CN217106864U

CN217106864U - Oil casing joint and oil casing assembly

Info

Publication number: CN217106864U
Application number: CN202121431236.2U
Authority: CN
Inventors: 李小兵; 胡志立; 李建亮; 田研; 吴丹; 黄电源; 张垂贵; 付强; 李健; 胡新太; 冉雪辉
Original assignee: Hengyang Valin Steel Tube Co Ltd
Current assignee: Hengyang Valin Steel Tube Co Ltd
Priority date: 2021-06-25
Filing date: 2021-06-25
Publication date: 2022-08-02
Anticipated expiration: 2031-06-25

Abstract

The utility model provides an oil casing connects and oil casing subassembly. The oil casing joint includes: an externally threaded nipple; the internal thread joint is in threaded connection with the external thread joint; the sealing structure comprises a first sealing conical surface and a second sealing conical surface which is in sealing fit with part of the first sealing conical surface, the first sealing conical surface is arranged on the partial outer wall surface of the external thread joint, and the second sealing conical surface is arranged on the partial inner wall surface of the internal thread joint. The technical scheme of the utility model in, oil casing joint has excellent sealed robust performance and compressive resistance under the combined load effect.

Description

Oil casing joint and oil casing assembly

Technical Field

The utility model relates to a petroleum pipe engineering technical field particularly, relates to an oil casing joint and oil sleeve subassembly.

Background

With the development environment of oil and gas fields becoming more complex, more strict requirements are put forward on the sealing performance of the threaded joint of the oil casing, namely the threaded joint still has excellent sealing robustness and excellent compression performance under various complex and severe working conditions such as stretching, compression, internal pressure, external pressure, bending and the like and accidental external factors. The standard API threaded oil casing has the problems of low connection strength of a threaded joint, poor composite load resistance, no air tightness and the like due to the design defects of the standard API threaded oil casing, cannot be qualified in harsh well conditions, and is mainly used for well conditions with low working condition requirements such as shallow wells, low-pressure wells and the like.

In the oil casing joint known by the inventor, the sealing structure of the oil casing joint is close to the shoulder, the sealing performance of the oil casing joint is seriously influenced by the stress state of the positioning shoulder, the stability of the sealing performance is not high, and in order to achieve 100% compression performance of the oil casing joint, a pipe end necking process is often needed, so that the production and processing cost is high.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide an oil casing joint and oil casing assembly, which has excellent sealing robustness and compression resistance under the action of a composite load.

In order to achieve the above object, according to an aspect of the present invention, there is provided an oil casing joint, comprising: an externally threaded nipple; the internal thread joint is in threaded connection with the external thread joint; the sealing structure comprises a first sealing conical surface and a second sealing conical surface which is in sealing fit with part of the first sealing conical surface, the first sealing conical surface is arranged on the partial outer wall surface of the external thread joint, and the second sealing conical surface is arranged on the partial inner wall surface of the internal thread joint.

Further, the seal structure further includes: first arc R ₁₀ The outer threaded joint is arranged on part of the outer wall surface of the outer threaded joint; second arc R ₂₀ (ii) a Third arc R ₂₁ Second circular arc R ₂₀ And a third arc R ₂₁ Are all arranged on part of the inner wall surface of the internal thread joint; from the thread structure to the direction of the shoulder structure, a first circular arc R ₁₀ Connected with the first sealing conical surface in sequence, and the second arc R ₂₀ A second sealing conical surface and a third circular arc R ₂₁ Are connected in sequence; wherein, from the direction of helicitic texture to circular bead structure, first sealed conical surface and second sealed conical surface all are close to the axis of oil casing coupling gradually, and have contained angle alpha between the axis of first sealed conical surface and oil casing coupling ₁ The second sealing conical surface and the axis of the oil sleeve joint form an included angle beta ₁ 。

Further, the first groove comprises a first cylindrical surface arranged on part of the outer wall surface of the external threaded joint, and the first cylindrical surface and the first circular arc R are arranged in the direction from the threaded structure to the shoulder structure ₁₀ The first sealing conical surface is connected with the second sealing conical surface in sequence; the distance between one end of the first cylindrical surface far away from the first sealing conical surface and the shoulder structure along the axial direction of the oil sleeve joint is L ₁₀ The length of the first sealing conical surface is L ₁₁ The distance between the center of the second sealing conical surface and the shoulder structure is L ₂₀ The length of the second sealing conical surface is L ₂₁ (ii) a Wherein L is more than or equal to 10mm ₁₀ ≤20mm，0.7≤L ₁₁ /L ₁₀ ≤0.9，0.6≤L ₂₀ /L ₁₀ ≤0.8，2mm≤L ₂₁ ≤4mm。

Further, alpha is more than or equal to 4.10 degrees ₁ ≤9.90°，0°≤β ₁ -α ₁ Not more than 0.5 degrees and a first circular arc R ₁₀ ≥10mm。

Further, by the direction of helicitic texture to circular bead structure, be equipped with interior screw thread section, second sealed conical surface and interior circular bead face on female adapter's the internal face in proper order, first recess is including setting up the first face of cylinder on the partial outer wall of external screw joint and setting up the groove structure on the partial internal face of internal screw joint, and groove structure is located between interior screw thread section and the second sealed conical surface, and groove structure and the first face of cylinder cooperation form first recess.

Furtherly, by the helicitic texture to the direction of circular bead structure, be equipped with the sealed conical surface of second and interior circular bead face on female adapter's the internal face in proper order, the second recess includes: the groove surface is arranged on part of the inner wall surface of the internal thread joint and is positioned between the second sealing conical surface and the internal shoulder surface; fourth arc R ₂₂ A part of the inner wall surface of the female screw joint, the groove surface passing through a fourth arc R ₂₂ Is connected with the inner shoulder surface; wherein, the groove surface and the fourth arc R ₂₂ And part of the inner shoulder surface and part of the first sealing conical surface jointly form a second groove.

Further, the groove face includes: one end of the second cylindrical surface is connected with the second sealing conical surface, and the other end of the second cylindrical surface is connected with the fourth arc R ₂₂ Connecting; or the first outer inclined plane and the second cylindrical surface are in the direction from the thread structure to the shoulder structure, and the second sealing conical surface, the first outer inclined plane, the second cylindrical surface and the fourth circular arc R are ₂₂ Are connected in sequence, the first outer inclined plane is gradually far away from the axis of the oil casing joint, and an included angle beta is formed between the first outer inclined plane and the axis of the oil casing joint ₂ Wherein, beta is more than or equal to 0 degree ₂ ≤15°。

Further, the second groove includes a female screw jointA second cylindrical surface on a portion of the inner wall surface, the shoulder structure comprising: an outer shoulder surface arranged on the end surface of the outer thread joint and connected with the first sealing conical surface, and an included angle alpha is formed between the outer shoulder surface and the vertical direction ₂ (ii) a An inner shoulder surface arranged on part of the inner wall surface of the inner threaded joint and connected with the second cylindrical surface, and an included angle beta is formed between the inner shoulder surface and the vertical direction ₃ (ii) a Wherein, the outer shoulder surface is in interference fit with the inner shoulder surface.

Furthermore, the outer shoulder surface is an outer inclined surface, the inner shoulder surface is an outer inclined surface, and the outer shoulder surface and the inner shoulder surface are both gradually far away from the axis of the oil sleeve joint from the direction of the thread structure to the shoulder structure; or, outer shoulder surface includes a plurality of second outer inclined planes that connect gradually, and interior shoulder surface includes a plurality of third outer inclined planes that correspond the setting with a plurality of second outer inclined planes, by the direction of helicitic texture to shoulder structure, the axis of oil casing coupling is all kept away from gradually on a plurality of second outer inclined planes and a plurality of third outer inclined planes, and the contained angle between the axis of two adjacent second outer inclined planes and oil casing coupling is different, and the contained angle between the axis of two adjacent third outer inclined planes and oil casing coupling is different.

Further, alpha is less than or equal to 5 degrees ₂ ≤15°，0°≤β ₃ -α ₂ ≤1°。

Furthermore, the external thread joint is provided with a fourth external inclined surface, the fourth external inclined surface is arranged on part of the inner wall surface of the external thread joint, the fourth external inclined surface is gradually far away from the axis of the oil sleeve joint and is connected with the external shoulder surface from the direction of the thread structure to the shoulder structure, and an included angle alpha is formed between the fourth external inclined surface and the axis of the oil sleeve joint ₄ Wherein, alpha is more than or equal to 6 degrees ₄ ≤20°。

Furthermore, the external thread joint is also provided with an inner hole surface which is connected with the fourth outer inclined surface and the outer shoulder surface, the inner hole surface is arranged on part of the inner wall surface of the external thread joint and is positioned between the fourth outer inclined surface and the outer shoulder surface, and the length of the inner hole surface is L along the axial direction of the oil casing joint ₁₂ 。

Further, the inner hole surface is a cylindrical surface.

Furthermore, the inner hole surface is an inner inclined surface and is inclined towards the platform from a thread structureThe direction of the shoulder structure is that the inner hole surface is gradually close to the axis of the oil sleeve joint, and an included angle alpha is formed between the inner hole surface and the axis of the oil sleeve joint ₃ Wherein, alpha is more than or equal to 0 degree ₃ ≤10°。

Further, L is more than or equal to 0mm ₁₂ ≤7mm。

According to another aspect of the present invention, there is provided an oil casing assembly, comprising an oil casing and an oil casing joint connected to the oil casing, wherein the oil casing joint is the above-mentioned oil casing joint.

By applying the technical scheme of the utility model, the threaded connection between the external thread joint and the internal thread joint is realized through the thread structure; the second sealing conical surface is in sealing fit with part of the first sealing conical surface to realize sealing, and the second sealing conical surface and the first sealing conical surface are conical surfaces, so that the sealing contact pressure of the sealing structure of the oil sleeve joint is uniformly distributed, the sealing structure has an excellent sealing distribution state, and effective sealing can be realized. Be equipped with the second recess between seal structure and the circular bead structure, make seal structure keep away from the circular bead structure, this greatly reduced the sealing performance of oil casing coupling receive the influence of shoulder stress state, improved the robustness of sealing performance, improved the resistance to compression performance and the anti torsion performance of oil casing coupling simultaneously.

Drawings

The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic structural view of a first embodiment of an oil casing joint according to the present invention;

FIG. 2 shows a schematic view of the male connection of the oil casing joint of FIG. 1;

FIG. 3 shows a schematic view of the female connection of the oil casing joint of FIG. 1;

FIG. 4 shows an enlarged partial view of the pin joint of FIG. 2;

FIG. 5 shows a partial enlarged view of the female fitting of FIG. 3;

fig. 6 shows a partially enlarged view of the female joint according to the second embodiment of the oil casing joint of the present invention;

fig. 7 shows a partially enlarged view of the male screw joint according to the third embodiment of the oil casing joint of the present invention;

fig. 8 is a partially enlarged view of a female joint according to a third embodiment of the oil casing joint according to the present invention;

fig. 9 shows a partially enlarged view of the male screw joint according to the fourth embodiment of the oil casing joint according to the present invention;

fig. 10 shows a partial enlarged view of the male screw joint according to embodiment five of the oil casing joint of the present invention.

Wherein the figures include the following reference numerals:

1. an externally threaded nipple; 11. a first sealing cone; 12. an outer shoulder surface; 121. a second outer bevel; 13. an inner bore surface; 14. a fourth outer slope; 2. an internal thread joint; 21. a second sealing cone; 22. a first outer slope; 23. a second cylindrical surface; 24. an inner shoulder surface; 241. a third outer slope; 10. a first cylindrical surface; 20. a groove structure; 30. a thread structure; 31. an internal thread section; 32. an external threaded section; 40. a first groove; 50. a sealing structure; 60. a second groove; 70. a shoulder structure.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present application, where the contrary is not intended, the use of directional words such as "upper, lower, top and bottom" is generally with respect to the orientation shown in the drawings, or with respect to the component itself in the vertical, perpendicular or gravitational direction; likewise, for ease of understanding and description, "inner and outer" refer to the inner and outer relative to the profile of the components themselves, but the above directional words are not intended to limit the invention.

In the correlation technique, the sealing effect of the seal structure of the oil casing joint that is formed by the cooperation of the arc surface and the cylindrical surface is relatively poor, consequently, in order to solve the above-mentioned problem, the utility model discloses reach the embodiment of the utility model provides an oil casing joint and oil casing assembly.

Example one

As shown in fig. 1 to 5, in the embodiment of the present invention, the oil casing joint includes an external thread joint 1 and an internal thread joint 2, and the internal thread joint 2 is in threaded connection with the external thread joint 1; the thread structure 30, the first groove 40, the sealing structure 50, the second groove 60 and the shoulder structure 70 are sequentially arranged between the male adapter 1 and the female adapter 2 along a direction parallel to the axis of the oil casing joint, the sealing structure 50 comprises a first sealing conical surface 11 and a second sealing conical surface 21 in sealing fit with part of the first sealing conical surface 11, the first sealing conical surface 11 is arranged on part of the outer wall surface of the male adapter 1, and the second sealing conical surface 21 is arranged on part of the inner wall surface of the female adapter 2.

In the above arrangement, the threaded connection between the male adapter 1 and the female adapter 2 is realized by the thread structure 30; the second sealing conical surface 21 is in sealing fit with part of the first sealing conical surface 11 to realize sealing, and the second sealing conical surface 21 and the first sealing conical surface 11 are conical surfaces, so that the sealing contact pressure of the sealing structure 50 of the oil sleeve joint is uniformly distributed, the sealing structure 50 has an excellent sealing distribution state, and effective sealing can be realized. And a second groove 60 is arranged between the sealing structure 50 and the shoulder structure 70, so that the sealing structure 50 is far away from the shoulder structure 70, the influence of the shoulder stress state on the sealing performance of the oil casing joint is greatly reduced, the robustness of the sealing performance is improved, and the compression resistance and the over-twisting resistance of the oil casing joint are improved.

In addition, the first groove 40 serves to store an excessive amount of thread grease, thereby avoiding the influence of thread grease pressure on the sealing performance. The second groove 60 serves to store an excessive amount of thread compound, thereby preventing the influence of the thread compound pressure on the sealing performance.

As shown in fig. 4 and 5, in the embodiment of the present invention, the sealing structure 50 further includes a first arc R ₁₀ The second arc R ₂₀ And a third arc R ₂₁ First arc of a circle R ₁₀ Is arranged on part of the outer wall surface of the external threaded joint 1; second arc R ₂₀ And a third arc R ₂₁ Are all arranged on part of the inner wall surface of the internal thread joint 2; a first arc R from the thread formation 30 in the direction of the shoulder formation 70 ₁₀ Connected with the first sealing conical surface 11 in sequence and provided with a second circular arc R ₂₀ A second sealing conical surface 21 and a third circular arc R ₂₁ Are connected in sequence; wherein, from the direction of the thread structure 30 to the shoulder structure 70, the first sealing conical surface 11 and the second sealing conical surface 21 both gradually approach the axis of the oil casing joint, and an included angle α is formed between the first sealing conical surface 11 and the axis of the oil casing joint ₁ The second sealing conical surface 21 forms an included angle beta with the axis of the oil sleeve joint ₁ 。

In the above arrangement, the first circular arc R provided on the male coupling 1 ₁₀ A first sealing conical surface 11 and a second circular arc R arranged on the internal thread joint 2 ₂₀ A second sealing conical surface 21 and a third circular arc R ₂₁ Together, form the actual sealing contact of the oil bushing joint, so that a better sealing action can be achieved.

This actual sealing contact position is not the conventional shoulder that closes on, but keeps away from the shoulder position, and this greatly reduced the sealing performance of oil casing coupling receive the influence of shoulder stress state, improved the robustness of sealing performance, improved the resistance to compression performance and the anti torsional properties of oil casing coupling simultaneously.

As shown in fig. 4 and 5, in the embodiment of the present invention, the first groove 40 includes a first cylindrical surface 10 disposed on a part of the outer wall surface of the external thread joint 1, the first cylindrical surface 10 and the first circular arc R are arranged in the direction from the thread structure 30 to the shoulder structure 70 ₁₀ Is connected with the first sealing conical surface 11 in sequence; the distance between the end of the first cylindrical surface 10 far from the first sealing conical surface 11 and the shoulder structure 70 along the axial direction of the oil casing joint is L ₁₀ The length of the first sealing cone 11 is L ₁₁ The distance between the center of the second sealing cone 21 and the shoulder structure 70 is L ₂₀ The length of the second sealing cone 21 is L ₂₁ (ii) a Wherein L is more than or equal to 10mm ₁₀ ≤20mm，0.7≤L ₁₁ /L ₁₀ ≤0.9，0.6≤L ₂₀ /L ₁₀ ≤0.8，2mm≤L ₂₁ ≤4mm。

The inventor knows a technical scheme named as 'an air-tight oil sleeve joint', the technical scheme is that threads are of a buttress structure, tooth tops and tooth bottoms are parallel to thread buses, a first positioning shoulder and a first sealing surface are designed at an external thread joint end, a corresponding second positioning shoulder and a second sealing surface are designed at an internal thread joint, the first sealing surface and the second sealing surface are conical surfaces with inclination angles beta, tan beta is more than or equal to 0.1 and less than or equal to 1.8, the traditional structure is better in processing detection performance and excellent in sealing performance, but the sealing structure is easy to accidentally damage during transportation or other operations, the sealing structure is close to the positioning shoulder, the sealing performance of the sealing structure is seriously influenced by the stress state of the positioning shoulder, and the stability of the sealing performance is not high.

The inventor knows a technical scheme of an oil casing threaded joint, the thread of the technical scheme is an improved buttress structure, a sealing structure adopts a structure that an outer sealing surface is a cylindrical surface and an inner sealing surface is a spherical surface, the sealing structure is difficult to produce, process and detect, and the sealing structure is easy to damage accidentally.

The embodiment of the utility model provides an in, based on the difference of oil casing screwed joint specification, the nose length L of external screwed joint 1 ₁₀ The following formula is satisfied: l is more than or equal to 10mm ₁₀ Less than or equal to 20 mm. The length L of the first sealing taper 11 of the male adapter 1 ₁₁ And length L of nose end ₁₀ The ratio range of (A) is: l is more than or equal to 0.7 ₁₁ /L ₁₀ Less than or equal to 0.9. The length L of the second sealing taper 21 of the female adapter 2 ₂₁ The range of (A) is as follows: l is not less than 2mm ₂₁ Less than or equal to 4 mm. Distance L from the center of the second seal taper surface 21 of the female adapter 2 to the inner shoulder surface 24 ₂₀ The length L of the nose end of the external thread joint 1 ₁₀ The following formula is satisfied: l is more than or equal to 0.6 ₂₀ /L ₁₀ ≤0.8。

After the arrangement, the sealing contact part of the oil sleeve threaded joint after the external thread and the internal thread are screwed is far away from the shoulder part, the rigidity of the sealing contact part is improved, and the influence of the shoulder stress state and the influence of excessive thread grease on the sealing contact state are effectively avoided, so that the sealing performance of the threaded joint under the complex working condition has excellent stability and compression performance. Compare with traditional screwed joint, the utility model discloses an oil casing screwed joint in the embodiment seals under various composite load effects robust performance and compressive resistance homoenergetic and greatly improves.

Preferably, in the embodiment of the present invention, α is not more than 4.10 ° < α ₁ ≤9.90°，0°≤β ₁ -α ₁ Not more than 0.5 degrees and a first circular arc R ₁₀ ≥10mm。

In the embodiment of the present invention, the angle α of the first sealing cone 11 of the male adapter 1 ₁ The range of (A) is as follows: alpha is not less than 4.10 degrees ₁ The sealing angle in the range is less than or equal to 9.90 degrees, so that the oil sleeve threaded joint has excellent sealing distribution state and good sealing surface anti-sticking performance. First circular arc R of male adapter 1 ₁₀ The size range of (A) is as follows: r ₁₀ The size of the sealing contact pressure is larger than or equal to 10mm, the peak value of one side of the sealing contact pressure can be effectively reduced by the larger arc angle, and the sticking probability is reduced. Angle β of second sealing taper 21 of female adapter 2 ₁ Angle alpha with the first sealing cone 11 of the male adapter 1 ₁ The following formula is satisfied: beta is not more than 0 degree ₁ -α ₁ Less than or equal to 0.5 degrees, the reduction of the sealing contact pressure close to one side of the pipe end caused by the influence of the necking of the pipe end is compensated, so that the sealing contact pressure of the oil sleeve threaded joint reaches uniform distribution, and the stable sealing effect is realized.

As shown in fig. 3 to 5, in the embodiment of the present invention, from the direction of the thread structure 30 to the shoulder structure 70, the inner thread section 31, the second sealing conical surface 21 and the inner shoulder surface 24 are sequentially arranged on the inner wall surface of the female thread joint 2, the first groove 40 includes the first cylindrical surface 10 arranged on the partial outer wall surface of the outer thread joint 1 and the groove structure 20 arranged on the partial inner wall surface of the inner thread joint 2, the groove structure 20 is located between the inner thread section 31 and the second sealing conical surface 21, and the groove structure 20 and the first cylindrical surface 10 cooperate to form the first groove 40.

In the above arrangement, the groove structure 20 and the first cylindrical surface 10 cooperate to form the first groove 40, and the first groove 40 can store excessive thread grease, so as to avoid the influence of the thread grease pressure on the sealing performance.

As shown in fig. 4 and 5, in the embodiment of the present invention, the second sealing conical surface 21 and the inner shoulder surface 24 are sequentially disposed on the inner wall surface of the female adapter 2 from the thread structure 30 to the shoulder structure 70, and the second groove 60 includes a groove surface and a fourth arc R ₂₂ The groove surface is arranged on part of the inner wall surface of the internal thread joint 2 and is positioned between the second sealing conical surface 21 and the internal shoulder surface 24; fourth arc R ₂₂ Is arranged on part of the inner wall surface of the internal thread joint 2, and the groove surface passes through a fourth circular arc R ₂₂ Connected with the inner shoulder surface 24; wherein, the groove surface and the fourth arc R ₂₂ Together, a portion of the inner shoulder surface 24 and a portion of the first sealing cone 11 form a second groove 60.

In the above arrangement, the groove surface and the fourth arc R ₂₂ The portion of the inner shoulder surface 24 and the portion of the first sealing cone surface 11 together form a second groove 60 such that the second groove 60 is formed between the sealing structure 50 and the shoulder structure 70, and the second groove 60 can store excess thread grease, thereby avoiding the influence of thread grease pressure on sealing performance.

As shown in fig. 5, in the embodiment of the present invention, the groove surface includes a second cylindrical surface 23, one end of the second cylindrical surface 23 is connected to the second sealing conical surface 21, and the other end of the second cylindrical surface 23 is connected to the fourth arc R ₂₂ And (4) connecting.

In the above arrangement, the groove surface includes the second cylindrical surface 23, and the fourth arc R ₂₂ The second groove 60 is formed by a part of the inner shoulder surface 24 and a part of the first sealing conical surface 11, and the second groove 60 can store excessive thread grease, so that the influence of the pressure of the thread grease on the sealing performance is avoided.

As shown in fig. 4 and 5, in an embodiment of the present invention, the shoulder structure 70 includes an outer shoulder surface 12 and an inner shoulder surface 24, the outer shoulder surface12 are arranged on the end surface of the external thread joint 1 and connected with the first sealing conical surface 11, and an included angle alpha is formed between the external shoulder surface 12 and the vertical direction ₂ (ii) a An inner shoulder surface 24 is provided on a part of the inner wall surface of the female screw joint 2 and connected to the second cylindrical surface 23, and an included angle β is formed between the inner shoulder surface 24 and the vertical direction ₃ (ii) a Wherein the outer shoulder surface 12 is in interference fit with the inner shoulder surface 24.

The utility model discloses an in the embodiment, outer shoulder surface 12 and the mutual interference contact of interior shoulder surface 24 after outer internal thread closes soon form shoulder structure 70, and shoulder structure 70 can improve the anti compression performance of oil casing screwed joint, plays supplementary sealed effect.

As shown in fig. 4 and 5, in the embodiment of the present invention, the outer shoulder surface 12 is an outer inclined surface, the inner shoulder surface 24 is an outer inclined surface, and the outer shoulder surface 12 and the inner shoulder surface 24 are both gradually away from the axis of the oil casing joint from the direction of the shoulder structure 70 from the thread structure 30. The arrangement is convenient for processing, the outer shoulder surface 12 and the inner shoulder surface 24 are easy to match, and the operation is convenient.

Preferably, in the embodiment of the present invention, α is not more than 5 ° < α ₂ ≤15°，0°≤β ₃ -α ₂ ≤1°。

In the embodiment of the present invention, the angle α of the outer shoulder surface 12 of the male screw 1 ₂ The range of (A) is as follows: alpha is not more than 5 degrees ₂ Less than or equal to 15 degrees, so that the stress of the shoulder surface is more uniform after the interference contact of the shoulder, and the oil sleeve threaded joint has good compression performance. Angle β of inner shoulder surface 24 of female screw joint 2 ₃ Angle alpha to the outer shoulder surface 12 of the pin 1 ₂ The following formula is satisfied: beta is not more than 0 degree ₃ -α ₂ Less than or equal to 1 degree, through the setting, compensated because the influence of body pipe end necking down causes to be close to the inside shoulder magnitude of interference of reducing to make shoulder surface contact atress comparatively even, and then make oil casing screwed joint have good compression performance.

In the embodiment of the present invention, as shown in fig. 4, the male connector 1 has a fourth outer inclined surface 14, and the fourth outer inclined surface 14 is disposed on a part of the inner wall surface of the male connector 1 from the thread structure 30 to the shoulder structure 70In the direction, the fourth outer inclined surface 14 gradually gets away from the axis of the oil casing joint and is connected with the outer shoulder surface 12, and an included angle alpha is formed between the fourth outer inclined surface 14 and the axis of the oil casing joint ₄ Wherein, alpha is more than or equal to 6 degrees ₄ ≤20°。

In the embodiment of the present invention, the angle α of the fourth outer inclined surface 14 provided on the pipe end inner surface of the male coupling 1 ₄ The range of (A) is as follows: alpha is not more than 6 degrees ₄ 20 DEG or less, which makes the thickness of the seal contact portion at an optimum value, thereby enabling the threaded joint to obtain a good balance between the seal contact state and the galling resistance.

The inventor knows a technical scheme named as a threaded joint structure of an airtight zigzag oil well pipe, the technical scheme adopts a zigzag tooth type structure, the tooth tops and the tooth bottoms are parallel to a threaded bus, the threaded connection strength is high, and the influence of external load on the sealing performance is reduced; the sealing structure and the positioning shoulder form a wedge-shaped structure to maintain the stability of sealing, and the included angles between the inner and outer sealing surfaces and the vertical line are respectively beta ₁ And beta ₂ ，β ₁ ＝β ₂ The technical scheme is that the threaded joint has good connection strength and sealing performance, and the angle is 75-105 degrees; however, the sealing structure is close to the positioning shoulder, the sealing performance of the sealing structure is seriously influenced by the stress state of the positioning shoulder, the stability of the sealing performance is not high, and meanwhile, in order to achieve 100% compression performance, the threaded joint of the oil casing pipe usually needs a pipe end necking process, so that the production and processing cost is high. By adopting the oil sleeve threaded joint in the technical scheme of the application, the sealing performance and the compression performance are greatly improved under the condition of no need of a necking process, and the production and processing cost can be reduced.

The utility model discloses a the embodiment of the utility model provides an oil casing screwed joint with excellent airtight robustness can, and this oil casing screwed joint still has good structural integrity and sealed integrality under various complicated abominable load operating modes, has excellent sealed robustness simultaneously, applicable in the oil gas well that geological conditions such as high temperature, high pressure, extra-deep are complicated.

In order to achieve the above object, the embodiments of the present invention adopt the following technical solutions:

the utility model discloses an in the embodiment, oil casing screwed joint connects the combination to form by external thread joint 1 and female connection 2 are twisted, and external thread joint 1 is body external thread joint, and female connection 2 is coupling female connection. The first sealing conical surface 11 of the external thread joint 1 is an inclined surface with taper, the pipe end is an outer shoulder surface 12, and the first sealing conical surface 11 and the outer shoulder surface 12 pass through a fifth circular arc R ₁₁ The nose end of the external thread joint 1 is L ₁₀ (i.e., the distance between the end of the first cylindrical surface 10 remote from the first sealing taper 11 and the outer shoulder surface 12 of the shoulder structure 70), the axial length L of the first sealing taper 11 of the male adapter 1 ₁₁ Is a given range value; the second sealing conical surface 21 of the female adapter 2 is far away from the inner shoulder surface 24, second cylindrical surfaces are respectively processed between the second sealing conical surface 21 and the inner shoulder surface 24 of the female adapter 2, and the distance L between the center of the second sealing conical surface 21 of the female adapter 2 and the inner shoulder surface 24 ₂₀ The axial length L of the second sealing taper 21 of the female adapter 2 for a given range of values ₂₁ Given range values.

An external thread joint 1 (shown in figure 2) is processed on the outer surface of the pipe end of the pipe body, and a pipe body thread part (namely an external thread section 32), a first cylindrical surface 10 and a first circular arc R are arranged on the external thread joint 1 ₁₀ Angle alpha ₁ First sealing conical surface 11, fifth circular arc R ₁₁ Angle alpha ₂ And the angle alpha of the outer shoulder surface 12 and the inner surface of the pipe end is machined ₄ And a fourth outer slope 14. Wherein the length L of the first sealing cone 11 ₁₁ And length L of nose end ₁₀ An enlarged view of a part of the male joint 1 for a given range of values is shown in fig. 4.

The inner surface of the coupling is processed with the female thread joint 2 (as shown in figure 3), and the female thread joint 2 is provided with a coupling thread part (namely a female thread section 31), a groove structure 20 and a second circular arc R ₂₀ Angle beta ₁ Second sealing conical surface 21, third arc R ₂₁ A second cylindrical surface 23, a fourth arc R ₂₂ Angle of beta ₃ Inner shoulder surface 24. Wherein the length L from the center of the second sealing cone 21 to the inner shoulder surface 24 ₂₀ And a second passwordLength L of conical surface 21 ₂₁ An enlarged view of a portion of the female adapter 2 for a given range of values is shown in fig. 5.

The groove structure 20 of the female adapter 2 can store redundant thread grease at the thread part, and the influence of the pressure of the thread grease on the adapter is reduced; meanwhile, a second groove 60 is formed between the second cylindrical surface 23 of the female adapter 2 and the first sealing conical surface 11 of the male adapter 1, and the second groove 60 can store excessive thread grease at the shoulder part, so that the influence of thread grease pressure on the sealing performance is avoided.

The embodiment of the utility model provides an in, oil casing screwed joint's key concrete parameter does: nose length L of male screw joint 1 ₁₀ The following formula is satisfied: l is more than or equal to 10mm ₁₀ Not more than 20mm, the length L of the first sealing conical surface 11 of the male adapter 1 ₁₁ And length L of nose end ₁₀ The ratio ranges are: l is more than or equal to 0.7 ₁₁ /L ₁₀ Not more than 0.9, the angle alpha of the first sealing conical surface 11 of the male adapter 1 ₁ The range of (A) is as follows: alpha is not less than 4.10 degrees ₁ Is less than or equal to 9.90 degrees and a first circular arc R of the external thread joint 1 ₁₀ The range of (A) is as follows: r is ₁₀ Not less than 10mm, angle alpha of external shoulder surface 12 of external thread joint 1 ₂ The range of (A) is as follows: alpha is not more than 5 degrees ₂ Not more than 15 degrees, and the angle alpha of the fourth outer inclined surface 14 of the male screw joint 1 ₄ The range of (A) is as follows: alpha is not more than 6 degrees ₄ Is less than or equal to 20 degrees. Angle β of second sealing taper 21 of female adapter 2 ₁ Angle alpha with the first sealing cone 11 of the male adapter 1 ₁ The following formula is satisfied: beta is not more than 0 degree ₁ -α ₁ Not more than 0.5 degrees, and the length L of the second sealing conical surface 21 of the female adapter 2 ₂₁ The range of (A) is as follows: l is not less than 2mm ₂₁ Not more than 4mm, and the angle beta of the inner shoulder surface 24 of the female adapter 2 ₃ Angle alpha to the outer shoulder surface 12 of the pin 1 ₂ The following formula is satisfied: beta is not more than 0 degree ₃ -α ₂ Less than or equal to 1 degree, and the distance L from the center of the second sealing conical surface 21 of the internal thread joint 2 to the inner shoulder surface 24 ₂₀ The length L of the nose end of the external thread joint 1 ₁₀ The following formula is satisfied: l is more than or equal to 0.6 ₂₀ /L ₁₀ Less than or equal to 0.8. The design of the key parameters ensures that the oil sleeve threaded joint has excellent sealing stability and compression resistanceAnd torsional resistance.

Example two

The difference between the second embodiment and the first embodiment is that, as shown in fig. 6, in the second embodiment, the groove surface includes a first outer inclined surface 22 and a second cylindrical surface 23, the direction from the thread structure 30 to the shoulder structure 70, a second sealing conical surface 21, the first outer inclined surface 22, the second cylindrical surface 23 and a fourth circular arc R ₂₂ Are connected in sequence, the first outer inclined plane 22 is gradually far away from the axis of the oil sleeve joint, and an included angle beta is formed between the first outer inclined plane 22 and the axis of the oil sleeve joint ₂ 。

In the above arrangement, the groove surface includes a first outer inclined surface 22 and a second cylindrical surface 23, the first outer inclined surface 22, the second cylindrical surface 23, and a fourth arc R ₂₂ The second groove 60 is formed by a part of the inner shoulder surface 24 and a part of the first sealing conical surface 11, and the second groove 60 can store excessive thread grease, so that the influence of the pressure of the thread grease on the sealing performance is avoided.

Preferably, in the embodiment of the present invention, β is not more than 0 ° < β ₂ Is less than or equal to 15 degrees. Set up like this, can increase the storage space of second recess 60, improve the effect of the excessive screw thread fat of second recess 60 storage, avoid screw thread fat pressure to sealing performance's influence.

In the embodiment of the present invention, the first outer inclined plane 22 and the second cylindrical surface 23 with a certain range of angle are respectively processed between the second sealing conical surface 21 and the inner shoulder surface 24 of the inner threaded joint 2, and the angle β of the first outer inclined plane 22 ₂ For a given range of values, the angle beta ₂ The range of (A) is as follows: beta is not more than 0 degree ₂ Less than or equal to 15 degrees (when beta) ₂ When the angle is equal to 0 °, the first outer inclined surface 22 is changed to a cylindrical surface, and the first outer inclined surface 22 and the second cylindrical surface 23 are the same surface, as shown in fig. 5).

The other structures in the second embodiment are the same as those in the first embodiment, and are not described herein again.

EXAMPLE III

The third embodiment is different from the first embodiment in that, as shown in fig. 7 and 8, in the third embodiment, the outer shoulder surface 12 includes a plurality of second outer inclined surfaces 121 connected in sequence, the inner shoulder surface 24 includes a plurality of third outer inclined surfaces 241 arranged corresponding to the plurality of second outer inclined surfaces, the plurality of second outer inclined surfaces 121 and the plurality of third outer inclined surfaces 241 are gradually away from the axis of the oil casing joint from the direction of the shoulder structure 70 by the thread structure 30, the included angles between two adjacent second outer inclined surfaces 121 and the axis of the oil casing joint are different, and the included angles between two adjacent third outer inclined surfaces 241 and the axis of the oil casing joint are different.

In the above arrangement, the external shoulder surface 12 of the male threaded joint 1 is a composite shoulder surface structure formed by combining a plurality of surfaces, as shown in fig. 7, so that the oil casing threaded joint has better compression resistance and bending resistance. The inner shoulder surface 24 of the female threaded joint 2 is a composite shoulder surface structure composed of a plurality of surfaces, as shown in fig. 8, so that the oil casing threaded joint has better compression resistance and bending resistance.

The other structures in the third embodiment are the same as those in the first embodiment, and are not described herein again.

Example four

The fourth embodiment differs from the first embodiment in that, as shown in fig. 9, the male fitting 1 further has an inner bore surface 13 connected to both the fourth outer inclined surface 14 and the outer shoulder surface 12, the inner bore surface 13 is provided on a part of the inner wall surface of the male fitting 1 and is located between the fourth outer inclined surface 14 and the outer shoulder surface 12, and the length L of the inner bore surface 13 in the axial direction of the oil casing joint is set to be equal to the length L of the inner bore surface 13 ₁₂ 。

By providing the inner bore surface 13, the nose of the male threaded joint 1 is made easier to deform, i.e., the axial rigidity is reduced, which makes the compression performance of the oil casing threaded joint improved.

Preferably, in the embodiment of the present invention, L is not less than 0mm ₁₂ Less than or equal to 7 mm. The arrangement is convenient to process, so that the nose end of the external thread joint 1 is easier to deform, namely, the axial rigidity is reduced, and the compression performance of the oil sleeve threaded joint is improved.

In the embodiment of the present invention, the inner surface of the pipe end of the external thread joint 1 is processed into the inner hole surface 13, and the length L of the inner hole surface 13 ₁₂ The length L of the inner bore surface 13 for a given range of values ₁₂ The range of (A) is as follows: l is not less than 0mm ₁₂ Less than or equal to 7mm (when L ₁₂ When the content is equal to 0, the content,i.e. the inner surface of the pipe end is provided with only a fourth outer bevel 14, i.e. the same construction as in the first embodiment shown in fig. 4).

As shown in fig. 9, in the embodiment of the present invention, the inner hole surface 13 is a cylindrical surface.

The other structures in the fourth embodiment are the same as those in the first embodiment, and are not described again here.

EXAMPLE five

The difference between the fifth embodiment and the fourth embodiment is that, as shown in fig. 10, in the fifth embodiment, the inner bore surface 13 is an inner inclined surface, and the inner bore surface 13 gradually approaches the axis of the oil casing joint from the thread structure 30 to the shoulder structure 70, and an included angle α is formed between the inner bore surface 13 and the axis of the oil casing joint ₃ Wherein, alpha is more than or equal to 0 degree ₃ ≤10°。

In the embodiment of the present invention, the inner surface of the pipe end of the external thread joint 1 is processed into the inner hole surface 13, and the length of the inner hole surface 13 is L ₁₂ Angle alpha ₃ Length L of inner bore surface 13 ₁₂ And angle alpha ₃ Are all given range values, angle alpha ₃ The range of (A) is as follows: alpha is not more than 0 degree ₃ Less than or equal to 10 degrees (when alpha is ₃ At 0 °, i.e., the inner bore surface 13 becomes a cylindrical surface, i.e., the same structure as in the fourth embodiment shown in fig. 9), the design of the inner bore surface 13 makes the nose end more likely to deform, i.e., the axial rigidity is reduced, which results in an improvement in the compression performance of the threaded joint.

The other structures in the fifth embodiment are the same as those in the fourth embodiment, and are not described herein again.

The embodiment of the utility model has the following advantage:

1. the optimized sealing surface structure and the optimized sealing surface position are adopted, so that the sealing integrity and the sealing robustness of the oil sleeve threaded joint are greatly improved;

2. after the oil casing threaded joint is screwed, the two sides of the actual sealing contact part form a groove structure, so that redundant thread grease smeared in the downhole operation can be stored, and the influence of the pressure of the thread grease on the performance of the threaded joint is reduced;

3. the angle relation between the sealing surface on the external thread joint and the sealing surface on the internal thread joint compensates the reduction of the sealing contact pressure at one side close to the pipe end caused by the influence of the necking of the pipe end, so that the sealing contact pressure of the oil sleeve threaded joint is uniformly distributed, and the stable sealing effect is realized;

4. the relationship between the angle of the outer shoulder surface on the external thread joint and the angle of the inner top shoulder on the internal thread joint compensates the reduction of interference close to the shoulder on the inner side of the pipe body caused by the influence of necking of the pipe end of the pipe body, so that the shoulder surfaces are in uniform stress contact, and the threaded joint has good compression performance;

5. adopt the utility model discloses oil sleeve screwed joint is under the condition that need not throat technology, and its sealing performance and compressibility are greatly improved.

The application belongs to the field of petroleum pipe engineering, and relates to a high-performance oil casing threaded joint which is mainly used for well conditions with strict requirements on air tightness and compression performance. The threaded joint is mainly used for the oil casing and the coupling in the petroleum industry and the oil casing and the coupling adopting the structure, and belongs to the technical field of oil pipes.

The embodiment of the utility model provides an in, oil casing subassembly includes oil casing and the oil casing joint of being connected with oil casing, and wherein, oil casing joint is foretell oil casing joint.

It should be noted that, in the embodiment of the present invention, the oil casing is a tubular structure, and the external thread joint 1 of the oil casing joint is connected with one end of the oil casing to form an integrated structure (in the embodiment of the present invention, the external thread joint 1 is processed on the outer surface of one end of the oil casing, that is, the external thread joint 1 and the oil casing are an integrated structure, and of course, the external thread joint 1 and the oil casing can be separately arranged and connected to form an integrated structure according to actual needs), and the external thread joint 1 is also a tubular structure; the female adapter 2 is also of a tubular structure, and the female adapter 2 is in threaded connection with the male adapter 1. The internal thread joint 2 is processed on the inner surface of a coupling, and the purpose that an oil casing is connected with the coupling through the oil casing joint is achieved through the connection of the internal thread joint 2 and the external thread joint 1 (of course, in the alternative embodiment of the application, the internal thread joint 2 can be processed on the inner surface of another oil casing according to actual needs, and thus the purpose that two oil casings are connected with each other can be achieved through the connection of the internal thread joint 2 and the external thread joint 1).

Because the oil sleeve subassembly of this application includes the oil sleeve joint of this application, consequently, the oil sleeve subassembly of this application also has the above-mentioned advantage of the oil sleeve joint of this application, and this is no longer repeated here.

EXAMPLE six

In the sixth embodiment, the pipe body is a 339.72mm × 12.19 mm-sized sleeve, the steel grade is P110, the API standard is adopted to specify the outer diameter of the coupling, and the material performance meets the API standard requirement.

The oil casing threaded joint has the following geometrical parameters: pitch P is 4 threads/inch, thread taper 1:16, L ₁₀ ＝19.5mm，L ₁₁ /L ₁₀ ＝0.89，α ₁ ＝7.2°，R ₁₀ ＝30mm，α ₂ ＝8°，α ₃ ＝0°，α ₄ ＝8°，β ₁ -α ₁ ＝0.4°，L ₂₁ ＝3.5mm，β ₂ ＝0°，β ₃ -α ₂ ＝1°，L ₂₀ /L ₁₀ ＝0.75。

The connection strength of the oil casing threaded joint reaches 9514kN, the compression strength reaches 9514kN, the air tightness reaches more than 48Mpa, the external pressure resistance reaches more than 17Mpa, the bending resistance reaches more than 20 degrees/30 meters, and the requirement of no thread gluing during 3 times of shackle removal is met. Meanwhile, the threaded joint of the oil casing has good operability such as buckling and inserting, and has excellent robustness of sealing performance.

EXAMPLE seven

In the seventh embodiment, the pipe body is an 88.9mm × 9.52mm oil pipe, the steel grade is P110, the API standard is adopted to specify the outer diameter of the coupling, and the material properties meet the API standard requirements.

The oil casing threaded joint has the following geometrical parameters: pitch P is 5 threads/inch, thread taper 1:16, L ₁₀ ＝12.5mm，L ₁₁ /L ₁₀ ＝0.84，α ₁ ＝7.2°，R ₁₀ ＝20mm，α ₂ ＝8°，α ₃ ＝0°，α ₄ ＝8°，β ₁ -α ₁ ＝0.4°，L ₂₁ ＝3.0mm，β ₂ ＝0°，β ₃ -α ₂ ＝1°，L ₂₀ /L ₁₀ ＝0.71。

The connection strength of the oil casing threaded joint reaches 1800kN, the compression strength reaches 1800kN, the air sealing performance reaches more than 142Mpa, the external pressure resistance reaches more than 145Mpa, the bending resistance reaches more than 45 degrees/30 meters, and the requirement of no thread gluing after being broken out for 10 times is met. Meanwhile, the threaded joint of the oil casing has good operability such as buckling and inserting; has excellent sealing performance and robustness.

From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the threaded connection between the external thread joint and the internal thread joint is realized through a thread structure; the second sealing conical surface is in sealing fit with part of the first sealing conical surface to realize sealing, and the second sealing conical surface and the first sealing conical surface are conical surfaces, so that the sealing contact pressure of the sealing structure of the oil sleeve joint is uniformly distributed, the sealing structure has an excellent sealing distribution state, and effective sealing can be realized. Be equipped with the second recess between seal structure and the circular bead structure, make seal structure keep away from the circular bead structure, this greatly reduced the sealing performance of oil casing coupling receive the influence of shoulder stress state, improved the robustness of sealing performance, improved the resistance to compression performance and the anti torsion performance of oil casing coupling simultaneously.

It is obvious that the above described embodiments are only some of the embodiments of the present invention, and not all of them. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall belong to the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An oil casing joint, comprising:

a male coupling (1);

the internal thread joint (2) is in threaded connection with the external thread joint (1);

wherein, along the direction that is on a parallel with the axis of oil casing coupling, screwed joint (1) with be equipped with helicitic texture (30), first recess (40), seal structure (50), second recess (60) and shoulder structure (70) between female connection (2) in proper order, seal structure (50) including first sealed conical surface (11) and with part first sealed conical surface (11) seal complex second sealed conical surface (21), first sealed conical surface (11) set up on the partial outer wall face of male connection (1), second sealed conical surface (21) set up on the partial internal face of female connection (2).

2. The oil casing joint according to claim 1, wherein the sealing structure (50) further comprises:

first arc R ₁₀ The outer wall surface of the external thread joint (1) is provided with a plurality of grooves;

second arc R ₂₀ ；

Third arc R ₂₁ Said second circular arc R ₂₀ And said third arc R ₂₁ Are all arranged on part of the inner wall surface of the female adapter (2); said first arc R being directed from said thread formation (30) towards said shoulder formation (70) ₁₀ And the first sealing conical surface (11) are connected in sequence, and the second circular arc R ₂₀ The second sealing conical surface (21) and the third arc R ₂₁ Are connected in sequence;

wherein, from the thread structure (30) to the direction of the shoulder structure (70), the first sealing conical surface (11) and the second sealing conical surface (21) are gradually close to the axis of the oil sleeve joint, and an included angle alpha is formed between the first sealing conical surface (11) and the axis of the oil sleeve joint ₁ The second sealing conical surface (21) and the axis of the oil sleeve joint form an included angle beta ₁ 。

3. The oil casing joint according to claim 2, characterized in that the first recess (40) comprises a first cylindrical surface (10) provided on a part of the outer wall surface of the male connector (1), the first cylindrical surface (10), the first circular arc R, in the direction from the thread formation (30) to the shoulder formation (70), the first cylindrical surface (10) ₁₀ Is connected with the first sealing conical surface (11) in sequence; the distance between one end of the first cylindrical surface (10) far away from the first sealing conical surface (11) and the shoulder structure (70) is L along the axial direction of the oil sleeve joint ₁₀ The length of the first sealing conical surface (11) is L ₁₁ The distance between the center of the second sealing conical surface (21) and the shoulder structure (70) is L ₂₀ The length of the second sealing conical surface (21) is L ₂₁ ；

Wherein L is more than or equal to 10mm ₁₀ ≤20mm，0.7≤L ₁₁ /L ₁₀ ≤0.9，0.6≤L ₂₀ /L ₁₀ ≤0.8，2mm≤L ₂₁ ≤4mm。

4. The oil casing joint according to claim 2, characterized in that α is 4.10 ° ≦ α ₁ ≤9.90°，0°≤β ₁ -α ₁ Not more than 0.5 degrees, the first circular arc R ₁₀ ≥10mm。

5. The oil casing joint according to any one of claims 1 to 4, characterized in that an internal thread section (31), the second sealing conical surface (21) and an internal shoulder surface (24) are sequentially arranged on an inner wall surface of the female joint (2) from the thread structure (30) to the shoulder structure (70), the first groove (40) comprises a first cylindrical surface (10) arranged on a part of an outer wall surface of the male joint (1) and a groove structure (20) arranged on a part of an inner wall surface of the female joint (2), the groove structure (20) is positioned between the internal thread section (31) and the second sealing conical surface (21), and the groove structure (20) and the first cylindrical surface (10) are matched to form the first groove (40).

6. The oil casing joint according to any one of claims 1 to 4, wherein a second sealing taper surface (21) and an inner shoulder surface (24) are provided on an inner wall surface of the female screw joint (2) in this order from the thread structure (30) toward the shoulder structure (70), and the second groove (60) comprises:

a recessed surface provided on a part of an inner wall surface of the female adapter (2) and located between the second seal tapered surface (21) and the inner shoulder surface (24);

fourth arc R ₂₂ Is arranged on part of the inner wall surface of the female adapter (2), and the groove surface passes through the fourth circular arc R ₂₂ Is connected with the inner shoulder surface (24);

wherein the groove surface and the fourth arc R ₂₂ Part of the inner shoulder surface (24) and part of the first sealing cone surface (11) together form the second groove (60).

7. The oil casing joint of claim 6, wherein the recessed surface comprises:

one end of the second cylindrical surface (23) is connected with the second sealing conical surface (21), and the other end of the second cylindrical surface (23) is connected with the second sealing conical surface (21)The fourth arc R ₂₂ Connecting; or,

a first outer inclined surface (22) and a second cylindrical surface (23), from the thread structure (30) to the direction of the shoulder structure (70), the second sealing conical surface (21), the first outer inclined surface (22), the second cylindrical surface (23) and a fourth circular arc R ₂₂ Connect gradually, just first outer inclined plane (22) are kept away from gradually the axis of oil casing connects, first outer inclined plane (22) with contained angle beta has between the axis of oil casing connects ₂ Wherein beta is more than or equal to 0 degree ₂ ≤15°。

8. The oil bushing joint according to any one of claims 1 to 4, characterized in that the second groove (60) comprises a second cylindrical surface (23) provided on a portion of an inner wall surface of the female joint (2), and the shoulder structure (70) comprises:

an outer shoulder surface (12) arranged on the end surface of the male adapter (1) and connected with the first sealing conical surface (11), wherein an included angle alpha is formed between the outer shoulder surface (12) and the vertical direction ₂ ；

An inner shoulder surface (24) provided on a part of an inner wall surface of the female adapter (2) and connected to the second cylindrical surface (23), the inner shoulder surface (24) having an angle β with the vertical direction ₃ ；

Wherein the outer shoulder surface (12) is an interference fit with the inner shoulder surface (24).

9. The oil casing joint according to claim 8,

the outer shoulder surface (12) is an outer inclined surface, the inner shoulder surface (24) is an outer inclined surface, and both the outer shoulder surface (12) and the inner shoulder surface (24) are gradually far away from the axis of the oil sleeve joint from the thread structure (30) to the direction of the shoulder structure (70); or,

outer shoulder surface (12) are including a plurality of second outer inclined planes (121) that connect gradually, interior shoulder surface (24) include with a plurality of second outer inclined planes (121) correspond a plurality of third outer inclined planes (241) that set up, by helicitic texture (30) to the direction of shoulder structure (70), it is a plurality of second outer inclined plane (121) and a plurality of third outer inclined plane (241) all keep away from gradually the axis of oil casing joint, adjacent two second outer inclined plane (121) with contained angle between the axis of oil casing joint is different, adjacent two third outer inclined plane (241) with contained angle between the axis of oil casing joint is different.

10. The oil casing joint according to claim 8, characterized in that α is 5 ° ≦ α ₂ ≤15°，0°≤β ₃ -α ₂ ≤1°。

11. The oil casing joint according to any one of claims 1 to 4, characterized in that the male joint (1) has a fourth outer chamfer (14), the fourth outer chamfer (14) being provided on a portion of the inner wall surface of the male joint (1), the fourth outer chamfer (14) gradually moving away from the axis of the oil casing joint and connecting with an outer shoulder surface (12) in the direction of the shoulder structure (70) from the thread structure (30), the fourth outer chamfer (14) having an angle α with the axis of the oil casing joint ₄ Wherein, alpha is more than or equal to 6 degrees ₄ ≤20°。

12. The oil casing joint according to claim 11, wherein the male joint (1) further has an inner bore surface (13) connected to both the fourth outer slope (14) and the outer shoulder surface (12), the inner bore surface (13) being provided on a part of an inner wall surface of the male joint (1) between the fourth outer slope (14) and the outer shoulder surface (12), the inner bore surface (13) having a length L in an axial direction of the oil casing joint ₁₂ 。

13. The oil casing joint according to claim 12, characterized in that the inner bore surface (13) is a cylindrical surface.

14. The oil casing joint according to claim 12, characterized in that the bore surface (13) is an inner chamfer, directed from the thread formation (30) to the boreDirection of shoulder structure (70), bore face (13) is close to gradually oil casing connects the axis of the joint, bore face (13) with have contained angle alpha between the axis of oil casing connects ₃ Wherein, alpha is more than or equal to 0 degree ₃ ≤10°。

15. The oil casing joint according to claim 12, wherein 0mm ≦ L ₁₂ ≤7mm。

16. An oil bushing assembly comprising an oil bushing and an oil bushing joint connected to the oil bushing, wherein the oil bushing joint is the oil bushing joint of any one of claims 1 to 15.