High-connection-strength direct-connection type threaded heat-insulation oil pipe

Abstract

The utility model discloses a high-connection-strength direct-connection type threaded heat insulation oil pipe. The oil pipe is good in extrusion resistance, high in overall strength, good in heat insulation effect and good in sealing performance. Comprising an outer pipe and an inner pipe, the inner pipe is sleeved with the outer pipe, one end of the outer pipe is provided with an internal thread section, the other end of the outer pipe is provided with an external thread section matched with the internal thread section, threads of the internal thread section and threads of the external thread section of the outer pipe are trapezoidal threads, and the two ends of the outer pipe are thickened. An outer sealing shoulder is arranged on the side, close to the inner thread section, of the outer thread section, an inner sealing shoulder is arranged on the side, away from the outer thread section, of the inner thread section, an outer sealing conical surface is arranged on the outer sealing shoulder, a sealing ring is fixedly arranged on the outer sealing conical surface, an inner sealing conical surface is arranged on the inner sealing shoulder, and a sealing groove corresponding to the sealing ring is formed in the inner sealing conical surface. An elastic gasket is fixedly arranged in the sealing groove, a plurality of positioning blocks are arranged on the outer wall of the inner pipe, and the positioning blocks are connected between the inner wall of the outer pipe and the outer wall of the inner pipe in an abutting mode.

Description

Technical Field

[0001] The utility model relates to the technical field of oil exploitation, in particular to a high-connection-strength direct-connection type threaded heat-insulated oil pipe. Background Art

[0002] With the continuous development of the oil extraction industry and the continuous increase in oil consumption, the extraction of heavy oil has become the main source of production for many oil companies at home and abroad. At present, the annual production of heavy oil in my country has reached more than 15 million tons. There are usually two extraction methods for heavy oil extraction: steam stimulation and steam flooding. Steam stimulation refers to a heavy oil extraction method that completes the three processes of steam injection, well shut-down and well production in the well. However, steam stimulation can usually only extract crude oil in a limited area of ​​the oil layer around the well point, and the crude oil recovery rate of steam stimulation is generally only 10-20%. Steam flooding refers to the continuous injection of steam from the gas injection well through an appropriate well network to form a steam belt around the injection well. The injected steam heats the underground crude oil and drives it to the surrounding production wells for production. Whether it is steam stimulation or steam flooding, insulated oil pipes are required in the extraction of heavy oil thermal recovery oil fields.

[0003] For example, the Chinese patent with publication number CN217206330U discloses a direct-connection type bushing-free special threaded insulated oil pipe, including an outer pipe, one side of the outer pipe is provided with an internal thread section, and the other side is provided with an external thread section; the internal thread section is provided with an internal sealing shoulder, a first section of internal thread, a second section of internal thread and an internal sealing structure in sequence, and the external thread section is provided with an external sealing shoulder, a first section of external thread, a second section of external thread and an external sealing structure in sequence. First, the outer pipe connection of the insulated oil pipe of the present application adopts a coupling-free direct connection form, which changes the connection form of the traditional insulated oil pipe processing coupling thread, improves the processing efficiency, and saves the processing cost; secondly, the outer pipe adopts an external thickening form, which improves the compression resistance of the insulated oil pipe connection; thirdly, the double-layer straight thread structure design improves the connection strength and safety factor; finally, the optimized design of the thread grease storage tank is conducive to the uniform and effective application of the thread grease, so that it can achieve the best sealing effect.

[0004] The special threaded insulated oil pipe disclosed in this patent improves the connection strength by designing two sections of threads. Its processing is relatively complicated. At the same time, the position of the inner pipe relative to the outer pipe cannot be guaranteed, resulting in poor anti-extrusion ability and thermal insulation effect. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the defects of the existing technical problems and provide a high connection strength direct-connection threaded insulated oil pipe, which has good anti-extrusion ability, high overall strength, good insulation effect and good sealing performance.

[0006] In order to solve the above technical problems, the technical solution of the utility model is: a high connection strength direct-connection threaded insulated oil pipe, including an outer pipe and an inner pipe, the outer pipe is sleeved on the outside of the inner pipe, one end of the outer pipe is provided with an internal thread section, and the other end of the outer pipe is provided with an external thread section matching the internal thread section. The threads of the internal thread section and the external thread section of the outer pipe are both trapezoidal threads, both ends of the outer pipe are thickened, the lengths of the internal thread section and the external thread section are 150mm-200mm, and an external seal is provided on the side of the external thread section close to the internal thread section. A shoulder, an inner sealing shoulder corresponding to the outer sealing shoulder is provided on the side of the internal thread section away from the external thread section, the outer sealing shoulder has an outer sealing cone surface, a sealing ring is fixedly provided on the outer sealing cone surface, the inner sealing shoulder has an inner sealing cone surface corresponding to the outer sealing cone surface, a sealing groove corresponding to the sealing ring is provided on the inner sealing cone surface, an elastic gasket is fixedly provided in the sealing groove, a plurality of positioning blocks are provided on the outer wall of the inner tube along its circumference, and the positioning blocks abut between the inner wall of the outer tube and the outer wall of the inner tube.

[0007] Furthermore, the elastic gasket is made of corrosion-resistant rubber.

[0008] Furthermore, the outer sealing shoulder also has an outer sealing plane fixedly connected to the outer sealing cone surface, and the inner sealing shoulder also has an inner sealing plane corresponding to the outer sealing plane.

[0009] Furthermore, the outer sealing plane is arranged on a side of the outer sealing conical surface away from the thread.

[0010] Furthermore, an external sealing structure is provided on a side of the external thread segment away from the internal thread segment, and the external sealing structure includes an external sealing surface with a conical structure and an external sealing end perpendicular to the axial direction of the outer tube.

[0011] Furthermore, an inner sealing structure corresponding to the outer sealing structure is provided on one side of the inner thread section close to the outer thread section, and the inner sealing structure includes an inner sealing surface corresponding to the outer sealing surface and an inner sealing end corresponding to the outer sealing end.

[0012] Furthermore, a sealing grease storage groove is formed between the inner sealing surface and the inner sealing end.

[0013] Furthermore, the threads of the internal thread section and the external thread section are both trapezoidal threads, the tooth profile is an isosceles trapezoid, and the tooth profile angle is 30°.

[0014] Furthermore, a heat insulation layer is provided between the outer tube and the inner tube, and the heat insulation layer is a heat insulation material filled between the inner tube and the outer tube.

[0015] By adopting the above technical solution, the utility model has the following beneficial effects:

[0016] 1. The inner and outer thread sections of the outer pipe are thickened to make the connection between the two oil pipes stronger. At the same time, the thickening can play a certain role in heat insulation;

[0017] 2. Compared with the commonly used oil pipes, the threaded section is lengthened to improve the connection strength;

[0018] 3. The outer sealing shoulder cooperates with the inner sealing shoulder to improve the sealing performance and connection strength when connecting the oil pipe;

[0019] 4. The threads of the internal and external thread sections of the outer tube are both trapezoidal threads, the tooth profile is an isosceles trapezoid, the tooth profile angle is 30°, the internal and external threads are tightly attached to the conical surface and are not easy to loosen, with good strength, adjustable gap and good process performance;

[0020] 5. The inner tube is always centered and coaxial with the outer tube, so that the insulation material can be evenly filled between the outer tube and the inner tube, thereby making the oil pipe more resistant to extrusion, with higher overall strength and better insulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a high connection strength direct-connection special threaded heat-insulated oil pipe of the utility model;

[0022] Figure 2 It is a structural schematic diagram of the internal thread section of the utility model;

[0023] Figure 3 It is a structural schematic diagram of the external thread section of the utility model;

[0024] Figure 4 for Figure 2 A magnified view of part A in FIG.

[0025] Figure 5 for Figure 3 A magnified view of part B in FIG.

[0026] Figure 6 for Figure 1 Schematic diagram of the cross section along the CC direction.

[0027] Figure numerals: 1. outer tube; 2. inner tube; 3. insulation layer; 4. inner thread section; 5. outer thread section; 6. inner sealing shoulder; 7. outer sealing shoulder; 8. inner sealing structure; 9. outer sealing structure; 21. positioning block; 61. inner sealing cone; 62. inner sealing plane; 63. sealing groove; 64. elastic gasket; 71. outer sealing cone; 72. outer sealing plane; 73. sealing ring; 81. sealing grease storage tank; 82. inner sealing surface; 83. inner sealing end; 91. outer sealing surface; 92. outer sealing end. DETAILED DESCRIPTION

[0028] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0029] like Figure 1-6 As shown, in this embodiment, a high connection strength direct-connection threaded insulated oil pipe is provided, including an outer pipe 1 and an inner pipe 2, the outer pipe 1 is sleeved on the outside of the inner pipe 2, an insulation layer 3 is provided between the outer pipe 1 and the inner pipe 2, both ends of the inner pipe 2 are fixedly connected to the outer pipe 1 by welding, one end of the outer pipe 1 is provided with an internal thread section 4, and the other end of the outer pipe 1 is provided with an external thread section 5 matched with the internal thread section 4, the threads of the internal thread section 4 and the external thread section 5 of the outer pipe 1 are both trapezoidal threads, and both ends of the outer pipe 1 are thickened to improve the connection strength and thermal insulation performance.

[0030] like Figure 1-5 As shown, in this embodiment, an external sealing shoulder 7 is provided on the side of the external thread section 5 on the outer tube 1 close to the internal thread section 4, and the external sealing shoulder 7 has an external sealing cone surface 71 and an external sealing plane 72 fixedly connected, a sealing ring 73 is fixedly provided on the external sealing cone surface 71, and the external sealing plane 72 is arranged on the side of the external sealing cone surface 71 away from the thread.

[0031] like Figure 1-5 As shown, in this embodiment, an inner sealing shoulder 6 corresponding to the outer sealing shoulder 7 is provided on the side of the inner thread section 4 on the outer tube 1 away from the outer thread section 5. The inner sealing shoulder 6 includes an inner sealing cone surface 61 corresponding to the outer sealing cone surface 71 and an inner sealing plane 62 corresponding to the outer sealing plane 72. A sealing groove 63 corresponding to the sealing ring 73 is provided on the inner sealing cone surface 61. An elastic gasket 64 is fixedly provided in the sealing groove 63. When the outer thread section 5 of one oil pipe is connected to the inner thread section 4 of another oil pipe, the outer sealing shoulder 7 abuts against the inner sealing shoulder 6, the sealing ring 73 is inserted into the sealing groove 63, and the end face of the sealing ring 73 abuts against the elastic gasket 64, so that the elastic gasket 64 undergoes elastic deformation, and the deformation of the elastic gasket 64 is used to fill the sealing groove 63, thereby improving the sealing performance during connection.

[0032] In this embodiment, an interference fit is formed between the outer sealing conical surface 71 and the inner sealing conical surface 61, thereby improving the sealing performance and the connection strength.

[0033] In this embodiment, the elastic gasket 64 is made of corrosion-resistant rubber.

[0034] like Figure 1-5As shown, in this embodiment, an outer sealing structure 9 is provided on the side of the external thread section 5 of the outer tube 1 away from the internal thread section 4, and the outer sealing structure 9 includes an outer sealing surface 91 of a conical structure and an outer sealing end 92 perpendicular to the axial direction of the outer tube 1. An inner sealing structure 8 corresponding to the outer sealing structure 9 is provided on the side of the internal thread section 4 of the outer tube 1 close to the external thread section 5, and the inner sealing structure 8 includes an inner sealing surface 82 corresponding to the outer sealing surface 91 and an inner sealing end 83 corresponding to the outer sealing end 92. A sealing grease storage groove 81 is formed between the inner sealing surface 82 and the inner sealing end 83. After the two ends of the two oil pipes are threadedly connected, the outer sealing end 92 of one oil pipe abuts against the inner sealing end 83 of the other oil pipe. The thread sealing grease in the sealing grease storage groove 81 can be evenly applied between the external thread and the internal thread along the gap between the external sealing surface 91 and the internal sealing surface 82, so as to form a contact surface between the external thread and the internal thread, thereby reducing friction and improving the sealing effect and service life.

[0035] In this embodiment, the threads of the internal thread section 4 and the external thread section 5 of the outer tube 1 are both trapezoidal threads, the tooth profile is an isosceles trapezoid, the tooth profile angle is 30°, the internal and external threads are tightly attached to the conical surface and are not easy to loosen. The 30° trapezoidal thread is thicker and stronger than the median diameter of the ordinary 60° or 55° thread. It is more wear-resistant than other threads, has good strength, adjustable clearance, and good process performance.

[0036] In this embodiment, the lengths of the internal thread section 4 and the external thread section 5 of the outer tube 1 are 150 mm-200 mm. Compared with commonly used oil pipes, the thread sections are lengthened to improve the connection strength.

[0037] In this embodiment, the thermal insulation layer 3 is a thermal insulation material filled between the inner tube 2 and the outer tube 1, such as perlite powder, ultrafine glass wool, argon, krypton, xenon, etc. The setting of the thermal insulation layer 3 enables the oil pipe to overcome the expansion and contraction caused by temperature changes, and can be used in a high temperature environment, thereby increasing its service life.

[0038] like Figure 6 As shown, in this embodiment, a plurality of positioning blocks 21 are provided on the outer wall of the inner tube 2 along its circumference, and the inner tube 2 is placed in the outer tube 1, and the positioning blocks 21 abut between the inner wall of the outer tube 1 and the outer wall of the inner tube 2, so that the inner tube 2 is always centered and remains coaxial with the outer tube 1, so that the thermal insulation material can be evenly filled between the outer tube 1 and the inner tube 2, so that the oil pipe has good anti-extrusion ability, higher overall strength, and better thermal insulation effect.

[0039] like Figure 1 As shown, in this embodiment, the internal thread section 4 and the external thread section 5 of the outer tube 1 are thickened so that the connection between the two oil pipes is stronger. At the same time, the thickening can play a certain role in heat insulation.

[0040] The utility model provides a high connection strength direct-connection threaded insulated oil pipe, whose processing process and advantages are: placing the inner pipe 2 in the outer pipe 1, the positioning block 21 abuts against the inner wall of the outer pipe 1, welding one end of the inner pipe 2 to the outer pipe 1, filling the insulation material between the outer pipe 1 and the inner pipe 2 from the other end of the inner pipe 2, and after filling, welding the other end of the inner pipe 2 to the outer pipe 1, and then processing the internal and external threads on both ends of the outer pipe 1, and connecting a certain number of oil pipes together according to usage requirements. Specifically, the external thread section 5 of the first oil pipe extends into the internal thread section 4 of the second oil pipe, and the two oil pipes are threadedly connected. After assembly, the outer sealing end 92 of the first oil pipe abuts against the inner sealing end 83 of the second oil pipe, and an interference fit is formed between the outer sealing cone surface 71 of the first oil pipe and the inner sealing cone surface 61 of the second oil pipe, thereby improving the sealing performance and connection strength, and the outer sealing shoulder 7 of the first oil pipe abuts against the inner sealing shoulder 6 of the second oil pipe, and the sealing The sealing ring 73 is inserted into the sealing groove 63, and the end face of the sealing ring 73 abuts against the elastic gasket 64, so that the elastic gasket 64 undergoes elastic deformation, and the deformation of the elastic gasket 64 is used to fill the sealing groove 63, thereby improving the sealing performance during connection; relative to the commonly used oil pipe, the thread section is lengthened to improve the connection strength; the threads of the external thread section 5 are all trapezoidal threads, the tooth profile is an isosceles trapezoid, the tooth profile angle is 30°, the internal and external threads are tightly attached to the conical surface and are not easy to loosen, and the 30° trapezoidal thread is thicker than the ordinary 6 The middle diameter of the 0° or 55° thread should be thick and strong. It is more wear-resistant than other threads, has good strength, adjustable gap and good process performance. A plurality of positioning blocks 21 are provided on the outer wall of the inner tube 2 along its circumference. The inner tube 2 is placed in the outer tube 1, and the positioning blocks 21 abut against the inner wall of the outer tube 1, so that the inner tube 2 is always centered and coaxial with the outer tube 1, so that the insulation material can be evenly filled between the outer tube 1 and the inner tube 2, so that the oil pipe has good anti-extrusion ability, higher overall strength and better insulation effect.

[0041] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high connection strength direct-connection threaded insulated oil pipe, comprising an outer pipe (1) and an inner pipe (2), wherein the outer pipe (1) is sleeved on the outside of the inner pipe (2), one end of the outer pipe (1) is provided with an internal thread section (4), and the other end of the outer pipe (1) is provided with an external thread section (5) matching with the internal thread section (4), characterized in that: The threads of the internal thread section (4) and the external thread section (5) of the outer tube (1) are both trapezoidal threads. Both ends of the outer tube (1) are thickened. The lengths of the internal thread section (4) and the external thread section (5) are 150 mm to 200 mm. An external sealing shoulder (7) is provided on the side of the external thread section (5) close to the internal thread section (4). An internal sealing shoulder (6) corresponding to the external sealing shoulder (7) is provided on the side of the internal thread section (4) away from the external thread section (5). The external sealing shoulder (7) has an external sealing cone surface (71 ), a sealing ring (73) is fixedly provided on the outer sealing cone surface (71), the inner sealing shoulder (6) has an inner sealing cone surface (61) corresponding to the outer sealing cone surface (71), a sealing groove (63) corresponding to the sealing ring (73) is opened on the inner sealing cone surface (61), an elastic gasket (64) is fixedly provided in the sealing groove (63), and a plurality of positioning blocks (21) are provided on the outer wall of the inner tube (2) along its circumference, and the positioning blocks (21) are abutted between the inner wall of the outer tube (1) and the outer wall of the inner tube (2).

2. A high connection strength direct-connection threaded insulated oil pipe according to claim 1, characterized in that: The elastic gasket (64) is made of corrosion-resistant rubber.

3. The high connection strength direct-connection threaded insulated oil pipe according to claim 1, characterized in that: The outer sealing shoulder (7) also has an outer sealing plane (72) fixedly connected to the outer sealing cone surface (71), and the inner sealing shoulder (6) also has an inner sealing plane (62) corresponding to the outer sealing plane (72).

4. A high connection strength direct-connection threaded insulated oil pipe according to claim 3, characterized in that: The outer sealing plane (72) is arranged on a side of the outer sealing conical surface (71) away from the thread.

5. The high connection strength direct-connection threaded insulated oil pipe according to claim 1, characterized in that: An external sealing structure (9) is provided on the side of the external thread section (5) away from the internal thread section (4), and the external sealing structure (9) comprises an external sealing surface (91) with a conical structure and an external sealing end (92) perpendicular to the axial direction of the outer tube (1).

6. A high connection strength direct-connection threaded insulated oil pipe according to claim 5, characterized in that: An inner sealing structure (8) corresponding to the outer sealing structure (9) is provided on one side of the inner thread section (4) close to the outer thread section (5), and the inner sealing structure (8) comprises an inner sealing surface (82) corresponding to the outer sealing surface (91) and an inner sealing end (83) corresponding to the outer sealing end (92).

7. A high connection strength direct-connection threaded insulated oil pipe according to claim 6, characterized in that: A sealing grease storage groove (81) is formed between the inner sealing surface (82) and the inner sealing end (83).

8. The high connection strength direct-connection threaded insulated oil pipe according to claim 1, characterized in that: The threads of the internal thread section (4) and the external thread section (5) are both trapezoidal threads, the tooth profile is an isosceles trapezoid, and the tooth profile angle is 30°.

9. The high connection strength direct-connection threaded insulated oil pipe according to claim 1, characterized in that: A heat insulation layer (3) is provided between the outer tube (1) and the inner tube (2); the heat insulation layer (3) is a heat insulation material filled between the inner tube (2) and the outer tube (1).

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