Dual differential pressure float collar

Abstract

The application provides a double-pressure-difference floating coupling, which comprises an outer cylinder, an upper joint arranged at the upper end of the outer cylinder, a lower joint arranged at the lower end of the outer cylinder, a pressure-resistant part arranged in the inner part of the outer cylinder in a sealed and fixed manner, and a drift diameter assembly arranged in the inner part of the outer cylinder, wherein the number of the drift diameter assembly is two, and the drift diameter assembly is arranged above and below the pressure-resistant part respectively, and the drift diameter assembly is configured to be capable of impacting the pressure-resistant part under the action of pressure. The application can realize the full drift diameter of the pipe column after the pressure-resistant part is broken, and can reduce the construction risk, and has the characteristics of simple structure, convenient construction and the like.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas drilling, completion and reservoir stimulation technology, specifically, it relates to a dual-pressure differential floating coupling. Background Technology

[0002] During the development of oil and gas wells, as exploration and development deepen, oil and gas wells face problems such as large water-to-vertical ratio and insufficient self-weight of tubing due to long horizontal sections, resulting in large frictional torque in the horizontal section and difficulty in lowering the tubing when it is lowered.

[0003] The floating coupling casing technology effectively solves the challenge of running completion tubing in wells with extended reach and long horizontal sections. This technology involves sealing a section of air or low-density drilling fluid at the bottom of the casing string using a floating coupling, allowing the casing string to float in the drilling mud of the inclined or horizontal sections of the well. This reduces friction between the casing string and the wellbore. After the casing string is in place, the sealed section is then opened to ensure unobstructed flow inside the casing string.

[0004] In existing technologies, there is a type of floating coupling with a pressure-resistant component. This type of coupling seals off a section of air or low-density drilling fluid using a pressure-resistant component. After the tubing string is in place, the pressure-resistant component is broken by direct pressure buildup. However, this pressure buildup method may result in the pressure-resistant component not being completely broken, meaning the tubing string may not have reached its full bore. If the pressure-resistant component is not completely broken, it will affect the passage performance of the cement plug during subsequent operations. The cement plug may be damaged by the residual pressure-resistant component during passage, preventing it from effectively scraping away residual cement in the tubing string. This increases the actual opening pressure of tools such as the pre-installed differential pressure sleeve in the tubing string and reduces the safety of other tools passing through, increasing construction risks. Furthermore, it may completely destroy the cement plug, causing it to fail due to pressure contact and seal failure, leading to cement backflow into the wellbore and creating complex wellbore conditions.

[0005] In addition, another type of floating coupling with a sliding sleeve and a pressure-resistant component exists in the existing technology. This type of floating coupling has a movable pressure-resistant component and a fixed impact sleeve inside, with a crushing disc positioned above the impact sleeve. The impact sleeve and the pressure-resistant component are then fixed together by shear pins. When it is necessary to crush the pressure-resistant component, pressure is pumped in from above the crushing disc, pushing the pressure-resistant component to shear the shear pins and then impact the impact sleeve, thereby completely crushing the pressure-resistant component. Although this technology can achieve full-bore tubing, it is essential to ensure that the pressure-resistant component does not shift relative to the main tubing of the floating coupling during the running-in process. In this structure, a large number of shear pins must be used to fix the pressure-resistant component and ensure its normal operation during running-in. Therefore, this structure requires a large number of shear pins, which are difficult to control, and are often distributed in multiple rows. This may cause uneven stress on the pins under the pressure of the drilling mud, leading to premature shearing, process failure, and preventing the tubing from being successfully run into place. The use of multiple shear pins results in extremely high pumping pressure during the crushing of the compression component. Since the compression component bears the pressure to shear the shear pins, such pumping pressure may cause the compression component to break prematurely. If the compression component breaks or the seal fails due to unforeseen circumstances before the shear pins break, the shear pins will not be able to cut through it, preventing the compression component from hitting the impact sleeve. This may prevent the tubing string from achieving full bore, affecting subsequent work and increasing operational risks. Summary of the Invention

[0006] To address the technical problems described above, this invention aims to propose a dual-pressure differential floating coupling, which can achieve full-bore tubing and reduce the risk of operational accidents.

[0007] According to the present invention, a dual-pressure differential floating coupling is provided, comprising: an outer cylinder; an upper connector disposed at the upper end of the outer cylinder; a lower connector disposed at the lower end of the outer cylinder; a pressure-resistant member disposed in a sealed manner inside the outer cylinder; and two through-hole components disposed inside the outer cylinder, respectively disposed above and below the pressure-resistant member, wherein the through-hole components are configured to impact the pressure-resistant member under pressure.

[0008] In one embodiment, the bore assembly includes an inner sleeve that is sealed and fixedly connected to the outer cylinder and an impact sleeve that is fixed to the inner sleeve by a shear pin.

[0009] In one embodiment, a C-shaped ring is provided on the outer wall of the inner sleeve, and a groove that mates with the C-shaped ring is provided on the inner wall of the outer cylinder.

[0010] In one embodiment, the upper end of the impact sleeve located above the anti-pressure member abuts against the upper connector, and the lower end abuts against the anti-pressure member.

[0011] In one embodiment, the impact sleeve includes a convex ring portion and an impact portion, the wall thickness of the convex ring portion is greater than the wall thickness of the impact portion, the convex ring portion is sealed to the outer cylinder, and the inner sleeve is sealed between the impact portion and the outer cylinder.

[0012] In one embodiment, a positioning protrusion for mounting the anti-pressure member is provided inside the outer cylinder, and a positioning end face is provided on the positioning protrusion, with the lower end of the anti-pressure member abutting against the positioning end face.

[0013] In one embodiment, the upper end of the lower connector extends into the interior of the outer cylinder and abuts against a bore assembly located below the pressure-resistant member.

[0014] In one embodiment, the inner diameter of the positioning protrusion is greater than or equal to the outer diameter of the impact sleeve.

[0015] In one embodiment, a sealing structure is provided on the pressure-resistant component, wherein the sealing structure is a single-sided seal or a multi-sided seal.

[0016] In one embodiment, the pressure-resistant component is made of a high-pressure resistant and fragile non-metallic material, including glass, ceramics, and resin, and the pressure-resistant component is cylindrical or spherical.

[0017] Compared with the prior art, this application has the following advantages.

[0018] This invention isolates the drilling mud through a pressure-resistant component during tubing string lowering. A section of air or low-density drilling fluid is sealed between the double-pressure differential floating coupling and the lower tubing string. Buoyancy reduces the weight of the tubing string entering the inclined or horizontal section of the well, thereby reducing friction and facilitating smooth lowering. In this invention, the pressure-resistant component is fixedly mounted inside the outer cylinder. The impact sleeve has a small axial pressure area and can be fixed inside the outer cylinder by a small number of shear pins, reducing the difficulty of pin control. During the crushing of the pressure-resistant component, the impact sleeve uses the pressure difference between its upper and lower ends to achieve displacement, shearing the shear pins and impacting the crushing disc. The debris from the pressure-resistant component is then carried out through circulation. With this setup, even if the pressure-resistant component fails prematurely, the impact sleeve can still complete displacement under pressure and impact the component. This invention achieves full-bore tubing after the pressure-resistant component is crushed, reduces construction risks, and features a simple structure and convenient construction. Attached Figure Description

[0019] The present invention will now be described with reference to the accompanying drawings.

[0020] Figure 1 This diagram shows an initial state schematic of an embodiment of the dual differential pressure floating coupling according to the present invention;

[0021] Figure 2This shows a schematic diagram of the compressive strength component after breakage according to an embodiment of the dual-pressure-difference floating coupling of the present invention;

[0022] Figure 3 A schematic diagram of another embodiment of the crushing disc according to the present invention is shown;

[0023] Figure 4 A schematic diagram showing the inner sleeve and outer sleeve connected by pins according to the present invention is provided.

[0024] In the figure: 1. Outer cylinder; 11. Positioning protrusion; 111. Positioning end face; 2. Upper connector; 3. Lower connector; 4. Pressure-resistant component; 41. Sealing structure; 5. Through-bore assembly; 51. Inner sleeve; 511. C-ring; 512. Groove; 52. Impact sleeve; 521. Protruding ring; 522. Impact part; 6. Shear pin.

[0025] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0026] The invention will now be described with reference to the accompanying drawings.

[0027] In this application, it should be noted that the direction of the material being lowered into the well near the wellhead according to the present invention is described as "upstream," "upper end," or similar terms, i.e. Figure 1 The upper side is shown; the direction away from the wellhead is described as "downstream," "lower end," or similar terms, i.e. Figure 1 The lower side is shown.

[0028] Figure 1 The structure of the dual differential pressure floating coupling 100 according to the present invention is shown. For example... Figure 1 As shown, the dual-differential pressure floating coupling 100 includes an outer cylinder 1, an upper connector 2, a lower connector 3, a pressure-resistant component 4, and two through-bore assemblies 5. The upper connector 2 and lower connector 3 are respectively sealed at the upper and lower ends of the outer cylinder 1. In this embodiment, the upper connector 2 and lower connector 3 are connected to the outer cylinder 1 via a threaded connection. It is easy to understand that both the upper connector 2 and lower connector 3 can connect to other downhole tubing. The pressure-resistant component 4 and the through-bore assemblies 5 are both disposed inside the outer cylinder 1. The pressure-resistant component 4 is sealed and fixed inside the outer cylinder 1, used to cooperate with other tubing connected to the dual-differential pressure floating coupling 100 to create a closed space. The two through-bore assemblies 5 are symmetrically arranged above and below the pressure-resistant component 4. Under a certain pressure, the through-bore assemblies 5 can impact the pressure-resistant component 4, breaking it and achieving full-bore operation.

[0029] In one embodiment, the bore assembly 5 includes an inner sleeve 51 and an impact sleeve 52. The inner sleeve 51 is fixedly connected to the outer cylinder 1 and connected to the impact sleeve 52 via a shear pin 6. There are various ways to fix the inner sleeve 51 to the outer cylinder 1, such as via a pin connection, etc. Figure 4 As shown, sealing is required.

[0030] In a preferred embodiment, the inner sleeve 51 is fixedly connected to the outer cylinder 1 by a snap-fit ​​connection. A C-ring 511 is provided on the outer wall of the inner sleeve 51, and a corresponding groove 512 is provided on the inner wall of the outer cylinder 1. In its natural state, the outer diameter of the C-ring 511 is larger than the outer diameter of the inner sleeve 51, and the inner diameter is smaller than the outer diameter of the inner sleeve 51. This design avoids directly installing shear pins on the cylinder wall of the outer cylinder 1, thereby enhancing the structural strength of the outer cylinder 1 and improving its sealing performance.

[0031] According to an embodiment of the present invention, the impact sleeve 52 includes a convex ring portion 521 and an impact portion 522. The wall thickness of the convex ring portion 521 is greater than that of the impact portion 522, and their inner diameters are equal. The convex ring portion 521 contacts the outer cylinder 1, and a sealing ring is provided between them. The impact portion 522 contacts the inner sleeve 51, and a sealing ring is also provided between them. A sealing ring is also provided between the inner sleeve 51 and the outer cylinder 1. With this arrangement, when the space above the pressure-resistant member 4 is pumped with pressure, the axial force of the impact sleeve 51 is applied to the upper end face of the convex ring portion 521 and the lower end face of the impact portion 522, respectively. Since the wall thickness of the convex ring portion 521 is greater than that of the impact portion 522, the area of ​​the upper end face of the convex ring portion 521 is greater than the area of ​​the lower end face of the impact portion 522. Under the pressure difference caused by the area difference at both ends, the impact sleeve 51 shears off the shear pin 6 and impacts the pressure-resistant member 4.

[0032] In this configuration, since the anti-pressure component 4 no longer controls the cutting shear pins 6, even if the anti-pressure component 4 fails, it will not affect the impact sleeve 52 impacting the anti-pressure component 4 under pressure. Furthermore, the impact sleeve 52 has a small force-bearing area, resulting in less pressure on it under the same pressure. Therefore, fewer shear pins 6 are required, reducing the design and control difficulty of the shear pins 6 during the design and production process, and also reducing the pressure control difficulty during the pumping process.

[0033] It is easy to understand that there is no sealed connection between the upper end of the impact sleeve 52 and the upper connector 2, so the pressure on the upper and lower ends of the impact sleeve 52 is equal. The force generated by the compression of air in the closed annular space formed between the impact sleeve 52, the outer cylinder 1, and the inner sleeve 51 is insufficient to affect the movement of the impact sleeve 52.

[0034] In one embodiment, the pressure-resistant component 4 is fixedly installed inside the outer cylinder 1 by abutting against other components. Specifically, a positioning protrusion 11 for installing the pressure-resistant component 4 is provided on the inner wall of the outer cylinder 1, and a positioning end face 111 is provided on the positioning protrusion 11. The pressure-resistant component 4 is sealed on the positioning protrusion 11, with one end abutting against the positioning end face 111 and the other end abutting against the through-diameter component 5, the upper end of which abuts against the upper connector 2.

[0035] To achieve the effect of sealing the tubular column with the pressure-resistant component 4, a sealing structure 41 can be set on any of the three surfaces in contact with the pressure-resistant component 4. The sealing structure 41 can be an O-ring on any of the aforementioned surfaces, a semi-enclosed seal on two adjacent surfaces, or a fully enclosed seal on all three surfaces.

[0036] Furthermore, to ensure that the pressure-resistant component 4 can withstand a certain pressure while also being broken by the impact sleeve 52, the pressure-resistant component 4 is made of a high-pressure resistant, brittle non-metallic material, such as glass, ceramics, or resin. To improve the pressure resistance of the pressure-resistant component 4 at the same thickness, in addition to… Figure 1 The cylinder shown can also be constructed as Figure 3 Other shapes, such as spherical shells, are shown.

[0037] In a preferred embodiment, the inner diameter of the positioning protrusion 11 is greater than or equal to the outer diameter of the impact sleeve 52. This ensures that the impact sleeve 52 can impact the pressure-resistant member 4 while also enveloping the pressure-resistant member 4 as securely as possible.

[0038] This invention can achieve multiple usage methods by controlling the strength of the shear pin 6. The usage method of reducing the running friction by sealing a section of air or low-density drilling fluid with the pressure-resistant component 4 is the same as the prior art. The main difference is the way the pressure-resistant component 4 breaks after the pump pressure is applied in place, as detailed below.

[0039] Method 1: When the strength of the shear pin 6 is low, i.e. after pumping pressure, the impact sleeve 52 above the pressure-resistant member 4 tends to move downward under pressure, and the shear pin 6 is sheared by the impact sleeve 52. Subsequently, the impact sleeve 52 impacts the pressure-resistant member 4, and the impact of the impact sleeve 52 causes a weak point on the pressure-resistant member 4 that matches the contour of the impact sleeve 52. After increasing the pumping pressure, the pressure-resistant member 4 breaks along the contour formed by the weak point. Then, the impact sleeve 52 below the pressure-resistant member 4 is subjected to pressure and impacts the pressure-resistant member 4, causing secondary crushing of the pressure-resistant member and ensuring full bore. The strength of the shear pin 6 used to fix the impact sleeve 52 below the pressure-resistant member 4 only needs to ensure that the impact sleeve 52 can be stably installed in the floating coupling during transportation and well insertion, thereby reducing the strength design difficulty of the shear pin 6 in this invention and ensuring that the shear pin can break normally under low pumping pressure.

[0040] It is easy to understand that the high-pressure resistant and fragile non-metallic materials such as glass, ceramics, and resin used in this embodiment have the physical property that once a weak point appears, it will break along the contour formed by the weak point when subjected to strong pressure again.

[0041] Method Two: When the strength of the shear pin 6 used to fix the impact sleeve 52 above the pressure-resistant component 4 is greater than that in Method One, that is, after the pumping pressure, the impact sleeve 52 above the pressure-resistant component 4 tends to move downward under the pressure. The shear pin 6 is sheared by the impact sleeve 52. Subsequently, the impact sleeve 52 impacts the pressure-resistant component 4. The impact of the impact sleeve 52 causes a crushing through hole on the pressure-resistant component 4 that matches the contour of the impact sleeve 52. Afterward, the impact sleeve 52 below the pressure-resistant component 4 is subjected to pressure and impacts the pressure-resistant component 4, causing secondary crushing of the pressure-resistant component, ultimately presenting... Figure 2 The effect shown achieves full bore. The strength of the shear pin 6 used to fix the impact sleeve 52 below the pressure-resistant component 4 only needs to ensure that the impact sleeve 52 can be stably installed inside the floating coupling during transportation and well insertion. This reduces the design difficulty of the shear pin 6 in this invention and ensures that the shear pin can break normally even under low pumping pressure.

[0042] Method 3: When the strength of the shear pin 6 used to fix the impact sleeve 52 above the pressure-resistant component 4 is greater than that in Method 2, that is, after the pumping pressure, the impact sleeve 52 above the pressure-resistant component 4 tends to move downward under pressure. However, the pressure-resistant component 4 breaks before the shear pin 6 used to fix the impact sleeve 52 above the pressure-resistant component 4, that is, the main body of the pressure-resistant component 4 explodes into fine particles. Then, the two shear pins 6 are sheared off respectively. Subsequently, the two impact sleeves 52 impact the pressure-resistant component 4 respectively, cleaning up the remaining parts at the edge of the pressure-resistant component 4 to achieve full bore. In a specific embodiment, the shear pin 6 used to fix the impact sleeve 52 above the pressure-resistant component 4 is a soluble pin made of high-strength soluble material. Before installation, a solid flux is first introduced into the pin hole where the soluble pin is installed for partial filling, and then the soluble pin is installed into the pin hole. Accordingly, after the floating coupling is installed, during the grouting process, a section of isolation fluid needs to be pumped into the floating coupling section before the mud is pumped in. The isolation fluid separates the mud from the solid flux and soluble pins, preventing the solid flux from causing the soluble pins to dissolve prematurely under the influence of the mud. The strength of the shear pins 6 used to fix the impact sleeve 52 below the pressure-resistant component 4 only needs to ensure that the impact sleeve 52 can be stably installed inside the floating coupling during transportation and well insertion, thereby reducing the design difficulty of the invention. In this embodiment, the pumping pressure does not need to exceed the burst pressure of the pressure-resistant component 4, thereby effectively preventing the mud from being squeezed into the formation due to excessive pumping pressure, thus reducing the formation oil and gas production. The specific working principle of this embodiment is as follows.

[0043] After the pump pressure is applied, the pressure-resistant component 4 ruptures before the soluble pin (i.e., the shear pin 6 used to fix the impact sleeve 52 above the pressure-resistant component 4). After the pressure-resistant component 4 bursts, the floating coupling section where the soluble pin is located is pressurized, causing the shear pin 6 used to fix the impact sleeve 52 below the pressure-resistant component 4 to be sheared off. The impact sleeve 52 then impacts the pressure-resistant component 4, clearing away the remaining parts of the burst pressure-resistant component 4. Simultaneously, the pre-pumped isolation fluid is replaced by the mud above and flows down along the tubing string, causing the isolation fluid to become ineffective. That is, the isolation fluid loses its protective effect on the solid flux and the soluble pin, and the solid flux comes into contact with the mud. The solid flux dissolves under the soaking of the mud, causing the soluble pin to dissolve rapidly. When the soluble pin loses strength due to dissolution, it is not necessary to increase the pump pressure. The soluble pin can be sheared off with a liquid column pressure or circulation pressure not exceeding that of the pressure-resistant component 4 bursting, thereby accelerating the impact sleeve 52 above the pressure-resistant component 4 downwards and impacting the remaining parts of the burst pressure-resistant component 4 again. Even when the liquid column pressure or circulating pressure is low, and the impact force generated by the two impact sleeves 52 cannot completely remove the residual part of the pressure-resistant component 4, the pressure difference force that always exists in the tubing (i.e., inside the floating coupling) acting on the two impact sleeves 52 can still crush the residual part after the pressure-resistant component 4 bursts. Since the residual part after the pressure-resistant component 4 bursts is not intact, its compressive strength decreases significantly under the impact crushing action. Thus, the residual part can be crushed into fine particles through the compression action, achieving full-bore. Under this setting, on the one hand, the pumping pressure required during the working process does not need to exceed the burst pressure of the pressure-resistant component 4, thereby solving the problem that mud may invade the formation under high pressure. On the other hand, the shear pin 6 used to fix the impact sleeve 52 above the pressure-resistant component 4 is a soluble pin. By dissolving, the strength of the soluble pin is reduced, which can more reliably complete the impact action of the impact sleeve 52 above the pressure-resistant component 4, avoiding the situation where the shear pin 6 used to fix the impact sleeve 52 above the pressure-resistant component 4 cannot shear off under the pressure operating window.

[0044] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing 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 invention should be included within the protection scope of the present invention.

Claims

1. A dual-pressure differential floating coupling, characterized in that, include: outer cylinder(1); The upper connector (2) is provided at the upper end of the outer cylinder; The lower connector (3) is provided at the lower end of the outer cylinder; A pressure-resistant component (4) is fixedly installed inside the outer cylinder in a sealed manner; And a through-hole assembly (5) disposed inside the outer cylinder, there are two through-hole assemblies, which are respectively disposed above and below the pressure-resistant member. The through-hole assembly is configured to impact the pressure-resistant member under pressure. The through-hole assembly (5) includes an inner sleeve (51) which is sealed and fixedly connected to the outer cylinder (1) and an impact sleeve (52) which is fixed to the inner sleeve by a shear pin. The impact sleeve is configured to shear the shear pin under the pressure difference caused by the area difference at both ends and impact the pressure-resistant member. After the pressure-resistant component breaks, the impact sleeve below the pressure-resistant component is subjected to pressure and impacts the pressure-resistant component.

2. The dual-pressure differential floating coupling according to claim 1, characterized in that, A C-ring (511) is provided on the outer wall of the inner sleeve (51), and a groove (512) that mates with the C-ring is provided on the inner wall of the outer cylinder (1).

3. The dual-pressure differential floating coupling according to claim 2, characterized in that, The upper end of the impact sleeve (52) located above the anti-pressure member (4) abuts against the upper connector (2), and the lower end abuts against the anti-pressure member (4).

4. The dual-pressure differential floating coupling according to claim 3, characterized in that, The impact sleeve (52) includes a convex ring portion (521) and an impact portion (522). The wall thickness of the convex ring portion is greater than the wall thickness of the impact portion. The convex ring portion is sealed to the outer cylinder (1). The inner sleeve (51) is sealed between the impact portion and the outer cylinder (1).

5. The dual-pressure differential floating coupling according to claim 4, characterized in that, A positioning protrusion (11) for installing the anti-pressure member (4) is provided inside the outer cylinder (1). A positioning end face (111) is provided on the positioning protrusion (11), and the lower end of the anti-pressure member (4) abuts against the positioning end face.

6. The dual-pressure differential floating coupling according to claim 5, characterized in that, The upper end of the lower connector (3) extends into the interior of the outer cylinder (1) and abuts against the bore assembly (5) located below the pressure-resistant member (4).

7. The dual-pressure differential floating coupling according to claim 6, characterized in that, The inner diameter of the positioning protrusion (11) is greater than or equal to the outer diameter of the impact sleeve (52).

8. The dual-pressure differential floating coupling according to claim 7, characterized in that, A sealing structure (41) is provided on the pressure-resistant component (4), and the sealing structure is a single-sided seal or a multi-sided seal.

9. The dual-pressure differential floating coupling according to claim 8, characterized in that, The pressure-resistant component (4) is made of a high-pressure resistant and fragile non-metallic material, including glass, ceramics, and resin. The pressure-resistant component (4) is cylindrical or spherical.

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