CN103321585B - S-shaped shoulder variable tooth width wedge-shaped coupling structure and oil well pipe structure - Google Patents

Abstract

The invention discloses an S-shaped shoulder-variable-tooth-width wedge-shaped coupling structure and an oil well pipe structure used in the petroleum steel pipe industry. Inner sealing surface transition arc surface smooth transition, inner sealing surface transition arc surface and inner sealing surface smooth transition, inner sealing surface and inner sealing arc surface smooth transition, inner sealing arc surface and inner shoulder surface transition arc smooth transition, inner shoulder surface The transition arc and the first inner pair of sealing surfaces are smoothly transitioned, the angle arc between the first inner pair of sealing surfaces and the inner shoulder surface is smoothly transitioned, the angle between the inner shoulder surface and the second inner pair of sealing surfaces is smoothly transitioned, and the first The second inner secondary sealing surface is in contact with the inner hole wall of the collar shoulder. Taper and taper radial diameter seals and apex arc seals are used to increase the sealing performance of threaded joint connections. Its shoulder surface adopts a non-planar large-angle reverse V-shaped structure, which significantly improves its anti-compression load capacity, anti-torque performance and high sealing performance under bending resistance.

Description

An S-shape shoulder variable tooth width wedge coupling structure and oil well tubular structure

technical field

The invention discloses a collar structure used in the oil drilling industry, and also discloses an oil well pipe structure used in the oil drilling industry.

Background technique

At present, the threaded connection structure of oil casing pipe in the oil well pipe industry is basically improved and innovated in accordance with API SPEC 5B "Code for Processing, Measurement and Inspection of Casing, Tubing and Line Pipe Threads". The overall connection quality is compared with API The quality of the threaded connection required by the standard has gradually been greatly improved, but it still cannot meet the requirements of oil field exploitation. Gradually, all oil fields in the world are putting forward higher and more ideal requirements for threaded connections, especially the requirements for the main performance indicators of oil well pipes are becoming more and more stringent.

Contents of the invention

One of the purposes of the present invention is to overcome the deficiencies in the prior art and provide an S-shaped shoulder that can increase the sealing performance, bending resistance, compressive load resistance and high torque resistance of threaded joints Variable tooth width wedge coupling structure.

Another object of the present invention is to provide an S-shaped shoulder variable tooth width wedge type oil well tubular structure used in conjunction with the S shape shoulder variable tooth width wedge type coupling structure.

According to the technical solution provided by the present invention, the S-shaped shoulder variable tooth width wedge-shaped coupling structure includes a coupling body, and the inner walls at both ends of the coupling body are internal thread sections of the coupling. There is a coupling shoulder between the threaded sections; in the direction from the two ends of the coupling body to the middle, the tooth width of the internal threaded section of the coupling increases gradually, and the tooth groove of the internal threaded section of the coupling The width is gradually reduced, the difference between the width of two adjacent teeth is equal to the difference between the width of two adjacent slots, the height of each tooth of the coupling internal thread section is equal, and the taper of the coupling internal thread section is 1:16 ~1:24; On the longitudinal section of the coupling body, each tooth on the coupling internal thread section is wedge-shaped, and there are barbs on both sides of the top of each tooth; each tooth on the coupling internal thread section The middle part of the top of the tooth is the inner tooth top surface, the inner tooth top surface is provided with the inner tooth top inner plane, the outer side of the inner tooth top surface is provided with the inner tooth top outer plane, and the inner tooth top inner plane and the inner tooth top surface The inner tooth top surface is connected by an inner transition arc, and the outer plane of the inner tooth top surface is connected with the inner tooth top surface by an outer transition arc of the inner tooth top surface. The middle part of the tooth groove is the inner tooth bottom surface, and the inner tooth bottom surface is a conical surface. The top surface of the tooth is a conical surface, and the taper of the bottom surface of the internal tooth and the top surface of the internal tooth is equal to the taper of the internal thread section of the coupling. The outer surface of the bottom, the outer wall of each tooth is provided with an inner guide surface, the angle formed by the inner guide surface and the axis of the coupling body is 79~85°, the inner wall of each tooth is provided with an inner bearing surface, and the inner bearing surface is in line with the coupling body axis. The angle formed by the axis of the coupling body is 76~82°, the bottom surface of the inner tooth bottom and the inner plane of the inner tooth bottom are connected through the inner transition arc of the inner tooth bottom surface, and the bottom surface of the inner tooth bottom and the outer plane of the inner tooth bottom pass through the inner tooth bottom surface The outer transition arc is connected, the outer plane of the inner tooth bottom and the inner guide surface are connected through the outer arc of the inner tooth bottom, the inner guide surface and the inner plane of the inner tooth top are connected through the inner arc of the inner tooth top, and the inner tooth bottom The plane and the inner bearing surface are connected by the inner arc of the inner tooth bottom, the inner bearing surface and the outer plane of the inner tooth top are connected by the outer arc of the inner tooth top, and the angle formed by the inner plane of the inner tooth bottom and the axis of the coupling body is 10~20°, the angle formed by the outer plane of the inner tooth top and the axis of the coupling body is 10~20°, the angle formed by the outer plane of the inner tooth bottom and the axis of the coupling body is 7~17°, and the inner tooth top The angle formed by the plane and the axis of the coupling body is 7~17°; and on the longitudinal section of the coupling body, the outer arc of the inner tooth tip at the innermost position and the transition arc surface of the inner sealing surface have a smooth transition, and the transition of the inner sealing surface Smooth transition between the arc surface and the inner sealing surface, smooth transition between the inner sealing surface and the inner sealing arc surface, smooth transition between the inner sealing arc surface and the inner shoulder surface, smooth transition between the inner shoulder surface and the first inner auxiliary sealing surface Transition, the arc of the angle between the first inner pair of sealing surface and the inner shoulder surface is smoothly transitioned, the angle between the arc of the inner shoulder surface and the second inner pair of sealing surface is smoothly transitioned, and the angle between the second inner pair of sealing surface and the collar shoulder is smooth. The inner hole walls are connected.

Preferably, the taper of the internal thread section of the coupling is 1:18-1:20.

Preferably, the thread number of the internal thread section of the coupling is 12~30; the width of the inner first button alveolar is 1.8~3.2mm; the pitch of the inner guide surface is: the width of the inner first button alveolar multiplied by the inner The multiple of the alveolar width of the first button, the pitch of the inner guide surface is 3.96~9.60, the multiple of the alveolar width of the inner first button is 2.2~3.0; the pitch of the inner bearing surface is equal to: (the total length of the internal thread minus 2 times the inner first button alveolar width)/(total deduction minus 1); the tooth width of the inner first deduction is: the thread pitch of the inner guide surface minus the alveolar width of the inner first deduction; the inner tooth height is: 1.5~2.5mm.

Preferably, on the longitudinal section of the coupling body, the tooth width of the first tooth of the internal thread section of the coupling is 1.8~3.2mm; the tooth height of each tooth of the internal thread section of the coupling is 1.5~2.5mm; The width of the plane is 0.5~3.0 mm; the width of the inner bearing surface is 0.5~2.0 mm; the width of the outer plane of the inner tooth bottom is 0.5~3.0 mm; the width of the outer plane of the inner tooth top is 0.5~3.0 mm; The width is 0.5~2.0 mm; the width of the inner plane of the inner tooth bottom is 0.5~3.0 mm; the width of the top surface of the inner tooth is 0.05~6.0 mm; the width of the bottom surface of the inner tooth is 0.05~6.0 mm; The radius is 0.20~0.50mm; the radius of the outer arc of the inner tooth bottom is 0.20~0.50mm; the radius of the inner arc of the inner tooth top is 0.20~0.50mm; the radius of the inner arc of the inner tooth bottom is 0.20~0.50mm; The radius of the transition arc outside the bottom surface of the tooth is 0.15~0.30mm; the radius of the transition arc inside the bottom surface of the inner tooth is 0.15~0.30mm; the radius of the transition arc inside the top surface of the inner tooth is 0.15~0.30mm; The radius of the transition arc is 0.15~0.30mm; the angle between the inner bearing surface and the axis of the coupling body is smaller than the angle between the inner guide surface and the axis of the coupling body, which is 2~6°.

Preferably, on the longitudinal section of the coupling body, the radius of the transitional arc surface of the inner sealing surface is 12-16 mm, the angle of the center of the circle corresponding to the transition arc surface of the inner sealing surface is 6-15°; the length of the inner sealing surface is 5-12 mm, The taper is 1:8~1:14; the radius of the inner sealing arc surface is 1.0~1.5mm, and the corresponding center angle of the inner sealing arc surface is 40~50°; the radius of the transition arc of the inner shoulder surface is 0.2~0.5mm, the center angle corresponding to the inner shoulder surface transition arc is 105~120°; the radius of the inner shoulder surface included angle arc is 0.2~1.0mm, and the inner shoulder surface included angle arc corresponds to The angle of the center of the circle is 65~75°; the angle formed by the first inner pair sealing surface and the second inner pair sealing surface is 120~150°; the angle formed by the second inner pair sealing surface and the inner hole wall of the collar shoulder The angle is 75~90°; the distance between the inner end of the inner sealing surface and the inner hole wall of the collar shoulder is 3.5~8.0mm.

An S-shaped shoulder variable-tooth wide wedge-shaped oil well pipe structure, including an oil well pipe body, the outer walls of both ends of the oil well pipe body are oil well pipe external thread sections, and an oil well pipe shoulder is arranged between the two sections of oil well pipe external thread sections , in the direction from the two ends of the oil well pipe body to the middle, the tooth width of the oil well pipe external thread section is gradually reduced, and the tooth space width of the oil well pipe external thread section is gradually increased. The difference in tooth width is equal to the difference in width between two adjacent tooth slots, the height of each tooth in the oil well pipe external thread section is equal, and the taper of the oil well pipe external thread section is 1:16~1:24; in the oil well pipe body In the longitudinal section, each tooth on the oil well pipe external thread section is wedge-shaped, and there are barbs on both sides of the top of each tooth; the top middle of each tooth on the oil well pipe external thread section is the top surface of the external tooth, The inner side of the top surface of the outer tooth is provided with an inner plane of the top of the outer tooth, and the outer surface of the top of the outer tooth is provided with an outer plane of the top of the outer tooth. , the outer plane of the outer tooth top and the top surface of the outer tooth are connected through the outer transition arc of the outer tooth top surface, the middle part of the tooth groove is the bottom surface of the outer tooth, the bottom surface of the outer tooth is a conical surface, the top surface of the outer tooth is a conical surface, and the outer tooth The taper of the top surface and the bottom surface of the external tooth is equal to the taper of the external thread section of the oil well pipe. The inner surface of the bottom surface of the external tooth is provided with the inner plane of the bottom surface of the external tooth, and the bottom surface of the external tooth is provided with an external surface of the bottom surface of the external tooth. The outer wall of each tooth There is an outer guide surface, the angle formed by the outer guide surface and the axis of the oil well tubular body is 79~85°, the inner wall of each tooth is provided with an outer bearing surface, and the angle formed by the outer bearing surface and the axis of the oil well tubular body is 76° ~82°, the bottom surface of the outer tooth and the inner plane of the bottom of the outer tooth are connected by an inner transition arc of the bottom of the outer tooth, the bottom of the outer tooth and the outer plane of the bottom of the outer tooth are connected by an outer transition arc of the bottom of the outer tooth, and the outer surface of the outer tooth bottom The plane and the outer bearing surface are connected by the outer arc of the outer tooth bottom; The inner arc of the bottom is connected, the outer guide surface and the outer plane of the outer tooth top are connected through the outer arc of the outer tooth top, the angle formed by the inner plane of the inner tooth bottom and the axis of the coupling body is 10~20°, The angle formed by the plane and the axis of the oil well pipe body is 10~20°, the angle formed by the outer plane of the outer tooth bottom and the axis of the oil well pipe body is 7~17°, and the angle formed by the inner plane of the outer tooth top and the axis of the oil well pipe body is 7~17°; and on the longitudinal section of the oil well pipe body, the outer circular arc of the outer tooth bottom at the outermost end and the transition surface of the outer sealing surface are smoothly transitioned, the transition surface of the outer sealing surface is connected with the outer sealing surface, and the outer sealing surface Smooth transition with the outer sealing arc surface, smooth transition between the outer sealing arc surface and the outer shoulder surface, smooth transition between the outer shoulder surface and the first outer sealing surface, and smooth transition between the first outer sealing surface and the outer The angle arc of the shoulder surface is smoothly transitioned, the angle arc of the outer shoulder surface and the second outer sealing surface are smoothly transitioned, the second outer sealing surface is connected with the inner wall boring surface, and the inner wall boring surface and the inner wall transition surface The transition surface of the inner wall is in contact with the inner hole wall of the outer threaded section of the oil well pipe.

Preferably, the taper of the oil well pipe external thread section is 1:18-1:20.

Preferably, the number of threads of the external thread section of the oil well pipe is 12-30; the width of the teeth of the first outer thread is 1.8-3.2 mm; the pitch of the outer guide surface is: the tooth width of the outer thread multiplied by the tooth width of the outer thread Multiple, the pitch of the outer guide surface is 3.96~9.60mm, the multiple of the tooth width of the outer first button is 2.2~3.0; the pitch of the outer bearing surface is: (total length of the external thread minus 2 times the tooth width of the outer first button)/(total The number of buckles minus 1); the alveolar width of the outer first buckle is: the pitch of the outer guide surface minus the tooth width of the outer first buckle; the height of the outer teeth is: 1.5~2.5mm.

Preferably, on the longitudinal section of the oil well pipe body, the tooth width of the first buckle of the oil well pipe external thread section is 1.8~3.2mm; the tooth height of each tooth of the oil well pipe external thread section is 1.5~2.5mm; The width of the plane is 0.5~3.0 mm; the width of the outer bearing surface is 0.5~2.0 mm; the width of the outer plane of the outer tooth bottom is 0.5~3.0 mm; the width of the outer plane of the outer tooth top is 0.5~3.0 mm; The width is 0.5~2.0 mm; the width of the inner plane of the outer tooth bottom is 0.5~3.0 mm; the width of the top surface of the outer tooth is 0.05~6.0 mm; the width of the bottom surface of the outer tooth is 0.05~6.0 mm; the outer arc of the outer tooth top The radius is 0.20~0.50mm; the radius of the inner arc of the outer tooth bottom is 0.20~0.50mm; the radius of the inner arc of the outer tooth top is 0.20~0.50mm; the radius of the outer arc of the outer tooth bottom is 0.20~0.50mm; The radius of the outer transition arc on the top surface of the tooth is 0.15~0.30mm; the radius of the transition arc on the top surface of the outer tooth is 0.15~0.30mm; the radius of the transition arc on the bottom surface of the outer tooth is 0.15~0.30mm; The radius of the transition arc is 0.15~0.30mm; the angle between the outer bearing surface and the axis of the oil well tubular body is smaller than the angle between the outer guide surface and the axis of the oil well tubular body, which is 2~6°.

Preferably, on the longitudinal section of the oil well pipe body, the length of the transition surface of the outer sealing surface is 1.0-2.5mm, and the transition surface of the outer sealing surface is parallel to the outer plane of the outer tooth bottom; the length of the outer sealing surface is 5-12mm, and its taper 1:8~1:14; the radius of the outer sealing arc surface is 1.0~1.5mm, and the corresponding center angle of the outer sealing arc surface is 40~50°; the radius of the transition arc of the outer shoulder surface is 0.2 ~0.5mm, the center angle corresponding to the transition arc of the outer shoulder surface is 105~120°; the angle formed by the first outer pair of sealing surfaces and the second outer pair of sealing surfaces is 120~150°; the second outer pair of sealing surfaces The angle formed with the bore surface of the inner wall is 75~90°; the length of the bore surface of the inner wall is 2~10mm; the length of the transition surface of the inner wall is 2~10mm; the distance between the outer end of the outer sealing surface and the bore surface of the inner wall The distance is 3.5~8.0mm.

The present invention has the following advantages:

1. The shape of the threaded tooth profile is improved, and the flank angle of the wedge-shaped double barb is adopted. The angle of the tooth flanks on both sides adopts the angle of the bearing surface greater than the angle of the guide surface, which can make the thread under the state of high torque machine tightening. The tooth flanks on both sides are in complete contact with the tooth flanks, and each tooth flank is evenly distributed under the state of interference fit force, which effectively improves its sealing performance and connection strength.

2. Improve the thread pitch of the tooth profile bearing surface and the tooth profile guide surface to be unequal, and the pitch of the guide surface is greater than the pitch of the bearing surface, the tooth width gradually increases, and the tooth alveolar width gradually decreases. Wide thread structure, at the same time, the helix angles of the two flanks are different, forming a certain included angle, the two flanks form a wedge-shaped cone surface, and the tooth shape of the internal and external threads cooperate to form a wedge-shaped cone surface and a wedge-shaped cone surface. The wedge-shaped thread matching structure is significantly different from the two parallel flanks of the API partial trapezoidal thread, which can significantly improve the connection strength, sealing performance, bending resistance and over-torque performance of the mated internal and external thread joints.

3. Improve the thread pitch of the tooth profile bearing surface and the tooth profile guide surface to be unequal, and the thread pitch of the guide surface is greater than the thread pitch of the bearing surface. The width of the tooth profile is smaller than the width of the tooth groove. The buckle is very simple and convenient, which eliminates the phenomenon of wrong buckle, and effectively improves the product quality and work efficiency.

4. Due to the use of the variable tooth width thread form with the pitch of the guide surface greater than the pitch of the bearing surface, it effectively reduces the various effects of the difference in the ellipticity of the pipe body and the coupling on the cooperation of the internal and external threads, especially for quick make-up and breakout No scratches and damages will occur on the threads of making and breaking out many times, which significantly improves the product qualification rate.

5. Adopting the thread design structure of wedge shape and variable tooth width will effectively improve the anti-tripping performance, tensile load resistance performance and bending resistance of the threaded joint, effectively improve the high composite bearing capacity of the threaded joint, and can provide a pipe equivalent to that of the pipe body Internal pressure resistance and connection strength.

6. The top and bottom of the thread are designed with three plane structures with different tapers or angles instead of arc surfaces, which reduces the difficulty of processing, achieves contact between planes, and eliminates the influence of internal and external threads under the influence of factors such as different ellipticities. , to improve the influence of interference fit on the sealing performance of threaded tooth profile.

7. A metal-to-metal sealing structure is added at the end of the thread, which adopts taper/taper radial diameter seal and apex arc seal, which significantly increases the sealing performance of the threaded joint connection. Its shoulder surface adopts a non-planar large-angle reverse V-shaped structure, which significantly improves its anti-compression load capacity, anti-torque performance and high sealing ability under bending resistance.

8. The length of the coupling shoulder plane is increased, and the coupling torque shoulder plane and the inner wall of the pipe adopt an inner flush design, which can effectively reduce the turbulence phenomenon when the corresponding medium passes in the pipeline, and minimize the energy loss.

9. The present invention is very suitable for deep wells, ultra-deep wells, and oil and gas wells requiring high sealing performance.

Description of drawings

Fig. 1 is a schematic structural view of a coupling body in the present invention.

FIG. 2 is an enlarged schematic view of part A in FIG. 1 .

FIG. 3 is an enlarged schematic view of part B in FIG. 1 .

Fig. 4 is a schematic structural view of the oil well tubular body in the present invention.

FIG. 5 is an enlarged schematic view of part C in FIG. 4 .

FIG. 6 is an enlarged schematic diagram of part D in FIG. 4 .

Fig. 7 is a schematic diagram of the combined structure of the coupling body and the oil well tubular body in the present invention.

Detailed ways

The present invention will be further described below in conjunction with specific examples.

An S-shaped shoulder variable tooth width wedge-shaped coupling structure, including a coupling body 1, the inner walls of both ends of the coupling body 1 are coupling internal thread sections 1.1, and there is a Coupling shoulder 1.2; in the direction from the two ends of the coupling body 1 to the middle, the tooth width of the coupling internal thread section 1.1 is gradually increased, and the tooth width of the coupling internal thread section 1.1 is Gradually reduce the setting, the difference between the width of two adjacent teeth is equal to the difference between the width of two adjacent tooth spaces, the height of each tooth of the coupling internal thread section 1.1 is equal, and the taper of the coupling internal thread section 1.1 is 1:16 ~1:24; On the longitudinal section of the coupling body 1, each tooth on the coupling internal thread section 1.1 is wedge-shaped, and barbs are provided on both sides of the top of each tooth; on the coupling internal thread section 1.1 The middle part of the top of each tooth is an inner tooth top surface 58, the inner side of the inner tooth top surface 58 is provided with an inner tooth top inner plane 56, and the outer side of the inner tooth top surface 58 is provided with an inner tooth top outer plane 53, and the inner tooth top surface 58 is provided with an inner tooth top outer plane 53. The plane 56 and the inner tooth top surface 58 are connected through the inner tooth top surface transition arc 69, the inner tooth top outer plane 53 and the inner tooth top surface 58 are connected through the inner tooth top surface outer transition arc 70, and the tooth groove The middle part is the inner tooth bottom surface 57, the inner tooth bottom surface 57 is a conical surface, and the inner tooth top surface 58 is a conical surface, and the taper of the inner tooth bottom surface 57 and the inner tooth top surface 58 is equal to the taper of the coupling internal thread section 1.1. The inner side of the bottom surface 57 is provided with an inner tooth bottom inner plane 51, and the outer side of the inner tooth bottom surface 57 is provided with an inner tooth bottom outer plane 54. The outer wall of each tooth is provided with an inner guide surface 55, and the inner guide surface 55 is connected to the coupling body 1 The angle formed by the axis of the collar is 79~85°, the inner side wall of each tooth is provided with an inner bearing surface 52, the angle formed by the inner bearing surface 52 and the axis of the coupling body 1 is 76~82°, the inner tooth bottom surface 57 and the inner tooth bottom surface 57 The inner planes 51 of the tooth bottoms are connected through the inner transitional arc 68 of the inner tooth bottoms, the inner tooth bottoms 57 and the outer planes 54 of the inner tooth bottoms are connected through the outer transitional arcs 67 of the inner tooth bottoms, the outer plane 54 of the inner tooth bottoms is connected with the inner tooth bottoms The guide surfaces 55 are connected through the inner tooth bottom outer arc 63, the inner guide surface 55 and the inner tooth top inner plane 56 are connected through the inner tooth top inner arc 64, and the inner tooth bottom inner plane 51 and the inner bearing surface 52 are connected. are connected by the inner arc 65 of the inner tooth bottom, the inner bearing surface 52 and the outer plane 53 of the inner tooth top are connected by the outer arc 66 of the inner tooth bottom, and the angle formed by the inner plane 51 of the inner tooth bottom and the axis of the coupling body 1 is 10~20°, the angle formed by the outer plane 53 of the inner tooth top and the axis of the coupling body 1 is 10~20°, the angle formed by the outer plane 54 of the inner tooth bottom and the axis of the coupling body 1 is 7~17°, The angle formed by the inner plane 56 of the inner tooth top and the axis of the coupling body 1 is 7~17°; and on the longitudinal section of the coupling body 1, the outer arc 66 of the inner tooth top at the innermost position transitions to the inner sealing surface The arc surface 72 has a smooth transition, the inner sealing surface transition arc surface 72 and the inner sealing surface 74 have a smooth transition, the inner sealing surface 74 and the inner sealing arc surface 82 have a smooth transition, the inner sealing arc surface 82 and the inner shoulder surface transition arc 84 have a smooth transition, The inner shoulder surface transition arc 84 and the first inner secondary sealing surface 78 are smooth Transition, the first inner secondary sealing surface 78 and the inner shoulder surface angle arc 86 transition smoothly, the inner shoulder surface angle arc 86 and the second inner secondary sealing surface 80 smoothly transition, the second inner secondary sealing surface 80 and the The inner hole walls of the collar shoulder 1.2 meet.

Preferably, the taper of the internal thread section 1.1 of the coupling is 1:18~1:20.

Preferably, the thread number of the internal thread section 1.1 of the coupling is 12~30; the width of the inner first button alveolar is 1.8~3.2mm; the pitch of the inner guide surface is: the width of the inner first button alveolar multiplied by The multiple of the alveolar width of the inner first button, the pitch of the inner guide surface is 3.96~9.60, the multiple of the alveolar width of the inner first button is 2.2~3.0; the pitch of the inner bearing surface is equal to: (the total length of the inner thread minus 2 times the inner first tooth socket width)/(total number of buttons minus 1); the tooth width of the inner first button is: the thread pitch of the inner guide surface minus the alveolar width of the inner first button; the inner tooth height is: 1.5~2.5mm.

Preferably, on the longitudinal section of the coupling body 1, the tooth width of the first button of the coupling internal thread section 1.1 is 1.8~3.2mm; the tooth height of each tooth of the coupling internal thread section 1.1 is 1.5~2.5mm; The width of the inner plane 56 of the tooth top is 0.5~3.0 mm; the width of the inner bearing surface 52 is 0.5~2.0 mm; the width of the outer plane 54 of the inner tooth bottom is 0.5~3.0 mm; the width of the outer plane 53 of the inner tooth top is 0.5~ 3.0 mm; the width of the inner guide surface 55 is 0.5~2.0 mm; the width of the inner plane 51 of the inner tooth bottom is 0.5~3.0 mm; the width of the inner tooth top surface 58 is 0.05~6.0 mm; the width of the inner tooth bottom surface 57 is 0.05 ~6.0 mm; the radius of the outer arc 66 of the inner tooth top is 0.20~0.50mm; the radius of the outer arc 63 of the inner tooth bottom is 0.20~0.50mm; the radius of the inner arc 64 of the inner tooth top is 0.20~0.50mm; The radius of the inner arc 65 of the tooth bottom is 0.20~0.50mm; the radius of the outer transition arc 67 of the inner tooth bottom is 0.15~0.30mm; the radius of the inner transition arc 68 of the inner tooth bottom is 0.15~0.30mm; the inner tooth top surface The radius of the inner transitional arc 69 is 0.15~0.30mm; the radius of the inner transitional arc 69 on the top surface of the inner tooth is 0.15~0.30mm; the angle between the inner bearing surface 52 and the axis of the coupling body 1 is smaller than the inner guide surface 55 The angle with the axis of the coupling body 1 is 2° to 6°.

Preferably, on the longitudinal section of the coupling body 1, the radius of the transition arc surface 72 of the inner sealing surface is 12-16mm, and the angle of the center of the circle corresponding to the transition arc surface 72 of the inner sealing surface is 6-15°; the length of the inner sealing surface 74 is 5°. ~12mm, the taper is 1:8~1:14; the radius of the inner sealing arc surface 82 is 1.0~1.5mm, and the corresponding center angle of the inner sealing arc surface 82 is 40~50°; the inner shoulder surface transition The radius of the arc 84 is 0.2~0.5mm, and the angle of the center of the inner shoulder surface transition arc 84 is 105~120°; the radius of the inner shoulder surface included angle arc 86 is 0.2~1.0mm, and the inner shoulder surface The angle of the circle center corresponding to the surface included angle arc 86 is 65~75°; the angle formed by the first inner auxiliary sealing surface 78 and the second inner auxiliary sealing surface 80 is 120~150°; the second inner auxiliary sealing surface 80 and The angle formed by the inner hole wall of the collar shoulder 1.2 is 75-90°; the distance between the inner end of the inner sealing surface 74 and the inner hole wall of the collar shoulder 1.2 is 3.5-8.0mm.

An S-shaped shoulder variable-tooth wide wedge-shaped oil well pipe structure, including an oil well pipe body 2, the outer walls of both ends of the oil well pipe body 2 are oil well pipe external thread sections 2.1, and an oil well pipe external thread section 2.1 is provided between the two oil well pipe external thread sections The oil well pipe shoulder 2.2 is set from the two ends of the oil well pipe body 2 to the middle, the tooth width of the oil well pipe external thread section 2.1 is gradually reduced, and the tooth width of the oil well pipe external thread section 2.1 is gradually reduced. Increase the setting, the difference between the width of two adjacent teeth is equal to the difference between the width of two adjacent slots, the height of each tooth of the oil well pipe external thread section 2.1 is equal, and the taper of the oil well pipe external thread section 2.1 is 1:16 ~1:24; On the longitudinal section of the oil well pipe body 2, each tooth on the oil well pipe external thread section 2.1 is wedge-shaped, and barbs are provided on both sides of the top of each tooth; on the oil well pipe external thread section 2.1 The middle part of the top of each tooth is an outer tooth top surface 26, the inner side of the outer tooth top surface 26 is provided with an outer tooth top inner plane 20, and the outer side of the outer tooth top surface 26 is provided with an outer tooth top outer plane 23, and the outer tooth top inner plane 23 is provided. The plane 20 and the top surface of the outer tooth 26 are connected through the inner transition arc 37 of the top surface of the outer tooth, and the outer plane 23 of the outer tooth top and the top surface of the outer tooth 26 are connected through the outer transition arc 36 of the top surface of the outer tooth. The middle part is the bottom surface 27 of the external tooth, the bottom surface 27 of the external tooth is a conical surface, and the top surface 26 of the external tooth is a conical surface, and the taper of the top surface 26 of the external tooth and the bottom surface 27 of the external tooth are equal to the taper of the external thread section 2.1 of the oil well pipe. The inner side of the bottom surface 27 is provided with an outer tooth bottom inner plane 25, and the outer side of the outer tooth bottom surface 27 is provided with an outer tooth bottom outer plane 22. The angle formed by the axis of each tooth is 79~85°, the inner wall of each tooth is provided with an outer bearing surface 21, the angle formed by the outer bearing surface 21 and the axis of the oil well tubular body 2 is 76~82°, the outer tooth bottom surface 27 and the outer tooth The inner planes 25 of the tooth bottom are connected through the inner transition arc 38 of the outer tooth bottom surface, the outer tooth bottom surface 27 and the outer tooth bottom outer plane 22 are connected through the outer transition arc 39 of the outer tooth bottom surface, and the outer tooth bottom outer plane 22 is connected with the outer tooth bottom surface The bearing surfaces 21 are connected by the outer arc 35 of the outer tooth bottom, the outer bearing surface 21 and the inner plane 20 of the outer tooth top are connected by the inner arc 34 of the outer tooth top, and the inner plane 25 of the outer tooth bottom and the outer guide surface 24 The outer guide surface 24 and the outer plane 23 of the outer tooth top are connected through the outer arc 32 of the outer tooth bottom, and the angle formed by the inner plane 51 of the inner tooth bottom and the axis of the coupling body 1 The angle formed by the outer surface 23 of the outer tooth top and the axis of the oil well pipe body 2 is 10~20°, and the angle formed by the outer surface 22 of the outer tooth bottom and the axis of the oil well pipe body 2 is 7~17°. The angle formed by the inner plane 20 of the outer tooth top and the axis of the oil well tubular body 2 is 7° to 17°; 73 smooth transition, outer sealing surface transition surface 73 and outer sealing surface 75 meet, outer sealing surface 75 and outer sealing arc surface 83 smoothly transition, outer sealing arc surface 83 and outer shoulder surface transition arc 85 smoothly transition, Outer shoulder transition circle The arc 85 has a smooth transition with the first outer sealing surface 79, the arc 87 at the angle between the first outer sealing surface 79 and the outer shoulder surface has a smooth transition, and the arc 87 at the angle between the outer shoulder surface and the second outer sealing surface 81 Smooth transition, the second outer auxiliary sealing surface 81 is in contact with the bore surface 77 of the inner wall, the bore surface 77 of the inner wall is in contact with the transition surface 89 of the inner wall, and the transition surface 89 of the inner wall is in contact with the inner hole wall of the external thread section 2.1 of the oil well pipe.

Preferably, the taper of the oil well pipe external thread section 2.1 is 1:18~1:20.

As a preference, the number of threads of the external thread section 2.1 of the oil well pipe is 12-30; the width of the teeth of the first outer thread is 1.8-3.2 mm; the pitch of the outer guide surface is: the tooth width of the outer thread multiplied by the tooth width of the outer thread The multiple of the outer guide surface pitch is 3.96~9.60mm, the multiple of the tooth width of the outer first button is 2.2~3.0; the pitch of the outer bearing surface is: (total length of the external thread minus 2 times the tooth width of the outer first button)/( The total number of buckles minus 1); the alveolar width of the outer first buckle is: the pitch of the outer guide surface minus the tooth width of the outer first buckle; the height of the outer teeth is: 1.5~2.5mm.

Preferably, on the longitudinal section of the oil well pipe body 2, the tooth width of the first buckle of the oil well pipe external thread section 2.1 is 1.8~3.2mm; the tooth height of each tooth of the oil well pipe external thread section 2.1 is 1.5~2.5mm; The width of the inner plane 20 of the tooth top is 0.5~3.0 mm; the width of the outer bearing surface 21 is 0.5~2.0 mm; the width of the outer plane 22 of the outer tooth bottom is 0.5~3.0 mm; the width of the outer plane 23 of the outer tooth top is 0.5~ 3.0 mm; the width of the outer guide surface 24 is 0.5~2.0 mm; the width of the inner plane 25 of the outer tooth bottom is 0.5~3.0 mm; the width of the top surface 26 of the outer tooth is 0.05~6.0 mm; the width of the bottom surface 27 of the outer tooth is 0.05 ~6.0 mm; the radius of the outer arc 32 of the outer tooth top is 0.20~0.50mm; the radius of the inner arc 33 of the outer tooth bottom is 0.20~0.50mm; the radius of the inner arc 34 of the outer tooth top is 0.20~0.50mm; The radius of the outer arc 35 of the bottom of the tooth is 0.20~0.50mm; the radius of the outer transition arc 36 of the top surface of the outer tooth is 0.15~0.30mm; the radius of the inner transition arc 37 of the top surface of the outer tooth is 0.15~0.30mm; The radius of the transition arc 38 on the bottom surface is 0.15~0.30mm; the radius of the transition arc 39 on the bottom surface of the outer tooth is 0.15~0.30mm; The angle between the 2 axes of the oil well pipe body is 2° to 6°.

Preferably, on the longitudinal section of the oil well pipe body 2, the length of the outer sealing surface transition surface 73 is 1.0-2.5 mm, and the outer sealing surface transition surface 73 is parallel to the outer plane 22 of the outer tooth bottom; the length of the outer sealing surface 75 is 5 mm. ~12mm, the taper is 1:8~1:14; the radius of the outer sealing arc surface 83 is 1.0~1.5mm, and the corresponding center angle of the outer sealing arc surface 83 is 40~50°; the outer shoulder surface transition The radius of the arc 85 is 0.2~0.5mm, and the angle of the center of the outer shoulder surface transition arc 85 is 105~120°; the angle formed by the first outer sealing surface 79 and the second outer sealing surface 81 is 120° ~150°; the angle formed by the second outer secondary sealing surface 81 and the inner wall boring surface 77 is 75~90°; the length of the inner wall boring surface 77 is 2~10mm; the length of the inner wall transition surface 89 is 2~10mm; The distance between the outer end of the sealing surface 75 and the bore surface 77 of the inner wall is 3.5-8.0 mm.

When in use, the oil well tubular body 2 and the oil well tubular body 2 are threaded through the coupling body 1 to form a casing string. The interior of the casing string forms a connected overall space channel, and the internal channel can withstand high-strength and complex external conditions. Force is applied without leakage or damage, meeting the requirements of oil and gas field production and use.

Parameter design requirement of the present invention:

The thread parameters of the coupling internal thread section 1.1 and the oil well pipe external thread section 2.1 are mostly the same, but the tolerance is different, in order to meet the interference fit requirements between the internal and external thread tooth profiles.

1. The total length of the external thread section 2.1 of the oil well pipe is the same as the total length of the internal thread section 1.1 of the coupling internal thread, and the length is within the range of 50~160mm, which varies according to the wall thickness and outer diameter of the pipe. You can refer to API SPEC 5B "Code for Machining, Measurement and Inspection of Casing, Tubing and Line Pipe Threads".

2. The number of teeth of oil well pipe external thread section 2.1 and oil well pipe external thread section 2.1 is determined according to the range of the total length of the thread, the width of the thread and the size of the pitch, and it is best to control it between 12 and 30 teeth. It is a selected quantity in thread comprehensive design.

3. The taper of the oil well pipe external thread section 2.1 is the same as that of the coupling internal thread section 1.1.

4. The tooth width of the 2.1 first buckle in the external thread section of the oil well pipe is the same as the 1.1 tooth groove width of the first buckle in the coupling internal thread section. The multiple requirements for the tooth width of the 2.1 first buckle in the external thread section of the oil well pipe are the same as the multiples of the tooth width of the 1.1 first buckle in the internal thread section of the coupling. The pitch of the outer guide surface of the outer thread section 2.1 of the oil well pipe is the same as that of the inner guide surface of the inner thread section 1.1 of the coupling. The pitch 15 of the outer bearing surface of the outer thread section 2.1 of the oil well pipe is the same as the pitch 46 of the inner bearing surface of the inner thread section 1.1 of the coupling.

5. The tooth width of the 2.1 first buckle in the external thread section of the oil well pipe is the same as the 1.1 tooth groove width of the first buckle in the coupling internal thread section. The tooth width increase of the follow-up external thread is the same as that of the tooth alveolar width increase of the follow-up internal thread.

6. The pitch of the outer bearing surface of the outer thread section 2.1 of the oil well pipe is the same as the pitch of the inner bearing surface of the inner thread section 1.1 of the coupling.

7. The formula for calculating the alveolar width of the first buckle in the external thread section 2.1 of the oil well pipe is: the pitch of the outer guide surface of the external thread section 2.1 of the oil well pipe - the tooth width of the first outer thread of the external thread section 2.1 of the oil well pipe, and the subsequent alveolar width It will gradually decrease, and the decrease is the difference between the pitch of the bearing surface minus the pitch of the guide surface, but not less than 0.02mm. The calculation formula for the tooth width of the first button of the coupling internal thread section 1.1 is: the pitch of the inner guide surface of the coupling internal thread section 1.1 - the width of the inner first button tooth socket of the coupling internal thread section 1.1, which is the same as it.

8. The increase of the tooth width of the external thread section 2.1 of the oil well pipe is the same as the decrease of the alveolar width, and the pitch of the external bearing surface and the pitch of the external guide surface of the external thread section 2.1 of the oil well pipe remain unchanged, while the gradual change It is the tooth width and alveolar width, which ensures smooth screwing of internal and external threads without interference;

The increase of the alveolar width of the internal thread of the coupling internal thread section 1.1 is the same as the reduction of the tooth width. Change, and gradually change the tooth width and alveolar width, to ensure smooth screwing of internal and external threads without interference. Ensure the normal fit of its internal and external threads.

9. The tooth height of the oil well pipe external thread section 2.1 is the same as that of the coupling internal thread section 1.1, both of which are between 1.5mm and 2.5mm, and the bottom of the tooth is parallel to the bottom of the tooth.

10. The angle between the outer bearing surface 21 and the axis of the oil well tubular body 2 is smaller than the angle between the outer guide surface 24 and the axis of the oil well tubular body 2, and a difference of 2~6° is maintained between them. The angle between the inner bearing surface 52 and the axis of the coupling body 1 is smaller than the angle between the inner guide surface 55 and the axis of the coupling body 1, and there is a difference of 2~6° between them, both of which are the same, forming a wedge shape Tooth angle.

11. The angle between the inner plane 20 of the outer tooth top and the axis of the oil well tubular body 2, the angle between the outer plane 22 of the outer tooth bottom and the axis 2 of the oil well tubular body, and the angle between the inner plane 51 of the inner tooth bottom and the axis of the coupling body 1 The angle between the outer plane 53 of the inner tooth top and the axis of the coupling body 1 is exactly the same, the angle between the outer plane 23 of the outer tooth top and the axis of the oil well tubular body 2, the inner plane 25 of the outer tooth bottom and the oil well tubular The angle between the axes of the body 2, the angle between the outer plane 54 of the inner tooth bottom and the axis of the coupling body 1, and the angle between the inner plane 56 of the inner tooth top and the axis of the coupling body 1 are all the same. The angle between the outer plane 22 of the outer tooth bottom and the axis of the oil well tubular body 2, the angle between the outer plane 23 of the outer tooth top and the axis of the oil well tubular body 2, the angle between the inner plane 56 of the inner tooth top and the axis of the coupling body 1 The angle, the angle between the outer plane 54 of the inner tooth bottom and the axis of the coupling body 1 is exactly the same. The angle between the outer plane 22 of the outer tooth bottom and the axis of the oil well tubular body 2, the angle between the inner plane 20 of the outer tooth top and the axis of the oil well tubular body 2, the angle between the outer plane 53 of the inner tooth top and the axis of the coupling body 1 The angle, the angle between the inner plane 51 of the inner tooth bottom and the axis of the coupling body 1 is exactly the same.

12. The radius of the outer arc 32 of the outer tooth top and the inner arc 34 of the outer tooth top and their corresponding center angles are the same, the radius of the outer arc 63 of the inner tooth bottom and the inner arc 65 of the inner tooth bottom and their corresponding center of circle The number of angles is the same, and the arc radius of the outer arc 32 of the outer tooth top and the inner arc 34 of the outer tooth top is greater than the radius of the outer arc 63 of the inner tooth bottom and the inner arc 65 of the inner tooth bottom by 0.05-0.20 mm. At the same time, the radii of the inner arc 33 of the outer tooth bottom and the outer arc 35 of the outer tooth bottom and their corresponding center angles are the same, and the radii of the inner arc 64 of the inner tooth top and the outer arc 66 of the inner tooth top and their corresponding center The number of angles is the same, the arc radius of the inner arc 33 of the outer tooth bottom and the outer arc 35 of the outer tooth bottom is greater than the radius of the inner arc 64 of the inner tooth top and the outer arc 66 of the inner tooth top by 0.05-0.20 mm. This can eliminate the phenomenon of touch damage and scratches that occur when it is an interference fit.

13. External transition arc 36 on the top surface of the external tooth, internal transition arc 37 on the top surface of the external tooth and internal transition arc 38 on the bottom surface of the external tooth, 39 external transition arc on the bottom surface of the external tooth, 67 external transition arc on the bottom surface of the internal tooth, The inner transition arc 68 on the bottom surface of the tooth, the inner transition arc 69 on the inner tooth top surface, and the outer transition arc 70 on the inner tooth top surface have the same radius, and their radii range from 0.20 mm to 0.50 mm.

14. The transition arc surface 72 of the inner sealing surface adopts a circular arc transition to facilitate an effective and smooth transition with the outer sealing surface 74 , and is tangent to the left plane 22 of the tooth bottom and the inner sealing surface 74 . It cannot interfere with the transitional surface 73 of the outer sealing surface.

15. The taper requirements of the inner sealing surface 74 and the outer sealing surface 75 are the same, and the same length and different tolerances meet the axial interference fit requirements. At the same time, the outer diameter of the inner sealing surface 74 is smaller than the outer diameter of the outer sealing surface 75, and the mutual deviation is in the range of 0.3~1.0mm. Meet radial interference fit requirements.

16. The distance between the inner end of the inner sealing surface 74 and the inner hole wall of the coupling shoulder 1.2 is the same as the distance between the outer end of the outer sealing surface 75 and the inner wall boring surface 77, so as to achieve the coupling platform The shoulder surface is flush with the inner wall boring plane 77, keeping the same plane, reducing the passage resistance of the fluid in the pipe body;

17. The angle formed by the first inner auxiliary sealing surface 78 and the second inner auxiliary sealing surface 80 is larger than the angle formed by the first outer auxiliary sealing surface 79 and the second outer auxiliary sealing surface 81, and the deviation is controlled within 0.5°~1.5° ° range, 0.5~1.0° is the best; the angle formed by the second inner sealing surface 80 and the inner hole wall of the coupling shoulder 1.2 is larger than the angle formed by the second outer sealing surface 81 and the inner wall boring surface 77 , its deviation is controlled in the range of 0.5°~1.5°, and 0.5~1.0° is the best; it can meet the requirements of the inner and outer shoulders under the plastic deformation state caused by machine tightening to achieve interference fit, and improve its torque resistance performance requirements .

18. The radius of the inner sealing arc surface 82 is less than or equal to the radius of the outer sealing arc surface 83, and its deviation is controlled within the range of 0.0~0.2mm, which is intended to satisfy the apex not to be damaged after the interference fit and to prevent breakout Damage to the sealing surface, increasing the number of make-up and break-out and related performance will not be affected.

19. The transitional arc 84 of the inner shoulder surface and the transitional arc 85 of the outer shoulder surface are relatively short, and they can only be equal.

20. The radius of the included angle arc 86 of the inner shoulder surface is greater than the radius of the included angle arc 87 of the outer shoulder surface, and its deviation is controlled within the range of 0.1-0.2mm, so that the apex of the inner shoulder surface will not be damaged after the interference fit.

The specific operation is as follows:

First, evenly apply a layer of oil-specific thread grease on the surface of the external thread of the oil well pipe body 2, and then insert any end of the coupling 1 into the external thread of the oil well pipe body 2. When inserting, the internal thread of the coupling body 1 should be The external thread of the oil well pipe body 2 is to be buckled, and the tooth top of the internal thread should be gently contacted with the tooth bottom of the external thread when the thread is buckled. Since the pitch of the tooth-shaped bearing surface and the tooth-shaped guide surface are not equal to the thread screwing Form, the tooth width of the thread at the end of the coupling and the end of the pipe body is smaller than the width of the alveolar, which is a thread tooth type with equal pitch and variable tooth width. Insert about 2 to 4 buckles first, and it is very easy to manually screw the internal and external threads manually. Due to the different tolerances of several parameters such as thread taper, pitch, tooth profile, and tooth height, the threaded connection cannot be screwed in place after hand-tightening, and it is necessary to further use high torque/high torque for machine screwing, slow or slow speed should be used conduct. At this time, the bearing surface, guide surface and tooth top and bottom of each tooth within the thread length are under the condition of uniform force to achieve the interference fit between the tooth forms, the sealing performance of the tooth structure is significantly improved, and the pipe body and coupling Differences in ovality have very little effect on thread fit. At the same time, the intersection line between the inner tooth bottom surface 57 and the end surface of the coupling shoulder 1.2 and the inner hole wall surface of the coupling shoulder 1.2, the intersection line between the outer tooth bottom surface 27 and the end surface of the coupling internal thread section 1.1 and the joint The surface between the inner hole walls of the hoop internal thread section 1.1 has achieved an interference fit, which greatly increases its high torque resistance performance, compressive load capacity and tensile load capacity. Its threaded joints have high sealing performance and high composite bearing capacity. After the screwing of the machine is completed, the ultra-thin special blade is used to detect the size of the gap after the interference fit of the inner and outer shoulders. There must be no gaps, and the tip of the blade cannot be inserted through the circular detection.

In the same fastening method, the coupling body 1 and the oil well tubular body 2 are closely matched based on the virtual middle diameter line, so that the oil well tubular body 2 and the oil well tubular body 2 are connected through the coupling body 1 to form oil. , Casing strings meet the production and use requirements of oil and gas fields. When the oil field is going downhole, the connectors are mechanically connected one by one to form an oil casing string of several thousand meters.

The working principle of the present invention is as follows:

The pipe body and the pipe body are connected several times in the form of threaded connection through couplings to form a casing string. The inside of the casing string forms a connected overall space channel. The internal channel can withstand high-intensity and complex forces from the outside without leakage or damage. Oil and gas field production and use requirements.

Claims (8)

1. An S-shaped shoulder variable tooth width wedge-shaped coupling structure, including a coupling body (1), the inner walls of both ends of the coupling body (1) are coupling internal thread sections (1.1), and the two-section coupling A coupling shoulder (1.2) is provided between the internal thread sections (1.1); the feature is that: in the direction from the two ends of the coupling body (1) to the middle, the coupling internal thread section (1.1) The tooth width of the coupling is gradually increased, and the tooth space width of the coupling internal thread section (1.1) is gradually reduced. The difference between the two adjacent tooth widths is equal to the difference between the adjacent two tooth space widths. The height of each tooth of the section (1.1) is equal, and the taper of the coupling internal thread section (1.1) is 1:16~1:24; on the longitudinal section of the coupling body (1), the coupling internal thread section (1.1 ) is wedge-shaped, and barbs are provided on both sides of the top of each tooth; the top middle of each tooth on the coupling internal thread section (1.1) is the top surface (58) of the internal tooth, and the internal tooth The inner side of the top surface (58) is provided with the inner tooth top plane (56), the outer side of the inner tooth top surface (58) is provided with the inner tooth top outer plane (53), and the inner tooth top inner plane (56) and the inner tooth top The surfaces (58) are connected through the inner transition arc (69) of the inner tooth top surface, and the outer plane of the inner tooth top (53) and the inner tooth top surface (58) are connected through the outer transition arc (70) of the inner tooth top surface connected, the middle part of the alveolar is the inner tooth bottom surface (57), the inner tooth bottom surface (57) is a conical surface, the inner tooth top surface (58) is a conical surface, and the inner tooth bottom surface (57), the inner tooth top surface (58) The taper is equal to the taper of the coupling internal thread section (1.1), the inner tooth bottom surface (57) is provided with the inner tooth bottom inner plane (51), and the outer side of the inner tooth bottom surface (57) is provided with the inner tooth bottom outer plane (54 ), the outer wall of each tooth is provided with an inner guide surface (55), the angle formed by the inner guide surface (55) and the axis of the coupling body (1) is 79~85°, and the inner wall of each tooth is provided with an inner guide surface (55). The bearing surface (52), the angle formed by the inner bearing surface (52) and the axis of the coupling body (1) is 76~82°, the inner tooth bottom surface (57) and the inner tooth bottom inner plane (51) pass through the inner tooth The inner transition arc (68) of the bottom surface is connected, the inner tooth bottom surface (57) and the outer plane of the inner tooth bottom (54) are connected through the outer transition arc (67) of the inner tooth bottom surface, and the inner tooth bottom outer plane (54) is connected to the inner tooth bottom outer plane (54). The guide surfaces (55) are connected through the inner tooth bottom outer arc (63), and the inner guide surface (55) is connected with the inner tooth top inner plane (56) through the inner tooth top inner arc (64). The bottom inner plane (51) and the inner bearing surface (52) are connected through the inner tooth bottom inner arc (65), and the inner bearing surface (52) and the inner tooth top outer plane (53) are connected through the inner tooth top outer circle The arc (66) is connected, the angle formed by the inner plane of the inner tooth bottom (51) and the axis of the coupling body (1) is 10~20°, and the angle formed by the outer plane of the inner tooth top (53) and the axis of the coupling body (1) The angle is 10~20°, the angle formed by the outer plane of the inner tooth bottom (54) and the axis of the coupling body (1) is 7~17°, the inner plane of the inner tooth top (56) and the coupling body (1) The angle formed by the axes is 7 ~17°; and on the longitudinal section of the coupling body (1), the outer circular arc of the inner tooth top (66) at the innermost position and the transitional arc surface of the inner sealing surface (72) have a smooth transition, and the transition arc surface of the inner sealing surface ( 72) has a smooth transition with the inner sealing surface (74), the inner sealing surface (74) has a smooth transition with the inner sealing arc surface (82), and the inner sealing arc surface (82) has a smooth transition with the inner shoulder surface (84). The transition arc (84) of the inner shoulder surface and the first inner auxiliary sealing surface (78) have a smooth transition, and the angle arc (86) between the first inner auxiliary sealing surface (78) and the inner shoulder surface has a smooth transition, and the inner shoulder The arc (86) of the included angle between the surfaces transitions smoothly with the second inner sealing surface (80), and the second inner sealing surface (80) connects with the inner hole wall of the collar shoulder (1.2); The thread number of the internal thread section (1.1) of the coupling is 12~30; the width of the inner first button alveolar is 1.8~3.2mm; the pitch of the inner guide surface is: the width of the inner first button alveolar multiplied by the inner The multiple of the alveolar width of the first button, the pitch of the inner guide surface is 3.96~9.60, the multiple of the alveolar width of the inner first button is 2.2~3.0; the pitch of the inner bearing surface is equal to: (the total length of the internal thread minus 2 times the inner first button alveolar width)/(total deduction minus 1); the tooth width of the inner first deduction is: the thread pitch of the inner guide surface minus the alveolar width of the inner first deduction; the inner tooth height is: 1.5~2.5mm. 2. The S-shaped shoulder variable tooth width wedge coupling structure according to claim 1, characterized in that: the taper of the internal thread section (1.1) of the coupling is 1:18~1:20. 3. The S-shaped shoulder variable tooth width wedge coupling structure according to claim 1, characterized in that: on the longitudinal section of the coupling body (1), the first tooth of the coupling internal thread section (1.1) The width is 1.8~3.2mm; the tooth height of each tooth of the coupling internal thread section (1.1) is 1.5~2.5mm; the width of the inner plane (56) of the inner tooth top is 0.5~3.0 mm; the inner bearing surface (52) The width of the outer surface of the inner tooth bottom (54) is 0.5~3.0 mm; the width of the outer surface of the inner tooth top (53) is 0.5~3.0 mm; the width of the inner guide surface (55) is 0.5 ~2.0 mm; the width of the inner plane (51) of the inner tooth bottom is 0.5~3.0 mm; the width of the inner tooth top surface (58) is 0.05~6.0 mm; the width of the inner tooth bottom surface (57) is 0.05~6.0 mm; The radius of the outer arc of the tooth top (66) is 0.20~0.50mm; the radius of the outer arc of the inner tooth bottom (63) is 0.20~0.50mm; the radius of the inner arc of the inner tooth top (64) is 0.20~0.50mm; The radius of the inner arc (65) of the inner tooth bottom is 0.20~0.50mm; the radius of the outer transition arc (67) of the inner tooth bottom is 0.15~0.30mm; the radius of the inner transition arc (68) of the inner tooth bottom is 0.15~ 0.30mm; the radius of the transition arc (69) on the top surface of the inner tooth is 0.15~0.30mm; the radius of the transition arc (69) on the top surface of the inner tooth is 0.15~0.30mm; the inner bearing surface (52) and the coupling The angle between the axes of the body (1) is 2-6° smaller than the angle between the inner guide surface (55) and the axes of the coupling body (1). 4. The S-shaped shoulder variable tooth width wedge coupling structure according to claim 1, characterized in that: on the longitudinal section of the coupling body (1), the radius of the transition arc surface (72) of the inner sealing surface is 12 ~16mm, the inner sealing surface transition arc surface (72) corresponds to the center angle of 6~15°; the length of the inner sealing surface (74) is 5~12mm, and its taper is 1:8~1:14; the inner sealing arc surface The radius of (82) is 1.0~1.5mm, and the center angle corresponding to the inner sealing arc surface (82) is 40~50°; the radius of the inner shoulder surface transition arc (84) is 0.2~0.5mm, and the inner platform The angle of the center of the shoulder surface transition arc (84) is 105~120°; the radius of the inner shoulder surface included angle arc (86) is 0.2~1.0mm, and the inner shoulder surface included angle arc (86) corresponds to The angle of the center of the circle is 65~75°; the angle formed by the first inner auxiliary sealing surface (78) and the second inner auxiliary sealing surface (80) is 120~150°; the second inner auxiliary sealing surface (80) and the joint The angle formed by the inner hole wall of the collar shoulder (1.2) is 75~90°; the distance between the inner end of the inner sealing surface (74) and the inner hole wall of the collar shoulder (1.2) is 3.5~8.0mm . 5. An S-shaped shoulder variable-tooth wide wedge-shaped oil well tubular structure, including an oil well tubular body (2). There is an oil well pipe shoulder (2.2) between the external thread sections (2.1), and the tooth width of the oil well pipe external thread section (2.1) is Gradually reduce the setting, the tooth space width of the oil well pipe external thread section (2.1) is set to gradually increase, the difference between two adjacent tooth widths is equal to the difference between the adjacent two tooth space widths, the oil well pipe external thread section (2.1) The height of each tooth is equal, and the taper of the oil well pipe external thread section (2.1) is 1:16~1:24; on the longitudinal section of the oil well pipe body (2), each tooth on the oil well pipe external thread section (2.1) The two teeth are wedge-shaped, and barbs are provided on both sides of the top of each tooth; the middle part of the top of each tooth on the oil well pipe external thread section (2.1) is the top surface of the external tooth (26), and the top surface of the external tooth (26 ) is provided with an outer tooth top inner plane (20), an outer tooth top surface (26) is provided with an outer tooth top outer plane (23), and an outer tooth top inner plane (20) and an outer tooth top surface (26) They are connected through the inner transition arc (37) of the outer tooth top surface, and the outer plane of the outer tooth top (23) and the outer tooth top surface (26) are connected through the outer transition arc (36) of the outer tooth top surface. The middle part is the bottom surface of the external tooth (27), the bottom surface of the external tooth (27) is a conical surface, the top surface of the external tooth (26) is a conical surface, and the taper of the top surface of the external tooth (26) and the bottom surface of the external tooth (27) is the same as that of the oil well pipe The taper of the external thread segment (2.1) is equal, the inner plane of the outer tooth bottom (27) is provided with the inner plane of the outer tooth bottom (25), the outer side of the outer tooth bottom surface (27) is provided with the outer plane of the outer tooth bottom (22), each The outer wall of the tooth is provided with an outer guide surface (24), the angle formed by the outer guide surface (24) and the axis of the oil well tubular body (2) is 79~85°, and the inner wall of each tooth is provided with an outer bearing surface (21 ), the angle formed by the outer bearing surface (21) and the axis of the oil well tubular body (2) is 76~82°, and the transition circle between the outer tooth bottom surface (27) and the outer tooth bottom inner plane (25) passes through the inner transition circle of the outer tooth bottom surface The arc (38) is connected, the bottom surface of the outer tooth (27) and the outer plane of the outer tooth bottom (22) are connected through the outer transition arc (39) of the outer tooth bottom surface, and the outer plane of the outer tooth bottom (22) and the outer bearing surface (21 ) are connected through the outer arc of the outer tooth bottom (35), the outer bearing surface (21) and the inner plane of the outer tooth top (20) are connected through the inner arc of the outer tooth top (34), and the inner plane of the outer tooth bottom ( 25) is connected with the outer guide surface (24) through the inner arc of the outer tooth bottom (33), and the outer guide surface (24) and the outer plane of the outer tooth top (23) are connected through the outer arc of the outer tooth top (32) connected, the angle formed by the inner plane of the inner tooth bottom (51) and the axis of the coupling body (1) is 10~20°, and the angle formed by the outer plane of the outer tooth top (23) and the axis of the oil well pipe body (2) is 10° ~20°, the angle formed by the outer plane of the outer tooth bottom (22) and the axis of the oil well pipe body (2) is 7~17°, the inner plane of the outer tooth top (20) and the oil well The angle formed by the axis of the pipe body (2) is 7~17°; and on the longitudinal section of the oil well pipe body (2), the outer circular arc (35) at the outermost end of the outer tooth bottom and the transition surface (73 ) smooth transition, the outer sealing surface transition surface (73) and the outer sealing surface (75) meet, the outer sealing surface (75) and the outer sealing arc surface (83) smooth transition, the outer sealing arc surface (83) and the outer The shoulder surface transition arc (85) is smoothly transitioned, the outer shoulder surface transition arc (85) and the first outer sealing surface (79) are smoothly transitioned, the first outer sealing surface (79) and the outer shoulder surface are clamped The corner arc (87) has a smooth transition, the angle arc (87) between the outer shoulder surface and the second outer sealing surface (81) has a smooth transition, the second outer sealing surface (81) and the inner wall boring surface (77) Connected, the inner wall boring surface (77) is connected to the inner wall transition surface (89), and the inner wall transition surface (89) is connected to the inner hole wall of the oil well pipe external thread section (2.1); The thread thread number of the external thread section (2.1) of the oil well pipe is 12~30; the width of the teeth of the outer first button is 1.8~3.2mm; the pitch of the outer guide surface is: the tooth width of the outer first button multiplied by the tooth width of the outer first button Multiple, the pitch of the outer guide surface is 3.96~9.60mm, the multiple of the tooth width of the outer first button is 2.2~3.0; the pitch of the outer bearing surface is: (total length of the external thread minus 2 times the tooth width of the outer first button)/(total The number of buckles minus 1); the alveolar width of the outer first buckle is: the pitch of the outer guide surface minus the tooth width of the outer first buckle; the height of the outer teeth is: 1.5~2.5mm. 6. The S-shaped shoulder variable tooth width wedge type oil well pipe structure according to claim 5, characterized in that: the taper of the oil well pipe external thread section (2.1) is 1:18~1:20. 7. The S-shaped shoulder variable-tooth wide wedge-shaped oil well pipe structure according to claim 5, characterized in that: on the longitudinal section of the oil well pipe body (2), the first tooth of the oil well pipe external thread section (2.1) The width is 1.8~3.2mm; the tooth height of each tooth of the oil well pipe external thread section (2.1) is 1.5~2.5mm; the width of the inner plane (20) of the outer tooth top is 0.5~3.0 mm; the outer bearing surface (21) The width of the outer surface of the outer tooth bottom (22) is 0.5~3.0 mm; the width of the outer surface of the outer tooth top (23) is 0.5~3.0 mm; the width of the outer guide surface (24) is 0.5 ~2.0 mm; the width of the inner plane (25) of the outer tooth bottom is 0.5~3.0 mm; the width of the top surface of the outer tooth (26) is 0.05~6.0 mm; the width of the bottom surface of the outer tooth (27) is 0.05~6.0 mm; The radius of the outer arc of the tooth top (32) is 0.20~0.50mm; the radius of the inner arc of the outer tooth bottom (33) is 0.20~0.50mm; the radius of the inner arc of the outer tooth top (34) is 0.20~0.50mm; The radius of the outer arc (35) of the outer tooth bottom is 0.20~0.50mm; the radius of the outer transition arc (36) of the outer tooth top surface is 0.15~0.30mm; the radius of the inner transition arc (37) of the outer tooth top surface is 0.15~0.30mm; the radius of the transition arc (38) on the bottom surface of the outer tooth is 0.15~0.30mm; the radius of the transition arc (39) on the bottom surface of the outer tooth is 0.15~0.30mm; the outer bearing surface (21) and the oil well pipe The angle between the axes of the body (2) is 2-6° smaller than the angle between the outer guide surface (24) and the axis of the oil well tubular body (2). 8. The S-shaped shoulder variable-tooth wide wedge-shaped oil well tubular structure according to claim 5, characterized in that: on the longitudinal section of the oil well tubular body (2), the length of the transition surface (73) of the outer sealing surface is 1.0 -2.5mm, the transition surface of the outer sealing surface (73) is parallel to the outer plane of the outer tooth bottom (22); the length of the outer sealing surface (75) is 5~12mm, and its taper is 1:8~1:14; the outer sealing circle The radius of the arc surface (83) is 1.0~1.5mm, the angle of the center of the outer sealing arc surface (83) is 40~50°; the radius of the transition arc (85) of the outer shoulder surface is 0.2~0.5mm, The angle of the center of the outer shoulder surface transition arc (85) is 105~120°; the angle formed by the first outer sealing surface (79) and the second outer sealing surface (81) is 120~150°; The angle formed by the second outer sealing surface (81) and the inner wall boring surface (77) is 75~90°; the length of the inner wall boring surface (77) is 2~10mm; the length of the inner wall transition surface (89) is 2~ 10mm; the distance between the outer end of the outer sealing surface (75) and the inner wall boring surface (77) is 3.5~8.0mm.