A corrosion protection device for the inner wall of an oil field station pipeline

Abstract

The application discloses a kind of anticorrosion devices for oil field station pipeline inner wall, it is related to oil and gas field corrosion and protection technical field, by sacrificing anode cathodic protection principle, the inner wall of pipeline is protected, and the anticorrosion effect is effectively monitored, the device includes metal cylinder, anode cylinder is arranged on the inner wall of the metal cylinder, the outer wall of anode cylinder is tightly attached on the inner wall of metal cylinder, observation window for observing anode cylinder is installed on the metal cylinder, two corrosion coupon holes are opened on metal cylinder 1, and metal coupon is installed in hole, reference electrode hole is opened on metal cylinder, Cu / CuSO4 reference electrode for measuring the protection potential of pipeline inner wall in real time is installed in reference electrode hole, the metal cylinder of device is provided with observation window, corrosion coupon and protection potential test three anticorrosion effect monitoring means, ensure that the corrosion condition of inner wall of metal cylinder and station pipeline inner wall can be timely explored at any time.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field corrosion and protection technology, and more specifically to the field of anti-corrosion device for the inner wall of pipelines in oilfield plants. Background Technology

[0002] With the continuous development of the oilfield, severe corrosion and frequent failures of pipelines within the oilfield plants have become major factors affecting normal production. Gathering and transportation stations collect produced fluids from various wells. Due to the incompatibility of formation water, the pipelines within these stations are prone to scaling, leading to increasingly severe under-scale corrosion and bacterial corrosion. Since the inner walls of the pipelines are in direct contact with the transported media, and many of these media contain various corrosive impurities such as highly salinized water, dissolved oxygen, carbon dioxide, oxygen sulfide, sulfate-reducing bacteria, and chloride ions, the combined effects of temperature, pressure, flow rate, and alternating stress exacerbate corrosion of the pipeline inner walls.

[0003] Currently, oilfields generally employ three methods for corrosion prevention and control of pipeline networks: 1) applying various liquid anti-corrosion and anti-scaling agents to bare pipes; 2) replacing pipes with non-metallic pipelines; and 3) applying coatings or linings to the inner layers of pipelines.

[0004] Regarding monitoring for corrosion protection, the monitoring methods vary depending on the specific corrosion protection technology. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned technical problems by designing a device for monitoring the corrosion protection function and effectiveness of pipeline inner walls in oilfield plants. This device utilizes the principle of sacrificial anode cathodic protection to protect the pipeline inner walls. The device's metal cylinder incorporates three monitoring methods for corrosion protection: an observation window, corrosion-resistant plates, and a protection potential test, enabling effective monitoring of corrosion protection.

[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0007] A corrosion protection device for the inner wall of pipelines in oilfield plants includes a metal cylinder. A first flange for connecting to an upstream pipeline is installed at the inlet end of the metal cylinder, and a second flange for connecting to a downstream pipeline is installed at the outlet end of the metal cylinder. The horizontal height of the first flange is less than that of the second flange. A hole is opened at the bottom of the metal cylinder, and a drain valve for discharging sediment is installed in the hole. An anode cylinder is disposed on the inner wall of the metal cylinder, with its outer wall tightly attached to the inner wall of the metal cylinder. An observation window for observing the anode cylinder is installed on the metal cylinder.

[0008] As a preferred embodiment, a first corrosion plate hole and a second corrosion plate hole are formed on the metal cylinder. Metal plates are installed in both the first and second corrosion plate holes. The metal plates in the first corrosion plate hole are insulated from the metal cylinder and the anode cylinder, respectively. The metal plates in the second corrosion plate hole are electrically connected to the metal cylinder and the anode cylinder, respectively.

[0009] As a preferred embodiment, a reference electrode hole is formed on the metal cylinder, and a Cu / CuSO4 reference electrode for real-time measurement of the protection potential of the pipeline inner wall is installed in the reference electrode hole.

[0010] As a preferred embodiment, a vent hole is provided on the metal cylinder, and a vent valve is installed in the vent hole.

[0011] As a preferred embodiment, a debris screen is installed at the discharge port inside the metal cylinder.

[0012] As a preferred embodiment, the anode cylinder is made of either aluminum alloy or zinc alloy sacrificial anode.

[0013] As a preferred embodiment, the metal cylinder is made of Q235 steel.

[0014] As a preferred option, the anode cylinder is made of either aluminum alloy or zinc alloy sacrificial anode, which is melted and then covers the inner surface of the metal cylinder, with a thickness of D1, where D1 ≥ 15 mm.

[0015] As a preferred embodiment, conductive metal strips are welded onto the inner wall of the metal cylinder.

[0016] As a preferred embodiment, the observation window is made of sight glass used in pressure vessels.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. In this invention, in order to reduce corrosion of the inner wall of the pipeline in the oilfield plant, an anode cylinder is designed inside the metal cylinder, which can effectively reduce the contact between various corrosive substances in the transported medium and the inner wall of the pipeline. In addition, in order to facilitate the installation of its metal fittings, a first flange and a second flange are designed. In order to effectively reduce the sediment entering from the upstream to the downstream end, the horizontal height of the liquid inlet end of the first flange of the metal cylinder is selected to be lower than the horizontal height of the liquid outlet of the second flange. Furthermore, in order to facilitate the subsequent treatment of the retained sediment, a drain valve for discharging sediment is designed to be installed in the hole of the metal cylinder 1 to discharge the sediment retained in the metal cylinder, which plays a certain filtering role.

[0019] 2. In this invention, two corrosion-resistant hanging plate holes are opened on the metal cylinder, and metal hanging plates are installed in the holes. The protection status of the pipeline is evaluated by the weightlessness method.

[0020] 3. In this invention, a reference electrode hole is opened on the metal cylinder, and a Cu / CuSO4 reference electrode for real-time measurement of the protection potential of the pipeline inner wall is installed in the reference electrode hole to determine the protection effect.

[0021] 4. In this invention, the anode cylinder is made of aluminum alloy or zinc alloy, which is melted and then covers the inner surface of the metal cylinder. The anode cylinder and the metal cylinder are electrically connected, which can effectively reduce the anode failure caused by uneven corrosion and crevice corrosion of the anode material and significantly extend its service life.

[0022] 5. In this invention, conductive metal strips are welded to the inner wall of the metal cylinder. The welding is mainly used to increase the conductivity of the metal cylinder and the anode cylinder, and to increase the adhesion of the anode cylinder. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is the invention Figure 1 Schematic diagram of the cross-sectional structure at point AA;

[0025] Figure 3 This is the invention Figure 1 Schematic diagram of the cross-sectional structure at point BB.

[0026] Reference numerals: 1. Metal cylinder; 2. Anode cylinder; 3. Observation window; 4-1. First corrosion plate hole; 4-2. Second corrosion plate hole; 5. Reference electrode hole; 6. Vent valve; 7. Drain valve; 8. Trash screen; 9-1. First flange; 9-2. Second flange; 10. Conductive metal strip. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0029] Example 1

[0030] like Figures 1-3 As shown, this embodiment provides an anti-corrosion device for the inner wall of pipelines in oilfield plants, including a metal cylinder 1. A first flange 9-1 for connecting to an upstream pipeline is installed at the inlet end of the metal cylinder 1, and a second flange 9-2 for connecting to a downstream pipeline is installed at the outlet end of the metal cylinder 1. The horizontal height of the first flange 9-1 is less than the horizontal height of the second flange 9-2. A hole is opened at the bottom of the metal cylinder 1, and a drain valve 7 for discharging sediment is installed in the hole. An anode cylinder 2 is provided on the inner wall of the metal cylinder 1, and the outer wall of the anode cylinder 2 is tightly attached to the inner wall of the metal cylinder 1. An observation window 3 for observing the anode cylinder 2 is installed on the metal cylinder 1.

[0031] In the above structure, to reduce corrosion of the inner wall of the metal cylinder 1 in the oilfield plant pipeline, an anode cylinder 2 is designed to effectively isolate various corrosive impurities in the transported medium from contact with the pipe wall of the metal cylinder 1. Furthermore, to facilitate the installation of its metal fittings, a first flange 9-1 and a second flange 9-2 are installed at both ends. The first flange 9-1 is used to connect to the upstream of the pipeline, and the second flange 9-2 is used to connect to the downstream of the pipeline. To effectively reduce sediment entering the downstream end, the first flange 9-1 of the metal cylinder 1 is used for liquid inlet. The horizontal height of the first flange 9-1 is lower than the horizontal height of the drain port of the second flange 9-2. The conveying medium then enters the internal space of the metal cylinder 1 through the drain port of the first flange 9-1 and is then discharged through the drain port of the second flange 9-2. The sediment in the conveying medium will remain in the metal cylinder 1. In order to facilitate the treatment of the sediment, a hole is designed at the bottom of the metal cylinder 1, and a drain valve 7 for discharging sediment is installed in the hole. The sediment remaining in the metal cylinder 1 can be discharged by controlling the drain valve 7.

[0032] Preferably, the observation window 3 is made of sight glass used in pressure vessels, which allows for visual observation of the wall thickness changes and surface corrosion of the anode cylinder 2.

[0033] Example 2

[0034] This embodiment is based on the previous embodiment, such as... Figures 1-3As shown, a first corrosion plate hole 4-1 and a second corrosion plate hole 4-2 are opened on the metal cylinder 1. Metal plates are installed in both the first corrosion plate hole 4-1 and the second corrosion plate hole 4-2. The metal plate in the first corrosion plate hole 4-1 is insulated from the metal cylinder 1 and the anode cylinder 2, respectively. The metal plate in the second corrosion plate hole 4-2 is electrically connected to the metal cylinder 1 and the anode cylinder 2, respectively. After the device is run for a period of time and then removed, the protection status of the pipeline is evaluated by the weightlessness method.

[0035] Furthermore, a reference electrode hole 5 is opened on the metal cylinder 1, and a Cu / CuSO4 reference electrode is installed in the reference electrode hole 5 for real-time measurement of the protection potential of the pipeline inner wall. The protection potential of the pipeline inner wall is measured in real time to determine the protection effect.

[0036] Meanwhile, a vent hole is opened on the metal cylinder 1, and a vent valve 6 is installed in the vent hole, which is mainly used to discharge the gas in the device and ensure that the liquid in the device is fully loaded.

[0037] Furthermore, a debris screen 8 is installed at the discharge port inside the metal cylinder 1, which is mainly used to intercept sediment in the device and ensure that sediment does not enter the downstream pipeline.

[0038] The anode cylinder 2 is made of either aluminum alloy or zinc alloy sacrificial anode. After melting, the sacrificial anode 2 covers the inner surface of the metal cylinder 11 with a thickness of D1, where D1 ≥ 15mm. The molten sacrificial anode is directly cast onto the inner surface of the metal cylinder 1. The anode cylinder 2 and the metal cylinder 1 are seamlessly and tightly electrically connected. The anode cylinder 2 provides a stable and continuous protective current, effectively reducing anode failure caused by uneven corrosion and crevice corrosion, and significantly extending service life. The metal cylinder 11 is also made of Q235 steel.

[0039] Finally, a conductive metal strip 10 is welded to the inner wall of the metal cylinder 11. The conductive metal strip is made of Q235 or the same material as the protected pipeline. It is welded to the metal cylinder 1 and is mainly used to increase the conductivity of the metal cylinder 1 and the anode cylinder 2.

[0040] In conclusion, as can be seen from the above embodiments, the present invention provides a simple and easy-to-operate device for monitoring corrosion protection and its effectiveness on the inner wall of oilfield pipelines. The present invention can protect the inner wall of pipelines and also includes three methods for monitoring the corrosion protection effect, enabling effective monitoring of the corrosion protection performance.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A corrosion protection device for the inner wall of pipelines in oilfield plants, characterized in that, The device includes a metal cylinder (1), with a first flange (9-1) installed at the inlet end of the metal cylinder (1) for connection to an upstream pipeline, and a second flange (9-2) installed at the outlet end of the metal cylinder (1) for connection to a downstream pipeline. The horizontal height of the first flange (9-1) is less than that of the second flange (9-2). A hole is opened at the bottom of the metal cylinder (1), and a drain valve (7) for discharging sediment is installed in the hole. An anode cylinder (2) is provided on the inner wall of the metal cylinder (1), and the outer wall of the anode cylinder (2) is tightly attached to the inner wall of the metal cylinder (1). An observation window (3) for observing the anode cylinder (2) is installed on the metal cylinder (1). A first corrosion plate hole (4-1) and a second corrosion plate hole (4-2) are provided on the metal cylinder (1). Metal plates are installed in both the first corrosion plate hole (4-1) and the second corrosion plate hole (4-2). The metal plates in the first corrosion plate hole (4-1) are insulated from the metal cylinder (1) and the anode cylinder (2), respectively. The metal plates in the second corrosion plate hole (4-2) are electrically connected to the metal cylinder (1) and the anode cylinder (2), respectively.

2. The anti-corrosion device for the inner wall of pipelines in oilfield plants according to claim 1, characterized in that, A reference electrode hole (5) is opened on the metal cylinder (1), and a Cu / CuSO4 reference electrode for real-time measurement of the protection potential of the inner wall of the pipeline is installed in the reference electrode hole (5).

3. The anti-corrosion device for the inner wall of pipelines in oilfield plants according to claim 2, characterized in that, A vent hole is provided on the metal cylinder (1), and a vent valve (6) is installed in the vent hole.

4. The anti-corrosion device for the inner wall of pipelines in oilfield plants according to claim 1, characterized in that, A debris screen (8) is installed at the discharge port inside the metal cylinder (1).

5. The anti-corrosion device for the inner wall of pipelines in oilfield plants according to claim 1, characterized in that, The anode cylinder (2) is made of either aluminum alloy or zinc alloy sacrificial anode.

6. The anti-corrosion device for the inner wall of pipelines in oilfield plants according to claim 1, characterized in that, The metal cylinder (1) is made of Q235 steel.

7. The anti-corrosion device for the inner wall of pipelines in oilfield plants according to claim 1, characterized in that, The anode cylinder (2) is made of either aluminum alloy or zinc alloy. After the sacrificial anode is melted, it covers the inner surface of the metal cylinder (1) with a thickness of D1 and D1 ≥ 15 mm.

8. The anti-corrosion device for the inner wall of pipelines in oilfield plants according to claim 1, characterized in that, Conductive metal strips (10) are welded to the inner wall of the metal cylinder (1).

9. A corrosion protection device for the inner wall of pipelines in oilfield plants according to claim 8, characterized in that, The conductive metal strip is made of Q235 or the same material as the protected pipeline.

10. A corrosion protection device for the inner wall of pipelines in oilfield plants according to claim 1, characterized in that, The observation window (3) is made of sight glass used in pressure vessels.

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