Pipeline inner wall anti-corrosion device

Abstract

The utility model relates to the field of oil and gas pipeline corrosion prevention, in particular to a pipeline inner wall corrosion prevention device. The device comprises an anode fixing seat, the anode fixing seat is of a sleeve structure, an inner hole of the anode fixing seat is provided with an inner step surface and is provided with an anode fixing rod, the anode fixing rod is provided with a protruding shoulder and is matched with the inner step surface in a stopping mode, the anode fixing rod is provided with an inner hole, and a flexible anode fixedly connected with the inner hole is installed in the inner hole in a penetrating mode. One end of the flexible anode penetrates through an inner hole of the fixing rod and is connected with a pressure sealing rod, the pressure sealing rod comprises a sleeve and a blocking head, at least part of the blocking head is larger than the sleeve in the radial direction of the sleeve, and an external electrode is fixedly connected into the sleeve in a sealed mode. One end of the sleeve penetrates through the pressure sealing cover and is in sealing fit with an inner hole formed in the pressure sealing cover; and the stopper is in stopping fit with the inner side of the pressure sealing cover. The anti-corrosion device can solve the sealing problem of connection between the anti-corrosion device and the pipeline, and is simple in structure and convenient to install.

Description

Technical Field

[0001] The utility model relates to the field of oil and gas pipeline anti-corrosion, in particular to a pipeline inner wall anti-corrosion device. Background Art

[0002] In oilfield operations, oil and gas gathering and transportation refers to the process of centralized collection, transportation and processing of oil and natural gas in the oilfield. Gathering and transportation pipelines play a very important role in the transportation link of the oil and gas gathering and transportation system. Existing gathering and transportation pipelines generally choose metal pipelines such as steel pipes. If media containing corrosive substances are transported for a long time, the inner wall of the pipeline will corrode, affecting the transportation of oil and gas.

[0003] Pipeline inner wall corrosion mainly includes electrochemical corrosion and chemical corrosion. Electrochemical corrosion refers to the galvanic reaction that occurs when impure metals come into contact with electrolyte solutions. The more active metals will lose electrons and be oxidized. For pipelines commonly used to transport oil and gas, electrochemical corrosion is the most common and more serious. Corrosion will shorten the service life of the pipeline and reduce the transportation capacity. Therefore, pipeline corrosion protection is one of the indispensable links in pipeline maintenance work.

[0004] Existing pipeline anti-corrosion technologies mainly include coating anti-corrosion, corrosion inhibitor anti-corrosion and electrochemical anti-corrosion. Coating anti-corrosion generally involves applying a layer of anti-corrosion coating on the surface. However, for the inner wall of the pipeline, high requirements are placed on the operating tools. The anti-corrosion coating needs to be evenly sprayed or applied on the inner wall of the pipeline, making the operating tool structure complex and costly. In addition, the anti-corrosion coating will fall off after being impacted and corroded by the substances in the pipeline for a long time. Corrosion inhibitor anti-corrosion achieves the effect of pipeline protection by adding a small amount of substances that can prevent or slow down metal corrosion. However, the application of corrosion inhibitors has certain limitations and can generally only be used in closed, circulating systems. For fluid oil and gas pipelines, the anti-corrosion effect is not ideal. Electrochemical anti-corrosion uses external current to change the metal potential and reach the passive zone to inhibit metal corrosion. For metal pipelines, this anti-corrosion method utilizes the metal properties of the pipeline. It has the advantages of high efficiency, environmental protection, easy operation and long anti-corrosion effect.

[0005] However, in the existing technology, the corrosion protection effects of coatings and corrosion inhibitors in pipelines are not ideal, and the electrochemical corrosion protection device is mainly used for corrosion protection of the outer wall of the pipeline, and is rarely used for the inner wall of the pipeline. When the device is used in the pipeline, it is necessary to open a hole in the pipeline and then carry out subsequent installation. Since oil and gas gathering pipelines mainly transport easily leaked substances such as oil and natural gas, the sealing of the electrochemical corrosion protection device also needs to be considered when operating in the pipeline. Utility Model Content

[0006] The purpose of the utility model is to provide a pipeline inner wall anti-corrosion device to solve the problem of poor anti-corrosion effect of the pipeline inner wall in the prior art.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a device for anti-corrosion of the inner wall of a pipeline, which includes an anode fixing seat, the anode fixing seat being a sleeve structure, an inner hole being provided in the anode fixing seat, the inner hole of the anode fixing seat being provided with an inner step surface, an anode fixing rod being installed in the inner hole of the anode fixing seat, a boss being provided on the anode fixing rod, and engaging with the inner step surface of the anode fixing seat through the boss, an inner hole being provided on the anode fixing rod and a flexible anode being passed through the inner hole, the flexible anode being fixedly connected to the anode fixing rod, and one end passing through the inner hole of the anode fixing rod and being connected to a pressure sealing rod, the pressure sealing rod including a sleeve and a stopper head which is at least partially larger than the sleeve in the radial direction of the sleeve, an external electrode being fixedly and sealedly connected in the sleeve, a pressure sealing cover being fixedly and sealedly connected to one end of the anode fixing seat, an inner hole being provided on the pressure sealing cover, one end of the sleeve passing through the pressure sealing cover and engaging with the inner hole of the pressure sealing cover in a sealing manner, and the stopper head engaging with the inner side stopper of the pressure sealing cover.

[0008] Furthermore, one of the inner hole wall of the anode fixing seat and the anode fixing rod is provided with a rotation-stopping groove, and the other is provided with a rotation-stopping protrusion, and the rotation-stopping groove is cooperatively connected with the rotation-stopping protrusion.

[0009] Furthermore, a clamping groove is provided on the inner wall of the sleeve, and a clamping spring is provided in the clamping groove.

[0010] Furthermore, the flexible anode is covered with a protective tube.

[0011] Furthermore, magnets are fixedly arranged on the outer surface of the protection tube along the length direction.

[0012] Furthermore, the flexible anode is independently provided with a micro reference electrode at one end away from the anode fixing seat, and the sleeve is provided with an external electrode corresponding to the micro reference electrode.

[0013] Furthermore, the micro reference electrode and the flexible anode are placed in parallel in the protective tube.

[0014] Furthermore, a flange is provided at one end of the anode fixing seat close to the pressure sealing cover, one of the flange and the pressure sealing cover is provided with a threaded hole, and the other is provided with a bolt hole, and the flange and the pressure sealing cover are connected by bolts provided in the threaded hole and the bolt hole.

[0015] Furthermore, a sealing ring is provided between the pressure sealing cover and the flange of the anode fixing seat.

[0016] Furthermore, a sealing ring is provided between the inner hole of the pressure sealing cover and the sleeve.

[0017] Beneficial effect: The pipeline inner wall anti-corrosion device of the present invention is a pioneering invention. The oil and gas pipeline inner wall anti-corrosion device of the present invention is different from the existing pipeline inner wall coating anti-corrosion technology and corrosion inhibitor anti-corrosion technology. It adopts electrochemical anti-corrosion that has advantages for metal pipelines. The device fixes the flexible anode in the pipeline through the anode fixing seat and the anode fixing rod. By connecting the external power supply, a stable loop is formed with the pipeline to complete the electron migration and achieve the anti-corrosion effect. The structure is simple and easy to install. Moreover, for oil fields with large construction volume, the larger the project volume, the more economical it is. The device uses cathodic protection to achieve good anti-corrosion effect for pipelines with metal characteristics. The fixed sealing connection between the pressure sealing cover and the anode fixing seat can effectively solve the sealing problem of the pipeline opening installation of the device. The external electrode on the pressure sealing rod is fixedly and sealedly connected to the pressure sealing cover through the sleeve. The external power supply serves as a bridge connecting the flexible anode and the external power supply, which can avoid the problem of poor sealing when the flexible anode is directly connected to the external power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of a pipeline inner wall anti-corrosion device provided by an embodiment of the present utility model;

[0019] Figure 2 for Figure 1 a cross-sectional view of the middle anode holder;

[0020] Figure 3 for Figure 2 Side view of the middle anode holder;

[0021] Figure 4 for Figure 1 A cross-sectional view of the middle anode fixing rod;

[0022] Figure 5 for Figure 1 a cross-sectional view of the medium pressure sealing cover;

[0023] Figure 6 for Figure 5 Side view of the medium pressure sealing cover;

[0024] Figure 7 for Figure 1 Cross-sectional view of the middle pressure sealing rod;

[0025] Figure 8 Schematic diagram of the connection clip.

[0026] In the figure: 1. Anode fixing seat; 2. Anode fixing rod; 3. Flexible anode; 4. Magnet; 5. Micro reference electrode; 6. Sealing ring; 7. Pressure sealing rod; 8. Pressure sealing cover; 9. Pipeline; 10. External power supply; 11. Connecting clip; 12. Flange; 13. External electrode; 14. Stopper; 15. Inner step surface; 16. Shoulder; 17. Bolt; 18. Sealing ring groove; 19. Bolt hole; 20. Threaded hole; 21. Nylon gasket; 22. Sleeve; 23. Anti-rotation protrusion; 24. Anti-rotation groove; 25. Notch; 26. Card slot; 27. Protective tube. DETAILED DESCRIPTION

[0027] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0028] The present invention addresses the problem of poor corrosion protection for the inner wall of a pipe in the prior art. The present invention utilizes the principle of cathodic protection to form a circuit between the metal pipe and the flexible anode via an external power supply, inhibiting electron migration in the metal pipe and thereby inhibiting or slowing corrosion of the metal pipe. The device utilizes components such as a pressure sealing cover and a pressure-sealed rod to address sealing issues during use. The present invention offers a simple structure, convenient installation, and excellent corrosion protection.

[0029] As a basic solution, Figure 1-8 As shown, the anti-corrosion device for the inner wall of a pipeline 9 of the present invention includes an anode fixing seat 1, which can be fixed to the pipeline 9 by welding. The welding method can ensure the sealing of the connection position, thereby preventing the leakage of substances in the pipeline 9. The anode fixing seat 1 is a sleeve structure, and an inner hole is provided in the anode fixing seat 1. The inner hole of the anode fixing seat 1 is provided with an inner step surface 15. The use of the inner step surface 15 can play a positioning role and facilitate the assembly of subsequent structures. An anode fixing rod 2 is installed in the inner hole of the anode fixing seat 1, and a boss 16 is provided on the anode fixing rod 2. The boss 16 is stopped and matched with the inner step surface 15 of the anode fixing seat 1. The anode fixing rod 2 is at risk of being pulled into the pipeline 9 under the action of the internal pressure of the pipeline 9. The stopping cooperation can effectively prevent the anode fixing rod 2 from moving towards the pipeline 9. Figure 1The anode fixing rod 2 is moved to the left in the direction shown. In addition, a notch 25 can be provided on the outer wall of the boss 16 of the anode fixing rod 2 to facilitate the subsequent removal of the anode fixing rod 2. An inner hole is provided on the anode fixing rod 2 and a flexible anode 3 is installed in the inner hole. The flexible anode 3 can make the potential distribution uniform during use, which can well avoid the problems of insufficient protection and over-protection. Moreover, the flexible anode 3 has a long service life and is easy to install. The flexible anode 3 and the anode fixing rod 2 can be fixedly connected by a connecting clip 11. The connecting clip 11 is conical and has a toothed structure at one end with a small diameter, which is convenient for clamping the flexible anode 3. The other end is used to be connected and fixed to the anode fixing rod 2 by crimping, and one end passes through the inner hole of the anode fixing rod 2 and is connected to a pressure sealing rod 7. A conductive wire clamp can be used here for connection to facilitate the installation and disassembly of the flexible anode 3. The pressure sealing rod 7 includes a sleeve 22 and a stopper 14 that is at least partially larger than the sleeve 22 in the radial direction of the sleeve 22. The sleeve 22 is fixed The sealing connection is with an external electrode 13, which can be made by epoxy resin 21. Epoxy resin 21 has good bonding performance and sealing. One end of the external electrode 13 is connected to the flexible anode 3 at the stopper 14 of the sleeve 22, and the other end is connected to the external power supply 10 outside the sleeve 22. Because the flexible anode 3 is a detachable component in the device, it is impossible to ensure the sealing of the connection when it is directly connected to the external power supply 10. Therefore, the external electrode 13 plays a bridge role as a part of the fixed sealing connection of the sleeve 22, which can not only connect the external power supply 10 but also ensure the sealing of the device. A pressure sealing cover 8 is fixedly and sealed at one end of the anode fixing seat 1. The pressure sealing cover 8 is provided with an inner hole. One end of the sleeve 22 passes through the pressure sealing cover 8 and is sealed with the inner hole of the pressure sealing cover 8 to ensure the sealing of the connection. The stopper 14 is matched with the inner stopper of the pressure sealing cover 8. The stopper match here is the same as the above, but the direction is different, which can prevent the pressure sealing rod 7 from moving towards Figure 1 Move to the right in the direction shown.

[0030] As a preferred embodiment, Figure 2-4 As shown, a rotation-stop groove 24 is provided on the inner hole of the anode fixing seat 1, and a rotation-stop protrusion 23 is provided on the anode fixing rod 2. The rotation-stop groove 24 is cooperated with the rotation-stop protrusion 23 to prevent the anode fixing rod 2 from rotating back and forth inside the anode fixing seat 1. In other embodiments, a rotation-stop groove 24 and a rotation-stop protrusion 23 can be provided on the inner step surface 15 of the anode fixing seat 1 and on the boss 16 of the anode fixing rod 2, which can also achieve the effect of stopping the rotation of the anode fixing rod 2.

[0031] As a preferred embodiment, Figure 5As shown, the inner wall of the sleeve 22 is provided with a groove 26, and a retaining spring is provided in the groove 26. The retaining spring can play a limiting role in preventing the pressure sealing rod 7 from falling into the pressure sealing cover 8. In other embodiments, it can be set as a spring washer, which also has the same limiting and stopping effect.

[0032] As a preferred embodiment, the flexible anode 3 is provided with a protective tube 27, which can protect the flexible anode 3 from being corroded by the substances in the pipeline 9, so that the service life of the flexible anode 3 is extended. In other embodiments, the protective tube 27 is omitted. Although the flexible electrode will always swing back and forth with the flow of substances in the pipeline, the flexible electrode can still play its role at this time.

[0033] As a preferred embodiment, Figure 1 As shown, the protective tube 27 is fixedly provided with magnets 4 on the outer surface along the length direction. When the protective tube 27 is placed in the pipe 9, the protective tube 27 will automatically approach and be magnetically attracted to the inner wall of the pipe 9 through the action of the magnet 4, which is convenient for the fixed installation of the protective tube 27 and prevents the protective tube 27 from swinging back and forth with the flow of the material in the pipe 9. In addition, it is also very convenient to disconnect from the pipe 9, which is conducive to subsequent maintenance and replacement without damaging the inner wall of the pipe 9. In other embodiments, an additional connection method such as welding fixation is required. For the narrow and long pipe 9, the operation is inconvenient or even impossible at deeper depths, and it is not conducive to subsequent replacement and disassembly.

[0034] As a preferred embodiment, Figure 1 As shown, the flexible anode 3 is independently provided with a micro reference electrode 5 at one end away from the anode fixing seat 1, and the sleeve 22 is provided with a micro reference electrode 5 corresponding to the micro reference electrode 5. Figure 7 The external electrode 13 shown, the micro reference electrode 5 is placed next to the flexible anode 3 and can be used as a reference electrode to facilitate monitoring the electric potential in the pipeline 9 in order to adjust the external power supply 10. The micro reference electrode 5 is first connected to the external electrode 13 like the flexible anode 3, and then connected to the negative pole of the external multimeter through the external electrode 13. The positive pole of the external multimeter is connected to the pipeline 9. In other embodiments, no reference electrode is provided, but this structure cannot measure and monitor the potential inside the pipe, and insufficient cathodic protection of the pipeline 9 may occur, affecting the anti-corrosion effect.

[0035] As a preferred embodiment, the micro reference electrode 5 and the flexible anode 3 are placed in parallel in the protective tube 27, and the micro reference electrode 5 is also placed in the protective tube 27 to protect it, so as to prevent the micro reference electrode 5 from being eroded and corroded by the substances in the pipeline 9, thereby reducing its service life. In other embodiments, the micro reference electrode 5 is placed directly in the pipeline 9. This method will cause the micro reference electrode 5 to need to be replaced or maintained frequently, increasing the maintenance cost of the entire device.

[0036] As a preferred embodiment, Figure 1-6 As shown, a flange 12 is provided at one end of the anode holder 1 close to the pressure sealing cover 8. A threaded hole 20 is provided on the flange 12, and a bolt hole 19 is provided on the pressure sealing cover 8. The flange 12 and the pressure sealing cover 8 are connected by bolts 17 provided in the threaded hole 20 and the bolt hole 19. The use of the bolts 17 for fixing is simple and convenient for subsequent disassembly. In other embodiments, a key and a keyway that cooperate with each other can be provided on the pressure sealing cover 8 and the flange 12 to achieve the connection between the two components.

[0037] As a preferred embodiment, a sealing ring 6 is provided on the flange 12, and the sealing ring is placed as follows. Figure 5 In the sealing ring groove 18 shown, a sealing ring 6 is provided at the connection point to prevent leakage of liquid or gas, which can effectively improve the airtightness of the device. A sealing ring 6 is provided on the inner hole of the pressure sealing cover 8. The sealing ring 6 provided here plays the same role as the former, but the position is different. The sealing ring 6 can be made of rubber material, and the rubber sealing ring 6 has good elasticity and wear resistance. In other embodiments, a metal sealing ring 6 or a sealing ring 6 of other materials can also be selected as long as the sealing effect can be achieved.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the description and drawings of the present invention shall also be included in the scope of protection of the present invention.

Claims

1. A pipeline inner wall anti-corrosion device, characterized in that: The device includes an anode fixing seat, which is a sleeve structure. An inner hole is provided in the anode fixing seat. The inner hole of the anode fixing seat is provided with an inner step surface. An anode fixing rod is installed in the inner hole of the anode fixing seat. A boss is provided on the anode fixing rod, and the boss cooperates with the inner step surface of the anode fixing seat through a stop. An inner hole is provided on the anode fixing rod and a flexible anode is passed through the inner hole. The flexible anode is fixedly connected to the anode fixing rod, and one end passes through the inner hole of the anode fixing rod and is connected to a pressure sealing rod. The pressure sealing rod includes a sleeve and a stop head that is at least partially larger than the sleeve in the radial direction of the sleeve. An external electrode is fixedly and sealed in the sleeve. A pressure sealing cover is fixedly and sealed at one end of the anode fixing seat. The pressure sealing cover is provided with an inner hole. One end of the sleeve passes through the pressure sealing cover and seals with the inner hole of the pressure sealing cover, and the stop head cooperates with the inner side stop of the pressure sealing cover.

2. The pipeline inner wall anti-corrosion device according to claim 1, characterized in that: A rotation-stopping groove is provided on the inner hole wall of the anode fixing seat and a rotation-stopping protrusion is provided on the anode fixing rod. The rotation-stopping groove is matched with the rotation-stopping protrusion.

3. The pipeline inner wall anti-corrosion device according to claim 1, characterized in that: A clamping groove is provided on the inner wall of the sleeve, and a clamping spring is provided in the clamping groove.

4. The pipeline inner wall anti-corrosion device according to claim 1, characterized in that: The flexible anode is covered with a protective tube.

5. The pipeline inner wall anti-corrosion device according to claim 4, characterized in that: The protection tube has magnets fixedly arranged on its outer surface along the length direction.

6. The pipeline inner wall anti-corrosion device according to claim 4, characterized in that: The flexible anode is independently provided with a micro reference electrode at one end away from the anode fixing seat, and the sleeve is provided with an external electrode corresponding to the micro reference electrode.

7. The pipeline inner wall anti-corrosion device according to claim 6, characterized in that: The micro reference electrode and the flexible anode are placed in parallel in the protection tube.

8. The pipeline inner wall anti-corrosion device according to claim 1, characterized in that: The anode fixing seat is provided with a flange at one end close to the pressure sealing cover. The flange and the pressure sealing cover are provided with a threaded hole and a bolt hole respectively. The flange and the pressure sealing cover are connected by bolts provided in the threaded hole and the bolt hole.

9. The pipeline inner wall anti-corrosion device according to claim 1, characterized in that: A sealing ring is provided between the pressure sealing cover and the flange of the anode fixing seat.

10. The pipeline inner wall anti-corrosion device according to claim 1, characterized in that: A sealing ring is provided between the inner hole of the pressure sealing cover and the sleeve.

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