted to the third sealing assembly is formed on the housing of the transmitter, and the third sealing assembly includes a first O-ring located in the second installation groove, and anti-deformation retaining rings are provided on both upper and lower sides of the first O-ring in the third sealing assembly.

[0007] The beneficial effects of the present invention are: (1) Compared with the prior art, by providing the second sealing assembly, 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, so that the metal sealing ring fits more closely with the inclined surfaces on both sides, thereby ensuring the stability of the metal seal; (2) The fourth sealing assembly is composed of a plurality of 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, the sealing assembly can also have a large deformation amount to ensure the sealing effect. (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 at 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 and further improve the sealing effect.

[0008] (4) By using the second sealing component in combination 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

[0009] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration: Figure 1 It is a cross-sectional view of a cable crossing device suitable for an airtight wellhead in Embodiment 1 of the present invention; Figure 2 for Figure 1 The enlarged view of A1 in the middle; Figure 3 for Figure 2 The enlarged view of A2 in the middle; Figure 4 for Figure 2 The enlarged view of A3 in the middle; Figure 5 for Figure 2The enlarged view of the A4 position in the middle; Figure 6 for Figure 2 The enlarged view of A5 in the middle; Figure 7 It is a schematic structural diagram of the fourth sealing assembly in the first embodiment of the present invention.

[0010] The following are marked in the accompanying drawings: Oil pipe cross 1, oil pipe cross 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 installation groove 23, first pressure test hole 24, cable passer 3, passer housing 31, first installation groove 311, second installation 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

[0011] Embodiment 1, see Figure 1-Figure 7 .

[0012] 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 which are 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.

[0013] like Figure 1 As 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 by threads. The tubing spool body 11 is provided with a receiving chamber 111 for installing the tubing hanger 2. The tubing hanger 2 is provided with a cable passer 3 and tubing 4, and the tubing hanger 2 falls into the receiving chamber 111 inside the tubing spool body 11 and is pressed and fixed by the upper flange 12. A plurality of square sealing rings 21 are provided on the circumference of the tubing hanger 2, so as to achieve sealing between the outer wall of the tubing hanger 2 and the tubing spool body 11. In addition, a plurality of top screw assemblies 13 are provided at the top of the tubing spool body 11, and the inner end of the top screw assemblies 13 is a conical surface, and a limiting groove matching the top screw assembly 13 is provided on the outer surface of the tubing hanger 2, and the top screw assembly 13 is pushed inward to be in close contact with the limiting groove, thereby further improving the sealing between the tubing hanger 2 and the tubing spool body 11.

[0014] A sealing assembly 5 is provided on the peripheral side of the cable pass-through 3. Figure 1As 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 which are 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 the 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 the sealing between the cable passer 3 and the upper flange 12.

[0015] like Figure 1 As shown, the cable passer 3 includes an external passer housing 31, the cross section of the passer housing 31 is a circle, a first installation groove 311 adapted to the first sealing component 51 is formed on the passer housing 31, and the first sealing component 51 includes a first O-ring 511 located in the first installation groove 311, and the first O-ring 511 is deformed in the first installation groove 311 by extrusion to achieve sealing. In this embodiment, three spaced first installation grooves 311 are formed on the passer housing 31, and the number of first sealing components 51 corresponding thereto is also three. It should be noted that when the number of first sealing components 51 is less than three, its sealing performance is insufficient and the sealing effect is poor. When the number of first sealing components 51 is greater than three, the complexity of the installation process is increased and the number of first installation grooves 311 on the passer housing 31 increases accordingly, which reduces the structural strength of the passer housing 31. Therefore, by limiting the number of first sealing components 51 to three, the convenience of installation can be improved while ensuring the sealing performance and the structural strength of the passer housing 31 can be ensured.

[0016] like Figure 2 , Figure 4 As shown, the top of the oil pipe hanger 2 is provided with a first sleeve screw-in groove 22 and a metal sealing ring installation groove 23 which are connected and coaxial from top to bottom, and the cable passer 3 penetrates the first sleeve screw-in groove 22 and the metal sealing ring installation groove 23 in the center direction. The second sealing assembly 52 includes a metal sealing ring 521 and a first sleeve 522 located above the metal sealing ring 521, wherein the metal sealing ring 521 falls into the metal sealing ring installation groove 23, the first sleeve 522 is located in the first sleeve screw-in groove 22, and the first sleeve 522 is sleeved on the periphery of the passer housing 31 and the two are threadedly connected. Apply external force to screw the first sleeve 522 downward, and the first sleeve 522 squeezes the metal sealing ring 521 during the downward movement, so that the metal sealing ring 521 is deformed, thereby filling the metal sealing ring installation groove 23 to achieve metal sealing.

[0017] 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-device housing 31 corresponding to the metal sealing ring installation groove 23 gradually increases from top to bottom, forming an outwardly inclined slope, and 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 penetrator housing 31 and the oil pipe hanger 2.

[0018] The first sleeve 522 presses down the metal sealing ring 521, and the metal sealing ring 521 is deformed laterally. At the same time, the inclined surfaces on both sides of the metal sealing ring 521 limit the lateral deformation of the metal sealing ring 521 to a certain extent, so that the metal sealing ring 521 fits more closely with the inclined surfaces on both sides, ensuring the stability of the metal seal. It should be further emphasized that the part of the transceiver housing 31 corresponding to the metal sealing ring installation groove 23 is thickened to resist the extrusion force on the transceiver housing 31 during the metal sealing process, thereby preventing the cable transceiver 3 from being deformed and facilitating the sealing effect.

[0019] A first pressure test hole 24 is opened on the side wall of the oil pipe hanger 2 . The first pressure test hole 24 is located between the first sealing component 51 and the second sealing component 52 . The sealing performance of the first sealing component 51 and the second sealing component 52 is tested through the first pressure test hole 24 .

[0020] 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 arranged between the cable pass-through 3 and the upper flange 12. Figure 5 As shown, in this embodiment, the third sealing assembly 53 is constructed in the same manner as the first sealing assembly 51, that is, a second mounting groove 312 adapted to the third sealing assembly 53 is formed on the housing 31 of the cable pass-through device, and the third sealing assembly 53 includes a first O-ring 511 located in the second mounting groove 312, and the first O-ring 511 is deformed in the second mounting groove 312 by extrusion, thereby achieving sealing between the cable pass-through device 3 and the upper flange 12. Similarly, similar to the first sealing assembly 51, the number of the third sealing assembly 53 is also set to 3, and the reason for this has been explained in the first sealing assembly 51, so it will not be repeated.

[0021] 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 connected to 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 .

[0022] The top surface of the upper flange 12 is provided with a second sleeve screw-in groove 121, and the cable passer 3 vertically penetrates the second sleeve screw-in groove 121 and is located at the center of the second sleeve screw-in groove 121. The fourth sealing component 54 falls into the bottom of the second sleeve screw-in groove 121, and a second sleeve 545 is provided above it. The second sleeve 545 is sleeved on the periphery of the passer housing 31 and the two are threadedly connected. By applying an external force to screw the second sleeve 545 downward, the second sleeve 545 squeezes the fourth sealing component 54 during the downward movement to cause it to deform laterally, thereby filling the second sleeve screw-in groove 121 and achieving a sealing effect.

[0023] like Figure 7 As shown, the fourth sealing assembly 54 is composed of a plurality of sealing parts, including an upper retaining ring 541 and a lower retaining ring 542 which are 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 opposite surfaces of the two retaining rings are concave. A V-shaped ring 543 is arranged between the upper retaining ring 541 and the lower retaining ring 542. The V-shaped ring 543 includes a plurality of first V-shaped rings 5431. The opening of the first V-shaped ring 5431 faces downward, and its top surface is in contact with the concave surface of the upper retaining ring 541. A second V-shaped ring 5432 of the same size is arranged between adjacent first V-shaped rings 5431. The openings of the first V-shaped ring 5431 and the second V-shaped ring 5432 face the same direction and are in close contact with each other. A second O-shaped ring 544 for transition is arranged between the first V-shaped ring 5431 at the end and the lower retaining ring 542.

[0024] It should be emphasized that, after comprehensive consideration of the axial dimension, friction resistance, lip wear and other factors of the fourth seal 54, the number of first V-rings 5431 is finally determined to be 3 and the number of second V-rings 5432 is 2, so as to ensure the best working performance of the fourth seal. In addition, the material of the first V-ring 5431 is polytetrafluoroethylene (PTFE), and the material of the second V-ring 5432 is hydrogenated nitrile rubber (HNBR). It can be seen that the hardness of the first V-ring 5431 is higher than that of the second V-ring 5432, that is, the wear resistance of the first V-ring 5431 is stronger than that of the second V-ring 5432, but the second V-ring 5432 is more likely to deform than the first V-ring 5431. Therefore, by arranging the second V-ring 5432 between adjacent first V-rings 5431 to form a sandwich structure, the sealing component can be ensured to have good wear resistance while also having a larger deformation amount to ensure the sealing effect. 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.

[0025] A third pressure test hole 15 is provided at 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 .

[0026] During the gas lift oil production process, the cable pass-through 3 will tend to slide upward under the action of gas pressure. Therefore, the first O-ring 511 in the first sealing component 51 and the first O-ring 511 in the third sealing component 53 are prone 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 component 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 component 53. By adding the anti-deformation retaining ring 512, the sealing pressure bearing capacity is improved while preventing the first O-ring 511 from being squeezed out of the groove, thereby avoiding damage to the first O-ring 511.

[0027] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. 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 crosser 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 crosser includes a crosser shell. A sealing assembly is arranged on the circumference of the cable crosser 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 crosser and the oil pipe hanger. The third sealing assembly and the fourth sealing assembly are used to achieve sealing between the cable crosser and the upper flange.

2. The cable crossing 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 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, a second sleeve is provided above it, and the second sleeve is sleeved on the periphery of the passer housing and the two are threadedly connected.

3. The cable crossing 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, and the first V-ring opens downward, and its top surface is in contact 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 arranged between the first V-ring at the end and the lower retaining ring.

4. The cable crossing 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 crossing 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 crossing 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 inwardly inclined slope. The diameter of the part of the penetration device shell 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 sealing space that is wide at the top and narrow at the bottom.

7. The cable crossing device suitable for an airtight wellhead according to claim 1, characterized in that: A first installation groove matched with the first sealing component is formed on the housing of the transmitter. The first sealing component includes a first O-ring located in the first installation groove. An anti-deformation retaining ring is arranged above the first O-ring in the first sealing component.

8. The cable crossing device suitable for an airtight wellhead according to claim 7, characterized in that: A second installation groove matched with 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 installation groove. Anti-deformation retaining rings are provided on both upper and lower sides of the first O-ring in the third sealing assembly.

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