Self-sealing type gas-liquid separation tool for natural gas hydrate

Abstract

The invention relates to a self-sealing type natural gas hydrate gas-liquid separation tool which comprises a sealing cylinder, a vortex variable-speed body is arranged in the sealing cylinder, at least two spiral bands are arranged on the outer wall of the vortex variable-speed body, a spiral space is formed between every two adjacent spiral bands, and sealing strips are arranged between the spiral bands and the inner wall of the sealing cylinder; the vortex variable-speed body is connected with a flow guide body which is provided with a flow guide hole; the bottom end of the sealing cylinder is hermetically communicated with a connecting body, and an overflowing channel is arranged in the connecting body; a rubber sleeve structure is arranged on the outer wall of the connecting body and can radially extrude and expand to abut against the inner wall of the oil pipe in a sealed mode. A setting structure is arranged at the bottom end of the outer wall of the connecting body. When the tool is assembled, sealing of the spiral band and the sealing barrel is completed through the sealing strips on the sealing barrel and the spiral band, the rubber barrel structure is extruded when the tool is set, effective sealing between the tool and an oil pipe is achieved, and the sealing performance and the gas-liquid separation capacity are improved; and a plurality of spiral spaces are formed by arranging a plurality of spiral belts, so that the vortex effect is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of natural gas exploitation, and in particular to a self-sealing natural gas hydrate gas-liquid separation tool. Background Art

[0002] Natural gas hydrates have great application value. They have the advantages of wide distribution range, huge reserves, green and efficient, and high density. At present, the main methods of natural gas hydrate exploitation are depressurization method, CO2 replacement method, thermal stimulation method, chemical inhibitor method and solid fluidization exploitation method. For depressurization exploitation of hydrates, due to the presence of free water and condensate in the gas layer, natural gas, water vapor and free water in droplet form are mixed together. When the droplet size is large or the gas energy is insufficient, the droplets will gather underground, resulting in a "liquid accumulation" phenomenon, which greatly affects the permeability of the reservoir gas, ultimately affecting the recovery rate and seriously interfering with the normal production of the hydrate well.

[0003] In order to reduce resource consumption in natural gas hydrate exploitation, ensure the continuity of exploitation, and improve the recovery rate, it is necessary to arrange gas-liquid separation tools underground in natural gas hydrates. At present, eddy current gas-liquid separation tools are commonly used in natural gas hydrate exploitation. There is a certain gap between the spiral belt on the eddy current speed changer of the eddy current gas-liquid separation tool and the pipe wall, which affects the eddy current generation effect of the eddy current tool, resulting in unsatisfactory gas-liquid separation effect. In addition, due to the limitation of a single spiral belt, the ability of the eddy current gas-liquid separation tool to form eddy currents needs to be strengthened.

[0004] Therefore, the inventor, relying on many years of experience and practice in related industries, proposes a self-sealing natural gas hydrate gas-liquid separation tool to overcome the defects of the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a self-sealing natural gas hydrate gas-liquid separation tool. When the tool is assembled, the sealing strips on the sealing tube and the spiral belt are used to complete the sealing of the spiral belt and the sealing tube. When the tool is sealed, the rubber tube structure is squeezed to achieve effective sealing between the tool and the oil pipe, thereby improving the sealing performance and gas-liquid separation ability; by arranging multiple spiral belts to form multiple spiral spaces, the natural gas flow containing bottom-hole liquid can achieve efficient gas-liquid separation of natural gas hydrate when passing through the tool, greatly improving the effect of the vortex effect.

[0006] The objective of the present invention is achieved in this way. A self-sealing natural gas hydrate gas-liquid separation tool comprises a sealing cylinder, wherein a vortex speed changer is arranged in the sealing cylinder, at least two spiral bands are arranged on the outer wall of the vortex speed changer, a spiral space is formed between the two adjacent spiral bands, and a sealing strip is arranged between the spiral band and the inner wall of the sealing cylinder; the first end of the vortex speed changer is connected to a guide body, and the guide body is provided with guide holes respectively connected with the spiral spaces; a connector is provided in the sealing connection at the bottom end of the sealing cylinder, and a flow channel which can be connected with the guide holes is provided in the connector; a rubber sleeve structure is provided on the outer wall of the connector from the top end to the inside, and the rubber sleeve structure can radially squeeze and seal against the inner wall of the oil pipe; a sealing structure is provided at the bottom end of the outer wall of the connector, and the sealing structure can be sealed on the inner wall of the oil pipe.

[0007] In a preferred embodiment of the present invention, the rubber cartridge structure includes a rubber cartridge body, and an upper shoulder guard and a lower shoulder guard are respectively arranged at both ends of the rubber cartridge body. The upper shoulder guard is fixed to the connecting body through an upper retaining ring, and the lower shoulder guard is provided with a lower retaining ring which can move axially along the connecting body.

[0008] In a preferred embodiment of the present invention, a first outer sliding conical surface with a diameter gradually decreasing from bottom to top is provided at the top of the rubber cylinder body, a first inner sliding conical surface is provided inside the upper shoulder guard, and the first outer sliding conical surface can move along the first inner sliding conical surface;

[0009] A second outer sliding conical surface with a diameter gradually decreasing from top to bottom is arranged at the bottom end of the rubber cylinder body, and a second inner sliding conical surface is arranged inside the lower shoulder guard. The second inner sliding conical surface can move along the second outer sliding conical surface and can push the rubber cylinder body to move upward to generate radial expansion.

[0010] In a preferred embodiment of the present invention, a positioning protruding ring is provided on the outer wall of the connecting body, and the positioning protruding ring can limit the lower retaining ring from below.

[0011] In a preferred embodiment of the present invention, the sealing structure includes a sealing device that can slide axially along the connecting body, and the inner wall of the sealing device is provided with a sealing inner conical surface; the bottom end of the outer wall of the connecting body is provided with a sealing outer conical surface upward, and the sealing inner conical surface can slide along the sealing outer conical surface; the bottom end of the sealing device is provided with a locking boss that can be sealed on the inner wall of the oil pipe.

[0012] In a preferred embodiment of the present invention, the locking boss is connected to the spring body via a shear pin.

[0013] In a preferred embodiment of the present invention, an inner boss is provided on the inner wall of the setting device, a positioning convex ring is provided on the outer wall of the connecting body, and the top surface of the inner boss can abut against the bottom surface of the positioning convex ring.

[0014] In a preferred embodiment of the present invention, the connector includes an upper connector and a lower connector, an upper center hole is arranged in the upper connector, and a lower center hole is arranged in the lower connector, the upper center hole and the lower center hole are connected to form the flow channel; the upper connector is fixedly connected to the bottom end of the sealing tube, and the rubber tube structure is sleeved on the upper connector; the top end of the sealing structure is sleeved on the upper connector.

[0015] In a preferred embodiment of the present invention, the top end of the eddy current speed changer is connected to a fishing head.

[0016] In a preferred embodiment of the present invention, the sealing cylinder, the eddy current transmission body, the spiral belt, the guide body, the connector and the sealing structure are made of alloy steel, and the sealing strip and the rubber cylinder body are made of rubber.

[0017] As described above, the self-sealing natural gas hydrate gas-liquid separation tool of the present invention has the following beneficial effects:

[0018] In the self-sealing natural gas hydrate gas-liquid separation tool of the present invention, a sealing strip is used to complete the sealing between the spiral belt and the sealing cylinder during assembly, and the compression and radial expansion of the rubber cylinder structure are used to complete the effective sealing between the tool and the oil pipe during setting, providing a completely sealed space for the natural gas flow, thereby improving the sealing performance and gas-liquid separation capability; in the present invention, a plurality of spiral belts are arranged to form a plurality of spiral spaces, and each spiral space is respectively connected to a guide hole, and the liquid-containing natural gas passing through the guide hole is respectively connected to each spiral space, so that the liquid-containing natural gas is fully accelerated and forms a vortex, so that the natural gas flow containing the bottom liquid accumulates when passing through the tool, and the vortex effect is fully generated, so that the efficient gas-liquid separation of natural gas hydrate is realized, and the effect of the vortex effect is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0020] in:

[0021] Figure 1 : It is a schematic structural diagram of the self-sealing natural gas hydrate gas-liquid separation tool of the present invention.

[0022] Figure 2 : It is a schematic diagram of the state of the present invention after being placed in the oil pipe.

[0023] In the figure:

[0024] 1. Fishing head; 2. Spiral belt; 3. Diversion body; 301. Diversion hole; 4. Upper shoulder guard; 5. Lower shoulder guard; 6. Upper connecting piece; 601. Positioning convex ring; 7. Lower connecting piece; 8. Spring body; 9. Sealing device; 901. Stopping boss; 902. Inner boss; 10. Lower retaining ring; 11. Rubber cylinder body; 12. Upper retaining ring; 13. Sealing cylinder; 14. Eddy current transmission body; 15. Sealing strip; 16. Oil pipe; 17. Oil pipe coupling; 18. Shear pin. DETAILED DESCRIPTION

[0025] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0026] The specific embodiments of the present invention described herein are only used to explain the purpose of the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be considered to belong to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] like Figure 1 , Figure 2As shown, the present invention provides a self-sealing natural gas hydrate gas-liquid separation tool, including a sealing cylinder 13, a vortex speed changer 14 is arranged in the sealing cylinder 13, at least two spiral bands 2 are arranged on the outer wall of the vortex speed changer 14 (the spiral bands 2 and the vortex speed changer 14 are welded), a spiral space is formed between two adjacent spiral bands 2, and a sealing strip 15 is arranged between the spiral band 2 and the inner wall of the sealing cylinder 13 (the sealing strip 15 is evenly arranged on the spiral band 2); the first end of the vortex speed changer 14 is connected to the guide body 3 ( The eddy current transmission body 14 is connected to the guide body 3 by threads, and the guide body 3 is connected to the sealing cylinder 13 by threads), and the guide body 3 is provided with guide holes 301 respectively connected with the spiral space; the bottom end of the sealing cylinder 13 is sealed and connected with a connector, and a flow channel connected with the guide hole is provided in the connector; a rubber sleeve structure is provided on the outer wall of the connector from the top to the inside, and the rubber sleeve structure can radially squeeze and seal against the inner wall of the oil pipe 16; a sealing structure is provided at the bottom end of the outer wall of the connector, and the sealing structure can be sealed on the inner wall of the oil pipe.

[0029] During operation, the natural gas flow containing bottom hole accumulation liquid enters the tool to the flow guide hole 301 of the flow guide body 3 through the flow passage of the connector. Each flow guide hole 301 corresponds to a spiral space. The natural gas flow containing bottom hole accumulation liquid is guided to the spiral space through the flow guide hole 301 to form an ascending spiral flow field. Due to the different densities, the bottom hole accumulation liquid with high density is accelerated and thrown to the oil pipe wall, and the natural gas with low density spirally rises near the center of the oil pipe, thereby realizing the diversion of the bottom hole accumulation liquid and the natural gas to spirally rise separately. The vortex effect improves the liquid carrying capacity of the ascending natural gas flow, and realizes the gas-liquid separation of natural gas hydrates.

[0030] In the self-sealing natural gas hydrate gas-liquid separation tool of the present invention, a sealing strip is used to complete the sealing between the spiral belt and the sealing cylinder during assembly, and the compression and radial expansion of the rubber cylinder structure are used to complete the effective sealing between the tool and the oil pipe during setting, providing a completely sealed space for the natural gas flow, thereby improving the sealing performance and gas-liquid separation capability; in the present invention, a plurality of spiral belts are arranged to form a plurality of spiral spaces, and each spiral space is respectively connected to a guide hole, and the liquid-containing natural gas passing through the guide hole is respectively connected to each spiral space, so that the liquid-containing natural gas is fully accelerated and forms a vortex, so that the natural gas flow containing the bottom liquid accumulates when passing through the tool, and the vortex effect is fully generated, so that the efficient gas-liquid separation of natural gas hydrate is realized, and the effect of the vortex effect is greatly improved.

[0031] Further, if Figure 1 , Figure 2 As shown, the rubber cylinder structure includes a rubber cylinder body 11, and an upper shoulder guard 4 and a lower shoulder guard 5 are respectively arranged at both ends of the rubber cylinder body 11. The upper shoulder guard 4 is fixed to the connector through an upper retaining ring 12, and the lower shoulder guard 5 is provided with a lower retaining ring 10 which can move axially along the connector.

[0032] Furthermore, a first outer sliding conical surface with a diameter gradually decreasing from bottom to top is provided at the top of the rubber cylinder body 11, and a first inner sliding conical surface is provided inside the upper shoulder guard 4, and the first outer sliding conical surface can move along the first inner sliding conical surface;

[0033] A second outer sliding cone surface with a diameter gradually decreasing from top to bottom is arranged at the bottom end of the rubber cylinder body 11, and a second inner sliding cone surface is arranged inside the lower shoulder guard 5. The second inner sliding cone surface can move along the second outer sliding cone surface and can push the rubber cylinder body 11 to move upward to generate radial expansion.

[0034] Further, if Figure 1 , Figure 2 As shown, a positioning protruding ring 601 is provided on the outer wall of the connector, and the positioning protruding ring 601 can limit the lower retaining ring 10 from below.

[0035] Further, if Figure 1 , Figure 2 As shown, the sealing structure includes a sealing device 9 which can slide axially along the connecting body, and the inner wall of the sealing device 9 is provided with a sealing inner conical surface; the bottom end of the outer wall of the connecting body is provided with a sealing outer conical surface upward, and the sealing inner conical surface can slide along the sealing outer conical surface; the bottom end of the sealing device 9 is provided with a locking boss 901 which can be sealed on the inner wall of the oil pipe.

[0036] Further, if Figure 1 , Figure 2 As shown, the locking boss 901 is connected to the spring body 8 via a shear pin 18. Specifically, an ear hole is provided on the locking boss, and the spring body is fixed by the shear pin 18 inserted into the ear hole.

[0037] Further, if Figure 1 , Figure 2 As shown, an inner boss 902 is provided on the inner wall of the setting device 9 , and the top surface of the inner boss 902 can abut against the bottom surface of the positioning convex ring 601 .

[0038] Before being lowered to the placement position, the spring body 8 is pressed between the inner wall of the oil pipe and the setting device 9, so that the bottom end of the setting device 9 remains in a tightened state.

[0039] When the tool string is dropped to the designed well depth, it is lifted up, the spring body 8 is loosened, the lower end of the sealing device 9 expands and is stuck in the tubing coupling 17 (existing technology), and then lowered. The shock tool causes the connector to move downward, and the lower end of the sealing device 9 expands to the maximum diameter and is firmly stuck in the maximum diameter of the outer cone of the lower sealing device. The locking boss 901 of the sealing device 9 is fixed to the tubing coupling to achieve sealing. At the same time, the sealing device 9 supports the lower retaining ring 10 and the lower shoulder guard 5 to complete the extrusion of the rubber sleeve body 11, and the rubber sleeve structure is compressed to achieve the sealing of the tool and the inner wall of the tubing.

[0040] Furthermore, the connector includes an upper connector 6 and a lower connector 7. An upper center hole is provided in the upper connector 6, and a lower center hole is provided in the lower connector 7. The upper center hole and the lower center hole are connected to form a flow passage. The upper connector 6 is fixedly connected to the bottom end of the sealing cylinder 13, and the rubber cylinder structure is sleeved on the upper connector 6. The top end of the setting seal structure is sleeved on the upper connector 6. The setting seal outer cone surface is provided on the outer wall of the lower connector 7.

[0041] The lower retaining ring 10, the lower shoulder guard 5, the rubber cylinder body 11, the upper shoulder guard 4, and the upper retaining ring 12 are pre-sleeved on the upper connecting piece 6 to form a rubber cylinder structure combination; the sealing device 9 is pre-sleeved on the upper connecting piece 6, and then the lower connecting piece 7 is connected to the upper connecting piece 6; the upper connecting piece 6 and the lower connecting piece 7 are connected by threads; the upper connecting piece 6 and the guide body 3 are connected by threads.

[0042] Further, if Figure 1 , Figure 2 As shown, the top end of the eddy current speed changer 14 is connected to the fishing head 1. The fishing head 1 and the eddy current speed changer 14 are connected by threads.

[0043] Furthermore, the main components of the present invention are all made of alloy steel, that is, the sealing cylinder 13, the eddy current transmission body 14, the spiral belt 2, the guide body 3, the connecting body (upper connecting piece 6, lower connecting piece 7) and the sealing structure (sealing device 9), the upper shoulder guard 4, the lower shoulder guard 5, the upper baffle ring 12, and the lower baffle ring 10 are made of alloy steel, and the sealing strip 15 and the rubber cylinder body 11 are made of rubber.

[0044] In a specific embodiment of the present invention, three spiral bands 2 are arranged on the outer wall of the vortex transmission body 14, the three spiral bands 2 constitute three spiral spaces, three guide holes 301 are arranged on the guide body 3, and each guide hole 301 is sealed and connected to one spiral space.

[0045] The self-sealing natural gas hydrate gas-liquid separation tool of the present invention is assembled as follows: Figure 1 As shown, the fishing head 1 is connected to the eddy current transmission body 14 by threads; the eddy current transmission body 14 is connected to the spiral belt 2 by welding; the sealing strip 15 is evenly arranged on the spiral belt 2; the eddy current transmission body 14 is connected to the guide body 3 by threads; the guide body 3 is connected to the sealing cylinder 13 by threads; the lower retaining ring 10 and the lower shoulder guard 5, the rubber cylinder body 11, the upper shoulder guard 4, and the upper retaining ring 12 are pre-mounted on the upper connecting piece 6 to form a combination; the upper connecting piece 6 and the guide body 3 are connected by threads; the sealing device 9 is pre-mounted on the upper connecting piece 6; the upper connecting piece 6 and the lower connecting piece 7 are connected by threads; the spring body 8 is installed in the ear hole of the sealing device 9 and fixed by the shear pin 18.

[0046] When the self-sealing natural gas hydrate gas-liquid separation tool of the present invention is deployed, the fishing head 1 is used to deploy the tool string to the designed well depth position through wire operation. Before being lowered to the deployment position, the spring body 8 is pressed between the oil pipe 16 and the sealing device 9, so that the lower end of the sealing device 9 remains in a tightened state; when the tool string is deployed to the designed well depth position, it is lifted up, the spring body 8 is loosened, the lower end of the sealing device 9 expands and is stuck at the oil pipe coupling 17, the lowering and shocking tool causes the upper connecting piece 6 to move downward, the lower end of the sealing device 9 expands to the maximum diameter and is firmly stuck at the maximum diameter of the lower connecting piece 7, the locking boss 901 at the lower end of the sealing device 9 is fixed to the oil pipe coupling 17 to achieve sealing; at the same time, the sealing device 9 supports the lower retaining ring 10 and the lower shoulder 5, completes the extrusion of the rubber cylinder body 11, and compresses the rubber cylinder body to achieve the sealing of the tool and the inner wall of the oil pipe, such as Figure 2 shown.

[0047] The working principle of the present invention is as follows: after the gas well is opened, the natural gas flow containing the bottom-hole accumulated liquid passes through the flow channel of the connector (the lower center hole of the lower connector 7 and the upper center hole of the upper connector 6), enters the self-sealing natural gas hydrate gas-liquid separation tool and enters the guide hole 301 of the guide body 3, and the natural gas flow containing the bottom-hole accumulated liquid is guided to the spiral space between the spiral belts 2 through the guide hole 301. Under the action of the three spiral belts 2, an ascending spiral flow field is formed. Due to the different densities, the bottom-hole accumulated liquid with high density is accelerated and thrown to the wall of the oil pipe, and the natural gas with low density spirally rises near the center of the oil pipe, and finally the bottom-hole accumulated liquid and the natural gas are separated and spirally rise, and are mixed and discharged from the wellhead at a certain height.

[0048] As described above, the self-sealing natural gas hydrate gas-liquid separation tool of the present invention has the following beneficial effects:

[0049] In the self-sealing natural gas hydrate gas-liquid separation tool of the present invention, a sealing strip is used to complete the sealing between the spiral belt and the sealing cylinder during assembly, and the compression and radial expansion of the rubber cylinder structure are used to complete the effective sealing between the tool and the oil pipe during setting, providing a completely sealed space for the natural gas flow, thereby improving the sealing performance and gas-liquid separation capability; in the present invention, a plurality of spiral belts are arranged to form a plurality of spiral spaces, and each spiral space is respectively connected to a guide hole, and the liquid-containing natural gas passing through the guide hole is respectively connected to each spiral space, so that the liquid-containing natural gas is fully accelerated and forms a vortex, so that the natural gas flow containing the bottom liquid accumulates when passing through the tool, and the vortex effect is fully generated, so that the efficient gas-liquid separation of natural gas hydrate is realized, and the effect of the vortex effect is greatly improved.

[0050] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A self-sealing natural gas hydrate gas-liquid separation tool, characterized in that: It comprises a sealing cylinder, in which an eddy current transmission body is arranged, on the outer wall of the eddy current transmission body at least two spiral bands are arranged, a spiral space is formed between the two adjacent spiral bands, and a sealing strip is arranged between the spiral band and the inner wall of the sealing cylinder; the first end of the eddy current transmission body is connected to a guide body, on which guide holes respectively connected with the spiral spaces are arranged; a connecting body is arranged in a sealing connection at the bottom end of the sealing cylinder, and a flow passage which can be connected with the guide holes is arranged in the connecting body; a rubber sleeve structure is arranged on the outer wall of the connecting body from the top end to the inside, and the rubber sleeve structure can radially squeeze and expand to seal against the inner wall of the oil pipe; a sealing structure is arranged at the bottom end of the outer wall of the connecting body, and the sealing structure can be sealed on the inner wall of the oil pipe.

2. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 1, characterized in that: The rubber cylinder structure includes a rubber cylinder body, and an upper shoulder guard and a lower shoulder guard are respectively arranged at both ends of the rubber cylinder body. The upper shoulder guard is fixed to the connecting body through an upper retaining ring, and the lower shoulder guard is provided with a lower retaining ring which can move axially along the connecting body.

3. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 2, characterized in that: A first outer sliding conical surface with a diameter gradually decreasing from bottom to top is arranged at the top of the rubber cylinder body, and a first inner sliding conical surface is arranged inside the upper shoulder guard, and the first outer sliding conical surface can move along the first inner sliding conical surface; A second outer sliding conical surface with a diameter gradually decreasing from top to bottom is arranged at the bottom end of the rubber cylinder body, and a second inner sliding conical surface is arranged inside the lower shoulder guard. The second inner sliding conical surface can move along the second outer sliding conical surface and can push the rubber cylinder body to move upward to generate radial expansion.

4. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 2, characterized in that: A positioning convex ring is arranged on the outer wall of the connecting body, and the positioning convex ring can limit the lower retaining ring from below.

5. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 2, characterized in that: The sealing structure includes a sealing device that can slide axially along the connecting body, and the inner wall of the sealing device is provided with a sealing inner conical surface; the bottom end of the outer wall of the connecting body is provided with a sealing outer conical surface upward, and the sealing inner conical surface can slide along the sealing outer conical surface; the bottom end of the sealing device is provided with a locking boss that can be sealed on the inner wall of the oil pipe.

6. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 5, characterized in that: The locking boss is connected to the spring body via a shear pin.

7. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 5, characterized in that: An inner boss is arranged on the inner wall of the setting device, and a positioning convex ring is arranged on the outer wall of the connecting body. The top surface of the inner boss can abut against the bottom surface of the positioning convex ring.

8. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 1, characterized in that: The connecting body includes an upper connecting piece and a lower connecting piece, an upper center hole is arranged in the upper connecting piece, and a lower center hole is arranged in the lower connecting piece, and the upper center hole and the lower center hole are connected to form the flow channel; the upper connecting piece is fixedly connected to the bottom end of the sealing cylinder, and the rubber cylinder structure is sleeved on the upper connecting piece; the top end of the sealing structure is sleeved on the upper connecting piece.

9. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 1, characterized in that: The top end of the eddy current speed changer is connected to a fishing head.

10. The self-sealing natural gas hydrate gas-liquid separation tool according to claim 2, characterized in that: The sealing cylinder, the eddy current transmission body, the spiral belt, the guide body, the connecting body and the setting seal structure are made of alloy steel, and the sealing strip and the rubber cylinder body are made of rubber.

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