Soluble packing device for operation under pressure

Abstract

The invention relates to the technical field of petrochemical engineering pipeline plugging, in particular to a soluble packing device for under-pressure operation, which comprises a lower joint, the top end of the lower joint is fixedly connected with a connecting cylinder, the connecting cylinder is connected with an upper slip assembly and a lower slip assembly, and a limiting assembly is arranged between the upper slip assembly and the lower slip assembly. A dissolving tank is formed in the lower connector and communicates with a through groove, the side wall of the through groove communicates with a liquid passing groove, the liquid passing groove communicates with the limiting assembly, the top end of the upper slip assembly is connected with an upper connector, a packing ball is attached to the upper connector, and a drainage ball is placed in the packing ball. Metal components in the lower connector, the upper slip assembly, the lower slip assembly, the limiting assembly, the packing ball and the drainage ball are all made of dissolvable metal materials, the dissolving mode that the connecting component is dissolved firstly and then the fixing component is dissolved is achieved through drainage dissolving liquid, obstruction of residues to oil and gas flowing is reduced, and the oil and gas recovery rate is increased.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical pipeline plugging, and in particular to a soluble sealing device for pressure operation. Background Art

[0002] During the oilfield exploitation process, segmented fracturing is required due to the different strength parameters of each section of the formation. During the pressurized operation, it is necessary to install and arrange the pipelines and other facilities on the well, so it is necessary to set a plug at the bottom of the casing to separate the downhole and the well. After the well preparation is completed, the plug needs to be opened to produce oil and gas. Therefore, the packer mainly isolates the production layer or the construction target layer to prevent the fluid and pressure between the layers from interfering with each other, and adapts to the construction needs of various layered technologies.

[0003] The soluble packer can be fully dissolved after the operation is completed, so that the packer can be completely unsealed smoothly and completely, ensuring the smooth flow of the wellbore. This can avoid the problem of traditional packers causing wellbore difficulties due to formation collapse during well repair operations, reduce well repair operations such as milling, and reduce the difficulty and cost of operations.

[0004] However, in practical applications, soluble packers are generally dissolved from top to bottom, which can easily cause the fixing components to dissolve first, and then the connecting components to fall down the oil well, resulting in the undissolved or incompletely dissolved parts becoming wellbore residues, hindering the flow of oil and gas, and in severe cases may cause wellbore blockage, affecting production efficiency and oil and gas recovery rate; at the same time, these residues may fall off due to fluid scouring or changes in formation pressure, causing damage to downhole tools and formation pollution, increasing the difficulty and cost of well repair operations. For this reason, it is necessary to propose a soluble isolation device for pressure-carrying operations, which can reduce the possibility of the connecting components falling down the oil well after the fixing components are dissolved first, reduce wellbore residues, ensure smooth flow of oil and gas, and improve production efficiency and oil and gas recovery rate. Summary of the invention

[0005] To solve the above problems, the present invention provides a soluble isolation device for pressure operation, which realizes a dissolution method of first dissolving the connecting components and then dissolving the fixed components by draining the dissolving liquid, thereby reducing the obstruction of the residue to the flow of oil and gas and improving the oil and gas recovery rate.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a soluble isolation device for pressure operation, comprising a lower joint for connecting to a device providing deep driving power, a hollow connecting cylinder fixedly connected to the top of the lower joint, an upper slip assembly and a lower slip assembly for deforming to increase the friction of the oil well side wall connected to the outer wall of the connecting cylinder through shear nails, a limiting assembly connected to the outer wall of the connecting cylinder through shear nails is provided between the upper slip assembly and the lower slip assembly, and the limiting assembly is used for limiting and fixing to cause the upper slip assembly and the lower slip assembly to deform;

[0007] A dissolving tank is provided in the lower joint, and the dissolving tank is connected with a through-slot provided in the connecting tube. The through-slot is an annular structure, and the side wall of the through-slot is connected with a liquid-passing tank corresponding to the position of the limit assembly. The liquid-passing tank is connected with the limit assembly. An upper joint connected to the connecting tube through a shear nail is provided at the top of the upper slip assembly. The upper joint is a cylindrical structure, and a hollow sealing ball is attached to the top of the upper joint. The diameter of the sealing ball is larger than the diameter of the upper joint, and a drainage ball for draining liquid into the through-slot is placed in the sealing ball.

[0008] The metal components in the lower joint, the upper slip assembly, the lower slip assembly, the limit assembly, the isolation ball and the drainage ball are all made of soluble metal materials.

[0009] The technical principle of the above scheme is as follows: the necessary structural stability and strength are provided during the sealing process through the cooperation of the limit assembly with the upper cava assembly and the lower cava assembly. The shear nails are connected to the outer wall of the connecting tube, which can provide the necessary structural stability and strength during the sealing process. The design of the shear nails allows the shear nails to be sheared off by applying pressure when necessary to achieve unsealing. The through groove design helps to evenly distribute the dissolved liquid in the connecting tube. Since the metal components of the sealing device are made of soluble metal materials, the components can be fully dissolved after the operation is completed, so that the sealer can be smoothly and completely unsealed.

[0010] The above scheme has the following beneficial effects:

[0011] 1. In this solution, since the key metal components of the isolation device are made of soluble metal materials, this ensures that after the isolation operation is completed, even if an unexpected situation occurs, the isolation device can automatically dissolve within a predetermined time to avoid long-term blockage of the oil well, thereby improving the safety of pressure operations.

[0012] 2. In this solution, during the dissolution process of the soluble isolation device, the drainage ball guides the dissolved liquid to flow into the through groove at the top of the connecting tube, and flows downward along the through groove to fill the dissolved groove and the limit block. The dissolution rate is affected by the contact area between the dissolved liquid and the material, among which the dissolved groove and the limit block are preferentially dissolved due to the accumulation of dissolved liquid. Subsequently, the dissolved liquid continues to act on the upper slip, upper cone, lower slip and lower cone, so as to achieve the sequential dissolution of the connecting components before the fixed components. Compared with the top-down dissolution mode, this method reduces the residual problem caused by the fixed components contacting the dissolved liquid first, effectively avoids the residual components in the oil well, and thus ensures the efficiency and quality of oil and gas extraction from the oil well.

[0013] Furthermore, the top surface of the connecting tube is a sloped structure in which the height of the inner ring cover is less than the height of the outer ring, and the top end of the through groove is connected to the top slope portion of the connecting tube.

[0014] Beneficial effects: This innovative design cleverly utilizes the sloped structural feature of the top surface of the connecting tube, successfully achieving seamless and efficient connection between the top of the through groove and the top of the connecting tube, significantly optimizing the flow path of the dissolved liquid in the through groove, reducing the flow resistance, and thus greatly improving the mass transfer efficiency and dissolution rate during the dissolution process, ensuring that the dissolved liquid can more fully contact and react with the substance to be dissolved, thereby improving the overall dissolution efficiency.

[0015] Furthermore, the diameter of the drainage ball is larger than the inner diameter of the connecting tube.

[0016] Beneficial effects: This design aims to ensure that the drainage ball can form a tight and reliable sealing structure when assembled into the connecting tube, effectively preventing the backflow of the dissolved liquid under the action of reverse pressure, thereby ensuring the continuity of the dissolution process. In addition, the design further optimizes the fluid mechanics characteristics, reduces the turbulence and eddy current of the fluid in the contact area between the drainage ball and the connecting tube, reduces energy loss, improves the smoothness and flow rate of the fluid, and thus significantly improves the drainage efficiency, ensuring that the dissolved liquid can enter the subsequent processing link efficiently and orderly.

[0017] Furthermore, the upper slip assembly comprises a first connecting ring fixedly connected to the bottom end of the upper joint, and a plurality of upper slips are fixedly connected to the first connecting ring along its circumference.

[0018] Beneficial effects: The design of the upper cava assembly, in which the first connecting ring is fixedly connected to the bottom end of the upper joint and a number of upper cava are fixedly connected along its circumference, provides a kind of structural stability and convenience of operation. The design enables the upper cava to evenly distribute the load, enhances the clamping ability of the downhole tubing, and facilitates the realization of automated or semi-automated cava operation, thereby improving operation efficiency and safety.

[0019] Furthermore, the limiting assembly includes a limiting block connected to the connecting tube via a shear nail, the limiting block is made of rubber material, an upper cone is fixedly connected to the top end of the limiting block, and a lower cone is fixedly connected to the bottom end of the limiting block.

[0020] Beneficial effects: When squeezed by external force, the lateral volume of the limit block will expand elastically. This phenomenon not only enhances its fixing effect in the structure and ensures the stability and alignment accuracy between components, but also, during the dissolution operation of the isolation device, the rubber limit block will dissolve preferentially and quickly compared with the soluble metal material due to its higher dissolution rate characteristics, so that the limit block can be decomposed before the upper and lower slips, thereby greatly reducing the amount of foreign matter residue in the oil well operation area. This is not only conducive to maintaining the cleanliness of the oil well and reducing potential production obstacles caused by foreign matter, but also effectively improves the oil and gas flow efficiency and overall production performance of the oil well by reducing the residue after dissolution.

[0021] Furthermore, the lower slip assembly includes a second connecting ring fixedly connected to the top end of the lower joint, and a plurality of lower slips are fixedly connected to the second connecting ring along its circumference.

[0022] Beneficial effects: The design of the lower slip assembly allows the load to be evenly distributed along the circumference of the connection ring, reducing local stress concentration and improving the stability and durability of the overall structure. In addition, several lower slips are fixedly connected along the circumference of the second connection ring, increasing the contact area with the side wall of the oil well, thereby enhancing the fixing ability and stability of the isolation device.

[0023] Furthermore, the inner walls of the upper slips are all fitted with the outer wall of the upper cone, the inner walls of the upper slips are fixedly connected with first teeth of an annular structure, and the outer wall of the upper cone is fixedly connected with a plurality of second teeth of annular structure.

[0024] Beneficial effects: The teeth of the annular structure between the upper slip and the upper cone cooperate with each other, which improves the stability and fixing ability of the bite and ensures the reliability in high-pressure working environment. In addition, the cooperation of the first teeth and the second teeth increases the friction between the upper slip and the upper cone, thereby improving the clamping force, which is crucial to maintaining the stability of the oil well isolation device.

[0025] Furthermore, the first tooth and the second tooth are both right-angled triangle structures, and the hypotenuse of the first tooth is arranged opposite to the hypotenuse of the second tooth.

[0026] Beneficial effects: The teeth of the right-angled triangle structure can form a more stable mechanical locking effect when they mesh with each other. The relative setting of the hypotenuse increases the contact area between the teeth, thereby improving the strength and stability of the meshing, and effectively preventing the disengagement caused by vibration or external force. In addition, the design of the right-angled triangle teeth makes the transmission force distribution between the teeth more uniform, reducing the wear and energy loss caused by stress concentration. At the same time, the relative configuration of the hypotenuse helps to achieve a smoother transition during the transmission process, reduces noise and vibration, and improves the overall transmission efficiency and system reliability.

[0027] Furthermore, the inner walls of the lower slips are all fitted with the outer wall of the lower cone, the inner walls of the lower slips are all fixedly connected with thread carvings, and the outer wall of the lower cone is provided with thread grooves corresponding to the thread carvings.

[0028] Beneficial effects: The tight fit between the thread engraving and the thread groove can also form an effective sealing barrier at the connection. This helps prevent fluid or gas leakage from the connection, improving the sealing performance and overall performance of the system. In addition, the tightening pressure of the limit block and the upper and lower slips can be transmitted through the thread, which has better stability than the tension transmission.

[0029] Furthermore, the upper cone and the lower cone are fixedly connected to elastic tooth blocks on one side close to the limit block.

[0030] Beneficial effect: The elastic tooth block design can increase the friction between the upper cone and the lower cone when they are in contact, thereby enhancing the locking effect between the two. This design helps prevent relative movement or loosening between the upper cone and the lower cone under vibration or external force, ensuring the stability and reliability of the entire structure.

[0031] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of an embodiment of a soluble packing device for pressure operation according to the present invention;

[0033] Figure 2 It is a front cross-sectional view of an embodiment of a soluble isolation device for pressure operation according to the present invention;

[0034] Figure 3 This is an embodiment of the soluble sealing device for pressure operation of the present invention Figure 2 The enlarged schematic diagram of point A in the middle;

[0035] Figure 4 This is an embodiment of the soluble sealing device for pressure operation of the present invention Figure 2 The enlarged schematic diagram of point B in the middle;

[0036] Figure 5 It is a schematic diagram of the dissolution of an embodiment of a soluble isolation device for pressure operation according to the present invention.

[0037] The figure marks in the drawings of the specification include: 1. lower joint; 2. connecting tube; 3. dissolving tank; 4. through tank; 5. liquid flow tank; 6. upper joint; 7. sealing ball; 8. drainage ball; 9. first connecting ring; 10. upper cava; 11. limit block; 12. upper cone; 13. lower cone; 14. second connecting ring; 15. lower cava; 16. first tooth; 17. second tooth; 18. thread engraving; 19. thread groove; 20. tooth block. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through shear nails, or connected in one piece; it can be a mechanical connection or an electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The following is further described in detail through specific implementation methods:

[0042] Embodiment 1:

[0043] As attached Figure 1 As shown: a soluble sealing device for pressure operation, including a lower joint 1 for connecting to a device providing depth power, the top of the lower joint 1 is fixedly connected to a connecting tube 2 integrally formed with the lower joint 1, the connecting tube 2 is a hollow connecting tube 2, the middle of the connecting tube 2 is connected to a limit block 11 through a shear nail, the top of the limit block 11 is fitted with an upper cone 12 connected to the outer wall of the connecting tube 2 through the shear nail, and the bottom of the limit block 11 is fitted with a lower cone 13 connected to the outer wall of the connecting tube 2 through the shear nail.

[0044] The top cone surface of the upper cone 12 is fitted with a plurality of upper slips 10, and the upper part of the connecting tube 2 is connected to the first connecting ring 9 through shear nails. The plurality of upper slips 10 are welded to the outer wall of the first connecting ring 9 and arranged along the circumference of the first connecting ring 9. The bottom cone surface of the lower cone 13 is fitted with a plurality of lower slips 15, and the lower part of the connecting tube 2 is connected to the second connecting ring 14 through shear nails. The plurality of lower slips 15 are welded to the outer wall of the first connecting ring 9 and arranged along the circumference of the second connecting ring 14. During the pressure operation of the oil well, when isolation operation is required, the injection head that drives the depth in the oil well operation is connected to the lower joint 1 to bring the isolation device as a whole to the target depth. During the isolation process, when the lower joint 1 is subjected to relatively upward pressure, the shear nails used for connection will be cut off in sequence from bottom to top so that each component can produce relative displacement.

[0045] First, the pressure exerted on the lower joint 1 will be transmitted to the second connecting ring 14 through the lower joint 1, so that the second connecting ring 14 moves toward the lower cone 13, and then the pressure is transmitted to the limit block 11, and then the limit block 11 pushes the upper cone 12 to move in the direction close to the first connecting ring 9, thereby squeezing the upper cava 10, so that the upper cava 10 slides relatively on the surface of the upper cone 12, and the lower cava 15 slides relatively on the surface of the lower cone 13, so that a plurality of upper cava 10 and lower cava 15 generate contact friction with the inner wall of the oil well, and generate a normal pressure perpendicular to the inner wall of the oil well, which is similar to the effect of increasing the volume and clamping it in the oil well, thereby realizing the fixation and sealing of the isolation device, so that the isolation device can work stably, prevent oil and gas leakage, and ensure the safety and efficiency of the operation.

[0046] Since the stopper 11 is made of rubber material, it has certain elasticity and ductility. During the process, the lateral volume of the stopper 11 squeezed will increase, which also plays a certain fixing role. In addition, during the dissolution of the isolation device, the rubber material is dissolved much faster than the soluble metal material, so the stopper 11 with connection and pressure transmission function will also dissolve before the upper slip 10 and the lower slip 15 with fixing function, thereby reducing the foreign matter residue in the oil well and improving the oil and gas production efficiency of the oil well.

[0047] When the fixing step in the packing operation is completed, Figure 1 As shown in the upper part of the embodiment, the sealing is realized by welding a cylindrical upper joint 6 at the top of the first connecting ring 9, and a hollow sealing ball 7 is attached to the top of the upper joint 6. After the injection head is driven back, the sealing ball 7 is dropped into the oil well. Since the diameter of the sealing ball 7 is larger than the inner diameter of the upper joint 6, the sealing ball 7 will be stuck at the opening of the upper joint 6, thereby effectively preventing the flow of oil and gas and achieving the purpose of sealing. In addition, a sealing ring is also connected to the opening of the upper joint 6. When the sealing ball 7 contacts the upper joint 6, the sealing ring can further prevent the flow of oil and gas and strengthen the blocking effect of the sealing ball 7.

[0048] As for the dissolution process, since the first connecting ring 9, the upper cone 12, the lower cone 13, the second connecting ring 14, the isolation ball 7 and several upper cavas 10 and lower cavas 15 are all made of soluble metal materials, the operator only needs to inject the dissolving liquid into the oil well to complete the dissolution of the isolation equipment, that is, the contact of the isolation.

[0049] When the dissolving liquid is injected into the oil well, the dissolving liquid will first be blocked by the isolation ball 7, and the dissolving liquid will first dissolve the isolation ball 7. Since a drainage ball 8 is placed in the isolation ball 7, and the diameter of the drainage ball 8 is larger than the inner diameter of the connecting tube 2, after the isolation ball 7 is completely dissolved, the drainage ball 8 will fall down and get stuck at the top opening of the connecting tube 2.

[0050] A dissolving tank 3 is provided in the lower joint 1, and the dissolving tank 3 is connected to a through tank 4 provided in the connecting tube 2, and the through tank 4 is an annular structure. Figure 2 As shown, the cross-sectional view of the connecting tube 2 presents a "U"-shaped structure, and the middle of the side wall of the through groove 4 is connected to a liquid passage 5 corresponding to the position of the limit block 11, and the liquid passage 5 is connected to the limit block 11. Figure 5 As shown, the drainage ball 8 guides the downward flow of the dissolved liquid into the through groove 4 connected to the top of the connecting tube 2, and the dissolved liquid flows down along the barrel groove to fill the dissolved groove 3 and the limit block 11, and the dissolution rate is determined by the contact area between the dissolved liquid and the substance. The volume of the dissolved liquid accumulated in the dissolved groove 3 and the limit block 11 determines that the lower joint 1 and the limit block 11 will become the first components to be dissolved. After the limit block 11 and the lower joint 1 are dissolved, the accumulated dissolved liquid dissolves the upper slips 10 and the upper cone 12 and the lower slips 15 and the lower cone 13 that play the role of expansion and fixing, so as to achieve the effect of dissolving the connecting part first and then dissolving the fixing part. Compared with dissolving from top to bottom, this dissolution method can reduce the problem of the connecting component remaining in the oil well due to the first contact of the fixing effect, and effectively avoid the residual components in the oil well affecting the efficiency and purity of oil and gas extraction from the oil well.

[0051] Embodiment 2:

[0052] As attached Figure 2 As shown, the difference from Example 1 is that the top surface of the connecting tube 2 is a sloped structure in which the inner ring cover height is less than the outer ring height, and the top of the through groove 4 is connected to the top slope of the connecting tube 2. The sloped structure design of the top surface of the connecting tube 2 helps to guide the dissolved liquid to flow from the top of the through groove 4 to the slope of the connecting tube 2. Such a design can ensure that the dissolved liquid is evenly distributed in the connecting tube 2, and can effectively prevent the dissolved liquid from accumulating at the top of the connecting tube 2, thereby avoiding uneven dissolution or overflow problems caused by local oversaturation.

[0053] Embodiment 3:

[0054] The difference from Example 2 is that the inner walls of the upper slips 10 are all in contact with the outer wall of the upper cone 12, and the inner walls of the upper slips 10 are all welded with first teeth 16 of an annular structure, as shown in FIG. Figure 3As shown, the outer wall of the upper cone 12 is welded with a plurality of second teeth 17 of annular structure, the first teeth 16 and the second teeth 17 are both right-angled triangle structures, and the hypotenuse of the first teeth 16 is arranged opposite to the hypotenuse of the second teeth 17. This design provides a mutual locking mechanism, so that a tight fit can be formed between the upper slip 10 and the upper cone 12, which enhances the fixing ability of the isolation device and ensures that when the oil well pressure changes, the upper slip 10 and the upper cone 12 will not slide relative to each other and reset, thereby reducing the fixing effect. In addition, the design of the first teeth 16 and the second teeth 17 helps to evenly distribute the pressure between the upper slip 10 and the upper cone 12, reduce local stress concentration, and thus improve the durability and reliability of the entire isolation device.

[0055] like Figure 4 As shown, the inner walls of several lower cava 15 are all fitted with the outer wall of the lower cone 13, the inner walls of the lower cava 15 are all engraved with threads 18, and the outer wall of the lower cone 13 is opened with thread grooves 19. The thread engravings 18 on the inner wall of the lower cava 15 correspond to the thread grooves 19 on the outer wall of the lower cone 13. The sliding fit of the thread can, on the one hand, make the lower cava 15 and the lower cone 13 tightly connected and enhance the fixing ability. On the other hand, by installing a motor on the injection head, an upward pressure can be generated on the lower joint 1 in a rotational manner. Compared with tightening the cava and the cone in a tensile manner, the rotational pressure method can provide a more stable tightening drive and reduce the provision of invalid supporting force.

[0056] Embodiment 4:

[0057] As attached Figure 2 As shown, the difference from Example 3 is that the upper cone 12 and the lower cone 13 are fixedly connected to the side close to the limit block 11 with an elastic tooth block 20, and the elastic tooth block 20 can provide a certain flexibility to compensate for the slight offset between the upper cone 12 and the lower cone 13, while absorbing the vibration caused by the pressure change or mechanical movement inside the oil well. In addition, the use of the elastic tooth block 20 enhances the reliability of the connection, because the tooth block 20 can withstand load changes and impacts to a certain extent, reducing the risk of connection failure due to excessive load.

[0058] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A soluble isolation device for pressure operation, comprising a lower joint (1) for connecting to a device providing deep driving power, characterized in that: The top of the lower joint (1) is fixedly connected to a hollow connecting tube (2); the outer wall of the connecting tube (2) is connected to an upper slip assembly and a lower slip assembly through shear nails for deforming to increase the friction of the oil well side wall; a limiting assembly connected to the outer wall of the connecting tube (2) through shear nails is provided between the upper slip assembly and the lower slip assembly; the limiting assembly is used for limiting and fixing to cause the upper slip assembly and the lower slip assembly to deform; A dissolving groove (3) is provided in the lower joint (1), and the dissolving groove (3) is connected to a through groove (4) provided in the connecting tube (2). The through groove (4) is an annular structure. The side wall of the through groove (4) is connected to a liquid-passing groove (5) corresponding to the position of the limit assembly. The liquid-passing groove (5) is connected to the limit assembly. An upper joint (6) connected to the connecting tube (2) via a shear nail is provided at the top of the upper slip assembly. The upper joint (6) is a cylindrical structure. A hollow sealing ball (7) is attached to the top of the upper joint (6). The diameter of the sealing ball (7) is larger than the diameter of the upper joint (6). A drainage ball (8) for draining the dissolved liquid into the through groove (4) is placed in the sealing ball (7); The metal components in the lower joint (1), the upper slip assembly, the lower slip assembly, the limit assembly, the isolation ball (7) and the drainage ball (8) are all made of soluble metal materials.

2. The soluble isolation device for pressure operation according to claim 1, characterized in that: The top surface of the connecting tube (2) is a sloped structure in which the height of the inner ring cover is less than the height of the outer ring, and the top end of the through groove (4) is connected to the top slope portion of the connecting tube (2).

3. The soluble isolation device for pressure operation according to claim 2, characterized in that: The diameter of the drainage ball (8) is greater than the inner diameter of the connecting tube (2).

4. The soluble isolation device for pressure operation according to claim 3, characterized in that: The upper slip assembly comprises a first connecting ring (9) fixedly connected to the bottom end of the upper joint (6), and a plurality of upper slips (10) are fixedly connected to the first connecting ring (9) along its circumference.

5. The soluble isolation device for pressure operation according to claim 4, characterized in that: The limiting assembly comprises a limiting block (11) connected to the connecting tube (2) via a shear nail, the limiting block (11) is made of a rubber material, an upper cone (12) is fixedly connected to the top end of the limiting block (11), and a lower cone (13) is fixedly connected to the bottom end of the limiting block (11).

6. The soluble isolation device for pressure operation according to claim 5, characterized in that: The lower slip assembly comprises a second connecting ring (14) fixedly connected to the top end of the lower joint (1), and a plurality of lower slips (15) are fixedly connected to the second connecting ring (14) along its circumference.

7. The soluble isolation device for pressure operation according to claim 6, characterized in that: The inner walls of the upper slips (10) are all fitted with the outer wall of the upper cone (12); the inner walls of the upper slips (10) are all fixedly connected with first teeth (16) of an annular structure; and the outer wall of the upper cone (12) is fixedly connected with a plurality of second teeth (17) of annular structure.

8. The soluble isolation device for pressure operation according to claim 7, characterized in that: The first tooth (16) and the second tooth (17) are both right-angled triangle structures, and the hypotenuse of the first tooth (16) and the hypotenuse of the second tooth (17) are arranged opposite to each other.

9. The soluble isolation device for pressure operation according to claim 8, characterized in that: The inner walls of the lower slips (15) are all fitted with the outer wall of the lower cone (13), the inner walls of the lower slips (15) are all fixedly connected with thread engravings (18), and the outer wall of the lower cone (13) is provided with thread grooves (19) corresponding to the thread engravings (18).

10. The soluble isolation device for pressure operation according to claim 9, characterized in that: The upper cone (12) and the lower cone (13) are both fixedly connected to a resilient tooth block (20) on one side close to the limit block (11).

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