CN112761539A - Anti-shearing airtight threaded joint - Google Patents
Anti-shearing airtight threaded joint Download PDFInfo
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- CN112761539A CN112761539A CN202110010598.2A CN202110010598A CN112761539A CN 112761539 A CN112761539 A CN 112761539A CN 202110010598 A CN202110010598 A CN 202110010598A CN 112761539 A CN112761539 A CN 112761539A
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- 238000010008 shearing Methods 0.000 title claims abstract description 16
- 238000007789 sealing Methods 0.000 claims abstract description 132
- 238000010168 coupling process Methods 0.000 claims abstract description 36
- 238000005859 coupling reaction Methods 0.000 claims abstract description 36
- 230000008878 coupling Effects 0.000 claims abstract description 35
- 210000003781 tooth socket Anatomy 0.000 claims description 10
- 238000005520 cutting process Methods 0.000 claims description 8
- 230000006835 compression Effects 0.000 abstract description 8
- 238000007906 compression Methods 0.000 abstract description 8
- 230000007246 mechanism Effects 0.000 abstract description 4
- 238000004026 adhesive bonding Methods 0.000 description 5
- 238000005452 bending Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000002929 anti-fatigue Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/02—Couplings; joints
- E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
- E21B17/042—Threaded
- E21B17/0426—Threaded with a threaded cylindrical portion, e.g. for percussion rods
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/02—Couplings; joints
- E21B17/08—Casing joints
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- Engineering & Computer Science (AREA)
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- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
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- Environmental & Geological Engineering (AREA)
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- Geochemistry & Mineralogy (AREA)
- Non-Disconnectible Joints And Screw-Threaded Joints (AREA)
Abstract
The invention provides a shear-resistant air-tight sealed threaded joint, which can prevent thread tripping under tensile and shear loads by connecting and matching external threads and internal threads on a pipe body and a coupling, and realize the sealing integrity under tensile/compression, internal/external pressure, over-torque and shear loads by the interference contact of a seal and a shoulder upper buckle; the first pipe body sealing surface and the first coupling sealing surface are arranged in an interference sealing mode to form a first sealing mechanism, and the second pipe body sealing surface and the second coupling sealing surface are arranged in a matched contact mode to form a second sealing mechanism; the connection strength and the sealing performance are effectively improved, the thread forms of the external thread and the internal thread are correspondingly provided with inclination angles, the two-stage contact of the upper thread negative angle is realized, and the thread is locked under a shearing load to avoid tripping.
Description
Technical Field
The invention relates to the technical field of petroleum and natural gas development, in particular to a shear-resistant air-tight threaded joint.
Background
The shale gas is subjected to multi-section volume fracturing, and the fracture of the shale reservoir layer slips along with the increase of fracturing times and the change of porosity. The structural and sealing integrity of a threaded joint is subject to failure under shear loading, resulting in seal leakage and galling. Therefore, the development of special threaded joints meeting the shearing load under specific working conditions is an important prerequisite for ensuring safe production.
The conventional special screwed joint needs to be developed aiming at the working conditions of a high-temperature high-pressure well and a horizontal well, and is mainly developed aiming at a thread and a sealing structure which are developed aiming at the load of crushing under tension/compression + bending + internal pressure and external pressure; the horizontal well is mainly developed with threads and sealing structures for rotary casing threads and sealing fatigue resistance and over-torque. Therefore, after the existing gas-tight special threaded connection is fractured for 10-20 times in the multi-section fracturing process of the shale gas exploitation horizontal well production casing, the casing threads are subjected to multiple thread connection tripping failure accidents, so that serious sealing leakage is caused, and the problems of structure and sealing failure of the thread connection under fracturing under a specific load shearing action are urgently needed to be solved.
The existing airtight special thread structure is characterized in that: the thread adopts a deviation ladder improved type, and the negative angle or positive angle (3 to-10 degrees) of the bearing surface; the positive angle of the guide surface is (10-45 degrees); the thread has strong tensile capacity, and the upper thread is easy to be buckled; the defect is that the thread is easy to separate under the shearing and extruding load, so that the thread is released; the sealing adopts a simple structure of conical surface to conical surface or spherical surface to conical surface; has the disadvantages of easy processing and measurement, and easy separation of the seal under shear load, resulting in leakage.
Disclosure of Invention
Aiming at the problem that threads are easy to separate under a shearing and extruding load and have thread tripping to cause leakage in a special air-tight thread structure in the prior art, the invention provides the anti-shearing air-tight thread joint, which effectively solves the defects of sealing failure of the thread joint, shearing failure of a torque shoulder, joint tripping and the like, and improves the reliable connection strength and sealing performance of the thread joint under complex working conditions of internal and external pressure, bending load, compression load, tensile load and the like.
The invention is realized by the following technical scheme:
a shear-resistant air-tight threaded joint comprises a pipe body and a coupling which are in threaded connection; the pipe body is sequentially provided with an external thread, a first pipe body sealing surface, an external shoulder surface and a second pipe body sealing surface from the middle part to the end part; the coupling is sequentially provided with internal threads, a first coupling sealing surface, an internal shoulder surface and a second coupling sealing surface from the end part to the middle part; the external thread is in upper-buckling fit connection with the internal thread, and the first pipe body sealing surface and the first coupling sealing surface are in interference sealing arrangement; the outer shoulder surface is in inclined sealing contact with the inner shoulder surface; the sealing surface of the second pipe body is in matched contact with the sealing surface of the second coupling; the thread forms of the external thread and the internal thread are correspondingly provided with inclination angles.
Preferably, two sides of teeth of the external thread are respectively a negative angle surface and a positive angle surface, and the external thread is sequentially provided with an internal spherical surface sealing section, a first external negative angle surface, an external straight surface, a second external negative angle surface, an external tangent angle surface, an external tooth top surface and an external guide surface; wherein the inner spherical surface sealing section, the first outer negative angle surface, the outer straight surface and the second outer negative angle surface are arranged on the negative angle surface; the outer guide surface is disposed on the positive angle surface.
Furthermore, the spherical radius of the inner spherical sealing section is 0.4-0.45 mm; the first outer negative angle surface and the second outer negative angle surface are obliquely arranged, the outer straight surface, the first outer negative angle surface and the second outer negative angle surface form a first tooth surface angle Q1, and the range of the first tooth surface angle Q1 is 3-10 degrees; the cutting angle of the external tangent angle surface is set in 45 degrees; the outer guide surface is arranged on the vertical surface of the tooth at a second tooth surface angle Q2, and the range of the second tooth surface angle Q2 is 10-25 degrees; the top surface of the outer teeth is arranged in a horizontal plane.
Preferably, the first pipe sealing surface comprises a first outer arc surface, a second outer arc surface and a third outer arc surface; wherein the arc radius of the first outer arc surface is 90-95 mm; the arc radius of the second outer arc surface is 80-85 mm; the arc radius of the third outer arc surface is 80-85 mm.
Preferably, the second tube body sealing surface comprises a first external taper surface, a second external taper surface and a third external taper surface, wherein the second external taper surface is arranged on the teeth at a fifth tooth surface angle Q5 with the horizontal plane, and the range of the fifth tooth surface angle Q5 is 10-15 degrees; the third external taper surface is arranged at a sixth face angle Q6 with the horizontal plane on the teeth, the sixth face angle Q6 being in the range of 30-45 degrees.
Preferably, two sides of the tooth socket of the internal thread are respectively a negative angle surface and a positive angle surface, and the internal thread is sequentially provided with an external spherical surface sealing section, a first internal negative angle surface, an internal straight surface, a second internal negative angle surface, an internal tangent angle surface, an internal tooth bottom surface, an internal guide surface and an angle tooth surface; wherein the outer spherical surface sealing section, the first inner negative angle surface, the inner straight surface and the second inner negative angle surface are arranged on the negative angle surface; the inner guide surface and the angled tooth surface are disposed on the positive angle surface.
Furthermore, the spherical radius of the sealing section of the outer spherical surface is 0.4-0.45 mm; the first inner negative angle surface and the second inner negative angle surface are obliquely arranged, the inner straight surface, the first inner negative angle surface and the second inner negative angle surface form a first tooth surface angle Q1, and the range of the first tooth surface angle Q1 is 3-10 degrees; the cutting angle of the internal tangent angle surface is set in 45 degrees; the inner guide surface is arranged on the vertical surface of the tooth at a second tooth surface angle Q2, and the range of the second tooth surface angle Q2 is 10-25 degrees; the angled flanks are disposed at a third face angle Q3 on the vertical face of the tooth, the third face angle Q3 being in the range of 30-45 ° with the bottom face of the tooth disposed in the horizontal plane.
Preferably, the interference magnitude of the sealing surface of the first coupling is sequentially increased by a first inner arc surface, a second inner arc surface and a third inner arc surface; wherein the interference range of the first inner arc surface is 0.2-0.3 mm; the interference range of the second inner arc surface is 0.3-0.4 mm; the interference range of the third inner arc surface is 0.4-0.5 mm.
Preferably, the second coupling sealing face comprises a first inner tapered face, a second inner tapered face and a third inner tapered face; the second inner taper surface is arranged on the tooth socket and forms a fifth tooth surface angle Q5 with the horizontal plane, and the range of the fifth tooth surface angle Q5 is 10-15 degrees; the third internal taper is disposed at a sixth face angle Q6 from the horizontal on the gullet, the sixth face angle Q6 ranging from 30 to 45 degrees.
Preferably, the outer shoulder surface is in inclined sealing contact with the inner shoulder surface, wherein the inclined surface and the vertical surface form a fourth face angle Q4 in the range of-10 to-5 °.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention provides a shear-resistant air-tight sealed threaded joint, which can prevent thread tripping under tensile and shear loads by connecting and matching external threads and internal threads on a pipe body and a coupling, and realize the sealing integrity under tensile/compression, internal/external pressure, over-torque and shear loads by the interference contact of a seal and a shoulder upper buckle; the first pipe body sealing surface and the first coupling sealing surface are arranged in an interference sealing mode to form a first sealing mechanism, and the second pipe body sealing surface and the second coupling sealing surface are arranged in a matched contact mode to form a second sealing mechanism; the connection strength and the sealing performance are effectively improved, the thread forms of the external thread and the internal thread are correspondingly provided with inclination angles, the two-stage contact of the upper thread negative angle is realized, and the thread is locked under a shearing load to avoid tripping.
Furthermore, two sides of teeth of the external thread are respectively a negative angle surface and a positive angle surface, and the external thread is sequentially provided with an internal spherical surface sealing section, a first external negative angle surface, an external straight surface, a second external negative angle surface, an external tangent angle surface, an external tooth top surface and an external guide surface; wherein the inner spherical surface sealing section, the first outer negative angle surface, the outer straight surface and the second outer negative angle surface are arranged on the negative angle surface; the outer guide surface is arranged on the positive angle surface, the negative angle surface and the positive angle surface are respectively arranged on two sides of the tooth socket of the internal thread, and the internal thread is sequentially provided with an external spherical surface sealing section, a first internal negative angle surface, an internal straight surface, a second internal negative angle surface, an internal tangent angle surface, an internal tooth bottom surface, an internal guide surface and an angle tooth surface; wherein the outer spherical surface sealing section, the first inner negative angle surface, the inner straight surface and the second inner negative angle surface are arranged on the negative angle surface; the inner guide surface and the angle tooth surface are arranged on the positive angle surface; the sealing performance between the external thread and the internal thread is improved.
Furthermore, the spherical radius of the inner spherical surface sealing section and the spherical radius of the outer spherical surface sealing section are both 0.4-0.45mm, and the effects of thread gluing resistance, reduction of stress concentration of the tooth bottom of the external thread and rotation bending fatigue resistance are achieved through the arc radius difference; the first outer negative angle surface and the second outer negative angle surface are obliquely arranged, the first inner negative angle surface and the second inner negative angle surface are obliquely arranged, the outer straight surface, the first outer negative angle surface, the second outer negative angle surface, the inner straight surface, the first inner negative angle surface and the second inner negative angle surface form a first tooth surface angle Q1 arrangement correspondingly, and the range of the first tooth surface angle Q1 is 3-10 degrees; the cutting angles of the external tangent angle surface and the internal tangent angle surface are both arranged at 45 degrees, so that the two-stage contact of an upper thread negative angle is realized, and the thread is locked under a shearing load to avoid tripping; the outer guide surface is arranged on the vertical surface of the tooth, and the inner guide surface is arranged on the vertical surface of the tooth at a second tooth surface angle Q2, wherein the range of the second tooth surface angle Q2 is 10-25 degrees; the top surface of the outer teeth and the bottom surface of the inner teeth are arranged in a horizontal plane, so that wrong buckling and sticking risks caused by wrong buckling deflection are corrected.
Further, the first pipe sealing surface comprises a first outer arc surface, a second outer arc surface and a third outer arc surface; wherein the arc radius of the first outer arc surface is 90-95 mm; the arc radius of the second outer arc surface is 80-85 mm; the arc radius of the third outer arc surface is 80-85 mm; the interference magnitude of the sealing surface of the first coupling is sequentially increased by a first inner arc surface 27, a second inner arc surface 28 and a third inner arc surface 29; wherein the interference range of the first inner arc surface 27 is 0.2-0.3 mm; the interference range of the second inner arc surface 28 is 0.3-0.4 mm; the interference range of the third inner arc surface 29 is 0.4-0.5 mm; the first pipe body sealing surface and the first coupling sealing surface are matched to form main sealing contact, the problem that the upper buckling seal is matched by one section of taper to be long in sliding contact distance and thread gluing is solved, taper gradients are increased in sequence, and the upper buckling contact area is reduced.
Further, the second tube sealing surface comprises a first outer tapered surface, a second outer tapered surface and a third outer tapered surface, wherein the second outer tapered surface is arranged on the teeth at a fifth tooth surface angle Q5 with the horizontal plane, and the range of the fifth tooth surface angle Q5 is 10-15 degrees; the third external taper surface and the horizontal surface on the tooth form a sixth tooth surface angle Q6, the range of the sixth tooth surface angle Q6 is 30-45 degrees, the second coupling sealing surface comprises a first internal taper surface, a second internal taper surface and a third internal taper surface; the second inner taper surface is arranged on the tooth socket and forms a fifth tooth surface angle Q5 with the horizontal plane, and the range of the fifth tooth surface angle Q5 is 10-15 degrees; the third inner taper surface and the horizontal surface on the tooth socket form a sixth tooth surface angle Q6, the range of the sixth tooth surface angle Q6 is 30-45 degrees, and the buckle-up prevention and the stable sealing are ensured.
Furthermore, the outer shoulder surface is in inclined sealing contact with the inner shoulder surface, wherein the range of a fourth tooth surface angle Q4 formed by the inclined surface and the vertical surface is-10 to-5 degrees, the contact counter force of the shoulder is ensured to increase the main sealing contact pressure of the third inner arc surface, and the uniform contact of the main seal is realized.
Drawings
FIG. 1 is a schematic view of the assembly of the screw joint structure of the present invention;
FIG. 2 is a schematic structural view of the male thread profile of the present invention;
FIG. 3 is a schematic view of the male thread seal and shoulder of the present invention;
FIG. 4 is a schematic view of the internal thread socket of the present invention;
FIG. 5 is a schematic view of the construction of the female thread seal and shoulder of the present invention;
FIG. 6 is a schematic view of the threading of the threaded connection of the present invention;
FIG. 7 is a schematic view of a shear test of the thread according to the present invention.
In the figure: 1-a pipe body; 2-coupling; 3-internal thread; 4-external threads; 5-inner spherical sealing section; 6-a first external negative angle surface; 7-outer straight surface; 8-a second negative outside angle face; 9-external corner surface; 10-top surface of external teeth; 11-outer guide surface; 12-a first extrados face; 13-a second outer arc surface; 14-a third extrados surface; 15-outer shoulder surface; 16-a first external taper surface; 17-a second external taper surface; 18-a third external taper face; 19-an insert sealing section; 20-a first inner negative angle surface; 21-inner straight surface; 22-a second inner negative angle surface; 23-inner tooth top arc surface; 24-the bottom surface of the internal teeth; 25-inner guide surface; 26-angle tooth surface; 27-a first inner arc surface; 28-second inner arc surface; 29-third inner arc surface; 30-inner shoulder surface; 31-a first inner taper surface; 32-a second inner taper surface; 33-a third inner taper surface; 34-a cannula; 35-arrow head; q1-first face angle; q2-second flank angle; q3-third face angle; q4-fourth face angle; q5-fifth face angle; q6-sixth face angle.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
The invention provides a shear-resistant air-tight threaded joint, which comprises a pipe body 1 and a coupling 2 which are connected in a threaded manner, as shown in figures 1 and 6; the pipe body 1 is sequentially provided with an external thread 4, a first pipe body sealing surface, an external shoulder surface 15 and a second pipe body sealing surface from the middle part to the end part; the coupling 2 is sequentially provided with internal threads 3, a first coupling sealing surface, an internal shoulder surface 30 and a second coupling sealing surface from the end part to the middle part; the external thread 4 is in upper-buckling fit connection with the internal thread 3, and a first pipe body sealing surface and a first coupling sealing surface are in interference sealing arrangement; the outer shoulder surface 15 is in inclined sealing contact with the inner shoulder surface 30; the sealing surface of the second pipe body is in matched contact with the sealing surface of the second coupling; the thread tooth forms of the external thread 4 and the internal thread 3 are both correspondingly provided with an inclination angle; the outer shoulder surface 15 is in angular sealing contact with the inner shoulder surface 30, wherein the angular surface and the vertical surface form a fourth tooth surface angle Q4 in the range-5-10 °.
According to the illustration of fig. 2, two sides of the teeth of the external thread 4 are respectively a negative angle surface and a positive angle surface, and the external thread 4 is sequentially provided with an internal spherical surface sealing section 5, a first external negative angle surface 6, an external straight surface 7, a second external negative angle surface 8, an external tangent angle surface 9, an external tooth top surface 10 and an external guide surface 11; wherein the inner spherical sealing section 5, the first outer negative angle surface 6, the outer straight surface 7 and the second outer negative angle surface 8 are arranged on the negative angle surface; the outer guide surface 11 is provided on a positive angle surface.
The spherical radius of the inner spherical sealing section 5 is 0.4-0.45 mm; the first outer negative angle surface 6 and the second outer negative angle surface 8 are obliquely arranged, the outer straight surface 7, the first outer negative angle surface 6 and the second outer negative angle surface 8 form a first tooth surface angle Q1 arrangement, and the range of the first tooth surface angle Q1 is 3-10 degrees; the cutting angle of the external tangent plane 9 is set in 45 degrees; the outer guide surface 11 is arranged at a second flank angle Q2 on the vertical surface of the tooth, the second flank angle Q2 ranging from 10 to 25 °; the external tooth top surface 10 is arranged in a horizontal plane.
Referring to fig. 3, the first tube sealing surface includes a first outer arcuate surface 12, a second outer arcuate surface 13, and a third outer arcuate surface 14; wherein, the arc radius of the first outer arc surface 12 is 90-95 mm; the arc radius of the second outer arc surface 13 is 80-85 mm; the arc radius of the third outer arc surface 14 is 80-85 mm. The second body sealing surface comprises a first external tapered surface 16, a second external tapered surface 17 and a third external tapered surface 18, wherein the second external tapered surface 17 is disposed at a fifth face angle Q5 with respect to the horizontal plane on the teeth, and the range of the fifth face angle Q5 is 10-15 degrees; the third external taper surface 18 is disposed at a sixth face angle Q6 from the horizontal on the tooth, the sixth face angle Q6 ranging from 30 to 45 °.
According to the illustration of fig. 4, the two sides of the tooth space of the internal thread 3 are respectively a negative angle surface and a positive angle surface, and the internal thread 3 is sequentially provided with an external spherical surface sealing section 19, a first internal negative angle surface 20, an internal straight surface 21, a second internal negative angle surface 22, an internal tangent angle surface 23, an internal tooth bottom surface 24, an internal guide surface 25 and an angle tooth surface 26; wherein the outer spherical surface sealing section 19, the first inner negative angle surface 20, the inner straight surface 21 and the second inner negative angle surface 22 are arranged on the negative angle surface; the inner guide surface 25 and the angled tooth surface 26 are provided on a positive angle surface.
The spherical radius of the outer spherical surface sealing section 19 is 0.4-0.45 mm; the first inner negative angle surface 20 and the second inner negative angle surface 22 are obliquely arranged, the inner straight surface 21, the first inner negative angle surface 20 and the second inner negative angle surface 22 form a first tooth surface angle Q1, and the range of the first tooth surface angle Q1 is 3-10 degrees; the cutting angle of the internal tangent plane 23 is set at 45 degrees; the inner guide surface 25 is arranged at a second flank angle Q2 on the vertical plane of the tooth, the second flank angle Q2 ranging from 10 to 25 °; angled tooth face 26 is disposed at a third face angle Q3 on the vertical face of the tooth, the third face angle Q3 being in the range of 30-45 ° with the tooth bottom face 24 disposed in the horizontal plane.
According to FIG. 5, the interference of the first coupling sealing surface is sequentially increased by a first inner arc surface 27, a second inner arc surface 28 and a third inner arc surface 29; wherein the interference range of the first inner arc surface 27 is 0.2-0.3 mm; the interference range of the second inner arc surface 28 is 0.3-0.4 mm; the interference range of the third inner cambered surface 29 is 0.4-0.5mm, and the second coupling sealing surface comprises a first inner tapered surface 31, a second inner tapered surface 32 and a third inner tapered surface 33; the second inner taper surface 32 is arranged on the tooth socket and forms a fifth tooth surface angle Q5 with the horizontal plane, and the range of the fifth tooth surface angle Q5 is 10-15 degrees; the third internal taper 33 is disposed at a sixth face angle Q6 from the horizontal on the gullet, the sixth face angle Q6 ranging from 30 to 45 degrees.
According to the invention, the external thread 4 and the internal thread 3 are matched through the upper buckle, so that the thread is prevented from being released under tensile and shearing loads. The seal and the shoulder are in buckled interference contact to realize the seal integrity under the conditions of tension/compression, internal pressure/external pressure, over torque and shear load.
The tooth form of the external thread 4 is matched with the internal thread 3, and the bearing surface adopts an internal spherical surface sealing section 5, a first external negative angle surface 6, an external straight surface 7, a second external negative angle surface 8 and an external tangent angle surface 9; the top surface 10 of the outer teeth adopts a parallel pipe axis; the outer guide surface 11 of the external thread 4 is arranged at a second flank angle Q2 on the vertical surface of the tooth, the second flank angle Q2 being in the range of 10-25 °; the internal thread guide surface adopts two sections of positive angle surfaces, the internal guide surface 25 is arranged on the vertical surface of the tooth in a second tooth surface angle Q2, and the range of the second tooth surface angle Q2 is 10-25 degrees; angled tooth face 26 is disposed at a third face angle Q3 on the vertical face of the tooth, the third face angle Q3 being in the range of 30-45 ° with the tooth bottom face 24 disposed in the horizontal plane.
The spherical radius of the thread bearing inner spherical sealing section 5 is 0.4-0.45mm, the spherical radius of the outer spherical sealing section 19 is 0.4-0.45mm, and the effects of thread gluing resistance, reduction of stress concentration of the tooth bottom of the external thread and anti-rotation bending fatigue are achieved through the arc radius difference; the outer straight surface 7, the first outer negative angle surface 6 and the second outer negative angle surface 8 form a first face angle Q1 arrangement, the range of the first face angle Q1 is 3-10 degrees, and the height is 0.25-0.356 of the tooth height; the outer straight surface 7 is 0.2-0.23 of the tooth height; the cutting angle of the external tangent plane 9 is 45 degrees and the width is 0.3-0.4 mm; the thread locking device is matched with an external spherical surface sealing section 19 of an internal thread bearing surface, a first internal negative angle surface 20, an internal straight surface 21, a second internal negative angle surface 22 and an internal tangent angle surface 23 to realize double-stage contact of an upper-buckling negative angle, and the thread is locked under a shearing load to avoid tripping; the straight surface transition outer straight surface 7 and the inner straight surface 21 enable the thread to be easily processed, change the stress distribution of the thread to offset the stress of a negative angle acting on the tooth bottom, and have good anti-fatigue effect; the external tangent angle surface 9 is in matched contact with the internal tangent angle surface 23, so that the stress concentration of a tooth root circular arc is reduced, the width of an external thread tooth top is reduced, and the upper thread is easy to be buckled.
The external tooth top surface 10 and the internal tooth bottom surface 24 are matched in a buckling mode, the automatic deviation adjustment is carried out in the buckling process of the parallel axis cylindrical surface, and the wrong buckling and gluing risks caused by buckling deviation are corrected.
The outer guide surface 11 is matched with the inner guide surface 25 and the angle tooth surface 26, the tooth crest width of the external thread is smaller than the tooth trough width of the internal thread, the opposite buckling is convenient, and the upper buckle is easy to screw in; the height of the angle tooth surface 26 is 2/5-3/5 of the tooth height, so that the inner guide surface 25 has enough contact area under the compression of the thread, and the purpose of compression resistance is achieved.
The external thread sealing surface consists of three sections of arc surfaces, and each section of arc surface is matched with different internal thread conical surfaces. The first outer arc surface 12, the second outer arc surface 13 and the third outer arc surface 14 are respectively matched with the first inner arc surface 27, the second inner arc surface 28 and the third inner arc surface 29 to form main sealing contact; wherein, the taper 1/8 of the first inner arc surface 27; the taper 1/5 of the second inner arcuate surface 28; the taper 1/2 of the third inner arc surface 29 reaches the taper gradient which increases in sequence and reduces the contact area of the upper buckle because a section of taper is adopted to match the long sliding contact distance of the upper buckle seal and the thread gluing; under tensile load, the first inner arc surface 27 is not easy to generate sealing contact, change and separate, and the sealing integrity under tension is ensured; 1/3 the length of each of the three segments of the seal is the total length of the seal; the third-stage sealing interference magnitude is gradually increased; the upper buckle is ensured not to be adhered and the sealing is stable; the outer shoulder surface 15 is in inclined sealing contact with the inner shoulder surface 30, a fourth tooth surface angle Q4 formed by the inclined surface and the vertical surface ranges from-10 to-5 degrees, the contact counter force of the shoulder is ensured to increase the main sealing contact pressure of the third inner arc surface 29, and uniform contact of the main seal is realized.
The shoulder clamping groove is formed by three sections of tapers, namely a first external taper surface 16, a second external taper surface 17 and a third external taper surface 18 which are matched with a first internal taper surface 31, a second internal taper surface 32 and a third internal taper surface 33; the cylindrical surface of the first external tapered surface 16 has the maximum thickness, and the external thread 4 is sealed without separation contact under a shearing load; the second inner taper surface 32 is arranged on the tooth socket and forms a fifth tooth surface angle Q5 with the horizontal plane, the range of the fifth tooth surface angle Q5 is 10-15 degrees, the third inner taper surface 33 is arranged on the tooth socket and forms a sixth tooth surface angle Q6 with the horizontal plane, the range of the sixth tooth surface angle Q6 is 30-45 degrees, the upper buckle sealing is realized, the buckling, the screwing in and the processing are easy, the third inner taper surface 33 is matched with the third outer taper surface 18 to realize a secondary shoulder, and the sealing deformation is resisted under the condition that the torque and the compression load are buckled; and the deformation of the external thread sealing surface is prevented from contacting and separating with the internal thread seal under the shearing load. The thread anti-shear load deformation and sealing are realized through the structural cooperation of the thread tooth form, the sealing structure, the shoulder and the clamping groove.
Examples
The special sealing threaded joint sleeves of different specifications can be selected according to the requirements of specific working conditions. And (5) machining by adopting a numerical control machine tool. The coupling and the pipe body are of the same steel grade or one higher steel grade, and the phosphating thickness of the internal thread is 15-25 mu m. And when the coupling is buckled, API thread grease is uniformly coated at two ends to clamp the middle part of the coupling, the factory end adopts maximum torque to buckle, and the field end adopts optimal torque to buckle.
For a commonly used 139.7 × 12.7mm standard sleeve steel grade Q125 material for shale gas, as shown in FIG. 7, a threaded joint of the invention is sleeved on a sleeve 34 and subjected to an internal pressure gas sealing test through a shear 35, and through the design of a thread structure, the tooth height is 1.7mm, the negative angle of a bearing surface is 10 degrees, and the positive angle of a guide surface angle is 15 degrees; the sealing taper is set according to the principle, the three-section taper is 1/8, 1/5 and 1/2, the shoulder angle is 10 degrees, the sealing length is 13mm, the height of the clamping groove is 11mm, the thickness of the first inner taper surface 31 of the clamping groove is 2.5mm, the thread upper buckle assembly of the specification is shown in figure 6, the main sealing third outer arc surface 14 and the third inner arc surface 29 are buckled up and then sealed to have the maximum interference, and the first outer arc surface 12 and the second outer arc surface 13 have the minimum interference with the first inner arc surface 27 and the second inner arc surface 28; the outer shoulder surface 15 and the inner shoulder surface 30 are in interference fit; the inner spherical surface sealing section 5 of the thread bearing surface is locked with the first outer negative angle surface 6 in an upper buckling way; the external tooth top surface 10 and the internal tooth bottom surface 24 are in contact with each other to be subjected to interference offset adjustment.
Claims (10)
1. The anti-shearing airtight threaded joint is characterized by comprising a pipe body (1) and a coupling (2) which are in threaded connection; the pipe body (1) is sequentially provided with an external thread (4), a first pipe body sealing surface, an external shoulder surface (15) and a second pipe body sealing surface from the middle part to the end part; the coupling (2) is sequentially provided with internal threads (3), a first coupling sealing surface, an internal shoulder surface (30) and a second coupling sealing surface from the end part to the middle part; the external thread (4) is connected with the internal thread (3) in a buckling fit manner, and the first pipe body sealing surface and the first coupling sealing surface are arranged in an interference sealing manner; the outer shoulder surface (15) is in inclined sealing contact with the inner shoulder surface (30); the sealing surface of the second pipe body is in matched contact with the sealing surface of the second coupling; and the thread tooth forms of the external thread (4) and the internal thread (3) are correspondingly provided with inclination angles.
2. The shear-resistant hermetic seal threaded joint according to claim 1, wherein the two sides of the teeth of the external thread (4) are respectively a negative angle surface and a positive angle surface, and the external thread (4) is sequentially provided with an internal spherical surface sealing section (5), a first external negative angle surface (6), an external straight surface (7), a second external negative angle surface (8), an external tangent angle surface (9), an external tooth top surface (10) and an external guide surface (11); wherein the inner spherical surface sealing section (5), the first outer negative angle surface (6), the outer straight surface (7) and the second outer negative angle surface (8) are arranged on the negative angle surface; the outer guide surface (11) is arranged on a positive angle surface.
3. A shear resistant hermetic threaded joint according to claim 2, characterized in that the spherical radius of said internal spherical sealing segment (5) is comprised between 0.4 and 0.45 mm; the first outer negative angle surface (6) and the second outer negative angle surface (8) are obliquely arranged, the outer straight surface (7), the first outer negative angle surface (6) and the second outer negative angle surface (8) form a first tooth surface angle Q1, and the range of the first tooth surface angle Q1 is 3-10 degrees; the cutting angle of the external tangent angle surface (9) is set in 45 degrees; the outer guide surface (11) is arranged on the vertical surface of the tooth at a second tooth surface angle Q2, and the range of the second tooth surface angle Q2 is 10-25 degrees; the top surface (10) of the outer teeth is arranged in a horizontal plane.
4. A shear resistant hermetic threaded joint as claimed in claim 1, wherein the first body sealing surface comprises a first external arc surface (12), a second external arc surface (13) and a third external arc surface (14); wherein the arc radius of the first outer arc surface (12) is 90-95 mm; the arc radius of the second outer arc surface (13) is 80-85 mm; the arc radius of the third outer arc surface (14) is 80-85 mm.
5. A shear resistant threaded joint according to claim 1 wherein the second body sealing surface comprises a first external tapered surface (16), a second external tapered surface (17) and a third external tapered surface (18), wherein the second external tapered surface (17) is disposed at a fifth face angle Q5 from the horizontal on the teeth, the fifth face angle Q5 being in the range 10 ° to 15 °; the third external taper surface (18) is arranged at a sixth face angle Q6 with the horizontal plane on the tooth, and the range of the sixth face angle Q6 is 30-45 degrees.
6. The shear resistant hermetic seal threaded joint according to claim 1, wherein the two sides of the tooth space of the internal thread (3) are respectively a negative angle surface and a positive angle surface, and the internal thread (3) is sequentially provided with an external spherical surface sealing section (19), a first internal negative angle surface (20), an internal straight surface (21), a second internal negative angle surface (22), an internal tangent angle surface (23), an internal tooth bottom surface (24), an internal guide surface (25) and an angle tooth surface (26); wherein the outer spherical surface sealing section (19), the first inner negative angle surface (20), the inner straight surface (21) and the second inner negative angle surface (22) are arranged on the negative angle surface; the inner guide surface (25) and the angled tooth surface (26) are arranged on a positive angle surface.
7. A shear resistant hermetic threaded joint as claimed in claim 7, characterized in that the spherical radius of said insert sealing section (19) is comprised between 0.4 and 0.45 mm; the first inner negative angle surface (20) and the second inner negative angle surface (22) are obliquely arranged, the inner straight surface (21), the first inner negative angle surface (20) and the second inner negative angle surface (22) form a first tooth surface angle Q1, and the range of the first tooth surface angle Q1 is 3-10 degrees; the cutting angle of the internal tangent angle surface (23) is set in 45 degrees; the inner guide surface (25) is arranged on the vertical surface of the tooth at a second tooth surface angle Q2, and the range of the second tooth surface angle Q2 is 10-25 degrees; the angled tooth flanks (26) are arranged in a third flank angle Q3 on the vertical plane of the tooth, the third flank angle Q3 being in the range of 30-45 DEG with the bottom flank (24) being arranged in a horizontal plane.
8. A shear resistant and gas tight threaded joint according to claim 1, wherein the interference of the sealing surface of the first coupling is sequentially increasing by a first internal arc surface (27), a second internal arc surface (28) and a third internal arc surface (29); wherein the interference range of the first inner arc surface (27) is 0.2-0.3 mm; the interference range of the second inner arc surface (28) is 0.3-0.4 mm; the interference range of the third inner arc surface (29) is 0.4-0.5 mm.
9. A shear resistant gas tight threaded joint according to claim 1, wherein the second collar sealing face comprises a first internal tapered face (31), a second internal tapered face (32) and a third internal tapered face (33); the second inner taper surface (32) is arranged on the tooth socket and forms a fifth tooth surface angle Q5 with the horizontal plane, and the range of the fifth tooth surface angle Q5 is 10-15 degrees; the third internal taper surface (33) is arranged at a sixth face angle Q6 with the horizontal plane on the tooth socket, and the range of the sixth face angle Q6 is 30-45 degrees.
10. A shear resistant hermetic threaded joint as claimed in claim 1, characterized in that said external shoulder surface (15) is in inclined sealing contact with the internal shoulder surface (30), wherein the inclined surface and the vertical surface form a fourth face angle Q4 in the range-10 to-5 °.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110010598.2A CN112761539B (en) | 2021-01-05 | 2021-01-05 | Anti-shearing airtight threaded joint |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110010598.2A CN112761539B (en) | 2021-01-05 | 2021-01-05 | Anti-shearing airtight threaded joint |
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| CN112761539A true CN112761539A (en) | 2021-05-07 |
| CN112761539B CN112761539B (en) | 2023-01-10 |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1355876A (en) * | 1999-04-23 | 2002-06-26 | 约翰·甘迪公司 | Thread form with multifaceted flanks |
| CN201574696U (en) * | 2009-12-10 | 2010-09-08 | 天津钢管集团股份有限公司 | Large-caliber fast screwing-up sleeve thread connecting structure |
| CN101899953A (en) * | 2010-08-16 | 2010-12-01 | 天津钢管集团股份有限公司 | Thread joint structure for high-performance oil casing |
| CN202165022U (en) * | 2011-04-08 | 2012-03-14 | 无锡西姆莱斯石油专用管制造有限公司 | Anti-bending oil tube threaded connection structure |
| CN105927167A (en) * | 2016-06-21 | 2016-09-07 | 西南石油大学 | Special-thread gas seal oil sleeve joint for ultra-deep wells |
| CN207647476U (en) * | 2017-11-14 | 2018-07-24 | 天津钢管集团股份有限公司 | Double-sealing face Special threading connector |
| CN108952594A (en) * | 2018-06-01 | 2018-12-07 | 江苏常宝钢管股份有限公司 | A kind of low stress screw connection structure |
| CN110476000A (en) * | 2017-03-31 | 2019-11-19 | 日本制铁株式会社 | Threaded joints for steel pipes |
-
2021
- 2021-01-05 CN CN202110010598.2A patent/CN112761539B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1355876A (en) * | 1999-04-23 | 2002-06-26 | 约翰·甘迪公司 | Thread form with multifaceted flanks |
| CN201574696U (en) * | 2009-12-10 | 2010-09-08 | 天津钢管集团股份有限公司 | Large-caliber fast screwing-up sleeve thread connecting structure |
| CN101899953A (en) * | 2010-08-16 | 2010-12-01 | 天津钢管集团股份有限公司 | Thread joint structure for high-performance oil casing |
| CN202165022U (en) * | 2011-04-08 | 2012-03-14 | 无锡西姆莱斯石油专用管制造有限公司 | Anti-bending oil tube threaded connection structure |
| CN105927167A (en) * | 2016-06-21 | 2016-09-07 | 西南石油大学 | Special-thread gas seal oil sleeve joint for ultra-deep wells |
| CN110476000A (en) * | 2017-03-31 | 2019-11-19 | 日本制铁株式会社 | Threaded joints for steel pipes |
| US20200025315A1 (en) * | 2017-03-31 | 2020-01-23 | Nippon Steel Corporation | Threaded Connection for Steel Pipe |
| CN207647476U (en) * | 2017-11-14 | 2018-07-24 | 天津钢管集团股份有限公司 | Double-sealing face Special threading connector |
| CN108952594A (en) * | 2018-06-01 | 2018-12-07 | 江苏常宝钢管股份有限公司 | A kind of low stress screw connection structure |
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| CN112761539B (en) | 2023-01-10 |
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