Plugging and repairing method for oil-filled submarine cable

Abstract

The invention relates to a plugging and repairing method for an oil-filled submarine cable. Comprising the following steps: stripping an outer protective layer of a section where a leakage point of the oil-filled submarine cable is located to expose an armor layer; a main shell of the oil-filled submarine cable plugging device is arranged outside an armor layer of a section where a leakage point of an oil-filled submarine cable is located in a sleeving mode, so that a sealing assembly in the main shell divides a space between the main shell and the oil-filled submarine cable into an oil drainage area and at least one sealing area located on the two sides of the oil drainage area in the axial direction of the main shell; the leakage point is located in the oil drainage area; an oil discharge valve located on the lower side of the oil drainage area is opened; injecting glue into each sealing area until the sealing areas are filled with the glue; waiting for solidification of the glue; and closing the oil discharge valve. According to the oil-filled submarine cable blocking and repairing method, leakage of the oil-filled submarine cable can be blocked on the premise that the armor layer is not damaged.

Description

Technical Field

[0001] The present application relates to the technical field of oil-filled submarine cable repair, and in particular to a method for sealing and repairing an oil-filled submarine cable. Background Art

[0002] Oil-filled submarine cable is a submarine cable that uses insulating oil as a pressurized fluid and allows the insulating oil to flow freely in the cable. When the oil-filled submarine cable is damaged, the insulating oil inside the cable will leak, which will not only pollute the seawater, but also affect the stable operation of the power grid system.

[0003] Currently, there are many ways to repair oil-filled submarine cables, including splicing repair, water-blocking repair and plugging repair. Among them, plugging repair is to form a physical plug on the outside of the damaged point without repairing the main body. Plugging repair has the technical advantages of being simple, fast and low-cost.

[0004] Currently, the plugging and repairing methods for oil-filled submarine cables mostly refer to the plugging and repairing methods for submarine oil and gas pipelines. However, the traditional plugging and repairing methods for submarine oil and gas pipelines are not ideal for the plugging and repairing of oil-filled submarine cables. Summary of the invention

[0005] Based on this, it is necessary to provide a method for plugging and repairing oil-filled submarine cables in order to improve the plugging and repairing effect of oil-filled submarine cables leakage.

[0006] The present application provides a method for plugging and repairing an oil-filled submarine cable, comprising the following steps:

[0007] The outer sheath of the oil-filled submarine cable at the leakage point is peeled off to expose the armor layer;

[0008] The main shell of the oil-filled submarine cable plugging device is sleeved outside the armor layer of the section where the leakage point of the oil-filled submarine cable is located, so that the sealing component in the main shell divides the space between the main shell and the oil-filled submarine cable into an oil leakage area and at least one sealing area respectively located on both sides of the oil leakage area along the axial direction of the main shell, and the leakage point is located in the oil leakage area;

[0009] Opening the oil drain valve located at the lower side of the oil drain area;

[0010] Injecting glue into each of the sealing areas until the glue fills the sealing area;

[0011] Waiting for the glue to cure;

[0012] Close the oil drain valve.

[0013] The technical solution is further described below:

[0014] In one embodiment, the step of injecting glue into each of the sealing areas until the glue fills the sealing area comprises:

[0015] Connecting the glue injection valve located at the lower side of the sealing area to the glue injection system;

[0016] Open the glue injection valve and the glue discharge valve located on the upper side of the sealing area;

[0017] The glue injection system injects glue into the sealing area at a first preset pressure through the glue injection valve;

[0018] When the glue discharge valve continues to discharge the glue for a first period of time, closing the glue discharge valve;

[0019] After the glue injection system continuously maintains the pressure of the sealing area at the second preset pressure for a second period of time, the glue injection valve is closed.

[0020] In one embodiment, the glue includes a high permeability agent and a low permeability agent, and the glue injection system injects glue into the sealing area through the glue injection valve at the first preset pressure; when the glue discharge valve continuously flows out the glue for a first time period, the glue discharge valve is closed; after the glue injection system continuously maintains the pressure of the sealing area at the second preset pressure for a second time period, the steps of closing the glue injection valve include:

[0021] The glue injection system first injects the high permeability agent into the sealing area at the first preset pressure;

[0022] When the high permeability agent continues to flow out of the glue discharge valve for the first period of time, closing the glue discharge valve;

[0023] The glue injection system continuously maintains the pressure of the sealing area at the second preset pressure for the second time period, and then opens the glue discharge valve;

[0024] The glue injection system then injects the low permeability agent into the sealing area at the first preset pressure;

[0025] When the low-permeability agent continues to flow out of the glue discharge valve for the first period of time, closing the glue discharge valve;

[0026] The glue injection system maintains the sealing area under pressure at the second preset pressure for the second period of time and then closes the glue injection valve.

[0027] In one embodiment, the first preset pressure ranges from 0.2Mpa to 0.4Mpa; and / or the second preset pressure ranges from 0.5Mpa to 1Mpa.

[0028] In one embodiment, the first time period is 10s-15s; and / or the second time period is 1min-3min.

[0029] In one embodiment, the high permeability agent is fluorosilicone rubber, organic silica gel or polyurethane glue; and / or the low permeability agent is fluorosilicone rubber or silicone rubber.

[0030] In one embodiment, the step of waiting for the glue to solidify comprises:

[0031] The time for waiting for the glue to cure is greater than or equal to 4 hours.

[0032] In one embodiment, the step of closing the oil drain valve further includes the following steps:

[0033] Check the leakage of oil-filled submarine cables;

[0034] If leakage still occurs, connecting shells are installed at both ends of the main shell, so that the connecting shells are sleeved outside the armor layer of the oil-filled submarine cable, and the space between the connecting shells and the oil-filled submarine cable forms a sealing area;

[0035] Injecting glue into the sealing area of ​​the connection housing until the glue fills the sealing area;

[0036] Wait for the glue in the connection shell to solidify.

[0037] In one embodiment, after the step of waiting for the glue in the connection housing to solidify, the following steps are also included:

[0038] Check the leakage of the oil-filled submarine cable again;

[0039] If leakage still occurs, another connection shell is installed at the end of the connection shell away from the main shell;

[0040] Injecting glue into the sealing area of ​​the added connection housing until the glue fills the sealing area;

[0041] Wait for the glue in the installed connection shell to solidify.

[0042] In one embodiment, before the step of injecting glue into each of the sealing areas until the glue fills the sealing area, the oil-filled submarine cable plugging and repairing method further includes:

[0043] Connecting the glue injection valve located at the lower side of the sealing area to the cleaning system;

[0044] Open the glue injection valve and the glue discharge valve located on the upper side of the sealing area;

[0045] The cleaning system introduces dry air into the sealing area through the glue injection valve to clean the insulating oil and seawater in the sealing area;

[0046] Close the glue discharge valve and the glue injection valve in sequence, and disconnect the cleaning system from the glue injection valve.

[0047] The above-mentioned plugging and repairing method for the oil-filled submarine cable is centered, by first peeling off the outer sheath of the section where the leakage point of the oil-filled submarine cable is located to expose the armor layer, and then arranging a main shell outside the armor layer, so that the sealing component in the main shell divides the space between the main shell and the oil-filled submarine cable into an oil leakage area and at least one sealing area on both sides of the oil leakage area, and at the same time, the leakage point is located in the oil leakage area, so that the leaked insulating oil can be discharged from the oil leakage area through the oil discharge valve, greatly reducing the possibility of insulating oil leakage to the sealing area, thereby preventing the glue in the sealing area from being washed away by the oil, ensuring the stability of the subsequent glue injection process into the sealing area, so that the glue injection can be carried out simultaneously during the oil discharge process, thereby improving the efficiency of plugging and repairing. At the same time, by applying glue to the sealing area with a certain pressure, the glue can penetrate to the outside of the PE layer along the copper strip gaps in the armor layer and the gaps between the armor layer and the PE layer under pressure to fill the copper strip gaps in the armor layer and the gaps between the armor layer and the PE layer, thereby avoiding the possibility of axial leakage of insulating oil along the copper strip gaps in the armor layer and the gaps between the armor layer and the PE layer, thereby achieving leakage sealing of the oil-filled submarine cable outside the PE layer without damaging the armor layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application.

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] In addition, the drawings are not drawn to a 1:1 scale, and the relative sizes of the various elements are drawn only as examples in the drawings and are not necessarily drawn according to the true scale.

[0051] Figure 1 The figure is a schematic structural diagram of an oil-filled submarine cable according to an embodiment.

[0052] Figure 2 The present invention is a schematic structural diagram of an oil-filled submarine cable plugging and repairing device according to one embodiment.

[0053] Figure 3It is a cross-sectional view of an oil-filled submarine cable plugging and repairing device according to one embodiment.

[0054] Figure 4 The present invention is a schematic flow chart of a method for plugging and repairing an oil-filled submarine cable according to an embodiment of the present invention.

[0055] Description of reference numerals:

[0056] 10. Oil-filled submarine cable; 11. Oil channel; 12. Conductor layer; 13. Insulation layer; 14. Lead sheath; 15. First non-woven fabric layer; 16. PE layer; 17. Second non-woven fabric layer; 18. Armor layer; 21. Main shell; 211. First half shell; 212. Second half shell; 213. Oil leakage area; 214. Sealing area; 22. Sealing assembly; 221. Sealing strip; 222. Ring sealing gasket; 23. Oil drain valve; 251. Glue injection valve; 252. Glue discharge valve; 30. Connection shell. DETAILED DESCRIPTION

[0057] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0058] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0059] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0060] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0061] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0062] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0063] As mentioned above, the traditional plugging and repairing method for submarine oil and gas pipelines is not ideal for plugging and repairing the oil-filled submarine cable 10. After extensive research, the inventors found that the reason is that the structure of the oil-filled submarine cable 10 is very different from that of the submarine oil and gas pipeline. Figure 1 The through-groove oil-filled submarine cable 10 includes an oil channel 11, a conductor layer 12, an insulating layer 13, a lead sheath 14, a first non-woven fabric layer 15, a PE layer 16, a second non-woven fabric layer 17, an armor layer 18, and an outer sheath (not shown) which are sequentially arranged from the inside to the outside. The gaps between the armor layer 18, the PE layer 16, and the outer sheath are relatively large, and the armor layer 18 is a cylindrical structure composed of a plurality of copper bars closely arranged along the circumferential direction, and there are also axial gaps between the copper bars. Therefore, when the oil-filled submarine cable 10 is damaged and the insulating oil inside the oil channel 11 leaks to the outside of the oil-filled submarine cable 10, the insulating oil can leak axially between the armor layer 18, the PE layer 16 and the outer sheath, and between the gaps between the copper bars of the armor layer 18.

[0064] The current plugging and repairing method cannot plug the gaps between the armor layer 18, the PE layer 16 and the outer sheath, and cannot solve the axial leakage problem of the oil-filled submarine cable 10. To achieve plugging, the submarine cable armor layer 18 can only be destroyed and plugging can be implemented from the surface of the submarine cable PE layer 16. After the submarine cable armor layer 18 is damaged, the oil-filled submarine cable 10 will lose the ability to withstand tensile loads. Considering the actual working conditions of the oil-filled submarine cable 10, the axial load of the oil-filled submarine cable 10 is inevitable. Therefore, it is urgent to develop a method for effectively plugging the leakage of insulating oil in the oil-filled submarine cable 10.

[0065] Based on this, an embodiment of the present application provides a method for plugging and repairing an oil-filled submarine cable 10, which is used to solve the axial leakage problem of the oil-filled submarine cable 10 without damaging the submarine cable armor layer 18. First, in order to better understand the technical solution of the present application, a plugging and repairing device for an oil-filled submarine cable 10 used in the plugging and repairing method for an oil-filled submarine cable 10 is briefly introduced in one embodiment. Specifically, see Figure 2 as well as Figure 3 The plugging and repairing device of the oil-filled submarine cable 10 of one embodiment comprises a main housing 21 and a sealing assembly 22, wherein the main housing 21 is used to be sleeved on the section where the leakage point of the oil-filled submarine cable 10 is located. The sealing assembly 22 is arranged in the main housing 21, and the sealing assembly 22 is used to separate the space between the main housing 21 and the oil-filled submarine cable 10 into an oil leakage area 213 corresponding to the leakage point and at least one sealing area 214 located on both sides of the oil leakage area 213 along the axial direction of the main housing 21, wherein the oil leakage area 213 is connected with an oil drain valve 23, and illustratively, two drain valves are provided, and one of the drain valves is located at the lower side of the oil leakage area 213. Each sealing area 214 is provided with a glue injection valve 251 and a glue discharge valve 252, and the glue injection valve 251 and the glue discharge valve 252 are arranged opposite to each other along the radial direction of the main housing 21, and the glue injection valve 251 is located below the glue discharge valve 252.

[0066] Specifically, see Figure 4 A method for plugging and repairing an oil-filled submarine cable 10 according to an embodiment of the present invention comprises the following steps:

[0067] S110: peeling off the outer sheath of the section where the leakage point of the oil-filled submarine cable 10 is located to expose the armor layer 18;

[0068] S120: The main housing 21 is sleeved outside the armor layer 18 of the section where the leakage point of the oil-filled submarine cable 10 is located, so that the sealing assembly 22 in the main housing 21 divides the space between the main housing 21 and the oil-filled submarine cable 10 into an oil leakage area 213 and at least one sealing area 214 located on both sides of the oil leakage area 213 along the axial direction of the main housing 21, and the leakage point is located in the oil leakage area 213;

[0069] Specifically, see Figure 1In one embodiment, the main housing 21 includes a first half shell 211 and a second half shell 212. The first half shell 211 and the second half shell 212 are connected to each other and together enclose a cylindrical structure. During installation, the first half shell 211 and the second half shell 212 are relatively sheathed on the section where the leakage point of the oil-filled submarine cable 10 is located. Then the first half shell 211 and the second half shell 212 are locked together to complete the installation of the main housing 21.

[0070] , combined with Figure 2 The sealing assembly 22 includes a sealing strip 221 and at least two annular sealing gaskets 222. The sealing strip 221 is arranged in the joint gap between the first half shell 211 and the second half shell 212, so as to seal the joint gap between the first half shell 211 and the second half shell 212 to prevent insulating oil or glue from leaking therefrom. Further, all the annular sealing gaskets 222 are arranged between the main shell 21 and the oil-filled submarine cable 10 along the axial direction of the main shell 21 at intervals and are sealed with the main shell 21 and the oil-filled submarine cable 10 to separate the space between the main shell 21 and the oil-filled submarine cable 10 to form an oil leakage area 213 and at least one sealing area 214 located on both sides of the oil leakage area 213.

[0071] S130: Open the oil drain valve 23 located at the lower side of the oil drain area 213;

[0072] Specifically, the oil drain area 213 is connected to two oil drain valves 23, which are arranged opposite to each other along the radial direction of the main housing 21. When draining the oil, the lower oil drain valve 23 is opened. Since the density of insulating oil is smaller than that of seawater, the seawater can be drained while draining the insulating oil.

[0073] S140: injecting glue into each sealing area 214 until the glue fills the sealing area 214;

[0074] Specifically, glue may be injected into the sealing area 214 through an underwater glue injection system.

[0075] S150: Wait for the glue to cure;

[0076] S160: Close the oil drain valve 23.

[0077] The above-mentioned plugging and repairing method of the oil-filled submarine cable 10 is centered, by first peeling off the outer sheath of the section where the leakage point of the oil-filled submarine cable 10 is located to expose the armor layer 18, and then arranging the main shell 21 outside the armor layer 18, so that the sealing component 22 in the main shell 21 divides the space between the main shell 21 and the oil-filled submarine cable 10 into an oil leakage area 213 and at least one sealing area 214 located on both sides of the oil leakage area 213, and at the same time, the leakage point is located in the oil leakage area 213, so that the leaked insulating oil can be discharged from the oil leakage area 213 through the oil discharge valve 23, greatly reducing the possibility of insulating oil leaking into the sealing area 214, thereby preventing the glue in the sealing area 214 from being washed away by the oil, ensuring the stability of the subsequent glue injection process into the sealing area 214, so that the glue injection can be carried out simultaneously during the oil discharge process, thereby improving the efficiency of plugging and repairing. At the same time, by applying glue to the sealing area 214 with a certain pressure, the glue can penetrate into the outside of the PE layer 16 along the copper strip gaps of the armor layer 18 and the gap between the armor layer 18 and the PE layer 16 under pressure to fill the copper strip gaps of the armor layer 18 and the gap between the armor layer 18 and the PE layer 16, thereby avoiding the possibility of axial leakage of insulating oil along the copper strip gaps of the armor layer 18 and the gap between the armor layer 18 and the PE layer 16, thereby achieving leakage sealing of the oil-filled submarine cable 10 outside the PE layer 16 without damaging the armor layer 18.

[0078] In one embodiment, the steps of step S140 include the following steps:

[0079] S141: Connecting the glue injection valve 251 located at the lower side of the sealing area 214 to the glue injection system;

[0080] S142: Open the glue injection valve 251 and the glue discharge valve 252 located on the upper side of the sealing area 214;

[0081] S143: The glue injection system injects glue into the sealing area 214 at a first preset pressure through the glue injection valve 251;

[0082] Specifically, each sealing area 214 is provided with a glue injection valve 251 and a glue discharge valve 252, and the glue injection valve 251 and the glue discharge valve 252 are arranged opposite to each other along the radial direction of the main shell 21, and the glue injection valve 251 is located below the glue discharge valve 252. The glue injection system injects glue into the sealing area 214 from bottom to top through the glue injection valve 251. Since the density of the sealant is greater than the density of seawater, the glue is injected from bottom to top, which can ensure that the seawater in the sealing area 214 can be discharged from the glue discharge valve.

[0083] Exemplarily, in one embodiment, the first preset pressure is in the range of 0.2Mpa-0.4Mpa. Specifically, if the first preset pressure is too small, the glue cannot be injected into the sealing area 214, and if the first preset pressure is too large, it is easy to exceed the safe pressure range of the oil-filled submarine cable 10 and increase the cost. By configuring the range of the first preset pressure to be 0.2Mpa-0.4Mpa, it is ensured that the glue can be smoothly injected into the sealing area 214 at a lower cost.

[0084] S144: When the glue discharge valve 252 continues to flow out glue for a first period of time, the glue discharge valve 252 is closed;

[0085] For example, in one embodiment, the first time period is 10s-15s. When the glue discharge valve 252 continues to discharge glue for 10s-15s, it means that the sealing area 214 has been filled with glue, ensuring that all seawater is discharged, thereby improving the plugging effect of the glue in the sealing area 214.

[0086] S145: After the glue injection system maintains the pressure of the sealing area 214 at the second preset pressure for a second period of time, the glue injection valve 251 is closed.

[0087] Specifically, after closing the glue discharge valve 252, by continuing to maintain the pressure in the sealing area 214 for a period of time, it can be ensured that the glue fully penetrates into the copper strip gaps of the armor layer 18 and the gaps between the armor layer 18 and the PE layer 16 to fill the copper strip gaps of the armor layer 18 and the gaps between the armor layer 18 and the PE layer 16, thereby avoiding the possibility of axial leakage of insulating oil along the copper strip gaps of the armor layer 18 and the gaps between the armor layer 18 and the PE layer 16, and at the same time ensuring that the sealing area 214 still has a large internal pressure after the glue is cured, thereby improving the sealing effect.

[0088] Exemplarily, in one embodiment, the range of the second preset pressure is 0.5Mpa-1Mpa. Specifically, after the plugging device of the oil-filled submarine cable 10 is installed, it will have a certain squeezing effect on the oil-filled submarine cable 10. In order to ensure that the external pressure applied to the oil-filled submarine cable 10 is within its safe bearing range, it is necessary to analyze the safe pressure-bearing stability range of the oil-filled submarine cable 10 through theory and experiments. According to simulation analysis, when the external pressure applied to the oil-filled submarine cable 10 is 2MPa, the maximum equivalent stress of the PE layer 16 of the oil-filled submarine cable 10 exceeds the yield limit of the material. At this time, the PE layer 16 of the oil-filled submarine cable 10 may yield. At the same time, according to experimental analysis, when the radially uneven pressure of the oil-filled submarine cable 10 reaches 2.0MPa, the lead sheath 14 of the oil-filled submarine cable 10 will reach the yield limit and deform. Therefore, the inventor of the present application combines theoretical and experimental analysis to set the upper limit of the second preset pressure to no more than 1Mpa. At the same time, if the second preset pressure is too low, the glue cannot penetrate into the gaps between the copper bars of the armor layer 18 and the gap between the armor layer 18 and the PE layer 16, and the pressure in the sealing area 214 cannot be guaranteed after the sealant is cured, resulting in a poor sealing effect. Therefore, the inventor of the present application combines theoretical and experimental analysis to set the lower limit value of the second preset pressure to greater than 0.5Mpa.

[0089] Furthermore, the second time period, that is, the time for maintaining the pressure in the sealing area 214 is 1 min-3 min. Specifically, if the pressure holding time is too short, good effects will not be achieved, and if the pressure holding time is too long, the cost will increase. By configuring the pressure holding time to be 1 min-3 min, the cost can be reasonably controlled while ensuring the pressure holding effect.

[0090] Optionally, in one embodiment, the glue used in the method for plugging and repairing the oil-filled submarine cable 10 includes a high-penetration agent and a low-penetration agent. Based on this, in one embodiment, the above steps S143 to S145 specifically include the following steps:

[0091] S1431: The glue injection system first injects a high-penetration agent into the sealing area 214 at a first preset pressure;

[0092] S1432: When the high-penetration agent continues to flow out of the glue discharge valve 252 for a first period of time, the glue discharge valve 252 is closed;

[0093] S1433: the glue injection system maintains the pressure of the sealing area 214 at the second preset pressure for a second period of time, and then opens the glue discharge valve 252;

[0094] S1434: The glue injection system injects a low-permeability agent into the sealing area 214 at a first preset pressure;

[0095] S1435: When the glue discharge valve 252 continues to flow out the low-permeability agent for a first period of time, the glue discharge valve 252 is closed;

[0096] S1436: The glue injection system maintains the sealing area 214 at the second preset pressure for a second period of time, and then closes the glue injection valve 251.

[0097] Specifically, a high penetrant is a sealant with low viscosity that can penetrate into tiny gaps and achieve the purpose of sealing and leak prevention after solidification. A low penetrant is a material with excellent elasticity and flexibility. It is not easy for a low penetrant to enter tiny gaps, but it has a filling and pressure-maintaining effect, and can balance the pressure of the insulating oil leaking from the oil-filled submarine cable 10. By first injecting a high penetrant into the sealing area 214 and maintaining the pressure for a certain period of time, and then injecting a low penetrant to replace the high penetrant and maintaining the pressure for a certain period of time, the high penetrant injected first can more easily penetrate into the gaps between the copper bars of the armor layer 18 and the gap between the armor layer 18 and the PE layer 16. After the high penetrant is replaced by the low penetrant, the low penetrant can balance the pressure of the insulating oil leaking from the oil-filled submarine cable 10, and at the same time prevent the cured high penetrant from being squeezed out of the gaps between the layers. This further improves the plugging and repair effect.

[0098] Alternatively, in one embodiment, the high permeability agent includes but is not limited to fluorosilicone rubber, organic silica gel or polyurethane glue, etc. For example, in one embodiment, fluorosilicone gel with a density of about 1.27 g / mm3 can be selected as the high permeability sealant. Alternatively, in one embodiment, the low permeability agent can be fluorosilicone raw rubber or silicone rubber.

[0099] Specifically, the steps of waiting for the glue to solidify include:

[0100] S151: The time for waiting for the glue to cure is greater than or equal to 4 hours.

[0101] Specifically, a curing time of no less than 4 hours can ensure that the glue is fully cured and ensure the sealing and repair effect after the glue is cured.

[0102] Optionally, referring to the figure, in one embodiment, after the step of closing the oil drain valve 23, the following steps are also included:

[0103] S161: Check the leakage of the oil-filled submarine cable 10;

[0104] Specifically, it is possible to observe by instruments or naked eyes whether there is any insulation oil leakage from both ends of the main housing 21 .

[0105] S162: If leakage still occurs, a connection shell 30 is installed at both ends of the main shell 21, so that the connection shell 30 is sleeved outside the armor layer 18 of the oil-filled submarine cable 10, and the space between the connection shell 30 and the oil-filled submarine cable 10 forms a sealing area 214.

[0106] Specifically, the structure of the connection shell 30 is a cylindrical structure, the connection shell 30 is sealed and connected to the main shell 21, and a sealing component 22 is also provided in the connection shell 30. The sealing component 22 seals and encloses the space between the connection shell 30 and the oil-filled submarine cable 10 to form a sealing area 214.

[0107] S163: injecting glue into the sealing area 214 of the connection housing 30 until the glue fills the sealing area 214;

[0108] Specifically, further, the sealing area 21433 of each connection housing 30 is also connected to a glue injection valve 251 and a glue discharge valve 252. Further, the step of injecting glue into the sealing area 214 of the connection housing 30 can refer to the above-mentioned steps S1431 to S1436 of injecting glue into the sealing area 214 of the main housing 21, which will not be repeated here.

[0109] S164: Wait for the glue in the connection shell 30 to solidify.

[0110] Specifically, when the sealing effect of the main shell 21 is not good, by adding a connecting shell 30 at the end of the main shell 21, the number of sealing areas 214 can be increased in the axial direction of the main shell 21, and then by injecting glue into the sealing areas 21433 of the connecting shell 30, the axial sealing effect can be enhanced to avoid axial leakage.

[0111] Furthermore, in one embodiment, the following steps are also included after step S164:

[0112] S165: Check the leakage of the oil-filled submarine cable 10 again:

[0113] S167: If leakage still occurs, install another connection housing at the end of the connection housing 30 away from the main housing 21;

[0114] S168: injecting glue into the sealing area 214 of the added connection housing 30 until the glue fills the sealing area 214;

[0115] S169: Wait for the glue in the added connection shell 30 to solidify.

[0116] Specifically, the installation method of the additional connection shell 30 and the method of injecting glue into the additional connection shell 30 can refer to the above steps S161 to S164 and will not be repeated here. Further, the steps S165 to S169 are cycled until there is no leakage in the oil-filled submarine cable 10, thereby ensuring that the leakage of the oil-filled submarine cable 10 is completely blocked and repaired.

[0117] Optionally, in one embodiment, before step S140: injecting glue into each sealing area 214 until the glue fills the sealing area 214, the insulating oil and seawater in the sealing area 214 may be cleaned first, specifically, the following steps are included:

[0118] S131: Connecting the injection valve 251 located at the lower side of the sealing area 214 to the cleaning system;

[0119] Specifically, in one embodiment, the cleaning system may be a high-pressure air source or an air pump.

[0120] S132: Open the glue injection valve 251 and the glue discharge valve 252 located on the upper side of the sealing area 214;

[0121] S133: The cleaning system introduces dry air into the sealing area 214 through the injection valve 251 to clean the insulating oil and seawater in the sealing area 214;

[0122] S134: close the glue discharge valve 252 and the glue injection valve 251 in sequence, and disconnect the cleaning system from the glue injection valve 251.

[0123] Specifically, dry air is first introduced into the sealing area 214 before glue injection, so as to clean out impurities such as insulating oil and seawater in the sealing area 214 to avoid affecting subsequent glue injection, thereby ensuring the stability of the glue after curing and further ensuring the sealing and repair effect.

[0124] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0125] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for plugging and repairing an oil-filled submarine cable, characterized in that: The following steps are involved: The outer sheath of the oil-filled submarine cable at the leakage point is peeled off to expose the armor layer; The main shell of the oil-filled submarine cable plugging device is sleeved outside the armor layer of the section where the leakage point of the oil-filled submarine cable is located, so that the sealing component in the main shell divides the space between the main shell and the oil-filled submarine cable into an oil leakage area and at least one sealing area respectively located on both sides of the oil leakage area along the axial direction of the main shell, and the leakage point is located in the oil leakage area; Opening the oil drain valve located at the lower side of the oil drain area; Injecting glue into each of the sealing areas until the glue fills the sealing area; Waiting for the glue to cure; Close the oil drain valve.

2. The method for plugging and repairing an oil-filled submarine cable according to claim 1, characterized in that: The step of injecting glue into each of the sealing areas until the glue fills the sealing area comprises: Connecting the glue injection valve located at the lower side of the sealing area to the glue injection system; Open the glue injection valve and the glue discharge valve located on the upper side of the sealing area; The glue injection system injects glue into the sealing area at a first preset pressure through the glue injection valve; When the glue discharge valve continues to flow out the glue for a first period of time, closing the glue discharge valve; After the glue injection system continuously maintains the pressure of the sealing area at the second preset pressure for a second period of time, the glue injection valve is closed.

3. The method for plugging and repairing an oil-filled submarine cable according to claim 2, characterized in that: The glue includes a high-permeability agent and a low-permeability agent, wherein the glue injection system injects glue into the sealing area through the glue injection valve at the first preset pressure; when the glue discharge valve continuously flows out the glue for a first time period, the glue discharge valve is closed; after the glue injection system continuously maintains the pressure of the sealing area at the second preset pressure for a second time period, the glue injection valve is closed. The steps include: The glue injection system first injects the high permeability agent into the sealing area at the first preset pressure; When the high permeability agent continues to flow out of the glue discharge valve for the first period of time, closing the glue discharge valve; The glue injection system continuously maintains the pressure of the sealing area at the second preset pressure for the second time period, and then opens the glue discharge valve; The glue injection system then injects the low permeability agent into the sealing area at the first preset pressure; When the low-permeability agent continues to flow out of the glue discharge valve for the first period of time, closing the glue discharge valve; The glue injection system maintains the sealing area under pressure at the second preset pressure for the second period of time and then closes the glue injection valve.

4. The method for plugging and repairing an oil-filled submarine cable according to claim 2 or 3, characterized in that ； The first preset pressure ranges from 0.2Mpa to 0.4Mpa; and / or the second preset pressure ranges from 0.5Mpa to 1Mpa.

5. The method for plugging and repairing an oil-filled submarine cable according to claim 2 or 3, characterized in that ； The first time period is 10s-15s; and / or the second time period is 1min-3min.

6. The method for plugging and repairing an oil-filled submarine cable according to claim 3, characterized in that: The high permeability agent is fluorosilicone rubber, organic silica gel or polyurethane glue; and / or the low permeability agent is fluorosilicone rubber or silicone rubber.

7. The method for plugging and repairing an oil-filled submarine cable according to claim 1, characterized in that: The step of waiting for the glue to solidify comprises: The time for waiting for the glue to cure is greater than or equal to 4 hours.

8. The method for plugging and repairing an oil-filled submarine cable according to claim 7, characterized in that: After the step of closing the oil drain valve, the method further includes the following steps: Check the leakage of oil-filled submarine cables; If leakage still occurs, connecting shells are installed at both ends of the main shell, so that the connecting shells are sleeved outside the armor layer of the oil-filled submarine cable, and the space between the connecting shells and the oil-filled submarine cable forms a sealing area; Injecting glue into the sealing area of ​​the connection housing until the glue fills the sealing area; Wait for the glue in the connection shell to solidify.

9. The method for plugging and repairing an oil-filled submarine cable according to claim 8, characterized in that: After the step of waiting for the glue in the connection housing to solidify, the following steps are also included: Check the leakage of the oil-filled submarine cable again; If leakage still occurs, another connection shell is installed at the end of the connection shell away from the main shell; Injecting glue into the sealing area of ​​the added connection housing until the glue fills the sealing area; Wait for the glue in the installed connection shell to solidify.

10. The method for plugging and repairing an oil-filled submarine cable according to claim 1, characterized in that: Before the step of injecting glue into each of the sealing areas until the glue fills the sealing area, the following steps are also included: Connecting the glue injection valve located at the lower side of the sealing area to the cleaning system; Open the glue injection valve and the glue discharge valve located on the upper side of the sealing area; The cleaning system introduces dry air into the sealing area through the glue injection valve to clean the insulating oil and seawater in the sealing area; Close the glue discharge valve and the glue injection valve in sequence, and disconnect the cleaning system from the glue injection valve.

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