Oilfield tree anti-corrosion sealing kit

Abstract

This utility model discloses an anti-corrosion sealing kit for a wellhead, including a packer ring connecting sleeve, an upper packer ring mounted on the upper end face of the packer ring connecting sleeve, and a lower packer ring mounted on the lower end face of the packer ring connecting sleeve; the packer ring connecting sleeve, the upper packer ring, and the lower packer ring are all metal rings; it also includes polytetrafluoroethylene (PTFE) sealing rings mounted on the outer surfaces of the upper and lower packer rings. This utility model is a sealing component that can be installed on the oil pipe cross-section or other parts requiring sealing in a wellhead. It can provide a sealing function under high pressure and also ensure stable performance and resistance to damage in a carbon dioxide environment, thereby preventing leakage during carbon dioxide injection and release of oil in the wellhead and better fulfilling its oil guiding function.

Description

Technical Field

[0001] This utility model relates to a sealing element, specifically an anti-corrosion sealing kit for oil well trees. Background Technology

[0002] Carbon dioxide injection technology is an effective means of improving oil well recovery in oilfields and is currently widely used in major oilfields both domestically and internationally. During the carbon dioxide injection, well shut-in, and blowout processes, a large amount of carbon dioxide is present in the wellhead Christmas tree. The sealing rings of the Christmas tree tubing are highly susceptible to swelling upon contact with carbon dioxide. The consequences of this swelling are: initially, a decrease in sealing pressure and slight leakage; in the middle stage, relaxation of flange bolt stress and the appearance of "black spots" (corrosion products) on the sealing surface; in the later stage, the sealing ring becomes stuck in the groove and difficult to remove; and ultimately, failure can lead to high pressure piercing the sealing line, triggering a blowout and creating a safety hazard. Utility Model Content

[0003] To address the problem of swelling and failure of the sealing ring of the wellhead tree when exposed to carbon dioxide, this invention provides a corrosion-resistant sealing kit for the wellhead tree. It can provide a sealing function under high pressure and ensure stable performance and resistance to damage in a carbon dioxide environment. This achieves the goal of preventing leakage during the carbon dioxide injection and release process of the wellhead tree and better fulfilling its function of guiding oil flow.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an anti-corrosion sealing kit for oil production trees, including a packer ring connecting sleeve, an upper packer ring assembled on the upper end face of the packer ring connecting sleeve, and a lower packer ring assembled on the lower end face of the packer ring connecting sleeve; the packer ring connecting sleeve, the upper packer ring, and the lower packer ring are all metal rings;

[0005] It also includes PTFE sealing rings fitted on the outer sides of the upper and lower sealing rings.

[0006] As a limitation of this utility model, the upper and lower end faces of the sealing ring connecting sleeve are provided with annular grooves, which are used to fit and install the upper or lower sealing ring.

[0007] As a further limitation of this utility model, the annular groove is coated with sealing grease.

[0008] As another limitation of this utility model, grooves for assembling polytetrafluoroethylene sealing rings are provided on the outer surfaces of both the upper and lower sealing rings.

[0009] As a further limitation of this utility model, the polytetrafluoroethylene sealing ring is an O-ring.

[0010] As another limitation of this utility model, the sealing ring connecting sleeve, the upper sealing ring and the lower sealing ring are assembled into an R-shaped ring.

[0011] By adopting the above-mentioned technical solution, the beneficial effects achieved by this utility model compared with the prior art are as follows:

[0012] (1) This utility model adopts a split structure. The split design allows each component to move freely during swelling, avoiding excessive internal stress caused by the volume expansion of the overall sealing structure and reducing the risk of sealing surface distortion. At the same time, this utility model also innovatively introduces a polytetrafluoroethylene (PTFE) sealing ring as an auxiliary seal on the sealing surface. PTFE material has good corrosion resistance and is effective against corrosive ions (H2S, CO2, Cl). - This invention is virtually inert to media such as acidic / alkaline fluids and hydrocarbon solvents, effectively preventing contact between the media and the metal sealing surface and avoiding swelling caused by hydrogen permeation / sulfidation reactions. In carbon dioxide huff and puff oil production processes, installing this invention inside the wellhead tree can effectively reduce the corrosive damage of carbon dioxide to the sealing parts, improve wellhead sealing performance, and ensure safe production.

[0013] (2) In this invention, sealing grease is applied to the annular groove of the sealing ring connecting sleeve. On the one hand, this fills the gap between the sealing ring connecting sleeve and the sealing ring, enhancing the sealing effect. On the other hand, it prevents the sealing ring from shifting during installation and use, thus preventing sealing failure after installation. In addition, the sealing grease also acts as a lubricant, solving the problem of time-consuming and laborious disassembly and replacement.

[0014] In summary, this utility model has a simple structure, is easy to manufacture, install and use, and has low cost. It is a sealing device used in the well production tree of oil wells implementing carbon dioxide huff and puff technology, and can play the role of self-protection against corrosion and high-pressure sealing. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0017] Figure 2 This is an exploded view of an embodiment of the present utility model;

[0018] Figure 3 This is a cross-sectional view showing the structural relationship of an embodiment of the present utility model;

[0019] Figure 4 This is a schematic diagram of the structure of the sealing ring connecting sleeve in an embodiment of this utility model;

[0020] Figure 5 This is a schematic diagram of the upper sealing ring in an embodiment of the present invention;

[0021] Figure 6This is a schematic diagram of the upper sealing ring from another angle in an embodiment of this utility model;

[0022] In the diagram: 1. Spacer ring connecting sleeve; 2. Upper spacer ring; 3. Lower spacer ring; 4. PTFE sealing ring; 5. Annular groove; 6. Groove. Detailed Implementation

[0023] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0024] This embodiment discloses an anti-corrosion sealing kit for wellheads. When this kit is installed inside the wellhead wellhead during carbon dioxide injection and release oil production, it can effectively reduce the corrosive damage of carbon dioxide to the sealing parts, improve the wellhead sealing performance, and ensure safe production.

[0025] like Figures 1 to 3 As shown, this embodiment includes a packer ring connecting sleeve 1, an upper packer ring 2, and a lower packer ring 3. When assembled, these three components form an R-type ring, which can be embedded in an API standard trapezoidal sealing groove. Alternatively, this embodiment can be designed as a BX-type ring, meaning that the packer ring connecting sleeve 1, upper packer ring 2, and lower packer ring 3 can be assembled to form a BX-type ring, compatible with flanges conforming to API 6BX specifications.

[0026] Furthermore, such as Figure 4 As shown, the sealing ring connecting sleeve 1 adopts a metal ring structure. Both the upper and lower end faces of the sealing ring connecting sleeve 1 are provided with annular grooves 5. The width of the annular grooves 5 is adapted to the width of the upper sealing ring 2 and the lower sealing ring 3. The upper sealing ring 2 can be fitted into the annular groove 5 on the upper end face of the sealing ring connecting sleeve 1, and the lower sealing ring 3 can be fitted into the annular groove 5 on the lower end face of the sealing ring connecting sleeve 1.

[0027] In this embodiment, both annular grooves 5 of the sealing ring connecting sleeve 1 are coated with sealing grease.

[0028] The materials of the sealing ring connecting sleeve 1, upper sealing ring 2, and lower sealing ring 3 can be high-strength stainless steel (such as ASTM A182 F316), alloy steel (such as F22), or corrosion-resistant alloy (such as Inconel 718 or Hastelloy). In this embodiment, high-strength stainless steel is used. Furthermore, the outer surfaces of the sealing ring connecting sleeve 1, upper sealing ring 2, and lower sealing ring 3 all have a soft metal plating (such as silver plating, copper plating, nickel plating, or nickel alloy plating). In this embodiment, a silver plating is used.

[0029] It should be noted that in this embodiment, "upper" and "lower" refer to... Figure 1 The identifiers in this document are for illustrative purposes only and are not intended to limit this embodiment.

[0030] The upper sealing ring 2 and the lower sealing ring 3 have the same structure. In this embodiment, the structure of the upper sealing ring 2 will be described using the upper sealing ring 2 as an example: Figure 5 and Figure 6 As shown, the upper sealing ring 2 also adopts a metal ring structure, and its width is adapted to the width of the annular groove 5 mentioned above, so as to achieve a fitting installation in the annular groove 5 of the sealing ring connecting sleeve 1. In this embodiment, an annular groove 6 is provided on the outer side of the upper sealing ring 2 for embedding the polytetrafluoroethylene sealing ring 4 described below.

[0031] In this embodiment, the "outer surface" refers to the end face of the upper sealing ring 2 away from the connecting sleeve 1 of the upper sealing ring 2.

[0032] More specifically, this embodiment also includes two polytetrafluoroethylene (PTFE) sealing rings 4, which are O-rings made of PTFE material.

[0033] The above-mentioned polytetrafluoroethylene sealing rings 4 are embedded in the grooves 6 on the outer sides of the upper sealing ring 2 and the lower sealing ring 3. The polytetrafluoroethylene sealing rings 4 are used to block the medium from contacting the metal sealing surface and prevent swelling caused by hydrogen permeation / sulfurization reaction.

[0034] When using this embodiment, apply sealant to the annular groove 5 of the packer ring connecting sleeve 1, then place the upper packer ring 2 in the annular groove 5 on the upper end face of the packer ring connecting sleeve 1, and place the lower packer ring 3 in the annular groove 5 on the lower end face of the packer ring connecting sleeve 1. After assembling the three to form an R-shaped ring, install this embodiment on the oil well trunk tubing cross or other parts that need sealing.

[0035] In use, polytetrafluoroethylene sealing rings 4 are embedded on the outer surfaces of both the upper sealing ring 2 and the lower sealing ring 3.

[0036] It should be noted that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A corrosion resistant seal kit for a Christmas tree, characterized in that: It includes a packer ring connecting sleeve, an upper packer ring fitted on the upper end face of the packer ring connecting sleeve, and a lower packer ring fitted on the lower end face of the packer ring connecting sleeve; the packer ring connecting sleeve, the upper packer ring, and the lower packer ring are all metal rings; It also includes PTFE sealing rings fitted on the outer sides of the upper and lower sealing rings.

2. The corrosion control seal kit for a Christmas tree as defined in claim 1, wherein: The upper and lower ends of the sealing ring connecting sleeve are provided with annular grooves, which are used to fit and install the upper or lower sealing ring.

3. The corrosion control seal kit for a Christmas tree as defined in claim 2, wherein: The annular groove is coated with sealant.

4. The corrosion control seal kit for a Christmas tree as claimed in any one of claims 1 to 3, wherein: Grooves for assembling PTFE sealing rings are provided on the outer surfaces of both the upper and lower spacers.

5. The corrosion control seal kit for a Christmas tree as defined in claim 4, wherein: The polytetrafluoroethylene (PTFE) sealing ring is an O-ring.

6. The corrosion resistant seal kit for a Christmas tree as claimed in any one of claims 1 to 3, 5, wherein: The sealing ring connecting sleeve, upper sealing ring, and lower sealing ring are assembled into an R-shaped ring.

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