Removable large-annulus expansion metal composite structure sealing assembly

Abstract

The utility model relates to the technical field of oil and gas field equipment, and discloses a removable large-annulus expansion metal composite structure sealing assembly which comprises a steel body arranged on a mandrel in a sleeving mode, a limiting ring protruding outwards is arranged on the outer wall of the middle of the steel body, and the parts, located on the two sides of the limiting ring, of the steel body are thin walls which deform under pressure. The outer surfaces of the two thin walls are sleeved with rubber sheets, the two rubber sheets are symmetrically arranged with the limiting ring as the center, and the inner walls of the rubber sheets are tightly attached to the outer walls of the thin walls and are bonded with the thin walls. The removable large-annulus expansion metal composite structure sealing assembly can resist the ultrahigh temperature of 260 DEG C and the ultrahigh pressure of 138 MPa, meets the ultrahigh-temperature and ultrahigh-pressure well and mine environment, and effectively blocks an annulus gap.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas field equipment, in particular to a removable large annulus expansion metal composite structure sealing component. Background Art

[0002] In the field of oil drilling tools, sealing technology plays an extremely important role, especially in the design and development of retrievable bridge plugs, where performance is one of the core requirements, covering operational safety and many other considerations. At the same time, in well repair operations, the deployment and recovery of high temperature and high pressure performance of sealing components is also crucial.

[0003] The bonding of metals to non-metallic materials has been a pillar industry for more than 75 years, with widespread success in a variety of drilling and production tools. During this period, the overall mechanical structure of the seal remained essentially the same, consisting of an annular fixed elastomeric seal insert, a casing slide, and a locking device, all mounted on a central shaft and compressed axially to form an annular seal. Subsequent developments have focused on different deployment systems and mechanical systems, whether seals, external components, or overall tool design, to support and enhance the functionality of the elastomeric seal element. The development of elastomeric materials has expanded from the original natural rubber compounds to include a variety of different polymers to meet various technical and environmental challenges. However, despite this long period of development, there is still no compound and new structure that can simultaneously adapt to all pressures, temperatures, and chemical environments encountered downhole. Therefore, many developers must make a trade-off between the mechanical properties of the elastomer and its thermochemical properties, choosing to focus on certain aspects.

[0004] As technology advances, traditional sealing technologies are being applied to an industry that is evolving at an ever-increasing pace. We have entered an era dominated by natural gas production, where higher temperatures and pressures are becoming more common. At the same time, the industry is adapting to increasingly stringent regulatory requirements in the design, testing and certification of all products, especially those that have a significant impact on safety.

[0005] According to the literature and current development trends, the demand for next-generation seals will shift from liquids to gases. It is expected that by 2030, most of the global energy production will come from natural gas. In addition, with the reuse of associated gas to enhance oil recovery and the promotion of carbon dioxide (CO2) application technology, the demand for downhole gas sealing capabilities will further increase.

[0006] This is a significant weakness of conventional solid elastomer sealing technology. It is much more difficult to form a completely gas-tight seal than a liquid seal, and most gases, especially CO2 and H2S, will cause the mechanical properties of the elastomeric material to degrade and make it susceptible to decompression damage (RGD) when recovering the tool from downhole. In addition, when the seal is recovered from the wellbore, if sufficient time is not allowed for gas desorption, the elastomer may cause severe rupture due to expansion and blistering. Whether the seal is caused by chemical or physical decompression, it will cause serious problems in the recovery of the tool. Summary of the invention

[0007] The purpose of the utility model is to address the deficiencies of the above-mentioned technology and provide a removable large annulus expansion metal composite structure sealing component that can withstand ultra-high temperatures of 260°C and ultra-high pressures of 138MPa, meet the ultra-high temperature and ultra-high pressure mine environment, and effectively seal the annular space gap.

[0008] To achieve the above-mentioned purpose, the utility model is designed with a removable large annulus expansion metal composite structure sealing assembly, including a steel body sleeved on a core shaft, a convex limiting ring being provided on the middle outer wall of the steel body, and the parts of the steel body located on both sides of the limiting ring are thin walls that are deformed under pressure, and the outer surfaces of the two thin walls are sleeved with rubber, and the two rubbers are symmetrically arranged with the limiting ring as the center, and the inner walls of the rubbers are tightly attached to the outer walls of the thin walls, forming a bonding relationship with the thin walls, so that when the rubber is expanded under longitudinal force, it can fit tightly to the casing or the open hole wall.

[0009] Preferably, one end of the rubber is against the limiting ring, and the thin wall is provided with a barb against the other end of the rubber, which can protect the rubber and ensure that the rubber will not be torn when the annulus is pressurized, thereby providing a good anti-extrusion effect.

[0010] Preferably, the thin wall is convex outwardly so that its outer surface is arc-shaped, and the two thin walls and the limiting ring form a W-shaped structure.

[0011] Preferably, the barb is provided with an inward chamfer at one end facing the rubber to wrap the end of the rubber, so that the rubber can be covered in an open and pressurized state without being affected by the extrusion force.

[0012] Preferably, the chamfer is 10° to 20°.

[0013] Preferably, the thickness of the thin wall varies with the setting force value required by the tool.

[0014] Preferably, the thickness of the thin wall is 1 mm to 3 mm.

[0015] Preferably, the upper end of the steel body is provided with an external thread, the outer diameter of which is smaller than the outer diameter of the steel body, and can be connected to the sealing tool body to achieve a series of actions such as sealing, pressure bearing, unsealing, and withdrawal.

[0016] Compared with the prior art, the utility model has the following advantages:

[0017] 1. Before the packer is started, the external thread is connected to the tool body, and the annulus will not be set in advance when a series of actions such as fluid replacement are performed. When the packer is started, the thin wall of the steel body and the rubber are opened in sequence to block the annulus to ensure that the packer fits tightly against the well wall;

[0018] 2. The structure is simple, the use of components is reduced, and the length of the sealing assembly is significantly shortened, resulting in a significant reduction in the size of the overall tool, thus providing greater convenience for deep-ground and deep-sea operations;

[0019] 3. The design of bonding between the steel body and the rubber enables the rubber to fit closely to the casing or the open hole wall when the rubber is subjected to longitudinal force expansion;

[0020] 4. Barbs are specially designed at both ends of the steel body to protect the rubber and ensure that the rubber will not be torn when the annulus is under pressure, thus providing a good anti-extrusion effect;

[0021] 5. Use metal materials with large deformation and good pressure bearing capacity as the sealing substrate. When subjected to axial pressure, the weak point, that is, the thin wall, will deform and swell first, and finally the steel body will open and make the bonded rubber fit closely to the open hole wall, effectively blocking the annular gap;

[0022] 6. One end of the steel body is provided with an external thread, which can be connected to the sealing tool body to realize a series of actions such as setting, pressure bearing, unsealing, and taking out. When the sealing work is completed and needs to be unsealed, the tool will unseal by rotating. In this process, the external thread is connected to the body of the sealing tool. With the help of the lifting force, the outer diameter of the thin wall can be restored to -3% to -5% of its original size, allowing the tool to be taken out smoothly;

[0023] 7. Metal materials with certain ductility and strength are selected, and organic polymer compounds resistant to special media are combined. Under the new API standard, it can reach V0-H level, with strong temperature and pressure resistance, and can withstand 20KPsi pressure in a sealed environment up to 260°C, with strong temperature and pressure resistance;

[0024] 8. Whether it is low pressure or high pressure working condition, it can achieve reliable gas sealing effect, which enhances the applicability and flexibility of the packer and enables it to adapt to various working conditions;

[0025] 9. It can be applied to casings of different pound grades, can effectively prevent the rubber cylinder from setting prematurely, and has strong pressure resistance and wide adaptability, avoiding leakage problems caused by improper use or environmental factors; BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The utility model discloses a removable large annular space expansion metal composite structure sealing component.

[0027] The components in the figure are numbered as follows:

[0028] Steel body 1, limiting ring 2, thin wall 3, rubber 4, barb 5, external thread 6. DETAILED DESCRIPTION

[0029] The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown, a removable large annulus expansion metal composite structure sealing component includes a steel body 1 sleeved on a core shaft, a convex limiting ring 2 is provided on the middle outer wall of the steel body 1, and the parts of the steel body 1 located on both sides of the limiting ring 2 are thin walls 3 that are deformed under pressure, and the outer surfaces of the two thin walls 3 are sleeved with rubber 4, and the two rubbers 4 are symmetrically arranged with the limiting ring 2 as the center, and the inner walls of the rubber 4 are tightly attached to the outer walls of the thin walls 3 to form a bonding relationship with the thin walls 3, so that when the rubber 4 is expanded under longitudinal force, it can fit tightly to the casing or the open hole wall.

[0031] Among them, one end of the rubber 4 is against the limiting ring 2, and the thin wall 3 is provided with a barb 5 that presses against the other end of the rubber 4, which can protect the rubber 4 and ensure that the rubber 4 will not be torn when the annulus is pressurized, thereby providing a good anti-extrusion effect. The barb 5 is provided with an inward chamfer on one end facing the rubber 4 to wrap the end of the rubber 4, and the chamfer is 10° to 20°. In this embodiment, the chamfer is 15°, which can wrap the rubber 4 in the open pressure without being affected by the extrusion force.

[0032] In this embodiment, the thin wall 3 is convex outwards so that its outer surface is arc-shaped, and the two thin walls 3 and the limiting ring 2 form a W-shaped structure.

[0033] In addition, the thickness of the thin wall 3 varies with the setting force value required by the tool. The thickness of the thin wall 3 is generally 1 mm to 3 mm, and is 2 mm in this embodiment.

[0034] At the same time, the upper end of the steel body 1 is provided with an external thread 6, whose outer diameter is smaller than that of the steel body 1, and can be connected to the sealing tool body to realize a series of actions such as setting, pressure bearing, unsealing, and withdrawal.

[0035] Finally, the material of the steel body 1 is heat-resistant steel, wear-resistant steel, stainless steel, carbon steel or 718 nickel alloy, and the material of the rubber 4 is nitrile rubber, hydrogenated nitrile rubber, fluororubber, or FFKM.

[0036] When this embodiment is used, before the packer is started, the external thread 6 is connected to the tool body, and the annulus will not be sealed in advance when performing a series of actions such as fluid replacement. When the packer is started, through compression sealing, the steel body 1 will first be subjected to the extrusion force, the thin wall 3 will deform and swell, and then the two rubbers 4 will be driven to expand and squeeze towards the middle at the same time. When the end of the rubber 4 close to the limit ring 2 contacts the limit ring 2 protruding from the middle of the steel body 1, the rubber 4 is further squeezed, so that the two rubbers 4 are in contact, and finally expand to be close to the annulus open hole or casing wall. At this time, the two rubbers 4 fill the entire W-shaped structure.

[0037] The utility model discloses a removable large annulus expansion metal composite structure sealing component. Before the packer is started, the external thread 6 is connected to the tool body. The annulus will not be sealed in advance when a series of actions such as fluid replacement are performed. When the packer is started, the thin wall of the steel body and the rubber are opened in sequence to seal the annulus to ensure that the packer fits tightly against the well wall. The structure is simple, the use of components is reduced, and the length of the sealing component is significantly shortened, resulting in a significant reduction in the overall tool size, thereby providing greater convenience for deep-earth and deep-sea operations. The design of bonding the steel body 1 and the rubber 4 enables the rubber 4 to fit tightly against the casing or the open hole wall when it is longitudinally stressed and bulged. Barbs 5 are specially designed at both ends of the steel body 1 to protect the rubber 4 and ensure that the rubber 4 will not be torn when the annulus is pressurized, thereby providing a good anti-extrusion effect. A metal material with a large deformation amount and good pressure-bearing capacity is used as the sealing substrate. When it is subjected to axial pressure When the force is applied, the weak part, i.e. the thin wall 3, is deformed and bulged first, and finally the steel body 1 opens and makes the bonded rubber 4 fit closely to the naked eye wall, effectively blocking the annular space gap; an external thread 6 is provided at one end of the steel body 1, and the external thread 6 can be connected to the sealing tool body to realize a series of actions such as setting, bearing pressure, unsealing, and taking out. When the sealing work is completed and needs to be unsealed, the tool will unseal by rotating. In this process, the external thread 6 is connected to the body of the sealing tool. With the help of the lifting force, the outer diameter of the thin wall 3 can be restored to -3% to -5% of its original size, allowing the tool to be taken out smoothly; metal materials with certain ductility and strength are selected, and combined with organic polymer compounds resistant to special media, under the new API standard, it can reach V0-H grade, with strong temperature and pressure resistance, and can withstand 20K in a sealing environment up to 260℃. Psi pressure, with strong temperature and pressure resistance; whether it is low-pressure or high-pressure conditions, it can achieve a reliable air-tight effect, enhance the applicability and flexibility of the packer, so that it can adapt to a variety of working conditions; it can be applied to casings of different pound grades, can effectively prevent the rubber cartridge from setting prematurely, and has strong pressure resistance and wide adaptability, avoiding leakage problems caused by improper use or environmental factors.

[0038] It should be noted that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the utility model thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the utility model is limited only by the scope of the claims.

[0039] The various aspects disclosed for describing the present specification and claims are merely examples, and therefore, the present specification and claims are not limited to the details shown. In the above description, when the detailed description of the related known functions or configurations is determined to be unnecessary to obscure the focus of the present specification and claims, the detailed description will be omitted.

[0040] Finally, it should be pointed out that the above content is a further detailed description of the utility model in combination with the specific implementation method. It cannot be considered that the specific implementation of the utility model is limited to these descriptions. For ordinary technicians in the technical field to which the utility model belongs, simple replacements made without departing from the concept of the utility model should be regarded as belonging to the protection scope of the utility model. The above embodiments are only more representative examples of the utility model. Obviously, the utility model is not limited to the above embodiments, and there can be many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the utility model should be considered to belong to the protection scope of the utility model.

Claims

1. A removable large annular expansion metal composite structure seal assembly, comprising a steel body (1) sleeved on a core shaft, characterized in that: The outer wall of the middle part of the steel body (1) is provided with an outwardly convex limiting ring (2), and the parts of the steel body (1) located on both sides of the limiting ring (2) are thin walls (3) that are deformed under pressure, and the outer surfaces of the two thin walls (3) are both covered with rubber (4), and the two rubbers (4) are symmetrically arranged with the limiting ring (2) as the center, and the inner walls of the rubbers (4) are tightly attached to the outer walls of the thin walls (3), forming a bonding relationship with the thin walls (3).

2. The removable large annulus expansion metal composite structure sealing assembly according to claim 1 is characterized in that: One end of the rubber (4) abuts against the limiting ring (2), and the thin wall (3) is provided with a barb (5) abutting against the other end of the rubber (4).

3. The removable large annulus expansion metal composite structure sealing assembly according to claim 1 is characterized in that: The thin wall (3) is convex outwards so that its outer surface is arc-shaped, and the two thin walls (3) and the limiting ring (2) form a W-shaped structure.

4. The removable large annulus expansion metal composite structure sealing assembly according to claim 2 is characterized in that: The barb (5) is provided with an inward chamfer at one end facing the rubber (4) so ​​as to wrap the end of the rubber (4).

5. The removable large annulus expansion metal composite structure sealing assembly according to claim 4 is characterized in that: The chamfer angle is 10° to 20°.

6. The removable large annulus expansion metal composite structure sealing assembly according to claim 1, characterized in that: The thickness of the thin wall (3) varies with the setting force value required by the tool.

7. The removable large annulus expansion metal composite structure sealing assembly according to claim 1, characterized in that: The thickness of the thin wall (3) is 1 mm to 3 mm.

8. The removable large annulus expansion metal composite structure sealing assembly according to claim 1, characterized in that: The upper end of the steel body (1) is provided with an external thread (6), the outer diameter of which is smaller than the outer diameter of the steel body (1).

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