Air-tight seal special buckle for geothermal well

Abstract

The utility model belongs to the technical field of geothermal energy development and utilization, and particularly relates to an air-tight sealing special buckle for a geothermal well, which comprises a sleeve and a connecting pipe, the sleeve is in threaded connection with the connecting pipe, a sealing ring is embedded in the sleeve, a reinforcing sealing mechanism is arranged at the end of the sleeve, the reinforcing sealing mechanism comprises a convex ring, and the convex ring is connected with the connecting pipe. And the convex ring is fixedly connected to the end part of the sleeve. According to the air-tight sealing special buckle for the geothermal well, a reinforcing sealing mechanism composed of a convex ring, an elastic piece, a pressing ring and a sealing air bag and a sealing ring embedded in a casing pipe form double sealing, and when a connecting pipe is screwed into the casing pipe to be tightly connected with the casing pipe, a wedge-shaped extrusion block is pressed to slide and compress the sealing air bag, so that the sealing air bag expands in the radial direction to fill a micro gap; meanwhile, the sealing ring and the protruding edge of the connecting pipe form end face sealing, the problem that a traditional single-thread structure is prone to generating micro gaps at high temperature and high pressure to cause gas leakage is effectively solved, and the long-term air tightness of connection of the underground sleeve and the connecting pipe is remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of geothermal energy development and utilization technology, specifically a special gas seal buckle for geothermal wells. Background Technology

[0002] The special gas-sealing thread for geothermal wells is a specialized casing connection technology designed for high temperature, high pressure, strong corrosion and complex geological conditions in geothermal resource development. Its core lies in achieving reliable connection and long-term airtightness of the downhole tubing through innovative thread structure and sealing mechanism.

[0003] Currently, existing gas-tight special couplings are connected by a section of thread, and the connection and sealing of the casing are achieved by the extrusion fit between the threads. However, due to the great depth of geothermal wells and the high temperature and pressure, micro-gaps are easily generated due to thread deformation under high temperature and pressure, which can lead to gas leakage. In order to improve the sealing effect of the gas-tight special coupling, a gas-tight special coupling for geothermal wells is proposed. Utility Model Content

[0004] The main objective of this invention is to provide a special gas seal for geothermal wells, which can solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model proposes a special gas-sealing fastener for geothermal wells, comprising a casing and a connecting pipe, wherein the casing and the connecting pipe are threaded together, a sealing ring is embedded in the casing, and a reinforcing sealing mechanism is provided at the end of the casing, the reinforcing sealing mechanism comprising:

[0006] A convex ring is fixedly connected to the end of the sleeve, and a spring is embedded on the side of the convex ring away from the sleeve.

[0007] A pressure ring is fixedly connected to the top of the spring sheet, and a connector is fixedly connected to the bottom of the spring sheet. A compression block is fixedly connected to the end of the connector away from the spring sheet. When the temperature change in the geothermal well causes the metal to expand and contract, the spring sheet can absorb stress fluctuations through deformation to maintain the continuous compression force of the sealing airbag.

[0008] and a sealing airbag, wherein the sealing airbag is embedded in the convex ring.

[0009] Preferably, the extrusion block is wedge-shaped and slides against the inner wall of the convex ring.

[0010] Preferably, the sealing airbag is annular, and the extrusion block abuts against the sealing airbag. When the connecting pipe is screwed in and tightly connected to the sleeve, the wedge-shaped extrusion block is pressed and slides, compressing the sealing airbag and causing it to expand radially to fill the micro gap.

[0011] Preferably, a raised edge is fixedly connected to one end of the connecting pipe near the sealing ring.

[0012] Preferably, the sealing ring has an annular groove on the side near the connecting pipe, and the annular groove matches the convex edge. When the connecting pipe is screwed in and tightly connected to the sleeve, the convex edge is inserted into the annular groove to form an end face seal.

[0013] Preferably, the inner wall of the sleeve is provided with a trapezoidal thread groove and a straight thread groove. The trapezoidal thread groove bears the main axial load, and the straight thread groove provides auxiliary radial positioning.

[0014] Preferably, an inlaid ring is provided between the trapezoidal thread groove and the straight thread groove, and the inlaid ring matches the sealing ring.

[0015] This utility model provides a special gas seal buckle for geothermal wells. It has the following beneficial effects:

[0016] (1) The special gas-sealing buckle of the geothermal well is formed by a reinforced sealing mechanism consisting of a convex ring, a spring, a pressure ring and a sealing air bladder. It forms a double seal with the sealing ring embedded in the casing. When the connecting pipe is screwed in and tightly connected to the casing, the wedge-shaped extrusion block is pressed and slides, compressing the sealing air bladder and causing it to expand radially to fill the micro gap. At the same time, the sealing ring and the convex edge of the connecting pipe form an end face seal, which effectively solves the problem that the traditional single thread structure is prone to micro gaps under high temperature and high pressure, leading to gas leakage. It significantly improves the long-term air tightness of the connection between the downhole casing and the connecting pipe.

[0017] (2) The special gas seal buckle for the geothermal well strengthens the elastic combination design of the spring and the pressure ring in the sealing mechanism. When the temperature change in the geothermal well causes the metal to expand and contract, the spring can absorb stress fluctuations through deformation and maintain the continuous pressing force of the sealing airbag. At the same time, the sliding fit structure between the wedge-shaped extrusion block and the inner wall of the convex ring allows for small radial displacement without damaging the sealing interface, so that the special buckle can adapt to the drastic working condition changes under the complex geological conditions of deep geothermal wells.

[0018] (3) The inner wall of the casing of the special gas-sealed threaded joint for the geothermal well adopts a composite design of trapezoidal thread groove and straight thread groove. The trapezoidal thread groove bears the main axial load, while the straight thread groove provides auxiliary radial positioning. This maintains the convenience of traditional threaded connection and disperses stress concentration through the synergistic effect of the double threads. Combined with the positioning and fixing of the sealing ring at the ring opening, it effectively reduces the risk of thread deformation under high temperature and high pressure environment and greatly improves the fatigue resistance and structural stability of the connection between the casing and the connecting pipe. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a frontal sectional view of the present invention.

[0022] Figure 3 This utility model Figure 2 Schematic diagram of structure A in the middle;

[0023] Figure 4 This utility model Figure 2 Schematic diagram of structure B in the middle;

[0024] Figure 5 This is a schematic diagram of the sealing ring structure of this utility model;

[0025] Figure 6 This is a schematic diagram of the front sectional view of the present invention;

[0026] Figure 7 This utility model Figure 6 Schematic diagram of the C-structure.

[0027] Explanation of icon numbers:

[0028] 1. Sleeve; 2. Connecting pipe; 3. Sealing ring; 4. Reinforcing sealing mechanism; 21. Raised edge; 31. Annular groove; 101. Offset trapezoidal thread groove; 102. Straight thread groove; 103. Inlaid ring mouth; 41. Raised ring; 42. Spring piece; 43. Pressure ring; 44. Connecting piece; 45. Extrusion block; 46. Sealing airbag.

[0029] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] Please see Figures 1-7 This utility model proposes a special gas seal buckle for geothermal wells, including a casing 1 and a connecting pipe 2, the casing 1 and the connecting pipe 2 are threaded together, a sealing ring 3 is embedded in the casing 1, and a reinforcing sealing mechanism 4 is provided at the end of the casing 1.

[0032] In this embodiment of the present invention, in order to enhance the stability of the connection between the sleeve 1 and the connecting pipe 2, the inner wall of the sleeve 1 is provided with a trapezoidal thread groove 101 and a straight thread groove 102. The trapezoidal thread groove 101 bears the main axial load, and the straight thread groove 102 provides auxiliary radial positioning. This maintains the convenience of traditional threaded connection, and disperses stress concentration through the synergistic effect of the double threads, effectively reducing the risk of thread deformation under high temperature and high pressure environment, and greatly improving the fatigue resistance and structural stability of the connection between the sleeve 1 and the connecting pipe 2.

[0033] Furthermore, to improve the sealing performance when the sleeve 1 is connected to the connecting pipe 2, the sealing mechanism 4 specifically includes a convex ring 41, a pressure ring 43, and a sealing airbag 46. The convex ring 41 is fixedly connected to the end of the sleeve 1. A spring piece 42 is embedded in the side of the convex ring 41 away from the sleeve 1. The pressure ring 43 is fixedly connected to the top of the spring piece 42. A connector 44 is fixedly connected to the bottom of the spring piece 42. A compression block 45 is fixedly connected to the end of the connector 44 away from the spring piece 42. The sealing airbag 46 is embedded in the convex ring 41. The compression block 45 is wedge-shaped and slides against the inner wall of the convex ring 41. The sealing airbag 46 is annular, and the compression block 45 abuts against the sealing airbag 46. When the connecting pipe 2 is screwed into and tightly connected to the casing 1, the connecting pipe 2 squeezes the pressure ring 43, which in turn squeezes the spring 42. This causes the spring 42 to move the connecting piece 44 and the extrusion block 45, compressing the sealing airbag 46. This causes the sealing airbag 46 to expand radially and fill the micro-gap after the casing 1 and the connecting pipe 2 are connected. Furthermore, when the temperature change in the geothermal well causes the metal to expand and contract, the spring 42 can absorb stress fluctuations through deformation, maintaining the continuous clamping force of the sealing airbag 46. At the same time, the sliding fit structure between the wedge-shaped extrusion block 45 and the inner wall of the convex ring 41 allows for small radial displacement without damaging the sealing interface, enabling this special buckle to adapt to the drastic changes in working conditions under the complex geological conditions of deep geothermal wells.

[0034] Furthermore, an inlaid ring 103 is provided between the trapezoidal thread groove 101 and the straight thread groove 102. The inlaid ring 103 matches the sealing ring 3. A protruding edge 21 is fixedly connected to one end of the connecting pipe 2 near the sealing ring 3. An annular groove 31 is opened on the side of the sealing ring 3 near the connecting pipe 2, and the annular groove 31 matches the protruding edge 21. When the connecting pipe 2 is screwed in and tightly connected to the casing 1, the protruding edge 21 is stably inserted into the annular groove 31 of the sealing ring 3 to form an end face seal. With the use of the enhanced sealing mechanism 4, the problem of gas leakage caused by micro-gap in traditional single thread structure under high temperature and high pressure is effectively solved, and the long-term airtightness of the connection between the downhole casing 1 and the connecting pipe 2 is significantly improved.

[0035] In this utility model, during use, the connecting tube 2 is screwed into the sleeve 1. During this process, the connecting tube 2 and the sleeve 1 are tightly connected by the trapezoidal thread groove 101 and the straight thread groove 102. During this process, the connecting tube 2 squeezes the pressure ring 43, and then the pressure ring 43 squeezes the spring piece 42, causing the spring piece 42 to drive the connecting piece 44 and the extrusion block 45 to move, squeezing the sealing airbag 46, so that the sealing airbag 46 expands radially to fill the micro gap after the sleeve 1 and the connecting tube 2 are connected; at the same time, the convex edge 21 is stably inserted into the annular groove 31 of the sealing ring 3 to form an end face seal.

[0036] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A special gas-sealing coupling for geothermal wells, comprising a casing (1) and a connecting pipe (2), characterized in that: The sleeve (1) is threadedly connected to the connecting pipe (2), a sealing ring (3) is embedded in the sleeve (1), and a reinforcing sealing mechanism (4) is provided at the end of the sleeve (1). The reinforcing sealing mechanism (4) includes: A protruding ring (41) is fixedly connected to the end of the sleeve (1), and a spring piece (42) is inlaid on the side of the protruding ring (41) away from the sleeve (1). A pressure ring (43) is fixedly connected to the top of a spring sheet (42), and a connector (44) is fixedly connected to the bottom of the spring sheet (42). A pressing block (45) is fixedly connected to one end of the connector (44) away from the spring sheet (42). and a sealing airbag (46), which is embedded in the protruding ring (41).

2. The special gas-sealing fastener for geothermal wells according to claim 1, characterized in that: The extrusion block (45) is wedge-shaped and slides against the inner wall of the convex ring (41).

3. The special gas-sealing fastener for geothermal wells according to claim 2, characterized in that: The sealing airbag (46) is annular, and the compression block (45) abuts against the sealing airbag (46).

4. The special gas-sealing fastener for geothermal wells according to claim 1, characterized in that: The connecting pipe (2) has a protruding edge (21) fixedly connected to one end near the sealing ring (3).

5. The special gas-sealing fastener for geothermal wells according to claim 4, characterized in that: The sealing ring (3) has an annular groove (31) on the side near the connecting pipe (2), and the annular groove (31) matches the protrusion (21).

6. The special gas-sealing fastener for geothermal wells according to claim 1, characterized in that: The inner wall of the sleeve (1) is provided with a trapezoidal thread groove (101) and a straight thread groove (102).

7. A special gas-sealing fastener for geothermal wells according to claim 6, characterized in that: An inlaid ring (103) is provided between the trapezoidal thread groove (101) and the straight thread groove (102), and the inlaid ring (103) matches the sealing ring (3).

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