High-performance small-caliber direct connection type oil pipe

Abstract

When two adjacent oil pipes are connected, the connection strength is high, the sealing performance is good, when a plurality of oil pipes are connected, the outer walls and the inner walls of the oil pipes do not protrude or sink, and the high-performance small-caliber direct-connection oil pipe is suitable for moving in a small-caliber oil well and does not hinder movement of a sucker rod in an oil pipe body when the sucker rod goes into the well. Comprising an oil pipe body, the oil pipe body comprises an inner pipe and an outer pipe, the inner pipe is fixedly installed in the outer pipe, one end of the outer pipe is a connecting end, the outer diameter of the connecting end corresponds to the outer diameter of the outer pipe, and the inner diameter of the connecting end corresponds to the inner diameter of the inner pipe. The end, away from the connecting end, of the inner pipe extends to the outside of the outer pipe, the end, away from the connecting end, of the inner pipe is provided with an external thread section, and the inner wall of the connecting end is provided with an internal thread section corresponding to the external thread section.

Description

Technical Field

[0001] The utility model relates to the technical field of oil exploitation and transportation, in particular to a high-performance small-diameter direct-connection oil pipe. Background Art

[0002] In oilfield mining, according to the different drilling depths of the oilfield, the prefabricated oil pipes of fixed sizes are generally connected in sequence to form oil pipes that meet the length requirements, and then the pumping rods are inserted into the oil pipes. Different oil pipes need to be selected due to the different sizes of oil wells and different geological conditions of oil fields. With the continuous rise in international oil prices, oil fields have carried out secondary development on some old wells that have been developed once and the oil wells that were sealed at that time because of certain difficulties in water injection and oil pressure to obtain more oil resources. At that time, these wells were abandoned and sealed because they were not suitable for mining and utilization compared with the economic benefits obtained due to the high cost and technical difficulty of secondary mining. However, with the current rise in oil prices, secondary mining can obtain better economic benefits. Therefore, some oil fields use small-diameter oil pipes to horizontally drill the original oil well pipes to exploit the remaining oil resources in the oil wells. Secondary mining of oil wells requires the use of oil pipes with smaller diameters and better toughness for mining.

[0003] For example, the Chinese patent with publication number CN102392609A provides a small-diameter oil pipe for secondary development of abandoned oil wells, which can ensure that the connection lengths between two adjacent oil pipes are consistent, realize the connection sealing between the two adjacent oil pipes, prevent oil and gas leakage in the pipe, and effectively avoid the occurrence of accidents. It includes an oil pipe body and connecting parts at both ends. The outer diameter of the connecting parts at both ends of the oil pipe is larger than the outer diameter of the oil pipe body. One end of the connecting part is provided with an external thread, and the other end of the connecting part is provided with an internal thread. The external thread cooperates with the internal thread of the adjacent oil pipe, and the internal thread cooperates with the external thread of the adjacent oil pipe. The connecting part of the external thread end is provided with a protruding positioning bayonet, and the connecting part of the internal thread end is provided with a positioning slot. A sealing gasket is provided in the positioning slot, and the protruding positioning bayonet cooperates with the positioning slot of the adjacent oil pipe, and the positioning slot cooperates with the protruding positioning bayonet of the adjacent oil pipe.

[0004] In order to improve the connection strength between two adjacent oil pipelines in this patent, the outer diameter of the connecting parts at both ends of the oil pipeline is larger than the outer diameter of the oil pipeline body, so that the outer diameters of the connected oil pipelines are inconsistent, which makes it inconvenient to move in the oil well. 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-performance small-diameter direct-connected oil pipe. When two adjacent oil pipes are connected, the connection strength is high and the sealing performance is good. When multiple oil pipes are connected, the outer walls and inner walls have no protrusions or depressions. It is suitable for movement in small-diameter oil wells and will not hinder the movement of the sucker rod in the oil pipe body when it is lowered into the well.

[0006] In order to solve the above technical problems, the technical solution of the utility model is: a high-performance small-diameter direct-connected oil pipe, including an oil pipe body, the oil pipe body including an inner tube and an outer tube, the inner tube fixedly installed inside the outer tube, one end of the outer tube is a connecting end, the outer diameter of the connecting end corresponds to the outer diameter of the outer tube, the inner diameter of the connecting end corresponds to the inner diameter of the inner tube, the end of the inner tube away from the connecting end extends to the outside of the outer tube, and the end of the inner tube away from the connecting end is provided with an external thread section, the inner wall of the connecting end is provided with an internal thread section corresponding to the external thread section, the internal thread section includes a first internal sealing structure, a first section of internal thread, a second section of internal thread and a second internal sealing cone surface arranged in sequence, and the external thread section includes a first external sealing structure, a first section of external thread, a second section of external thread and a second external sealing cone surface arranged in sequence.

[0007] Furthermore, the inner tube is fixedly connected to the outer tube by welding, and a heat insulating material is filled between the inner wall of the outer tube and the outer wall of the inner tube.

[0008] Furthermore, the threads of the internal thread section and the external thread section are both triangular threads.

[0009] Furthermore, the first internal sealing structure includes an internal sealing step and a first internal sealing cone surface located on the side of the first section of the internal thread close to the inner tube, a sealing gasket is fixedly connected to the side of the internal sealing step away from the inner tube, and the first internal sealing cone surface is located between the sealing gasket and the first section of the internal thread.

[0010] Furthermore, the first outer sealing structure includes an outer sealing step and a first outer sealing cone surface, the outer sealing step is located on a side of the first section of outer thread away from the connecting end, and the first outer sealing cone surface is located between the outer sealing step and the first section of outer thread.

[0011] Furthermore, the inner diameter of the sealing gasket corresponds to the outer diameter of the inner tube, and the thickness of the sealing gasket corresponds to the distance between the end of the inner tube away from the connecting end and the outer sealing step.

[0012] Furthermore, the second inner sealing cone surface is located between the end of the connecting end and the second section of the inner thread.

[0013] Furthermore, the second outer sealing cone surface corresponds to the second inner sealing cone surface, and the second outer sealing cone surface is located between the outer tube and the second section of the external thread.

[0014] Furthermore, a sealing ring is fixedly provided on the end of the connecting end away from the inner tube, and a sealing groove corresponding to the sealing ring is provided on the end of the outer tube away from the connecting end.

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

[0016] 1. The connecting end is thickened so that the outer diameter of the connecting end corresponds to the outer diameter of the outer tube, and the inner diameter of the connecting end corresponds to the inner diameter of the inner tube, ensuring that there is no protrusion or depression on the outer wall and inner wall of multiple tubing bodies when they are connected, which is suitable for movement in small-diameter oil wells and will not hinder the movement of the sucker rod in the tubing body when it is lowered into the well;

[0017] 2. The threads of the internal thread section and the external thread section are both triangular threads, and the internal and external threads of the two sections cooperate with each other, which increases the connection strength;

[0018] 3. When two adjacent oil pipe bodies are connected, the first inner sealing structure cooperates with the first outer sealing structure, the second outer sealing cone surface cooperates with the second inner sealing cone surface, and the sealing ring cooperates with the sealing groove, which can ensure the sealing performance during connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a high-performance small-diameter direct-connection oil pipe of the utility model;

[0020] Figure 2 for Figure 1 A magnified view of part A in FIG.

[0021] Figure 3 It is a structural schematic diagram of the outer tube of the utility model;

[0022] Figure 4 It is a structural schematic diagram of the inner tube of the utility model.

[0023] Reference numerals: 1, oil pipe body; 2, inner pipe; 3, outer pipe;

[0024] 21. External thread section; 30. Connecting end; 31. Internal thread section;

[0025] 211, first external sealing structure; 212, first section of external thread; 212, second section of external thread;

[0026] 214, second outer sealing cone surface; 2111, outer sealing step; 2112, first outer sealing cone surface;

[0027] 311, first internal sealing structure; 312, first section of internal thread; 313, second section of internal thread;

[0028] 314, second inner sealing cone surface; 3111, inner sealing step; 3112, first inner sealing cone surface;

[0029] 3113, sealing gasket; 301, sealing ring; 302, sealing groove. DETAILED DESCRIPTION

[0030] 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.

[0031] like Figure 1-4 As shown, in this embodiment, a high-performance small-diameter direct-connected oil pipe is provided, including an oil pipe body 1, the oil pipe body 1 includes an inner pipe 2 and an outer pipe 3, the inner pipe 2 is fixedly installed inside the outer pipe 3, one end of the outer pipe 3 is a connecting end 30, the end of the inner pipe 2 away from the connecting end 30 extends to the outside of the outer pipe 3, and the end of the inner pipe 2 away from the connecting end 30 is provided with an external thread section 21, and the inner wall of the connecting end 30 is provided with an internal thread section 31 corresponding to the external thread section 21.

[0032] In this embodiment, the inner tube 2 is fixedly connected to the outer tube 3 by welding, and the inner wall of the outer tube 3 and the outer wall of the inner tube 2 are filled with insulation materials, such as perlite powder, ultrafine glass wool, argon, krypton, xenon, etc. The provision of the insulation material enables the oil pipe to overcome the expansion and contraction caused by temperature changes, and can be used in a high temperature environment to increase its service life. At the same time, it can reduce heat loss and is beneficial to the overall insulation of the oil pipe during drilling.

[0033] In this embodiment, two adjacent oil pipe bodies 1 are fixedly connected by the internal thread section 31 of the connecting end 30 and the external thread section 21 on the inner tube 2. The connecting end 30 is thickened so that the outer diameter of the connecting end 30 corresponds to the outer diameter of the outer tube 3, and the inner diameter of the connecting end 30 corresponds to the inner diameter of the inner tube 2, ensuring that there is no protrusion or depression on the outer wall and the inner wall of multiple oil pipe bodies 1 when they are connected. They are suitable for movement in small-diameter oil wells and will not hinder the movement of the sucker rod in the oil pipe body 1 when it is lowered into the well.

[0034] In this embodiment, the internal thread section 31 includes a first section of internal thread 312 and a second section of internal thread 313, and the external thread section 21 includes a first section of external thread 212 and a second section of external thread 213 that cooperate with the first section of internal thread 312 and the second section of internal thread 313. The two sections of internal and external threads cooperate with each other. The threads of the internal thread section 31 and the external thread section 21 are both triangular threads. The triangular threads are mainly used for connection. The triangular threads have good self-locking properties and high strength, which is beneficial to improving the connection strength when two adjacent oil pipe bodies 1 are connected.

[0035] In this embodiment, since the connecting end 30 is thickened, the heat loss at the connection point of the two adjacent oil pipe bodies 1 is small when they are connected. At the same time, the internal thread section 31 includes a first section of internal thread 312 and a second section of internal thread 313, and the external thread section 21 includes a first section of external thread 212 and a second section of external thread 213 that match the first section of internal thread 312 and the second section of internal thread 313. The two sections of internal and external threads match each other, thereby increasing the connection strength.

[0036] In this embodiment, the internal thread section 31 also includes a first internal sealing structure 311, which is located on the side of the first section internal thread 312 close to the inner tube 2, and the first internal sealing structure 311 includes an internal sealing step 3111 and a first internal sealing cone 3112 located on the side of the connecting end 30 close to the inner tube 2, and a sealing gasket 3113 is fixedly connected to the side of the internal sealing step 3111 away from the inner tube 2, and the first internal sealing cone 3112 is located between the sealing gasket 3113 and the first section internal thread 312, and the external thread section 21 also includes a first external sealing structure 211 corresponding to the first internal sealing structure 311, and the first external sealing structure 211 is located on the side of the first section external thread 212 close to the outer tube 3, and the first external sealing structure 211 includes an external sealing step 2111 and a first external sealing cone 2112, and the external sealing step 21 11 is located on the side of the inner tube 2 away from the connecting end 30, the first outer sealing cone surface 2112 is located between the outer sealing step 2111 and the first section of the outer thread 212, when two adjacent oil pipe bodies 1 are connected, the first outer sealing cone surface 2112 and the first inner sealing cone surface 3112 abut against each other, and the two ends of the sealing gasket 3113 abut between the outer sealing step 2111 on the inner tube 2 and the inner sealing step 3111 of the connecting end 30, and the inner diameter of the sealing gasket 3113 corresponds to the outer diameter of the inner tube 2, so that the sealing gasket 3113 is sleeved on the inner tube 2, and the thickness of the sealing gasket 3113 corresponds to the distance between the end of the inner tube 2 away from the connecting end 30 and the outer sealing step 2111, so that the end of the inner tube 2 away from the connecting end 30 abuts on the inner sealing step 3111 of the connecting end 30 of the adjacent outer tube 3.

[0037] In this embodiment, the internal thread section 31 also includes a second internal sealing cone surface 314, which is located between the end of the connecting end 30 and the second section internal thread 313. The external thread section 21 also includes a second external sealing cone surface 214 connected to the second internal sealing cone surface 314, which is located between the second section external thread 213 and the end of the outer tube 3 away from the connecting end 30.

[0038] In this embodiment, a sealing ring 301 is fixedly provided on the end of the connecting end 30 away from the inner tube 2, and a sealing groove 302 corresponding to the sealing ring 301 is opened on the end of the outer tube 3 away from the connecting end 30. When two adjacent oil pipe bodies 1 are connected, the second outer sealing cone surface 214 and the second inner sealing cone surface 314 abut against each other, and the end of the connecting end 30 away from the inner tube 2 abuts against the end of the outer tube 3 of the adjacent oil pipe body 1 away from the connecting end 30, and the sealing ring 301 is inserted into the sealing groove 302.

[0039] The connection method of the utility model is as follows: two adjacent oil pipe bodies 1 are fixedly connected by the internal thread section 31 of the connecting end 30 and the external thread section 21 on the inner pipe 2. When connected, the first outer sealing cone surface 2112 and the first inner sealing cone surface 3112 abut against each other, and the two ends of the sealing gasket 3113 abut between the outer sealing step 2111 on the inner pipe 2 and the inner sealing step 3111 of the connecting end 30. The sealing gasket 3113 is sleeved on the inner pipe 2. The end of the inner tube 2 away from the connecting end 30 abuts against the inner sealing step 3111 of the connecting end 30 of the adjacent oil pipe body 1. At the same time, the second outer sealing cone 214 and the second inner sealing cone 314 abut against each other. The end of the connecting end 30 away from the inner tube 2 abuts against the end of the outer tube 3 of the adjacent oil pipe body 1 away from the connecting end 30. The sealing ring 301 is inserted into the sealing groove 302. The connecting end 30 is thickened so that the connecting end 30 The outer diameter corresponds to the outer diameter of the outer tube 3, and the inner diameter of the connecting end 30 corresponds to the inner diameter of the inner tube 2, ensuring that there is no protrusion or depression on the outer wall and the inner wall of multiple oil pipe bodies 1 when connected. It is suitable for moving in small-diameter oil wells and will not hinder the movement of the sucker rod in the oil pipe body 1 when the sucker rod is lowered into the well. Since the connecting end 30 is thickened, the heat loss at the connection point of two adjacent oil pipe bodies 1 is small when they are connected. At the same time, the internal thread section 31 includes a first section of internal thread 312 and a second section of internal thread 313, and the external thread section 21 includes a first section of external thread 212 and a second section of external thread 213 that match the first section of internal thread 312 and the second section of internal thread 313. The two sections of internal and external threads match each other to increase the connection strength; the first internal sealing structure 311 matches the first external sealing structure 211, the second external sealing cone surface 214 and the second internal sealing cone surface 314 abut and match each other, and the sealing ring 301 matches the sealing groove 302 to ensure the sealing performance during connection.

[0040] 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-performance small-diameter direct-connection oil pipe, comprising an oil pipe body (1), wherein the oil pipe body (1) comprises an inner pipe (2) and an outer pipe (3), wherein the inner pipe (2) is fixedly mounted inside the outer pipe (3), and characterized in that: One end of the outer tube (3) is a connecting end (30), the outer diameter of the connecting end (30) corresponds to the outer diameter of the outer tube (3), the inner diameter of the connecting end (30) corresponds to the inner diameter of the inner tube (2), the end of the inner tube (2) away from the connecting end (30) extends to the outside of the outer tube (3), and the end of the inner tube (2) away from the connecting end (30) is provided with an external thread section (21), the inner wall of the connecting end (30) is provided with an internal thread section (31) corresponding to the external thread section (21), the internal thread section (31) comprises a first internal sealing structure (311), a first section of internal threads (312), a second section of internal threads (313) and a second internal sealing cone surface (314) which are arranged in sequence, and the external thread section (21) comprises a first external sealing structure (211), a first section of external threads (212), a second section of external threads (213) and a second external sealing cone surface (214) which are arranged in sequence.

2. A high-performance small-diameter direct-connection oil pipe according to claim 1, characterized in that: The inner tube (2) is fixedly connected to the outer tube (3) by welding, and a heat insulating material is filled between the inner wall of the outer tube (3) and the outer wall of the inner tube (2).

3. The high-performance small-diameter direct-connection oil pipe according to claim 1, characterized in that: The threads of the internal thread section (31) and the external thread section (21) are both triangular threads.

4. The high-performance small-diameter direct-connection oil pipe according to claim 1, characterized in that: The first inner sealing structure (311) comprises an inner sealing step (3111) and a first inner sealing conical surface (3112) located on a side of the first section of the inner thread (312) close to the inner tube (2); a sealing gasket (3113) is fixedly connected to the side of the inner sealing step (3111) away from the inner tube (2); and the first inner sealing conical surface (3112) is located between the sealing gasket (3113) and the first section of the inner thread (312).

5. The high-performance small-diameter direct-connection oil pipe according to claim 4, characterized in that: The first outer sealing structure (211) comprises an outer sealing step (2111) and a first outer sealing conical surface (2112); the outer sealing step (2111) is located on a side of the first section of outer thread (212) away from the connecting end (30); and the first outer sealing conical surface (2112) is located between the outer sealing step (2111) and the first section of outer thread (212).

6. The high-performance small-diameter direct-connection oil pipe according to claim 5, characterized in that: The inner diameter of the sealing gasket (3113) corresponds to the outer diameter of the inner tube (2), and the thickness of the sealing gasket (3113) corresponds to the distance between the end of the inner tube (2) away from the connecting end (30) and the outer sealing step (2111).

7. The high-performance small-diameter direct-connection oil pipe according to claim 1, characterized in that: The second inner sealing conical surface (314) is located between the end of the connecting end (30) and the second section of the inner thread (313).

8. The high-performance small-diameter direct-connection oil pipe according to claim 1, characterized in that: The second outer sealing conical surface (214) corresponds to the second inner sealing conical surface (314), and the second outer sealing conical surface (214) is located between the outer tube (3) and the second section of the outer thread (213).

9. The high-performance small-diameter direct-connection oil pipe according to claim 1, characterized in that: A sealing ring (301) is fixedly provided at the end of the connecting end (30) away from the inner tube (2), and a sealing groove (302) corresponding to the sealing ring (301) is provided at the end of the outer tube (3) away from the connecting end (30).

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