Long-term wellhead sealing device for carbon dioxide geological storage

Abstract

The application discloses a wellhead long-term sealing device in carbon dioxide geological storage, which comprises a grouting cavity and an assembly port coaxially arranged upward along a vertical direction at a soil matrix of a wellhead, a radial length of the assembly port is smaller than that of the grouting cavity, the radial length of the assembly port is smaller than that of the wellhead, an assembly shell is assembled at the assembly port, the grouting cavity and the wellhead, and an outer peripheral wall of the assembly shell is supported on an inner peripheral wall of the assembly port and an inner peripheral wall of the wellhead, a pressure opening and closing mechanism, an elastic flow resistance mechanism, a first blocking mechanism and a second blocking mechanism are sequentially arranged upward along the vertical direction in the assembly shell. The application can effectively improve the sealing effect of the wellhead, improve the ability to resist external factors, effectively avoid the carbon dioxide from seeping out from the soil matrix near the wellhead, and regularly discharge accumulated water or sludge, thereby preventing damage to mechanical parts. The application is suitable for the technical field of long-term sealing of wellheads.

Description

Technical Field

[0001] This invention belongs to the technical field of oil and gas engineering, specifically relating to a long-term wellhead sealing device for carbon dioxide geological storage. Background Technology

[0002] In carbon dioxide geological storage projects, long-term wellhead sealing is a core requirement for ensuring the safety and effectiveness of storage. Its main purpose is to prevent carbon dioxide leakage, ensure environmental safety, and prevent impacts on the surrounding ecosystem and human health. If carbon dioxide migrates along faults or abandoned wells, it may pollute groundwater (forming carbonic acid, dissolving minerals, and affecting water quality). Maintaining reservoir pressure ensures storage stability. If the wellhead seal fails, carbon dioxide may escape along the wellbore, leading to a decrease in reservoir pressure and affecting storage efficiency. High-pressure supercritical carbon dioxide can remain stable in deep formations, but after leakage, it may transform into a gas, expanding in volume and exacerbating the leakage risk. If carbon dioxide leakage leads to pressure imbalance, it may trigger microseismic events or formation slippage. Therefore, long-term sealing can reduce interference with underground fluid movement and maintain geological stability.

[0003] In existing storage methods, mechanical seals are generally used. However, during long-term storage, changes in environmental factors such as temperature and humidity can alter the pressure inside the well, reducing the effectiveness of the mechanical seal. Furthermore, carbon dioxide can gradually seep out through the connection between the wellhead and the mechanical seal, as well as from the surrounding soil, further diminishing the storage effect. Additionally, the bond between the mechanical seal and the soil matrix at the wellhead is significantly affected by environmental factors, such as extreme heat, extreme cold, or water immersion, which can weaken the bond and lead to reduced or no storage effectiveness. Summary of the Invention

[0004] This invention provides a long-term sealing device for wellheads in carbon dioxide geological storage, which improves the sealing effect of the wellhead, enhances the ability to resist the influence of external factors, effectively prevents carbon dioxide from seeping out from the soil matrix near the wellhead, and can periodically discharge accumulated water or silt to prevent damage to mechanical parts.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A long-term sealing device for the wellhead in carbon dioxide geological storage includes a grouting cavity and an assembly port coaxially opened at the soil matrix at the wellhead in a vertical direction. The radial length of the assembly port is less than the radial length of the grouting cavity and the radial length of the wellhead. An assembly shell is assembled at the assembly port, the grouting cavity, and the wellhead, and the outer peripheral wall of the assembly shell is supported by the inner peripheral wall of the assembly port and the inner peripheral wall of the wellhead. A pressure opening and closing mechanism, an elastic flow blocking mechanism, a primary barrier mechanism, and a secondary barrier mechanism are sequentially arranged in a vertical direction inside the assembly shell.

[0007] Furthermore, the assembly shell includes a central cylinder, an upper support cylinder, and a lower support cylinder arranged coaxially. The upper and lower support cylinders are detachably installed at the upper and lower ends of the central cylinder, respectively. The outer peripheral wall of the upper support cylinder is supported on the inner peripheral wall of the assembly shell, and the outer peripheral wall of the lower support cylinder is supported on the inner peripheral wall of the wellhead. The central cylinder extends into the grouting cavity, and an annular grouting area is formed between the central cylinder and the grouting cavity.

[0008] Furthermore, the central cylinder includes multiple arc-shaped cylinder plates evenly arranged circumferentially along the grouting cavity. The multiple arc-shaped cylinder plates are spliced ​​together to form a complete cylindrical structure. An upper connecting edge and a lower connecting edge are respectively constructed at the upper and lower ends of each arc-shaped cylinder plate. The upper connecting edge is detachably connected to the lower end wall of the upper supporting cylinder, and the lower connecting edge is detachably connected to the upper end wall of the lower supporting cylinder.

[0009] Furthermore, multiple connecting holes are spaced apart on each of the arc-shaped cylindrical plates, and anchor rods are installed in each connecting hole. The end of each anchor rod away from the arc-shaped cylindrical plate extends into the grouting area.

[0010] Furthermore, multiple vertical holes are uniformly formed along the circumference of the grouting cavity within the soil matrix, and grouting pipes are inserted into each of the vertical holes. The lower end of the grouting pipe passes through the grouting area from the ground surface, and multiple grouting holes are spaced apart on the peripheral wall of the grouting pipe.

[0011] Furthermore, the pressure opening and closing mechanism includes an opening and closing component and an elastic connecting component connected sequentially from bottom to top. The lower end of the opening and closing component is connected to the assembly shell, and the upper end of the opening and closing component is connected to the elastic connecting component. The upper end of the elastic connecting component is connected to the connecting rod. The upper end of the connecting rod passes through the primary barrier mechanism and the secondary barrier mechanism in sequence and extends above the ground surface.

[0012] Furthermore, the opening and closing assembly includes a lower horn body whose large diameter end is detachably connected to the assembly shell. The diameter of the lower horn body gradually decreases upward in the vertical direction. An upper horn body is provided above the lower horn body. The large diameter end of the upper horn body is movably sleeved outside the small diameter end of the lower horn body. The small diameter end of the upper horn body is connected to an elastic connecting assembly.

[0013] Furthermore, a connecting sleeve is constructed at the center of the small diameter end of the lower horn body, and multiple conductive ports are uniformly opened along the circumference of the small diameter end of the lower horn body. A plug-in rod is constructed at the center of the small diameter end of the upper horn body. The plug-in rod is movably inserted into the connecting sleeve. Multiple conductive channels are uniformly opened along the circumference of the lower horn body. These conductive channels are connected to the connecting sleeve through the confluence cavity at the small diameter end of the lower horn body. A first connecting channel connecting the connecting sleeve and the elastic connecting assembly is opened in the plug-in rod, and a second connecting channel is opened in the connecting rod.

[0014] Furthermore, the elastic connection assembly includes an assembly constructed on the small-diameter end of the upper horn body, and a vertical spring is provided within the assembly. The two ends of the vertical spring are detachably connected to the small-diameter end of the upper horn body and the lower end of the connecting rod, respectively.

[0015] Furthermore, the elastic flow-blocking mechanism includes an elastic flow-blocking filling layer whose lower end is connected to the assembly shell via an annular edge. A flared opening and a vertical opening are sequentially formed in the middle of the elastic flow-blocking filling layer from bottom to top. The opening and closing component is assembled inside the flared opening, and the elastic connecting component is assembled inside the vertical opening. An adjusting ring is connected to the upper end of the elastic flow-blocking filling layer, and adjusting vertical rods are symmetrically rotatably connected to the adjusting ring. Each adjusting vertical rod sequentially passes through the primary barrier mechanism and the secondary barrier mechanism and extends out of the ground. The adjusting vertical rods are threadedly connected to the primary barrier mechanism and the secondary barrier mechanism, respectively.

[0016] The present invention, by employing the aforementioned structure, achieves the following technological advancements compared to existing technologies: Because the grouting cavity is larger than the assembly port and wellhead, after the assembly shell is installed, the inner circumferential walls of the assembly port and wellhead are supported by the assembly shell. This allows the assembly shell to firmly bond with the soil matrix, preventing relative movement between the assembly shell and the soil matrix under harsh external environmental conditions. Furthermore, carbon dioxide-resistant cement (such as polymer-modified cement) is used to fill the grouting cavity, working in conjunction with the assembly shell to seal the soil matrix surrounding the upper part of the wellhead. This prevents carbon dioxide from escaping from the wellhead and the surrounding soil matrix, further restricting the displacement of the assembly shell and resulting in a tighter bond between the assembly shell and the soil matrix. The present invention also incorporates a pressure-operated opening and closing mechanism and an elastic flow-blocking mechanism within the assembly shell. When changes occur in temperature and humidity within the well, gas carrying moisture or impurities rises. If this gas enters the connection between the primary and secondary barrier mechanisms and the assembly shell, long-term exposure and corrosion can reduce the sealing performance of these connections. Because this invention employs a pressure-driven opening and closing mechanism, when the gas pressure inside the well increases, the gas drives the pressure-driven opening and closing mechanism to open. This allows the gas to enter the assembly shell and be restricted by the elastic flow-blocking mechanism, preventing moisture and impurities in the gas from being trapped and gradually deposited at the lower part of the assembly shell, facilitating the subsequent removal of accumulated water or sludge. This effectively prevents damage to the connections of mechanical components caused by moisture and impurities. Furthermore, when the gas-driven pressure-driven opening and closing mechanism opens, the upper part of the elastic flow-blocking mechanism gradually becomes denser, while the lower part becomes looser, improving the interception effect of the upper part of the elastic flow-blocking mechanism on moisture and impurities in the gas, while ensuring that the intercepted moisture and impurities smoothly pass through the lower part of the elastic flow-blocking mechanism and settle in the lower area of ​​the assembly shell. This invention can also install a gas storage tank outside the well. When the pressure inside the well is too high, gas will automatically enter the gas storage tank, gradually reducing the pressure inside the well to a predetermined range, thereby achieving a pressure relief effect. This invention employs a primary and a secondary barrier mechanism to achieve a two-stage seal. Combined with a pressure-operated opening and closing mechanism, it effectively prevents carbon dioxide leakage. In summary, this invention effectively improves the sealing effect at the wellhead, enhances resistance to external factors, effectively prevents carbon dioxide from seeping out from the soil matrix near the wellhead, and allows for the periodic removal of accumulated water or silt, preventing damage to mechanical components. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0018] In the attached diagram:

[0019] Figure 1 This is a schematic diagram of the structure installed at the wellhead soil matrix according to an embodiment of the present invention;

[0020] Figure 2 This is an axial structural cross-sectional view of the embodiment of the present invention installed at the wellhead soil matrix;

[0021] Figure 3 for Figure 2 Enlarged view of the structure at part A in the middle;

[0022] Figure 4 for Figure 2 Enlarged view of the structure of part B in the middle;

[0023] Figure 5 This is a cross-sectional view of the soil matrix at the wellhead in an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the structure of an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the disassembled assembly shell according to an embodiment of the present invention;

[0026] Figure 8 This is a schematic diagram of the connection between the primary barrier mechanism, the connecting rod, and the pressure opening and closing mechanism in an embodiment of the present invention.

[0027] Figure 9 This is a schematic diagram of the structure after the connecting rod and the primary barrier mechanism are separated according to an embodiment of the present invention;

[0028] Figure 10 This is a schematic diagram of the disassembled pressure opening and closing mechanism according to an embodiment of the present invention;

[0029] Figure 11 This is a schematic diagram of the pressure opening and closing mechanism from another angle after disassembly according to an embodiment of the present invention;

[0030] Figure 12 This is an axial structural cross-sectional view of the lower horn body in the pressure opening and closing mechanism of an embodiment of the present invention;

[0031] Figure 13 This is an axial structural cross-sectional view of the upper horn body in the pressure opening and closing mechanism of an embodiment of the present invention;

[0032] Figure 14 This is an axial structural cross-sectional view of the elastic flow-blocking mechanism according to an embodiment of the present invention;

[0033] Figure 15 This is an axial structural cross-sectional view of the secondary barrier mechanism according to an embodiment of the present invention.

[0034] Component markings: 100-Soil matrix, 101-Wellhead, 102-Grouting chamber, 103-Assembly port, 104-Vertical hole, 200-Assembly shell, 201-Arc-shaped cylinder plate, 202-Connecting hole, 203-Upper connecting edge, 204-Lower connecting edge, 205-Upper support cylinder, 206-First fixing edge, 207-Lower support cylinder, 300-Pressure opening and closing mechanism, 301-Lower horn body, 302-Assembly edge, 303-Opening and closing cover, 304-First end seat, 305-Conducting port, 306-Connecting sleeve, 307-Conducting channel, 308-Gathering cavity, 309-Upper horn body, 310-Second end seat, 311-Plug-in rod, 312-First connecting channel, 313-Assembly assembly, 314-Vertical spring, 315-Lower spring seat, 316-Upper spring seat, 400-First stage Barrier mechanism, 401-First disc seat, 402-First limiting flange, 403-First central hole, 404-Annular assembly groove, 405-Assembly ring, 406-First transmission hole, 500-Connecting rod, 501-Plunger body, 502-Second limiting flange, 503-Vertical rod body, 504-Second connecting channel, 505-Connector head, 506-Control valve, 600-Elastic flow-blocking mechanism, 601-Elastic flow-blocking filling layer, 602-Annular edge, 603-Bell mouth, 604-Vertical mouth, 605-Adjusting ring, 606-Adjusting vertical rod, 607-Operating handwheel, 700-Secondary barrier mechanism, 701-Second disc seat, 702-Second central hole, 703-Second transmission hole, 704-Second fixed edge, 800-Grouting pipe, 900-Anchor rod, 1000-Accumulation area. Detailed Implementation

[0035] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0036] This invention discloses a long-term wellhead sealing device for carbon dioxide geological storage, such as... Figure 1-15As shown, the device includes a grouting cavity 102, an assembly port 103, an assembly shell 200, a pressure opening and closing mechanism 300, an elastic flow-blocking mechanism 600, a primary barrier mechanism 400, and a secondary barrier mechanism 700, with all the aforementioned technical features having coincident axes. The grouting cavity 102 and the assembly port 103 are vertically upwardly formed at the soil matrix 100 of the wellhead 101. The radial length of the assembly port 103 is less than the radial length of the grouting cavity 102, and the radial length of the assembly port 103 is less than the radial length of the wellhead 101. The assembly shell 200 of this invention is assembled at the assembly port 103, the grouting cavity 102, and the wellhead 101. The outer peripheral wall of the assembly shell 200 corresponding to the assembly port 103 is supported on the inner peripheral wall of the assembly port 103, and the outer peripheral wall of the assembly shell 200 corresponding to the wellhead 101 is supported on the inner peripheral wall of the wellhead 101. The pressure opening and closing mechanism 300, the elastic flow blocking mechanism 600, the primary blocking mechanism 400 and the secondary blocking mechanism 700 of the present invention are all assembled in the assembly housing 200, and these components are arranged sequentially upward in the vertical direction. The working principle and advantages of this invention are as follows: Since the size of the grouting cavity 102 is larger than that of the assembly port 103 and the wellhead 101, after the assembly shell 200 is installed, the inner peripheral walls of the assembly port 103 and the wellhead 101 are supported by the assembly shell 200. In this way, the assembly shell 200 can be firmly bonded to the soil matrix 100, thereby preventing relative movement between the assembly shell 200 and the soil matrix 100 under the influence of harsh external environment. Furthermore, carbon dioxide resistant cement (such as polymer modified cement) is used to fill the grouting cavity 102, so that it works with the assembly shell 200 to seal the soil matrix 100 around the upper part of the wellhead 101, thereby preventing carbon dioxide from overflowing from the wellhead 101 and the surrounding soil matrix 100, and further restricting the displacement of the assembly shell 200, so that the bonding between the assembly shell 200 and the soil matrix 100 is even tighter. This invention incorporates a pressure-operated opening and closing mechanism 300 and an elastic flow-blocking mechanism 600 within the assembly shell 200. When changes occur in temperature and humidity within the well, the gas inside the well carries moisture or impurities upwards. If these impurities enter the connection between the primary barrier mechanism 400 and the assembly shell 200, or / or the connection between the secondary barrier mechanism 700 and the assembly shell 200, long-term exposure and corrosion can reduce the sealing performance of these connections. Because this invention utilizes the pressure-operated opening and closing mechanism 300, when the gas pressure inside the well increases, the gas drives the pressure-operated opening and closing mechanism 300 to open. This allows the gas to enter the assembly shell 200 and is then restricted by the elastic flow-blocking mechanism 600. This prevents moisture and impurities in the gas from being trapped and gradually deposited at the lower part of the assembly shell 200, facilitating the subsequent removal of accumulated water or sludge. This effectively prevents moisture and impurities from damaging the connections of the mechanical components.Furthermore, when the gas-driven pressure opening and closing mechanism 300 is opened, the upper part of the elastic flow-blocking mechanism 600 gradually becomes denser due to the pressure opening and closing mechanism 300, while the lower part of the elastic flow-blocking mechanism 600 becomes looser. This improves the interception effect of the upper part of the elastic flow-blocking mechanism 600 on moisture and impurities in the gas, while ensuring that the intercepted moisture and impurities smoothly pass through the lower part of the elastic flow-blocking mechanism 600 and fall into the lower area of ​​the assembly shell 200. This invention allows for the installation of a gas storage tank outside the well. When the pressure inside the well is too high, the gas automatically enters the gas storage tank, gradually reducing the pressure inside the well to a predetermined range, thereby achieving pressure relief. This invention, by employing a primary barrier mechanism 400 and a secondary barrier mechanism 700, achieves a two-stage sealing purpose, and in conjunction with the pressure opening and closing mechanism 300, effectively prevents carbon dioxide leakage. In summary, the present invention can effectively improve the sealing effect of the wellhead 101, enhance its resistance to external factors, effectively prevent carbon dioxide from seeping out from the soil matrix 100 near the wellhead 101, and periodically discharge accumulated water or silt, preventing damage to mechanical parts.

[0037] As a preferred embodiment of the present invention, such as Figure 2 , 6As shown in Figure 7, the assembly shell 200 includes a central cylindrical body, an upper supporting cylindrical body 205, and a lower supporting cylindrical body 207 coaxially arranged. The upper supporting cylindrical body 205 is detachably connected to the upper end of the central cylindrical body, and the lower supporting cylindrical body 207 is detachably connected to the lower end of the central cylindrical body. A first fixing edge 206 is constructed at the upper end of the upper supporting cylindrical body 205, which is detachably connected to a second fixing edge 704 on the secondary barrier mechanism 700. In this embodiment, the outer peripheral wall of the upper supporting cylindrical body 205 is supported on the inner peripheral wall of the assembly shell 200, and the outer peripheral wall of the lower supporting cylindrical body 207 is supported on the inner peripheral wall of the wellhead 101. The central cylindrical body extends into the grouting cavity 102, and an annular grouting area is formed between the central cylindrical body and the grouting cavity 102. In this embodiment, the upper support cylinder 205 stabilizes the assembly port 103, preventing deformation or collapse of the soil matrix 100 at the assembly port 103. Similarly, the lower support cylinder 207 stabilizes the upper part of the wellhead 101, preventing deformation or collapse of the soil matrix 100 at the wellhead 101. Since the size of the grouting cavity 102 is larger than the assembly port 103, in order to facilitate the smooth passage of the middle cylinder through the assembly port 103 and its assembly into the grouting cavity 102, the following measures are taken: the middle cylinder includes multiple arc-shaped cylinder plates 201. These arc-shaped cylinder plates 201 are evenly arranged along the circumference of the grouting cavity 102, and these arc-shaped cylinder plates 201 are spliced ​​together to form a complete cylindrical structure. In this embodiment, an upper connecting edge 203 is constructed at the upper end of each arc-shaped cylindrical plate 201, and a lower connecting edge 204 is constructed at the lower end of each arc-shaped cylindrical plate 201. The upper connecting edge 203 is detachably connected to the lower end wall of the upper supporting cylinder 205, and the lower connecting edge 204 is detachably connected to the upper end wall of the lower supporting cylinder 207. In order to improve the connection strength between the concrete and the middle cylinder in the grouting cavity 102, and to improve the integrity of the middle cylinder and the concrete, thereby ensuring that the middle cylinder will not undergo displacement exceeding the threshold when the external environment changes, the measures taken are as follows: multiple connecting holes 202 are spaced apart on the arc-shaped cylindrical plate 201. These connecting holes 202 are preferably evenly distributed on the arc-shaped cylindrical plate 201, and the distance between the connecting holes 202 should not be too close to avoid affecting the strength of the arc-shaped cylindrical plate 201 itself. An anchor rod 900 is installed in each connection hole 202. The end of each anchor rod 900 away from the arc-shaped cylinder plate 201 extends into the grouting area. Generally, the end of the anchor rod 900 is inserted into the connection hole 202 and then fixed to the arc-shaped cylinder plate 201 by welding. In this embodiment, the part of each anchor rod 900 that extends into the middle cylinder is connected to the corresponding part of the elastic flow-blocking mechanism 600, so that it fixes the outer peripheral wall of the elastic flow-blocking mechanism 600. This ensures that the elastic flow-blocking mechanism 600 can elastically return to its original position after the external force disappears, and avoids the elastic flow-blocking mechanism 600 from being stretched or compressed and failing to return to its original position, thus reducing the barrier effect against water and impurities.

[0038] As a preferred embodiment of the present invention, such as Figure 2 , 5 As shown, multiple vertical holes 104 are uniformly formed around the grouting cavity 102 within the soil matrix 100. A grouting pipe 800 is inserted into each vertical hole 104. The lower end of each grouting pipe 800 extends downwards from the ground surface through the grouting area and is anchored within the soil matrix 100 below the grouting area. Multiple grouting holes are spaced apart on the periphery of the grouting pipe 800. In this embodiment, concrete grout is pressurized and injected into the grouting area through the grouting pipe 800. After the grouting area is filled, pressurized grouting continues, allowing the concrete grout to penetrate into the pores and cracks of the soil matrix 100, thereby sealing the area around the wellhead 101 and preventing carbon dioxide from escaping from the area around the wellhead 101. Furthermore, after the concrete solidifies, the grouting pipe 800 and the anchor rod 900 cooperate to form a supporting framework, thereby enhancing the strength of the concrete.

[0039] As a preferred embodiment of the present invention, such as Figure 2 , 3As shown in Figures 4, 8, 10, 11, 12, and 13, the pressure opening and closing mechanism 300 includes an opening and closing assembly and an elastic connecting assembly. The opening and closing assembly and the elastic connecting assembly are connected sequentially from bottom to top. The lower end of the opening and closing assembly is detachably connected to the bottom wall of the middle cylinder, and the upper end of the opening and closing assembly is connected to the elastic connecting assembly. The upper end of the elastic connecting assembly is connected to a connecting rod 500, the upper end of which passes through a primary barrier mechanism 400 and a secondary barrier mechanism 700 and extends above the ground surface. In this embodiment, the opening and closing assembly includes a lower horn body 301 and an upper horn body 309. An mounting edge 302 is constructed at the large-diameter end of the lower horn body 301, which is connected to the bottom wall of the middle cylinder by multiple connecting bolts. The diameter of the lower horn body 301 gradually decreases upwards in the vertical direction. A first end seat 304 is constructed at the small-diameter end of the lower horn body 301, and an opening and closing cover 303 is formed on the outer peripheral wall of the upper part of the lower horn body 301. The upper horn body 309 is coaxially disposed above the lower horn body 301. The large-diameter end of the upper horn body 309 is movably fitted onto the opening and closing cover 303 of the lower horn body 301. A second end seat 310 is constructed at the small-diameter end of the upper horn body 309, and the second end seat 310 is connected to the elastic connecting assembly. In this embodiment, a connecting sleeve 306 is constructed at the center of the upper end of the first end seat 304 of the lower horn body 301. A plurality of through holes 305 are evenly formed along the circumference of the first end seat 304. A plug-in rod 311 is constructed at the center of the lower end of the second end seat 310 of the upper horn body 309. The plug-in rod 311 is movably inserted into the connecting sleeve 306. A plurality of through channels 307 are evenly formed along the circumference of the lower horn body 301. The system includes a manifold 308, which communicates with the lower end of a connecting sleeve 306. Each conductive channel 307 communicates with the connecting sleeve 306 via the manifold 308. The end of each conductive channel 307 away from the manifold 308 communicates with an accumulation area 1000 via an assembly edge 302. The accumulation area 1000 is formed outside the assembly edge 302 and in the lower region of the elastic flow-blocking filling layer 601. Water and impurities of equal diameter are collected within the accumulation area 1000 after passing through the elastic flow-blocking filling layer 601. In this embodiment, a first connecting channel 312 is provided within the plug-in rod 311, which connects the connecting sleeve 306 and the elastic connecting assembly. A second connecting channel 504 is provided within the connecting rod 500. In this embodiment, the upper end of the connecting rod 500 is connected to the inlet end of a suction pump. By controlling the operation of the suction pump, it is able to remove accumulated water or sludge from the accumulation area 1000.The elastic connection assembly of this embodiment includes a mounting bracket 313, a vertical spring 314, a lower spring seat 315, and an upper spring seat 316. The mounting bracket 313 is constructed on the upper end of the second end seat 310 of the upper horn body 309. The vertical spring 314 is disposed inside the mounting bracket 313. The lower spring seat 315 and the upper spring seat 316 are respectively constructed on both ends of the vertical spring 314. The lower spring seat 315 is detachably connected to the second end seat 310, and the upper spring seat 316 is detachably connected to the lower end of the connecting rod 500. The working principle and advantages of this embodiment are as follows: When the gas pressure inside the well increases, the gas passes through the guide port 305 and drives the upper horn body 309 to move upward. At this time, the vertical spring 314 is compressed and stores energy, and a flow channel is formed between the upper horn body 309 and the opening and closing cover 303. The gas enters the assembly shell 200 through the flow channel, and the gas comes into contact with the elastic flow-blocking filling layer 601. The elastic flow-blocking filling layer 601 blocks the moisture and impurities in the gas, so that the gas components and non-gas components are fully separated, so that the non-gas components can eventually gather in the accumulation area 1000. During the upward movement of the upper horn body 309, it presses upward on the corresponding part of the elastic flow-blocking filling layer 601, reducing the pores in the upper part of the elastic flow-blocking filling layer 601 and improving its contact effect with the gas. The lower part of the elastic flow-blocking filling layer 601 is then pulled upward, increasing its pores, allowing non-gas components to pass smoothly through the lower part of the elastic flow-blocking filling layer 601 into the accumulation zone 1000. After the gas enters the gas storage tank and the well pressure drops to a predetermined range, the vertical spring 314 drives the upper horn body 309 to gradually return to its original position, closing the flow passage.

[0040] As a preferred embodiment of the present invention, such as Figure 2 , 14As shown, the elastic flow-blocking mechanism 600 includes an elastic flow-blocking filling layer 601. An annular edge 602 is fixedly connected to the lower outer edge of the elastic flow-blocking filling layer 601. The annular edge 602 is detachably connected to the lower inner wall of the middle cylinder. A flared opening 603 and a vertical opening 604 are sequentially opened from bottom to top in the middle of the elastic flow-blocking filling layer 601. The lower flared body 301 and the upper flared body 309 of the opening and closing assembly are both assembled in the flared opening 603 and are respectively adapted to the corresponding parts of the flared opening 603. The elastic connecting assembly is assembled in the vertical opening 604. In this way, during the relative movement of the lower flared body 301 and the upper flared body 309, the upper flared body 309 drives the corresponding part and above of the elastic flow-blocking filling layer 601 to press upward, thereby changing the pore size of different areas of the elastic flow-blocking filling layer 601. In this embodiment, an adjusting ring 605 is connected to the upper end of the elastic flow-blocking filling layer 601. Adjusting vertical rods 606 are symmetrically rotatably connected to the adjusting ring 605. Each adjusting vertical rod 606 passes sequentially through the primary barrier mechanism 400 and the secondary barrier mechanism 700 and extends out of the ground. The adjusting vertical rods 606 are threadedly connected to both the primary and secondary barrier mechanisms 400 and 700, respectively. An operating handwheel 607 is installed at the upper end of the adjusting vertical rod 606. In this embodiment, rotating the operating handwheel 607 causes the adjusting vertical rod 606 to move downwards vertically. This, in turn, compresses the elastic flow-blocking filling layer 601 downwards through the adjusting ring 605, thereby adjusting the pore size of the elastic flow-blocking filling layer 601. This adjusts the flow-blocking effect of the elastic flow-blocking filling layer 601 on the gas, ultimately achieving the blocking of moisture and impurities.

[0041] As a preferred embodiment of the present invention, such as Figure 2 , 8 As shown in Figures 9 and 10, the connecting rod 500 includes a vertical rod body 503, a plunger body 501, and a connector 505 connected sequentially from top to bottom. The upper end of the second connecting channel 504 passes through the upper end of the vertical rod body 503, and the lower end of the second connecting channel 504 passes through the lower end of the connector 505. A control valve 506 is installed on the upper part of the vertical rod body 503. This control valve 506 is a one-way valve, used to open and close the upper part of the second connecting channel 504, as the medium is conveyed outward from the second connecting channel 504. A second limiting flange is constructed on the outer peripheral wall of the plunger body 501, extending radially outward from the plunger body 501.

[0042] As a preferred embodiment of the present invention, such as Figure 2 , 8As shown in Figure 9, the primary blocking mechanism 400 includes a first disc base 401. A first limiting flange 402 is constructed on the outer peripheral wall of the first disc base 401, extending radially outward along the first disc base 401. An annular groove is constructed on the inner peripheral wall of the upper support cylinder 205. The first disc base 401 is assembled inside the upper support cylinder 205, and the first limiting flange 402 is assembled inside the annular groove. A first central hole 403 is constructed at the center of the first disc base 401, and the plunger body 501 of the connecting rod 500 is assembled inside the first central hole 403. An annular mounting groove 404 and a recess are sequentially constructed vertically downward at the upper end of the first disc base 401, with the radial length of the recess being less than that of the annular mounting groove 404. The second limiting flange 502 of the plunger body 501 is fitted into the groove. An assembly ring 405 is detachably connected to the annular assembly groove 404 to restrict the second limiting flange 502 within the groove, thereby fixing the plunger body 501 to the first disc seat 401. Two first transmission holes 406 are symmetrically opened on the first disc seat 401 at the first central hole 403. The adjusting vertical rod 606 is threadedly connected to the first disc seat 401 through the corresponding first transmission holes 406.

[0043] As a preferred embodiment of the present invention, such as Figure 2 , 15 As shown, the secondary barrier mechanism 700 includes a second plate seat 701, which is mounted on the upper part of the upper support cylinder 205. A second fixing edge 704 is constructed at the upper outer edge of the second plate seat 701, and the second fixing edge 704 is detachably connected to the aforementioned first fixing edge 206. In this embodiment, a second central hole 702 is provided at the center of the second plate seat 701, and two second transmission holes 703 are symmetrically provided on both sides of the second central hole 702. The vertical rod 503 of the connecting rod 500 passes through the second central hole 702 and passes through the second plate seat 701. The adjusting vertical rod 606 is threadedly connected to the second plate seat 701 through the corresponding second transmission hole 703.

[0044] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit 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 scope of protection of the claims of the present invention.

Claims

1. A wellhead long-term sealing device in carbon dioxide geological storage, characterized in that: The application relates to a grouting device for a wellhead, which comprises a grouting cavity coaxially arranged in a soil matrix of a wellhead in a vertical direction, and an assembling opening coaxially arranged in the grouting cavity in the vertical direction, wherein the radial length of the assembling opening is smaller than that of the grouting cavity, the radial length of the assembling opening is smaller than that of the wellhead, an assembling shell is assembled in the assembling opening, the grouting cavity and the wellhead, and the outer peripheral wall of the assembling shell is supported on the inner peripheral wall of the assembling opening and the inner peripheral wall of the wellhead; a pressure opening and closing mechanism, an elastic flow resistance mechanism, a first blocking mechanism and a second blocking mechanism are sequentially arranged in the assembling shell in the vertical direction; the pressure opening and closing mechanism comprises a closing assembly and an elastic connecting assembly which are sequentially connected from bottom to top, the lower end of the closing assembly is connected with the assembling shell, the upper end of the closing assembly is connected with the elastic connecting assembly, the upper end of the elastic connecting assembly is connected with a connecting rod, the upper end of the connecting rod sequentially penetrates through the first blocking mechanism and the second blocking mechanism and extends above the ground surface; the closing assembly comprises a lower horn body which is detachably connected with the assembling shell at the large-diameter end, the caliber of the lower horn body is tapered in the vertical direction, an upper horn body is arranged above the lower horn body, the large-diameter end of the upper horn body is movably sleeved on the small-diameter end of the lower horn body, and the small-diameter end of the upper horn body is connected with the elastic connecting assembly; the elastic connecting assembly comprises an assembling sleeve arranged on the small-diameter end of the upper horn body, a vertical spring is arranged in the assembling sleeve, and the two ends of the vertical spring are detachably connected with the small-diameter end of the upper horn body and the lower end of the connecting rod respectively; the elastic flow resistance mechanism comprises an elastic flow resistance filling layer which is connected with the assembling shell through an annular ring, a horn opening and a vertical opening are sequentially arranged in the middle part of the elastic flow resistance filling layer from bottom to top, the closing assembly is assembled in the horn opening, the elastic connecting assembly is assembled in the vertical opening, an adjusting ring is connected with the upper end of the elastic flow resistance filling layer, adjusting vertical rods are symmetrically and rotatably connected with the adjusting ring, and the adjusting vertical rods sequentially penetrate through the first blocking mechanism and the second blocking mechanism and extend above the ground surface, and the adjusting vertical rods are threadedly connected with the first blocking mechanism and the second blocking mechanism respectively.

2. The long-term wellhead containment device for carbon dioxide geological storage according to claim 1, characterized in that: The assembling shell comprises a middle cylinder, an upper supporting cylinder and a lower supporting cylinder which are coaxially arranged, the upper supporting cylinder and the lower supporting cylinder are detachably installed on the upper and lower ends of the middle cylinder respectively, the outer peripheral wall of the upper supporting cylinder is supported on the inner peripheral wall of the assembling shell, the outer peripheral wall of the lower supporting cylinder is supported on the inner peripheral wall of the wellhead, the middle cylinder extends into the grouting cavity, and an annular grouting area is formed between the middle cylinder and the grouting cavity.

3. The long-term wellhead containment device for carbon dioxide geological storage according to claim 2, characterized in that: The middle cylinder comprises a plurality of arc-shaped cylinder plates which are uniformly arranged along the circumference of the grouting cavity, the arc-shaped cylinder plates are mutually spliced and form a complete cylindrical structure, upper and lower connecting edges are arranged on the upper and lower ends of each arc-shaped cylinder plate respectively, the upper connecting edge is detachably connected with the lower end wall of the upper supporting cylinder, and the lower connecting edge is detachably connected with the upper end wall of the lower supporting cylinder.

4. The long-term wellhead containment device for carbon dioxide geological storage according to claim 3, characterized in that: A plurality of connecting holes are arranged on each arc-shaped cylinder plate at intervals, and anchor rods are assembled in the connecting holes, and the ends of the anchor rods away from the arc-shaped cylinder plates extend into the grouting area.

5. The long-term wellhead containment device for carbon dioxide geological storage according to claim 2, characterized in that: A plurality of vertical holes are evenly formed in the soil matrix along the circumference of the grouting cavity, a grouting pipe is inserted into each vertical hole, the lower end of the grouting pipe penetrates the grouting area from the ground surface, and a plurality of grouting holes are evenly formed on the circumferential wall of the grouting pipe.

6. The long-term wellhead containment device for carbon dioxide geologic sequestration of claim 1, wherein: A connecting sleeve is formed at the center of the small-diameter end of the lower horn body, a plurality of guide openings are evenly formed on the circumference of the small-diameter end of the lower horn body, a plug-in rod is formed at the center of the small-diameter end of the upper horn body, the plug-in rod is movably inserted into the connecting sleeve, a plurality of guide channels are evenly formed on the circumference of the lower horn body, the guide channels are communicated with the connecting sleeve through the converging cavity at the small-diameter end of the lower horn body, a first communication channel is formed in the plug-in rod to communicate the connecting sleeve and the elastic connection assembly, and a second communication channel is formed in the connecting rod.

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