Elbow device and coiled tubing

Abstract

The utility model relates to an elbow device and a coiled tubing, the elbow device comprises a first elbow, the first elbow comprises a first end and a second end which are oppositely arranged, the first end of the first elbow is provided with a first shaft shoulder, and the first shaft shoulder is provided with a first sealing surface; the connecting piece is arranged at the first end of the first bent pipe, a first groove is formed in the end, facing the first bent pipe, of the connecting piece, and the first shaft shoulder is connected with the first groove; the sealing ring is arranged between the first shaft shoulder and the first groove, and the first sealing surface abuts against the sealing ring; wherein the first sealing surface is at least provided with a first corrosion-resistant layer. Elbow leakage and failure caused by corrosion of acid liquid in a pipeline to a sealing surface can be effectively prevented, so that the service life of the elbow device is prolonged, and the long-term working reliability of the elbow device is improved.

Description

Technical Field

[0001] This application relates to the field of oil pipeline technology, and in particular to a bend device and a coiled tubing. Background Technology

[0002] High-pressure swivel joints are crucial connecting devices for high-pressure fracturing media transport in oil and gas field development and production enhancement operations. A high-pressure swivel joint is a rigid metal pipeline connector that can flexibly change its spatial angle, allowing for 360° rotation and angle changes of the manifold, enabling highly flexible connection of manifolds in confined spaces.

[0003] In related technologies, existing movable elbows are made of low-carbon alloy steel through carburizing and quenching. Movable elbows themselves lack corrosion resistance. Therefore, after a period of use, corrosion will occur at the packing sealing surface, leading to leaks and affecting the elbow's service life. Fracturing fluid will continuously remain between the packing sealing surface and the sealing element, causing severe corrosion of the sealing surface and gradually corroding into the pipeline, leading to seal failure, affecting the elbow's service life, and in severe cases, causing leaks that threaten life and property safety. Utility Model Content

[0004] This application provides an elbow device and a continuous tubing to solve the technical problem that after long-term operation, existing movable elbows will suffer severe corrosion of the sealing surface due to the presence of fracturing fluid inside the elbow, leading to seal failure and affecting the service life of the elbow.

[0005] In a first aspect, this application provides an elbow device, comprising:

[0006] The first bend includes a first end and a second end disposed opposite to each other in its own axial direction. The first end of the first bend is provided with a first shoulder, and the first shoulder has a first sealing surface.

[0007] A connector is disposed at the first end of the first bend, and a first groove is provided at the end of the connector facing the first bend, and the first shoulder is connected to the first groove.

[0008] A sealing ring is disposed between the first shoulder and the first groove, and the first sealing surface abuts against the sealing ring.

[0009] The first sealing surface is provided with at least one first corrosion-resistant layer.

[0010] In one possible implementation, the first groove has a second sealing surface that abuts against the sealing ring, and the second sealing surface is provided with at least one second corrosion-resistant layer.

[0011] In one possible implementation, the first groove has a third sealing surface, which is disposed adjacent to the second sealing surface and abuts against the sealing ring. The third sealing surface is provided with at least one third corrosion-resistant layer.

[0012] In one possible implementation, the thickness of the first corrosion-resistant layer, the second corrosion-resistant layer, and the third corrosion-resistant layer is greater than or equal to 0.5 mm.

[0013] In one possible implementation, the hardness of the first corrosion-resistant layer, the second corrosion-resistant layer, and the third corrosion-resistant layer is set to 35HRC-45HRC.

[0014] In one possible implementation, the first corrosion-resistant layer, the second corrosion-resistant layer, and the third corrosion-resistant layer are alloy layers comprising a nickel-based alloy and tungsten carbide weld overlay.

[0015] In one possible implementation, a transition layer is provided on the first sealing surface.

[0016] In one possible implementation, the first corrosion-resistant layer is provided in two layers, and the transition layer is provided between the two layers of the first corrosion-resistant layer.

[0017] In one possible implementation, a second bend is included, which is disposed at the second end of the first bend. The second end of the first bend has a second groove, and the second bend has a second shoulder connected to the second groove. The second groove has a fourth sealing surface, and the fourth sealing surface has at least one fourth corrosion-resistant layer.

[0018] Secondly, this application provides a continuous tubing, including the elbow device as described above.

[0019] The technical solutions provided in this application have the following advantages compared with the prior art:

[0020] The elbow device and continuous tubing provided in this application embodiment include a first elbow, a connector, and a sealing ring. The elbow is mounted on a first groove via a first shoulder. The sealing ring deforms under force, causing the first sealing surface of the first shoulder to tightly abut against the sealing ring, preventing acidic liquids from the pipeline from penetrating to the first sealing surface. Since at least one first corrosion-resistant layer (which can be a corrosion-resistant alloy layer) is provided on the first sealing surface, the first shoulder has sufficient erosion resistance, and the acidic liquids in the pipeline can effectively prevent corrosion of the first sealing surface, thus preventing elbow leakage and failure. This improves the service life and long-term operational reliability of the elbow device. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0024] Figure 1 This is a schematic diagram of the structure of an elbow device provided in one embodiment of this application;

[0025] Figure 2 for Figure 1 Enlarged diagram of section A in the middle;

[0026] Figure 3 This is a schematic diagram of the structure of an elbow device provided in another embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. First bend; 11. First shoulder; 111. First sealing surface; 111a. First corrosion-resistant layer; 111b. Transition layer; 12. Second groove; 121. Fourth sealing surface; 121a. Fourth corrosion-resistant layer; 2. Connector; 21. First groove; 211. Second sealing surface; 211a. Second corrosion-resistant layer; 212. Third sealing surface; 212a. Third corrosion-resistant layer; 3. Sealing ring; 4. Second bend; 5. Dustproof ring; 6. Steel ball; 7. Plug; 8. Wing nut. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0031] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0032] In related technologies, existing movable elbows are made of low-carbon alloy steel through carburizing and quenching, and are inherently not corrosion-resistant. When operating movable elbows, 15%-20% hydrochloric acid solution (fracturing fluid) needs to be conveyed. Due to pressure penetration, fracturing fluid will remain between the packing sealing surface and the sealing element after a period of use. This will cause severe corrosion of the sealing surface, and the corrosion will gradually penetrate into the pipeline, leading to seal failure, affecting the elbow's service life, and in severe cases, causing leakage and threatening life and property safety.

[0033] To address the technical problem that existing flexible elbows suffer from severe corrosion of the sealing surface due to fracturing fluid remaining inside the elbow after prolonged operation, leading to seal failure and affecting the elbow's service life, this application provides an elbow device and continuous tubing that can effectively prevent acidic liquids in the pipeline from corroding the sealing surface and causing elbow leakage failure, thereby improving the service life and long-term operational reliability of the elbow device.

[0034] Figure 1 and Figure 2The elbow device provided in this application includes a first elbow 1, a connector 2, and a sealing ring 3. The first elbow 1 includes a first end and a second end disposed opposite to each other in its own axial direction. The first end of the first elbow 1 is provided with a first shoulder 11, and the first shoulder 11 has a first sealing surface 111. The connector 2 is disposed at the first end of the first elbow 1, and the end of the connector 2 facing the first elbow 1 is provided with a first groove 21. The first shoulder 11 is connected to the first groove 21. The sealing ring 3 is disposed between the first shoulder 11 and the first groove 21, and the first sealing surface 111 abuts against the sealing ring 3. The first sealing surface 111 is provided with at least one first corrosion-resistant layer 111a.

[0035] It should be noted that the traditional process involves carburizing and quenching the first bend 1 and the connector 2 to increase their hardness. A sealing ring 3 is also placed between the contact surfaces of the first bend 1 and the connector 2 to improve the sealing performance and prevent liquid erosion. However, after a period of operation, due to the liquid pressure inside the bend penetrating to the contact surface, fracturing fluid will remain between the bend and the sealing ring 3. Over time, this will lead to corrosion of the contact surface and cause the bend to leak and fail.

[0036] Understandably, by embedding the first shoulder 11 into the first groove 21, the sealing ring 3 deforms under force, causing the first sealing surface 111 of the first shoulder 11 to tightly abut against the sealing ring 3, preventing acidic liquid in the pipeline from penetrating to the first sealing surface 111. Since at least one first corrosion-resistant layer 111a is provided on the first sealing surface 111, which can be a corrosion-resistant alloy layer, the first shoulder 11 can be guaranteed to have sufficient erosion resistance, and can effectively prevent acidic liquid in the pipeline from corroding the first sealing surface 111 and causing elbow leakage failure, thereby improving the service life and long-term operational reliability of the elbow device.

[0037] The first corrosion-resistant layer 111a can be configured as one layer or multiple layers. Multiple layers of the first corrosion-resistant layer 111a can improve the erosion resistance of the first sealing surface 111 of the first bend 1, and further improve the service life and long-term working reliability of the bend device.

[0038] For example, connector 2 can be a union joint in the prior art, which can be a conventional welded union or a threaded union; connector 2 can also be a flange joint in the prior art.

[0039] like Figure 2As shown, in one embodiment, the first groove 21 has a second sealing surface 211, which abuts against the sealing ring 3. The second sealing surface 211 is provided with at least one second corrosion-resistant layer 211a. It is understood that by embedding the first shoulder 11 into the first groove 21, the sealing ring 3 deforms under force, causing the second sealing surface 211 of the first groove 21 to tightly abut against the sealing ring 3, preventing acidic liquids in the pipeline from penetrating to the second sealing surface 211. Since at least one second corrosion-resistant layer 211a is provided on the second sealing surface 211, which can be a corrosion-resistant alloy layer, the second sealing surface 211 of the connector 2 can be guaranteed to have sufficient erosion resistance and can effectively prevent acidic liquids in the pipeline from corroding the second sealing surface 211 and causing elbow leakage failure, thereby improving the service life and long-term operational reliability of the elbow device.

[0040] In one embodiment, such as Figure 2 As shown, the first groove 21 has a third sealing surface 212, which is adjacent to the second sealing surface 211. The third sealing surface 212 abuts against the sealing ring 3, and the third sealing surface 212 is provided with at least one third corrosion-resistant layer 212a. It can be understood that by embedding the first shoulder 11 into the first groove 21, the sealing ring 3 deforms under force, causing the third sealing surface 212 of the first groove 21 to tightly abut against the outer wall of the sealing ring 3, preventing acidic liquid in the pipeline from penetrating to the third sealing surface 212. Since at least one third corrosion-resistant layer 212a is provided on the third sealing surface 212, which can be a corrosion-resistant alloy layer, it ensures that the third sealing surface 212 of the connector 2 has sufficient erosion resistance and effectively prevents acidic liquid in the pipeline from corroding the third sealing surface 212, causing elbow leakage failure, thereby improving the service life and long-term operational reliability of the elbow device.

[0041] In some embodiments, the thicknesses of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a are greater than or equal to 0.5 mm, such that the hardness of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a is greater than 30 HRC, thereby ensuring the erosion resistance of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a. The first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a can withstand 15%-20% hydrochloric acid corrosion, while also preventing erosion damage or wear from liquids inside the pipeline. For example, the thicknesses of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a can be set to 0.5 mm, 1 mm, 1.5 mm, etc.

[0042] Optionally, the materials of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a include, but are not limited to, nickel-based alloys, cobalt-based alloys, and stainless steel.

[0043] In some embodiments, the hardness of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a is set to 35HRC-45HRC. It should be noted that the substrate of the first elbow can be made of low-carbon alloy steel such as SAE4715 or SAE8620, and other parts of the first elbow need to be heat-treated (such as carburizing and quenching) to increase the surface hardness to above 55HRC.

[0044] In some embodiments, the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a are alloy layers comprising a nickel-based alloy and tungsten carbide weld overlay, thereby ensuring the erosion resistance of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a. Specifically, the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a are welded using a laser cladding method.

[0045] In one example, the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a are alloy layers formed by welding Ni40 alloy and tungsten carbide. The thickness of this alloy layer is 0.5 mm. The chemical composition of the first corrosion-resistant layer 111a, the second corrosion-resistant layer 211a, and the third corrosion-resistant layer 212a, by mass percentage, is: C≤1.25%, Si≤3.3%, Fe≤5%, Cr: 5%~5.5%, W: 28%~30%, with the balance being Ni. After the corrosion-resistant layers are formed, they are carburized and quenched. The hardness of the corrosion-resistant layers is 35HRC-45HRC, and the surface hardness of the remaining areas is 55HRC-60HRC.

[0046] In some embodiments, the first elbow may also be arranged in a multi-layer structure at the positions of the first sealing surface 111, the second sealing surface 211, and the third sealing surface 212 to improve erosion resistance and effectively prevent acidic liquids in the pipeline from corroding the sealing surfaces and causing elbow leakage failure.

[0047] Furthermore, such as Figure 3As shown, a transition layer 111b is provided on the first sealing surface 111. The material of the transition layer 111b includes, but is not limited to, nickel-based alloys, cobalt-based alloys, and stainless steel. The transition layer 111b can be formed by welding Ni20 alloy or Ni25 alloy onto the sealing surface to make the structural hardness of the transition layer 111b greater than or equal to 55HRC. Then, Ni40 alloy and tungsten carbide are welded onto the transition layer 111b to form the first corrosion-resistant layer 111a. That is to say, the first sealing surface 111 can be set as a multi-layer structure of transition layer 111b + corrosion-resistant layer to improve the corrosion resistance of the first sealing surface 111.

[0048] In one example, such as Figure 3 As shown, the substrate of the first elbow can be carburized and quenched first, and then a Ni25 alloy can be used as a base layer to form a transition layer 111b structure to prevent the carburized layer from cracking. The thickness of the transition layer 111b is 0.5mm. Then, a 1mm corrosion-resistant layer is formed using powder containing 30% WC. The powder containing 30% WC can form a corrosion-resistant layer that is free of defects after cladding. This allows for more flexible arrangement of the process and can also improve the wear and corrosion resistance of the first sealing surface 111.

[0049] In some embodiments, the first corrosion-resistant layer 111a is provided in two layers, and the transition layer 111b is provided between the two layers of the first corrosion-resistant layer 111a. That is, the first sealing surface 111 can be provided with a multi-layer structure of corrosion-resistant layer + transition layer 111b + corrosion-resistant layer.

[0050] In addition, the second sealing surface 211 and the third sealing layer can also be configured as a multi-layer structure as described above, which will not be elaborated here.

[0051] In some embodiments, such as Figure 1 As shown, the device includes a second bend 4, which is disposed at the second end of the first bend 1. The second end of the first bend 1 has a second groove 12. The second bend 4 has a second shoulder that connects to the second groove 12. The second groove 12 has a fourth sealing surface 121, and the fourth sealing surface 121 has at least one fourth corrosion-resistant layer 121a. The processing technology and expected technical effects of the fourth corrosion-resistant layer 121a can be referred to the aforementioned embodiments, and will not be elaborated upon here. It is understood that the bend device can be formed by sequentially connecting multiple bends, and has the characteristics of flexibility, impact resistance, vibration resistance, and large flow rate.

[0052] like Figure 1As shown, a dustproof ring 5 is provided on the side wall of the first end of the first bend 1. The dustproof ring 5 prevents external dust from entering the pipe during the connection of the movable bend, improving operational reliability. The inner wall of the connector 2 has multiple first semicircular grooves, and the outer wall of the first bend 1 has multiple second semicircular grooves. The multiple first semicircular grooves and second semicircular grooves are arranged in a one-to-one correspondence, and are engaged by steel balls 6. A plug 7 is provided on the connector 2 along its radial direction. The plug 7 improves the connection reliability between the connector 2 and the first bend 1. A wing nut 8 is provided at the end of the connector 2 away from the first bend, providing quick installation and removal and pressure-resistant sealing, facilitating transportation and storage.

[0053] This application provides a coiled tubing, including the elbow device as described above. Since the coiled tubing provided in this application includes the aforementioned elbow device, it naturally possesses the technical effects of the aforementioned elbow device.

[0054] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a specific order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0055] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0056] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A bend device, characterized in that, include: The first bend (1) includes a first end and a second end disposed opposite to each other in its own axial direction. The first end of the first bend (1) is provided with a first shoulder (11) and the first shoulder (11) has a first sealing surface (111). A connector (2) is disposed at the first end of the first bend (1). The connector (2) has a first groove (21) at one end facing the first bend (1). The first shoulder (11) is connected to the first groove (21). A sealing ring (3) is disposed between the first shoulder (11) and the first groove (21), and the first sealing surface (111) abuts against the sealing ring (3); The first sealing surface (111) is provided with at least one first corrosion-resistant layer (111a).

2. The elbow device according to claim 1, characterized in that, The first groove (21) has a second sealing surface (211), which abuts against the sealing ring (3), and the second sealing surface (211) is provided with at least one second corrosion-resistant layer (211a).

3. The elbow device according to claim 2, characterized in that, The first groove (21) has a third sealing surface (212), which is adjacent to the second sealing surface (211). The third sealing surface (212) abuts against the sealing ring (3). The third sealing surface (212) is provided with at least one third corrosion-resistant layer (212a).

4. The elbow device according to claim 3, characterized in that, The thickness of the first corrosion-resistant layer (111a), the second corrosion-resistant layer (211a), and the third corrosion-resistant layer (212a) is greater than or equal to 0.5 mm.

5. The elbow device according to claim 3, characterized in that, The hardness of the first corrosion-resistant layer (111a), the second corrosion-resistant layer (211a), and the third corrosion-resistant layer (212a) is set to 35HRC-45HRC.

6. The elbow device according to claim 3, characterized in that, The first corrosion-resistant layer (111a), the second corrosion-resistant layer (211a) and the third corrosion-resistant layer (212a) are alloy layers consisting of nickel-based alloy and tungsten carbide weld overlay.

7. The elbow device according to claim 1, characterized in that, A transition layer (111b) is provided on the first sealing surface (111).

8. The elbow device according to claim 7, characterized in that, The first corrosion-resistant layer (111a) is provided in two layers, and the transition layer (111b) is provided between the two layers of the first corrosion-resistant layer (111a).

9. The elbow device according to claim 1, characterized in that, The device includes a second bend (4), which is disposed at the second end of the first bend (1). The second end of the first bend (1) is provided with a second groove (12). The second bend (4) is provided with a second shoulder connected to the second groove (12). The second groove (12) has a fourth sealing surface (121), and the fourth sealing surface (121) is provided with at least one fourth corrosion-resistant layer (121a).

10. A continuous tubing, characterized in that, Includes the elbow device as described in any one of claims 1 to 9.

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