A downset differential float collar

Abstract

The application provides a down differential pressure floating coupling, which comprises an upper joint, the upper joint comprises a joint part and an assembling part, the inner diameter of the assembling part is smaller than that of the joint part; a lower joint is arranged at the lower end of the assembling part; a sealing fixed sleeve is arranged in the assembling part; and a striking sleeve is arranged in the assembling part through a shear pin. The striking sleeve is arranged above the sealing assembly, the area of the upper end pressure surface of the striking sleeve is larger than that of the lower end pressure surface, so that the striking sleeve can cut the shear pin under the action of pressure and strike the sealing assembly. The application can realize full gauge of the pipe string after the rupture disc is broken, reduce the construction risk, and has the characteristics of simple structure and convenient construction.

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 differential pressure 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 fracturing disc floating coupling. This type of coupling seals a section of air or low-density drilling fluid through a fracturing disc. After the tubing string is in place, the fracturing disc is broken by direct pressure buildup. However, the pressure buildup method may result in incomplete fracturing of the disc, meaning the tubing string may not reach full bore. Incomplete fracturing of the disc can affect the passage performance of cement plugs during subsequent operations. When the cement plug passes through, it may be damaged by the remaining fracturing disc, preventing effective scraping of 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, severely affecting cementing quality, and even causing the cement plug to fail due to pressure contact or 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 fracture disc exists in the existing technology. This type of floating coupling has a movable fracture disc and a fixed impact sleeve inside. The fracture disc is positioned above the impact sleeve, and the impact sleeve and the fracture disc are fixed together by shear pins. When it is necessary to fracture the fracture disc, pressure is pumped from above the fracture disc, pushing the fracture disc to shear the shear pins and then impact the impact sleeve, thereby completely fracturing the fracture disc. Although this technology can achieve full-bore tubing, it is necessary to ensure that the fracture disc does not shift relative to the main tubing of the floating coupling during the running process. In this structure, a large number of shear pins must be used to fix the fracture disc and ensure that the fracture disc works normally during the running process. Therefore, this structure requires a large number of shear pins, which are difficult to control. Moreover, they are often distributed in multiple rows, which may cause uneven stress on the pins under the pressure of the mud in the well, resulting in premature shearing and process failure, and causing the tubing to fail to run into place smoothly. The use of multiple shear pins results in extremely high pumping pressure during the crushing of the rupture disc. Since the rupture disc bears the pressure to shear the shear pins, such pumping pressure may cause the rupture disc to break prematurely. If the rupture disc breaks before the shear pins break due to unforeseen circumstances or if the seal fails, the shear pins will not be able to cut, preventing the rupture disc from hitting the impact sleeve and thus preventing the pipe string from reaching its full diameter, which seriously affects subsequent construction operations. Summary of the Invention

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

[0007] According to the present invention, a lower differential pressure floating coupling is provided, comprising: an upper connector, the upper connector including a connector portion and an assembly portion, the inner diameter of the assembly portion being larger than the inner diameter of the connector portion; a lower connector disposed at the lower end of the assembly portion; and a rupture disc sealed and fixedly sleeved within the assembly portion;

[0008] An impact sleeve is provided within the assembly section by shear pins; wherein the impact sleeve is located below the rupture disc, and the area of ​​the pressure-bearing surface of the impact sleeve away from the rupture disc is larger than the area of ​​the pressure-bearing surface near the rupture disc, so that the impact sleeve can shear the shear pins under pressure and impact the rupture disc.

[0009] In one embodiment, a base is fixedly provided between the rupture disc and the assembly part, and a sealing element is provided between the base and the assembly part, wherein the rupture disc and the base are sealed and fixedly connected.

[0010] In one embodiment, the base includes a fifth fitting portion and a sixth fitting portion disposed at the lower end of the fifth fitting portion, a first step is provided on the inner wall of the fifth fitting portion, and the rupture disc is fixedly disposed on the first step.

[0011] In one embodiment, a pressure ring is further fitted inside the assembly section, with both ends of the pressure ring abutting against the joint section and the rupture disc, respectively.

[0012] In one embodiment, the impact sleeve is fixedly connected to the base by a shear pin.

[0013] In one embodiment, the impact sleeve includes a first fitting portion and a second fitting portion, wherein the outer diameter of the first fitting portion is smaller than the outer diameter of the second fitting portion, and the inner diameter of the first fitting portion is equal to the inner diameter of the second fitting portion; the inner diameter of the fifth fitting portion is equal to the outer diameter of the first fitting portion, and the inner diameter of the sixth fitting portion is equal to the outer diameter of the second fitting portion; a sealing element is provided between the first fitting portion and the fifth fitting portion, and a sealing element is provided between the second fitting portion and the sixth fitting portion.

[0014] In one embodiment, the upper portion of the lower connector extends into the assembly portion and abuts against the sixth fitting portion.

[0015] In one embodiment, an end face sealing ring is provided between the rupture disc and the pressure ring.

[0016] In one embodiment, the rupture disc is made of a high-pressure resistant, fragile non-metallic material, including glass and ceramics.

[0017] In one embodiment, the rupture disc is cylindrical or spherical.

[0018] Compared with the prior art, this application has the following advantages.

[0019] This invention isolates the drilling mud through a fracture disc during tubing string insertion and seals a section of air or low-density drilling fluid between the differential pressure floating coupling and the tubing string. Buoyancy reduces the weight of the tubing string entering the inclined or horizontal section of the well, thereby reducing tubing string insertion friction and facilitating smooth insertion. In this invention, the fracture disc is fixedly mounted within the assembly section, and the impact sleeve is only mounted within the assembly section via a few shear pins, reducing the difficulty of pin design and control. During the fracture disc fracturing process, the impact sleeve utilizes the pressure difference between its upper and lower end faces to achieve displacement, shearing the shear pins and impacting the fracture disc. Finally, the fragments from the fracture disc are carried out through circulation. With this setup, even if the fracture disc fails prematurely, the impact sleeve can still complete displacement under pressure and impact the fracture disc. This invention achieves full-bore tubing insertion after the fracture disc is fractured, reduces construction risks, and features a simple structure and convenient construction. Attached Figure Description

[0020] The invention will now be described with reference to the accompanying drawings.

[0021] Figure 1 This diagram shows an initial state schematic of an embodiment of the differential pressure floating coupling according to the present invention;

[0022] Figure 2 This shows a schematic diagram of the rupture disc after it breaks, according to an embodiment of the differential pressure floating coupling of the present invention;

[0023] Figure 3 A schematic diagram of another embodiment of the crushing disc according to the present invention is shown;

[0024] Figure 4 A schematic diagram of another embodiment of the differential pressure floating coupling according to the present invention is shown.

[0025] In the diagram: 1. Upper connector; 11. Connector section; 12. Assembly section; 21. Base; 22. Rupture disc; 23. Fifth assembly section; 231. First step; 24. Sixth assembly section; 31. Impact sleeve; 311. First assembly section; 312. Second assembly section; 34. Shear pin; 4. Lower connector; 5. End face sealing ring; 6. Pressure ring; 61. Second step.

[0026] 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

[0027] The invention will now be described with reference to the accompanying drawings.

[0028] 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 left side shown; the direction away from the wellhead is described as "downstream," "lower end," or similar terms, i.e. Figure 1 The right side is shown.

[0029] Figure 1 The structure of the differential pressure floating coupling 100 according to the present invention is shown. For example... Figure 1As shown, the differential pressure floating coupling 100 includes an upper connector 1, a lower connector 4, a rupture disc 22, and an impact sleeve 31. The upper connector 1 includes a connector portion 11 and an assembly portion 12 located at the lower end of the connector portion 11. The inner diameter of the assembly portion 12 is larger than the inner diameter of the connector portion 11. The lower connector 4 is sealed at the lower end of the assembly portion 12 via a threaded connection. It is easy to understand that both the upper connector 1 and the lower connector 4 can be connected to other downhole tubing. The rupture disc 22 and the impact sleeve 31 are both located within the assembly portion 12. The rupture disc 22 is sealed and fixed within the assembly portion 12, and the impact sleeve 31 is fixed within the assembly portion 12 via a shear pin 34, located below the rupture disc 22. Furthermore, the pressure-bearing area at the upper end of the impact sleeve 31 is smaller than the pressure-bearing area at the lower end. When full bore tubing is required, the pumping pressure within the floating coupling 100 is differentially pressured downwards from the wellhead. Because the rupture disc 22 separates the impact sleeve 31 from the pumping pressure, the impact sleeve 31 is not affected by the pumping pressure before the rupture disc 22 bursts. Only after the rupture disc 22 bursts will the pressure affect the impact sleeve 31 through the burst disc 22. Under equal pressure, when the pressure difference between the upper and lower pressure surfaces of the impact sleeve 31 exceeds the rated shear force of the shear pin 34, the shear pin 34 is sheared, and the impact sleeve 31 will then impact the rupture disc 22, thereby breaking the rupture disc 22 and achieving full bore. In this configuration, after the floating coupling is lowered into place, as long as the rupture disc 22 successfully bursts, the impact sleeve 31 will impact the rupture disc 22 under pressure, thus achieving full bore.

[0030] In this embodiment, the shear pins 34 serve only an initial fixing function, primarily preventing the impact sleeve 31 from accidentally colliding with the rupture disc 22 during the handling and insertion of the floating coupling into the well. Therefore, the number and strength of the shear pins 34 required in this invention are small. With this setup, there is no need for meticulous design of the required strength of the shear pins 34, thereby reducing the difficulty of controlling the shear pins 34 during the design and production of the device. Furthermore, since only a small pressure difference is needed to shear the shear pins 34 during operation, the construction risk of the shear pins 34 failing to shear or the impact sleeve 31 failing to start under pressure operating conditions can be eliminated. Thus, without increasing the pumping pressure, the impact sleeve 31 can smoothly begin to move and collide with the rupture disc 22 under the pressure at the moment of rupture. This prevents excessive impact tonnage under high pumping pressure, which could lead to deformation or damage at the tip of the impact sleeve 31, reducing the strength requirements and control difficulty of the impact sleeve 31, and also reducing the pressure control difficulty during the pumping process.

[0031] According to the present invention, after the rupture disc 22 is ruptured, the pressure above the rupture disc 22 is transmitted to the impact sleeve 31. Therefore, even if the impact sleeve 31 does not completely remove the ruptured residue of the rupture disc 22 under the impact, the impact sleeve 31 will still generate a pressure differential force under the downhole fluid column pressure or circulating pressure during subsequent operations. Under the influence of the ever-present pressure differential force, the impact sleeve 31 crushes the residue of the rupture disc 22. Since the residue is not intact, its compressive strength is greatly reduced under the impact crushing action of the impact sleeve 31. Thus, the residue can be crushed into fine particles through the crushing action, achieving full borehole penetration.

[0032] As wellbore depth and vertical depth increase, higher pressure-bearing capacity fracture discs 22 are required. If existing sliding-sleeve fracture disc floating couplings are used, the control of shear pins and impact sleeves becomes increasingly difficult within a certain pressure operating window, making it difficult to achieve full bore after the high-pressure-bearing capacity fracture disc 22 breaks. Therefore, to reduce construction difficulty, two low-pressure-bearing capacity fracture discs 22 are typically placed at different well depths of the tubing string for dual-floating installation. However, the floating coupling described in this invention can meet the full bore requirement of the tubing string after the high-pressure-bearing capacity fracture disc 22 breaks, achieving cost reduction and efficiency improvement. Of course, this invention is also compatible with the aforementioned dual-floating installation requirements, thereby further covering the tubing string installation needs in deep and ultra-deep wells.

[0033] According to a preferred embodiment of the present invention, a base 21 is fixedly provided between the rupture disc 22 and the assembly part 12, and a sealing element is provided between the base 21 and the assembly part 12, thereby sealingly and fixedly connecting the rupture disc 22 and the base 21. With this arrangement, during installation, the rupture disc 22 can be first installed onto the base 21, and then the base 21 can be inserted into the assembly part 12. Since the axial length of the base 21 is greater than the axial length of the rupture disc 22, it is more convenient to insert the rupture disc 22 into the assembly part 12 via the base 21.

[0034] According to one embodiment of the present invention, the base 21 includes a fifth fitting portion 23 and a sixth fitting portion 24 disposed at the lower end of the fifth fitting portion 23. A first step 231 is provided on the inner wall of the fifth fitting portion 23, and the rupture disc 22 is sealed and fixedly disposed on the first step 231.

[0035] In one specific embodiment, a pressure ring 6 is also fitted inside the assembly part 12. The upper end of the pressure ring 6 abuts against the connector part 11, the lower end of the pressure ring 6 abuts against the rupture disc 22, the lower end of the rupture disc 22 abuts against the stepped surface of the first step 231, and the lower end of the base, i.e., the sixth fitting part 24, abuts against the lower connector. This mutual abutment method for fixing internal parts reduces the use of connecting parts such as screws, simplifies the internal structure, and facilitates assembly. During the use of the device, the base 21 is also subjected to axial forces, such as the force due to the pressure difference on the end face of the base 21 itself. Therefore, fixing the two ends of the base 21 by abutting against other components provides a more secure and reliable fixation.

[0036] In a preferred embodiment, to achieve a sealing effect on the rupture disc 22, a sealing ring can be provided between the contact surfaces of the rupture disc 22 and the first step 231 and / or the pressure ring 6. In this embodiment, a sealing groove is provided on the lower end face of the pressure ring 6, and an end face sealing ring 5 is provided in the sealing groove. Providing the end face sealing ring 5 between the rupture disc 22 and the pressure ring 6 is more convenient than installing a sealing ring on the step surface of the first step 221, which would cause the overall outer diameter to increase. Figure 1 The sealing ring installation method shown can obtain a wider shoulder support, protect the weak edge of the rupture disc 22, and also obtain a thicker impact sleeve 31 with greater impact strength. This makes the floating coupling of the present invention not only have the full bore of the entire pipe, but also have a smaller tool outer diameter on the entire pipe, which facilitates the lowering of the pipe.

[0037] According to one embodiment of the present invention, in order to satisfy the condition that the area of ​​the pressure-bearing surface of the impact sleeve 31 away from the rupture disc 22 is larger than the area of ​​the pressure-bearing surface near the rupture disc 22, the impact sleeve 31 includes a first fitting portion 311 and a second fitting portion 312. The outer diameter of the first fitting portion 311 is smaller than the outer diameter of the second fitting portion 312, and the inner diameter of the first fitting portion 311 is equal to the inner diameter of the second fitting portion 312. The inner diameter of the fifth fitting portion 23 is equal to the outer diameter of the first fitting portion 311, and the inner diameter of the sixth fitting portion 24 is equal to the outer diameter of the second fitting portion 312. A sealing element is provided between the first fitting portion and the fifth fitting portion, and a sealing element and a shear pin 34 are provided between the second fitting portion and the sixth fitting portion. In this way, the second fitting portion 312 is sealed and fitted inside the sixth fitting portion 24, and the first fitting portion 311 is sealed and fitted inside the fifth fitting portion 23. The upper pressure-bearing surface of the impact sleeve 31 is the upper end face of the first fitting part 311, and the lower pressure-bearing surface of the impact sleeve 31 is the lower end face of the second fitting part 312. Under the same pressure, the axial pressure on the upper end face of the first fitting part 311 is greater than the axial pressure on the lower end face of the second fitting part 312, thereby achieving the purpose of the impact sleeve 31 shearing the shear pin 34 and impacting the rupture disc 22 under the action of the pumping pressure. In addition, fixing the impact sleeve 31 to the base 21 by the shear pin 34 avoids directly installing the shear pin on the assembly part 12, thereby enhancing the overall strength and sealing of the assembly part 12.

[0038] It is easy to understand that there is no sealed connection between the lower end face of the impact sleeve 31 and the lower connector 4, so the pressure on the upper end face and the lower end face of the impact sleeve 31 is equal. The force generated by the compression of the air in the closed annular space formed between the impact sleeve 31 and the base 21 is insufficient to affect the movement of the impact sleeve 31.

[0039] In a preferred embodiment, to ensure that the rupture disc 22 can withstand a certain pressure while also being shattered by the impact sleeve 31, the rupture disc 22 is made of a high-pressure resistant, brittle non-metallic material, such as glass or ceramic. Furthermore, to improve the pressure resistance of the rupture disc 22 at the same thickness, the rupture disc 22, in addition to... Figure 1 The cylinder shown can also be constructed as Figure 3 Other shapes, such as spherical shells, are shown.

[0040] like Figure 1 As shown, in conjunction with the above embodiments, the assembly process of the lower pressure differential floating coupling 100 is as follows: An end face sealing ring 5 is installed in the sealing groove of the pressure ring 6; sealing rings are installed in the sealing grooves of the inner and outer walls of the base 21, and the rupture disc 22 is installed onto the first step 231 of the base 21; the pressure ring 6 is then assembled according to… Figure 1 The direction shown connects to the base 21, abutting against the rupture disc 22; a sealing ring is installed in the sealing groove on the outer wall of the impact sleeve 31, according to... Figure 1Install the assembly into the base 21 in the indicated direction, and insert the shear pin 34 for fixing the impact sleeve 31 from the outer wall of the base 21; assemble the assembled parts according to... Figure 1 Insert the upper connector 1 in the indicated direction, and install the lower connector 4 at the lower end of the upper connector 1, so that the top of the lower connector 4 abuts against the base 21. The sealing rings and sealing methods mentioned above include skeleton sealing rings, O-rings, etc.

[0041] According to a specific embodiment of the present invention, a second step 61 is provided on the pressure ring 6. The diameter of the step surface of the second step 61 is greater than or equal to the outer diameter of the first fitting portion 311. This arrangement allows the impact sleeve 31 to pass over the rupture disc 22 after impacting it. Figure 2 The location shown allows for more effective sealing of the remaining annular portion of the ruptured disc 22.

[0042] To further simplify the assembly of the present invention, another embodiment is also provided. For example... Figure 4 As shown, the original pressure ring 6 is removed, and the shape of the upper end of the base 21 is changed so that the upper end of the rupture disc 22 can abut against the upper connector 1, thereby reducing the assembly difficulty. Correspondingly, a step is provided on the upper connector 1 to serve as the original second step 61.

[0043] The method of reducing the friction of the drilling fluid by sealing a section of air or low-density drilling fluid with the fracture disc 22 in this invention is the same as that in the prior art. The main difference is the method of fracture of the fracture disc 22 after it is pumped into place and pressure is applied, as follows.

[0044] After the pumping pressure exceeds the design strength of the rupture disc 22, the rupture disc 22 bursts, forming fine fragments. Subsequently, the hydraulic column pressure or circulating pressure in the downhole tubing is transmitted to the area around the impact sleeve 31, causing the impact sleeve 31 to move towards the rupture disc 22, thereby shearing the shear pin 34. The impact sleeve 31 then impacts the rupture disc 22 with the pressure difference force under the hydraulic column pressure or circulating pressure, impacting the rupture disc 22 and removing any remaining material after the rupture disc 22 bursts through secondary crushing, achieving full bore.

[0045] According to the method of crushing and breaking the disc provided by the present invention, the lower pressure differential floating coupling 100 provided by the present invention can achieve full bore, and the design strength of the shear pin 34 can be within a large range, thereby reducing the design difficulty of the shear pin 34 and improving practicality and safety.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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 differential pressure floating coupling, characterized in that, include: The upper connector (1) includes a connector portion (11) and an assembly portion (12), wherein the inner diameter of the assembly portion is larger than the inner diameter of the connector portion; The lower connector (4) is provided at the lower end of the assembly part; A sealed, fixed rupture disc (22) is fitted inside the assembly part. A base (21) is fixed between the rupture disc (22) and the assembly part (12). The top of the lower connector abuts against the base. The base (21) includes a fifth fitting part (23). A first step (231) is provided on the inner wall of the fifth fitting part (23). The rupture disc (22) is fixedly mounted on the first step (231). Impact sleeve (31) is installed in the assembly section by shear pin; The impact sleeve (31) is located below the rupture disc. The area of ​​the pressure-bearing surface of the impact sleeve away from the rupture disc is larger than the area of ​​the pressure-bearing surface near the rupture disc. When the pumping pressure is greater than the design strength of the rupture disc, the rupture disc bursts. Subsequently, the pressure in the downhole tubing is transmitted to the area around the impact sleeve, causing the impact sleeve to move towards the rupture disc. This allows the impact sleeve to shear the shear pin under pressure and impact the rupture disc.

2. The differential pressure floating coupling according to claim 1, characterized in that, A seal is provided between the base and the assembly part, and the rupture disc is fixedly connected to the base in a sealed manner.

3. The differential pressure floating coupling according to claim 2, characterized in that, The base (21) includes a sixth fitting (24) disposed at the lower end of the fifth fitting.

4. The differential pressure floating coupling according to claim 3, characterized in that, A pressure ring (6) is also fitted inside the assembly part (12), and the two ends of the pressure ring abut against the joint part (11) and the rupture disc (22) respectively.

5. The differential pressure floating coupling according to claim 4, characterized in that, The impact sleeve (31) is fixedly connected to the base (21) by a shear pin.

6. The differential pressure floating coupling according to claim 5, characterized in that, The impact sleeve (31) includes a first fitting part (311) and a second fitting part (312). The outer diameter of the first fitting part is smaller than the outer diameter of the second fitting part, and the inner diameter of the first fitting part is equal to the inner diameter of the second fitting part. The inner diameter of the fifth fitting part (23) is equal to the outer diameter of the first fitting part, and the inner diameter of the sixth fitting part (24) is equal to the outer diameter of the second fitting part. A sealing element is provided between the first fitting part and the fifth fitting part, and between the second fitting part and the sixth fitting part.

7. The differential pressure floating coupling according to claim 6, characterized in that, The upper part of the lower connector (4) extends into the assembly part and abuts against the sixth fitting part (24).

8. The differential pressure floating coupling according to claim 7, characterized in that, An end face sealing ring (5) is provided between the rupture disc (22) and the pressure ring (6).

9. The differential pressure floating coupling according to any one of claims 1 to 8, characterized in that, The rupture disc (22) is made of a high-pressure resistant and fragile non-metallic material, including glass, ceramics, and resin.

10. The differential pressure floating coupling according to any one of claims 1 to 8, characterized in that, The rupture disc (22) is cylindrical or spherical.

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