A leak-proof wellhead device for deep geological storage of mine water

Abstract

The present invention discloses a leak-proof wellhead device for deep geological storage of mine water, which relates to the field of wellhead sealing technology. The device comprises a wellhead pressure-bearing module, an axial displacement compensation module, a shear module, and a sealing module. The wellhead pressure-bearing module is used to connect the wellhead casing and the surface pipeline, and the lower end of the wellhead pressure-bearing module is connected to the upper end of the axial displacement compensation module, and the lower end of the axial displacement compensation module is connected to the upper end of the sealing module. The shear module is disposed within the sealing module and is used to break up impurities in the mine water that enters the wellhead pressure-bearing module. The lower end of the sealing module is used to be sleeved on the outer periphery of the upper end of the wellhead casing, and the sealing module is used to prevent the mine water in the wellhead casing from flowing out. The present invention can effectively solve the problem of mine water leakage and simultaneously prevent the accumulation and blockage of impurities in the mine water.

Description

Technical Field

[0001] The present invention relates to the technical field of wellhead sealing, and in particular to a leakage-proof wellhead device for deep geological sealing of mine water. Background Art

[0002] Coal mining areas often encounter the problem of high salinity, which poses a great threat to coal mining and the safety of miners. To solve this problem, deep geological storage methods for high salinity water have begun to be applied. The wellhead device is a key component of deep geological storage equipment. As an important device connecting the pump station pipeline and the injection well, it plays an important role in bearing water pressure, monitoring pressure, and preventing leakage during the water injection process. During use, high-intensity water injection will adversely affect the pressure resistance and service life of the wellhead device. Therefore, there is a special need for a leak-proof wellhead device that can be used in deep geological storage of mine water.

[0003] Existing wellhead devices usually have certain disadvantages. Since they usually use flanges to directly connect the wellhead device and the water injection wellhead, there is a problem of stress concentration, and leakage is prone to occur when there is a high water pressure inside the pipeline for a long time; in addition, coal mine water contains impurities such as high salinity, high hardness and suspended particulate matter. These impurities will accumulate during the sealing process and have an adverse effect on the service life and performance of the wellhead device, resulting in device failure and reduced efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a leakage-proof wellhead device for deep geological storage of mine water, so as to solve the problems existing in the above-mentioned prior art, effectively solve the problem of mine water leakage, and avoid the accumulation and blockage of impurities in the mine water.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a leakage-proof wellhead device for deep geological sealing of mine water, comprising a wellhead pressure-bearing module, an axial displacement compensation module, a shear module and a sealing module. The wellhead pressure-bearing module is used to connect the wellhead casing and the ground pipeline, and the lower end of the wellhead pressure-bearing module is connected to the upper end of the axial displacement compensation module, and the lower end of the axial displacement compensation module is connected to the upper end of the sealing module. The shear module is arranged in the sealing module, and the shear module is used to crush impurities in the mine water entering the wellhead pressure-bearing module. The lower end of the sealing module is used to be sleeved on the outer periphery of the upper end of the wellhead casing, and the sealing module is used to prevent the mine water in the wellhead casing from flowing out.

[0007] Preferably, a plurality of communication ports are provided on the side wall of the wellhead pressure-bearing module, and the communication ports are used to connect to the ground pipeline through a flange, and a transition fit is adopted between the flange and the ground pipeline.

[0008] Preferably, the axial displacement compensation module is a bellows compensation tube, the upper end of the bellows compensation tube and the lower end of the wellhead pressure module are welded by submerged arc welding, and the lower end of the bellows compensation tube and the sealing module are detachably connected.

[0009] Preferably, the sealing module includes a sealing shell and a sealing assembly, the shear module is installed in the upper part of the sealing shell, and the sealing assembly is installed in the middle part of the sealing shell. The upper end of the sealing shell is detachably connected to the axial displacement compensation module, and the lower end of the sealing shell is welded and fixed to the outer periphery of the wellhead casing. The sealing assembly is used to be set at the upper end of the wellhead casing.

[0010] Preferably, the upper end of the sealing housing is connected to the axial displacement compensation module via a clamp.

[0011] Preferably, the sealing assembly includes a mechanical sealing element, a metal self-tightening ring and an adsorption element, the adsorption element is located below the shear module, and the adsorption element is used to filter impurities in mine water, the mechanical sealing element is located below the adsorption element, the metal self-tightening ring is located below the mechanical sealing element, and a circle of annular groove is provided on the inner wall of the sealing shell corresponding to the position of the metal self-tightening ring, the metal self-tightening ring is installed in the annular groove, the mechanical sealing element is arranged corresponding to the upper end of the wellhead casing, and the metal self-tightening ring is arranged corresponding to the outer periphery of the upper end of the wellhead casing.

[0012] Preferably, the mechanical sealing element includes a stationary ring and a rotating ring, the stationary ring is located below the rotating ring, and the rotating ring is sleeved on the outer circumference of a rotating shaft, the stationary ring is connected to the inner wall of the sealing shell, and the rotating shaft can drive the rotating ring to rotate, and a plurality of grooves are provided at the lower end of the outer edge of the rotating ring, and a plurality of guide holes are provided at the outer edge of the stationary ring, and a metal sheet is rotatably connected to each of the guide holes. When water flows from top to bottom, the metal sheet can be rotated to open the guide hole, and when water flows from bottom to top, the metal sheet can be rotated to block the guide hole.

[0013] Preferably, the adsorption element is a nanocomposite material layer.

[0014] Preferably, the shear module includes a connecting shaft, a fixed ring and a plurality of rotating blades. A water pass plate is provided in the sealed shell, and the water pass plate can allow mine water to pass through. The connecting shaft is installed in the middle of the upper end of the water pass plate. The fixed ring is rotatably installed on the outer periphery of the connecting shaft. The plurality of rotating blades are evenly arranged around the outer periphery of the fixed ring, and the first end of the rotating blade is fixed to the outer wall of the fixed ring, and the second end of the rotating blade extends toward the inner wall of the sealed shell.

[0015] Preferably, the shear module also includes a fixed blade, which is mounted on the connecting shaft and arranged around the outer circumference of the connecting shaft. The fixed blade is located below the rotating blade, and when the rotating blade rotates, it can shear and crush impurities in the mine water together with the fixed blade.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The leakage-proof wellhead device for deep geological sealing of mine water provided by the present invention comprises a wellhead pressure-bearing module, an axial displacement compensation module, a shear module and a sealing module. The wellhead pressure-bearing module is used to connect the wellhead casing and the ground pipeline so as to facilitate the mine water to be passed into the wellhead casing through the ground pipeline, and the pressure is carried by the wellhead pressure-bearing component to improve the stability of the overall structure. The lower end of the wellhead pressure-bearing module is connected to the upper end of the axial displacement compensation module, and the lower end of the axial displacement compensation module is connected to the upper end of the sealing module, and then the axial displacement caused by the movement of the formation is compensated by the axial displacement compensation module, the mechanical vibration is absorbed, the shear The cutting module is arranged in the sealing module, and the shearing module is used to crush the impurities in the mine water entering the wellhead pressure module, and then shear and crush the impurities with larger particles into small particles, so as to avoid the accumulation of large-particle impurities in the leakage-proof wellhead device used for deep geological storage of mine water, and damage its internal structure, thereby affecting normal operation. The lower end of the sealing module is used to be sleeved on the outer periphery of the upper end of the wellhead casing, and the sealing module is used to prevent the mine water in the wellhead casing from flowing back from bottom to top, and to avoid leakage at the connection between the sealing module and the wellhead casing due to excessive pressure during the process of injecting mine water into the wellbore. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic structural diagram of a leak-proof wellhead device for deep geological storage of mine water in the present invention;

[0020] Figure 2 Schematic diagram of the structure of the shear module in the present invention;

[0021] Figure 3 Schematic diagram of the structure of the sealing module in the present invention;

[0022] In the figure: 1-wellhead pressure module, 2-axial displacement compensation module, 3-sealing shell, 4-rotating blade, 5-fixed blade, 6-connecting shaft, 7-water plate, 8-fixed ring, 9-adsorption element, 10-rotating ring, 11-stationary ring, 12-metal self-tightening ring, 13-wellhead casing, 14-rotating shaft, 15-groove, 16-diversion hole, 17-metal sheet. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention 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 making creative efforts are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a leakage-proof wellhead device for deep geological storage of mine water, so as to solve the problems existing in the prior art, effectively solve the problem of mine water leakage, and avoid the accumulation and blockage of impurities in the mine water.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1-Figure 3 As shown, this embodiment provides a leakage-proof wellhead device for deep geological storage of mine water, including a wellhead pressure-bearing module 1, an axial displacement compensation module 2, a shear module and a sealing module. The wellhead pressure-bearing module 1 is used to connect the wellhead casing 13 and the ground pipeline, so as to facilitate the mine water to be passed into the wellhead casing 13 through the ground pipeline, and the pressure is carried by the wellhead pressure-bearing component to improve the stability of the overall structure. The lower end of the wellhead pressure-bearing module 1 is connected to the upper end of the axial displacement compensation module 2, and the lower end of the axial displacement compensation module 2 is connected to the upper end of the sealing module, and then the axial displacement caused by the formation movement is compensated by the axial displacement compensation module 2, and the absorption mechanism is used to absorb the pressure. Mechanical vibration, the shear module is arranged in the sealing module, and the shear module is used to crush the impurities in the mine water entering the wellhead pressure module 1, and then shear and crush the impurities with larger particles into small particles, so as to avoid the accumulation of large-particle impurities in the leakage-proof wellhead device used for deep geological storage of mine water, and damage its internal structure, thereby affecting normal operation. The lower end of the sealing module is used to be sleeved on the outer periphery of the upper end of the wellhead casing 13, and the sealing module is used to prevent the mine water in the wellhead casing 13 from flowing back from bottom to top, and to avoid leakage at the connection between the sealing module and the wellhead casing 13 due to excessive pressure during the process of injecting mine water into the wellbore.

[0027] Specifically, a number of connecting ports are provided on the side wall of the wellhead pressure-bearing module 1, which are used to connect to the ground pipeline through flanges, and a transition fit is adopted between the flanges and the ground pipeline, thereby realizing a detachable connection between the wellhead pressure-bearing module 1 and the ground pipeline through the flanges to form a first-level pressure barrier above the wellhead casing 13.

[0028] The axial displacement compensation module 2 is a corrugated compensation tube, which can be used to achieve axial compensation of the wellhead casing 13, and the compensation amount is large, thereby compensating for the axial displacement caused by the formation movement. The upper end of the corrugated compensation tube and the lower end of the wellhead pressure module 1 are submerged arc welded, and the lower end of the corrugated compensation tube and the sealing module can be detachably connected. People in this field can also choose other connection methods according to actual needs.

[0029] The sealing module includes a sealing shell 3 and a sealing assembly. The shear module is installed in the upper part of the sealing shell 3, and the sealing assembly is installed in the middle part of the sealing shell 3. The shear module can shear the impurities in the mine water after the mine water enters the sealing shell 3 through the upper end of the sealing shell 3 and before reaching the sealing assembly, so as to avoid the accumulation of large-particle impurities in the mine water at the sealing assembly, affecting the normal operation and service life of the equipment. The upper end of the sealing shell 3 and the axial displacement compensation module 2 can be detachably connected, and the lower end of the sealing shell 3 is welded and fixed to the outer periphery of the wellhead casing 13. The sealing assembly is used to be connected to the upper end of the wellhead casing 13, which can realize pressure gradient sealing.

[0030] The upper end of the sealing housing 3 is connected to the axial displacement compensation module 2 via a clamp, which ensures connection stability while facilitating installation and disassembly.

[0031] The sealing assembly includes a mechanical sealing element, a metal self-tightening ring 12 and an adsorption element 9, forming a three-stage sealing structure. The adsorption element 9 is located below the shearing module, and after the shearing element shears the large-particle impurities in the mine water into small particles, the impurities in the mine water can be further filtered through the adsorption element 9, thereby improving the impurity treatment effect and impurity treatment efficiency. The mechanical sealing element is located below the adsorption element 9, so that the mine water adsorbed by the adsorption element 9 can flow through the mechanical sealing element and enter the wellhead casing 13. The mechanical sealing element is sleeved on the outer periphery of the upper end of the wellhead casing 13. The metal self-tightening ring 12 is located below the mechanical sealing element, and a circle of annular grooves is provided on the inner wall of the sealing shell 3 corresponding to the position of the metal self-tightening ring 12. The metal self-tightening ring 12 is installed in the annular groove. As a preferred solution in this embodiment, a ring is formed at the lower end of the sealing shell 3 toward the center of the sealing shell 3. The shaft extends to form a step surface, and the upper end of the step surface and the inner side wall of the sealing shell 3 can form an annular groove. The metal self-tightening ring 12 is arranged corresponding to the outer periphery of the upper end of the wellhead casing 13 to form a seal for the connection between the sealing shell 3 and the wellhead casing 13. In the initial state, the metal self-tightening ring 12 has a certain pre-tightening force due to its own elasticity. During operation, when mine water contacts the inner surface of the metal self-tightening ring 12 in the sealing shell 3, a higher pressure is generated, making the contact between the metal self-tightening ring 12 and the wellhead casing 13 and the contact between the metal self-tightening ring 12 and the sealing shell 3 tighter, thereby making the seal more reliable. When the pressure in the sealing shell 3 decreases, the pressure acting on the sealing shell 3 also decreases. While ensuring a good seal, the pressure of the metal self-tightening ring 12 on the connection between the wellhead casing 13 and the sealing shell 3 is reduced, thereby reducing wear.

[0032] The mechanical seal element consists of a stationary ring 11 and a rotating ring 10. The stationary ring 11 is positioned below the rotating ring 10, which is sleeved around a rotating shaft 14. The stationary ring 11 is connected to the inner wall of the sealing housing 3, and the rotating shaft 14 drives the rotating ring 10 to rotate. The rotation of the rotating ring 10 relative to the stationary ring 11 provides a seal. The rotating ring 10 is preferably made of a wear-resistant material (such as tungsten carbide), while the stationary ring 11 is preferably made of a corrosion-resistant non-metallic material (such as graphite). The contact surfaces of the rotating and stationary rings 10 and 11 are precision ground and polished to form a micron-level fit. When mine water enters the sealing housing 3, the water pressure acts on the back of the rotating ring 10, pushing it toward the stationary ring 11 and strengthening the seal surface fit. A number of grooves 15 are evenly processed on the edge of the sealing surface of the rotating ring 10, and guide holes 16 are processed on the edge of the sealing surface of the stationary ring 11 at positions corresponding to the grooves 15 of the rotating ring 10. A movable metal sheet 17 is set in each guide hole 16. The metal sheet 17 is hinged to the hole wall of the guide hole 16 through a pin, and the top can rotate around the pin. In the initial state, the metal sheet 17 fits the inner wall of the guide hole 16 to block the channel. When the mine water flows from top to bottom, it flows into the guide hole 16 through the groove 15 and pushes the metal sheet 17 to rotate around the pin. At this time, the metal sheet 17 rotates The metal sheet 17 is rotated in the opposite direction to rotate until it is in close contact with the sealing surface of the rotating ring 10, thereby blocking the diversion hole 16 and preventing the mine water from passing through the diversion hole 16. Under the action of the reverse water pressure, the rotating ring 10 further presses the stationary ring 11, forming a zero-gap seal between the metal sheet 17 and the rotating ring 10, blocking the backflow of water and forming an axial seal. At the same time, when designing the metal sheet 17, a torsion spring structure can be designed at the pin shaft so that in the absence of external force, the metal sheet 17 is in a state of blocking the diversion hole 16. When the water flows from top to bottom, the pressure of the water flow can overcome the elastic force of the torsion spring and push the metal sheet 17 open. When the water flow stops, the metal sheet 17 is driven by the torsion spring to resume the blocking state of the diversion hole 16. In addition, in order to further prevent the metal sheet 17 from opening when the water flows from bottom to top, a limit block can be fixed to the inner wall of the diversion hole 16 at a position above the free end of the metal sheet 17. When the water flows from top to bottom, the metal sheet 17 is limited below the limit block and cannot continue to rotate, thereby effectively blocking the diversion hole 16. The adsorption element 9 is a nanocomposite material layer, such as a graphene-modified polymer, a ceramic-based nanomaterial, etc., which has excellent corrosion resistance. Those skilled in the art can select specific materials according to actual needs.

[0033] The shearing module includes a connecting shaft 6, a fixed ring 8 and multiple rotating blades 4. A water pass plate 7 is provided in the sealed shell 3. The water pass plate 7 can allow mine water to pass through. The connecting shaft 6 is installed in the middle of the upper end of the water pass plate 7. Then, through the setting of the water pass plate 7, while ensuring that the mine water can pass smoothly, it is also convenient to install the connecting shaft 6. The fixed ring 8 is rotatably installed on the outer periphery of the connecting shaft 6. Multiple rotating blades 4 are evenly arranged around the outer periphery of the fixed ring 8, and the first end of the rotating blade 4 is fixed to the outer wall of the fixed ring 8. The second end of the rotating blade 4 extends toward the inner wall of the sealed shell 3. Then, as the mine water enters, the mine water can push the rotating blade 4 to rotate and cut the impurities in the mine water.

[0034] As a preferred solution of this embodiment, the shearing module also includes a fixed blade 5, which is installed on the connecting shaft 6 and is arranged around the outer periphery of the connecting shaft 6. The fixed blade 5 is located below the rotating blade 4, and the gap between the fixed blade 5 and the rotating blade 4 is small. As long as the fixed blade 5 does not affect the rotation of the rotating blade 4, and the rotating blade 4 and the fixed blade 5 can work together to act on the impurities in the mine water, the rotating blade 4 can shear and crush the impurities in the mine water together with the fixed blade 5 when rotating.

[0035] As another preferred solution of this embodiment, the structural design of the shearing module can also be designed as a connecting shaft 6 connecting the rotating blade 4, while the fixed blade 5 is connected to a fixed structure such as the side wall of the sealing shell 3, and the connecting shaft 6 can rotate. At the same time, the connecting shaft 6 can also be coaxially connected to the rotating shaft 14, so that the connecting shaft 6 can drive the rotating shaft 14 to rotate, and then the rotation of the rotating ring 10 is realized through the rotation of the rotating shaft 14, and the sealing effect is achieved through the cooperation of the stationary ring 11 and the rotating ring 10.

[0036] As another preferred solution of this embodiment, the fixed blade 5 can also be installed on the inner wall of the sealed shell 3, and the fixed blade 5 is arranged around the outer periphery of the axis of the sealed shell 3, the second end of the rotating blade 4 is arranged close to the fixed blade 5, and when the rotating blade 4 rotates, it can shear and crush impurities in the mine water together with the fixed blade 5.

[0037] In order to ensure the cutting effectiveness of the rotating blade 4 and the fixed blade 5, a driving device such as a hydraulic motor can be added in this embodiment to drive the rotating blade 4 to rotate, thereby increasing the rotation speed of the rotating blade 4 and increasing the shear force between the rotating blade 4 and the fixed blade 5, thereby achieving effective cutting of impurities in the mine water.

[0038] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A leak-proof wellhead device for deep geological storage of mine water, characterized by: The wellhead pressure-bearing module comprises a wellhead pressure-bearing module, an axial displacement compensation module, a shear module, and a sealing module. The wellhead pressure-bearing module is used to connect the wellhead casing and the ground pipeline, and the lower end of the wellhead pressure-bearing module is connected to the upper end of the axial displacement compensation module, and the lower end of the axial displacement compensation module is connected to the upper end of the sealing module. The shear module is arranged in the sealing module and is used to crush impurities in the mine water entering the wellhead pressure-bearing module. The lower end of the sealing module is used to be sleeved on the outer periphery of the upper end of the wellhead casing, and the sealing module is used to prevent the mine water in the wellhead casing from flowing out. The sealing module includes a sealing housing and a sealing assembly. The shear module is installed in the upper portion of the sealing housing, and the sealing assembly is installed in the middle portion of the sealing housing. The upper end of the sealing housing is detachably connected to the axial displacement compensation module. The lower end of the sealing housing is welded and fixed to the outer periphery of the wellhead casing. The sealing assembly is used to be arranged at the upper end of the wellhead casing. The sealing assembly includes a mechanical sealing element, a metal self-tightening ring and an adsorption element. The adsorption element is located below the shear module and is used to filter impurities in mine water. The mechanical sealing element is located below the adsorption element. The metal self-tightening ring is located below the mechanical sealing element. An annular groove is provided on the inner wall of the sealing shell at a position corresponding to the metal self-tightening ring. The metal self-tightening ring is installed in the annular groove. The mechanical sealing element is provided corresponding to the upper end of the wellhead casing, and the metal self-tightening ring is provided corresponding to the outer periphery of the upper end of the wellhead casing. The mechanical sealing element includes a stationary ring and a rotating ring. The stationary ring is located below the rotating ring and is sleeved on the outer circumference of a rotating shaft. The stationary ring is connected to the inner wall of the sealing housing. The rotating shaft can drive the rotating ring to rotate. A plurality of grooves are provided at the lower end of the outer edge of the rotating ring. A plurality of guide holes are provided at the outer edge of the stationary ring. A metal sheet is rotatably connected to each of the guide holes. When water flows from top to bottom, the metal sheet can be rotated to open the guide hole. When water flows from bottom to top, the metal sheet can be rotated to block the guide hole.

2. The anti-leakage wellhead device for deep geological storage of mine water according to claim 1, characterized in that: A plurality of communication ports are provided on the side wall of the wellhead pressure-bearing module. The communication ports are used to connect to the ground pipeline through flanges, and a transition fit is adopted between the flanges and the ground pipeline.

3. The anti-leakage wellhead device for deep geological storage of mine water according to claim 1, characterized in that: The axial displacement compensation module is a corrugated compensation tube, the upper end of the corrugated compensation tube and the lower end of the wellhead pressure module are welded by submerged arc welding, and the lower end of the corrugated compensation tube and the sealing module can be detachably connected.

4. The anti-leakage wellhead device for deep geological storage of mine water according to claim 1, characterized in that: The upper end of the sealing housing is connected to the axial displacement compensation module via a clamp.

5. The anti-leakage wellhead device for deep geological storage of mine water according to claim 1 is characterized in that: The adsorption element is a nanocomposite material layer.

6. The anti-leakage wellhead device for deep geological storage of mine water according to claim 1, characterized in that: The shearing module includes a connecting shaft, a fixed ring and a plurality of rotating blades. A water pass plate is provided in the sealed shell, and the water pass plate can allow mine water to pass through. The connecting shaft is installed in the middle of the upper end of the water pass plate. The fixed ring is rotatably installed on the outer periphery of the connecting shaft. The plurality of rotating blades are evenly arranged around the outer periphery of the fixed ring, and the first end of the rotating blade is fixed to the outer wall of the fixed ring, and the second end of the rotating blade extends toward the inner wall of the sealed shell.

7. The anti-leakage wellhead device for deep geological storage of mine water according to claim 6, characterized in that: The shearing module also includes a fixed blade, which is mounted on the connecting shaft and arranged around the outer circumference of the connecting shaft. The fixed blade is located below the rotating blade, and when the rotating blade rotates, it can shear and crush impurities in the mine water together with the fixed blade.

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