CN216077002U - Oil casing joint and have its oil casing subassembly - Google Patents

Abstract

The utility model provides an oil casing joint and an oil casing assembly with the same. 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 sealing conical surface and a sealing cambered surface in sealing fit with the partial sealing conical surface, the sealing conical surface is arranged on the partial inner wall surface of the internal thread joint, and the sealing cambered surface is arranged on the partial outer wall surface of the external thread joint. The technical scheme of the utility model can solve the problem of poor sealing stability of the oil casing joint in the prior art.

Description

Oil casing joint and have its oil casing subassembly

Technical Field

The utility model relates to the technical field of threaded connection of oil well pipes, in particular to an oil casing joint and an oil casing assembly with the same.

Background

Along with the development environment of oil and gas fields becoming more complex, stricter requirements are put forward on the sealing performance of the oil casing threaded joint, namely, the oil casing threaded joint still keeps 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

The utility model mainly aims to provide an oil casing joint and an oil casing assembly with the same, and aims to solve the problem of poor sealing stability of the oil casing joint in the prior art.

In order to achieve the above object, according to one 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 sealing conical surface and a sealing cambered surface in sealing fit with the partial sealing conical surface, the sealing conical surface is arranged on the partial inner wall surface of the internal thread joint, and the sealing cambered surface is arranged on the partial outer wall surface of the external thread joint. Furthermore, the sealing structure also comprises a first circular arc R11 arranged on part of the inner wall surface of the internal thread joint, the first circular arc R11 and the sealing conical surface are sequentially connected from the thread structure to the direction of the shoulder structure, the sealing conical surface is gradually close to the axis of the oil casing joint, and an included angle alpha 1 is formed between the sealing conical surface and the axis of the oil casing joint; the sealing arc surface has a second circular arc R21.

Further, the second groove comprises a first cylindrical surface arranged on the inner wall surface of part of the internal threaded joint, and the first circular arc R11, the sealing conical surface and the first cylindrical surface are sequentially connected from the threaded structure to the direction of the shoulder structure; the oil casing joint also comprises a second cylindrical surface arranged on part of the outer wall surface of the external thread joint, and the second cylindrical surface and the sealing cambered surface are sequentially connected from the thread structure to the direction of the shoulder structure; along the axial direction of the oil casing joint, the distance between one end of the first cylindrical surface close to the sealing conical surface and the shoulder structure is L12, the distance between one end of the sealing conical surface far away from the first cylindrical surface and the shoulder structure is L11, and the distance between one end of the second cylindrical surface far away from the sealing cambered surface and the shoulder structure is L21, wherein L11 is more than or equal to 12mm and less than or equal to 18mm, L12/L11 is more than or equal to 0.4 mm and less than or equal to 0.8, and L21 is more than or equal to 14mm and less than or equal to 20 mm.

Furthermore, alpha 1 is more than or equal to 3 degrees and less than or equal to 10 degrees, R11 is more than or equal to 4mm and less than or equal to 8mm, and R21 is more than or equal to 50mm and less than or equal to 120 mm.

Further, the thread structure includes: the internal thread section is arranged on part of the inner wall surface of the internal thread joint; the external thread section is arranged on part of the outer wall surface of the external thread joint, the internal thread section and the external thread section are both provided with a bearing surface, a guide surface angle A2 and a thread taper A3, and an included angle A1 is formed between the bearing surface and the vertical direction; wherein A1 is more than or equal to-1 degree and less than or equal to-8 degrees, A2 is more than or equal to 10 degrees and less than or equal to 25 degrees, and A3 is more than or equal to 2 degrees and less than or equal to 8 degrees.

Furthermore, the external thread section has an external tooth height h1, the internal thread section has an internal tooth height h2, wherein h1 is more than or equal to 0.7mm and less than or equal to 1.8mm, and h2 is h1+ (0.05-0.55) mm.

Furthermore, the second groove comprises a first cylindrical surface and a third circular arc R12 which are arranged on the partial inner wall surface of the internal thread joint, and the sealing conical surface, the first cylindrical surface and the third circular arc R12 are sequentially connected from the thread structure to the direction of the shoulder structure; the oil casing joint also comprises a second cylindrical surface and a fourth circular arc R22 which are arranged on the partial outer wall surface of the external thread joint, and the second cylindrical surface, the sealing cambered surface and the fourth circular arc R22 are sequentially connected from the thread structure to the direction of the shoulder structure; the oil casing joint also comprises a first inner inclined plane arranged on the partial inner wall surface of the outer threaded joint, the first inner inclined plane is gradually far away from the axis of the oil casing joint from the direction of the threaded structure to the shoulder structure, and an included angle beta 1 is formed between the first inner inclined plane and the horizontal direction; wherein R12 is more than or equal to 0.6mm and less than or equal to 1.5mm, R22-R12 is more than or equal to 0mm and less than or equal to 0.5mm, beta 1 is more than or equal to 6 degrees and less than or equal to 10 degrees.

Further, the first groove comprises a second inner inclined plane, a surface and a third inner inclined plane which are arranged on the partial inner wall surface of the inner threaded joint, the second inner inclined plane, the surface and the third inner inclined plane are sequentially connected in the direction from the threaded structure to the shoulder structure, the third inner inclined plane is gradually close to the axis of the oil casing joint, an included angle is formed between the third inner inclined plane and the axis of the oil casing joint, and the second inner inclined plane, the surface, the third inner inclined plane and the partial outer wall surface of the outer threaded joint jointly form the first groove.

Further, the shoulder structure includes: the outer shoulder surface is arranged on the end surface of the outer threaded joint, and an included angle beta 2 is formed between the outer shoulder surface and the vertical direction; the inner shoulder surface is arranged on part of the inner wall surface of the inner threaded joint and is connected with the sealing conical surface, and an included angle alpha 2 is formed between the inner shoulder surface and the vertical direction; wherein, the outer shoulder surface is in interference fit with the inner shoulder surface.

Furthermore, alpha 2 is more than or equal to 6 degrees and less than or equal to 15 degrees, and beta 2-alpha 2 is more than or equal to 0.2 degrees and less than or equal to 0.5 degrees.

According to another aspect of the present invention, there is provided an oil bushing assembly including an oil bushing and the above-described oil bushing joint connected to the oil bushing.

By applying the technical scheme of the utility model, the conical surface is arranged on the sealing part to seal the cambered surface, so that the contact pressure of the sealing surface after the upper buckle is ensured, and the effective sealing of the joint is realized; in addition, the sealing surface is separated from the shoulder surface by arranging the second groove between the sealing structure and the shoulder structure, so that the influence of the stress deformation of the shoulder on the sealing performance of the joint is greatly reduced, the sealing stability of the joint is improved, and the compression performance of the oil sleeve joint is improved; through the arrangement, the oil casing joint has good sealing performance and strong tensile and compression resistance.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the utility model and, together with the description, serve to explain the utility model and not to limit the utility model. In the drawings:

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

FIG. 2 shows a cross-sectional view of the female connection end of the oil casing joint of FIG. 1 according to the present invention;

FIG. 3 shows a cross-sectional view of the male connection end of the oil casing joint of FIG. 1 according to the present invention;

FIG. 4 shows an enlarged partial view of a pipe end of the female fitting of FIG. 2 according to the present invention;

FIG. 5 is an enlarged partial view of a pipe end of the externally threaded fitting of FIG. 3 according to the present invention;

FIG. 6 shows an enlarged partial view of the male threaded section of the male connection of FIG. 3 according to the present invention; and

fig. 7 shows a close-up view of the female thread segment of the female connection end of fig. 2 according to the present invention.

Wherein the figures include the following reference numerals:

1. an internal thread joint; 12. sealing the conical surface; 13. a first cylindrical surface; 14. an inner shoulder surface; 2. an externally threaded nipple; 21. a second cylindrical surface; 22. sealing the arc surface; 23. an outer shoulder surface; 24. a first inner inclined plane; 30. a thread structure; 31. an internal thread section; 32. an external threaded section; 40. a first groove; 41. a second inner slope; 42. a surface; 43. a third inner slope; 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 embodiments with reference to the attached drawings.

Among the oil casing joints known to the inventors, there is a zigzag oil casing pipe nipple joint structure which employs a hook-type thread, a taper-to-taper seal structure, a seal face connected to a shoulder face, the joint sealing performance greatly affected by shoulder deformation, and poor seal stability; still another kind of oil casing threaded connection structure, this screwed joint has set up the screw thread hold up tank in sealed position, has improved sealed face contact pressure's stability to a certain extent, but this joint design is complicated, and the processing degree of difficulty is big.

Therefore, it is desirable to provide an oil casing joint having a stable sealing performance.

As shown in fig. 1 to 5, the present invention provides an oil casing joint. The oil casing joint of the embodiment comprises an external thread joint 2 and an internal thread joint 1, wherein the internal thread joint 1 is in threaded connection with the external thread joint 2; wherein, along the direction that is on a parallel with the axis of oil casing connects, be equipped with helicitic texture 30, first recess 40, seal structure 50, second recess 60 and shoulder structure 70 between screwed joint 2 and the female adapter 1 in proper order, seal structure 50 includes sealed conical surface 12 and with the sealed cambered surface 22 of partly sealed conical surface 12 seal fit, sealed conical surface 12 sets up on the part internal wall face of screwed joint 1, sealed cambered surface 22 sets up on the part outer wall face of screwed joint 2.

In the above arrangement, the threaded connection between the female adapter 1 and the male adapter 2 is realized by the thread structure 30; the sealing conical surface 12 is in sealing fit with the sealing cambered surface 22 to realize sealing, and the sealing structure 50 forms conical surface-to-cambered surface sealing, so that the contact pressure of the sealing surface after the upper buckle is ensured, and effective sealing can be realized.

Further, the first groove 40 may be used to store excess sealing grease, thereby avoiding the influence of the thread grease pressure on the sealing performance; 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 stability of the sealing performance is improved, and the compression resistance and the over-torsion resistance of the oil casing joint are improved; shoulder structures 70 are provided at the ends of the threaded joint for limiting the two pipe sections to be connected while further enhancing the sealing performance of the threaded joint.

As shown in fig. 4 and 5, in the embodiment of the present invention, the seal structure 50 further includes a first circular arc R11 provided on a part of the inner wall surface of the female screw joint 1, and the first circular arc R11 and the seal tapered surface 12 are connected in sequence from the screw structure 30 toward the shoulder structure 70.

In the technical scheme, the stress concentration can be reduced by arranging the first circular arc R11, so that the pressure on the sealing surface in the process of screwing is reduced; meanwhile, the first circular arc R11 is arranged between the first groove 40 and the sealing structure 50, so that the third inner inclined surface 43 on the first groove 40 is transited to the sealing conical surface 12 through the first circular arc R11, connection between structures is smoother, unnecessary friction generated in the threaded connection process of the oil sleeve joint is avoided, and sealing performance is improved.

As shown in fig. 4 and 5, in the embodiment of the present invention, the sealing conical surface 12 gradually approaches the axis of the oil casing joint, and an included angle α 1 is formed between the sealing conical surface 12 and the axis of the oil casing joint; the sealing arc surface 22 has a second arc R21.

In the above technical solution, from the direction of the thread structure 30 to the shoulder structure 70, the sealing conical surface 12 gradually inclines to the direction close to the axis of the oil casing joint, and the sealing cambered surface 22 of the male adapter 2 has the second circular arc R21, and the sealing cambered surface 22 and the sealing conical surface 12 form a conical surface-to-cambered surface sealing structure 50, so that the contact pressure of the sealing surface after the top-off can be ensured, and effective sealing can be realized; further, the first and second grooves 40 and 60 provided at both sides of the sealing structure 50 serve to store an excessive amount of thread grease, thereby avoiding an influence of thread grease pressure on sealing performance.

As shown in fig. 4 and 5, in the embodiment of the present invention, the second groove 60 includes the first cylindrical surface 13 provided on a part of the inner wall surface of the female screw joint 1, and the first circular arc R11, the sealing tapered surface 12, and the first cylindrical surface 13 are connected in order from the screw structure 30 toward the shoulder structure 70.

Through the arrangement, an annular space is formed between the first cylindrical surface 13 and the sealing cambered surface 22 on the male adapter 2, and is used for storing redundant thread grease after the sealing conical surface 12 and the sealing cambered surface 22 are buckled up, so that the influence of the pressure of the thread grease on the sealing performance is avoided.

Through setting up first face of cylinder 13, seal structure 50 sets up with shoulder structure 70 separation, and like this, seal structure 50 keeps away from shoulder structure 70 to greatly reduced the sealing performance of oil casing coupling receive the influence of shoulder stress state, improved sealing performance's stability, improved the resistance to compression performance and the resistance to torsion performance of oil casing coupling simultaneously.

As shown in fig. 4 and 5, in the embodiment of the present invention, the oil casing joint further includes a second cylindrical surface 21 provided on a part of the outer wall surface of the male screw joint 2, and the second cylindrical surface 21 and the sealing arc surface 22 are connected in sequence from the screw structure 30 toward the shoulder structure 70.

Through the arrangement, a first groove 40 is formed between the second cylindrical surface 21 and part of the inner wall surface of the female adapter 1, and the first groove 40 is used for storing excessive sealing grease, so that the influence of the pressure of the sealing grease on the sealing performance is avoided, and the sealing stability is improved.

As shown in fig. 4 and 5, in the embodiment of the present invention, along the axial direction of the oil casing joint, the distance between the end of the first cylindrical surface 13 close to the sealing conical surface 12 and the shoulder structure 70 is L12, the distance between the end of the sealing conical surface 12 far from the first cylindrical surface 13 and the shoulder structure 70 is L11, and the distance between the end of the second cylindrical surface 21 far from the sealing arc surface 22 and the shoulder structure 70 is L21, wherein L11 is greater than or equal to 12mm and less than or equal to 18mm, L12/L11 is greater than or equal to 0.8 and L21 is greater than or equal to 14mm and less than or equal to 20 mm.

Through the arrangement, on one hand, the sealing surface between the sealing conical surface 12 and the sealing arc surface 22 can be ensured to have enough contact length and contact pressure, and on the other hand, the second groove 60 can be ensured to have enough space, so that after the sealing surface is buckled, the contact pressure of the sealing surface is reasonable, and the sealing stability is ensured; moreover, the second groove 60 is arranged at a position close to the end part, which is beneficial to storing redundant thread grease at the sealing surface and improving the sealing stability, and further, the sealing structure 50 is far away from the shoulder structure 70, so that the rigidity of the sealing part is increased, the influence of shoulder interference on the sealing surface is avoided, and the sealing stability of the joint can be improved. The reasonable end part length L21 is set, the end part deforms when being buckled, so that the contact pressure distribution of the shoulder surface is more uniform; meanwhile, the minimum thickness of the end part is ensured, and the compression resistance of the joint can be improved.

That is to say, after setting up like this, the sealed contact site of outer internal thread back oil casing screwed on keeps away from the circular bead position, and the rigidity at sealed contact site is improved, has effectively avoided sealed contact state to receive the influence of shoulder atress state and the influence of excessive screw thread fat to make threaded joint sealing performance have excellent stability ability and compression performance under complicated operating mode. Compared with the traditional threaded joint, the oil casing threaded joint in the embodiment of the utility model has the advantages that the sealing robustness and the compression resistance can be greatly improved under various composite loads.

As shown in FIGS. 4 and 5, in the examples of the present invention, 3. ltoreq. alpha.1.ltoreq.10, 4 mm. ltoreq.R 11.ltoreq.8 mm, and 50 mm. ltoreq.R 21.ltoreq.120 mm.

In the technical scheme, the included angle between the sealing conical surface 12 and the horizontal direction is more than or equal to 3 degrees and less than or equal to alpha 1 and less than or equal to 10 degrees, the radius of the second circular arc R21 is more than or equal to 50mm and less than or equal to R21 and less than or equal to 120mm, the sealing conical surface 12 with the angle and the size is in sealing fit with the sealing cambered surface 22, the contact pressure of the sealing surface after the upper buckle is ensured, and effective sealing is realized; the radius of the first circular arc R11 is 4mm < R11 < 8mm, and the arrangement can reduce stress concentration on the inner wall surface of the threaded joint, thereby improving the rigidity of the threaded joint.

As shown in fig. 2 and 3, in the embodiment of the present invention, the thread structure 30 includes an internal thread section 31 provided on a part of the inner wall surface of the internal threaded joint 1 and an external thread section 32 provided on a part of the outer wall surface of the external threaded joint 2.

With the above arrangement, the female screw section 31 is screw-fitted with the male screw section 32, so that the female screw joint 1 and the male screw joint 2 can be connected; and the threaded connection mode is adopted, so that the connection is reliable, and meanwhile, the sealing performance of the joint is further improved.

Preferably, the internal thread section 31 and the external thread section 32 are hook-shaped threads, so that the bending resistance, the internal pressure resistance and the external pressure resistance of the threaded joint can be improved while the connection function is achieved, and the consistent tensile and compression capacities of the oil casing joint and the pipe body of the oil casing to be connected are ensured.

As shown in fig. 6 and 7, in the embodiment of the present invention, based on the specifications of the oil casing threaded joint, the internal thread section 31 and the external thread section 32 both have a bearing surface, a guide surface angle a2 and a thread taper A3, and the bearing surface has an included angle a1 with the vertical direction; wherein A1 is more than or equal to-1 degree and less than or equal to-8 degrees, A2 is more than or equal to 10 degrees and less than or equal to 25 degrees, and A3 is more than or equal to 2 degrees and less than or equal to 8 degrees.

Through the arrangement, the connection strength and the bending resistance of the oil casing joint can be improved; in addition, different tapers can be selected according to different specifications of the oil casing to be connected, and the connection strength and the machining efficiency are guaranteed.

As shown in fig. 6 and 7, in the embodiment of the present invention, the external thread section 32 has an external tooth height h1, and the internal thread section 31 has an internal tooth height h2, wherein h1 is 0.7mm ≦ 1.8mm, and h2 ═ h1+ (0.05-0.55) mm.

Through the arrangement, the internal pressure resistance, the external pressure resistance and the bending resistance of the oil sleeve joint can be further enhanced, and the connection strength is improved.

In the embodiment of the present invention, in order to improve the joint connection strength and the bending resistance, both the outer pitch P1 of the outer threaded section 32 and the inner pitch P2 of the inner threaded section 31 are set within the range of 4TPI to 8 TPI.

As shown in fig. 4, in the embodiment of the present invention, the second groove 60 includes the first cylindrical surface 13 and the third circular arc R12 provided on a part of the inner wall surface of the female screw joint 1, and the sealing tapered surface 12, the first cylindrical surface 13 and the third circular arc R12 are connected in sequence from the screw structure 30 toward the shoulder structure 70.

In the above technical scheme, the first cylindrical surface 13 is connected with the third circular arc R12, and the first cylindrical surface 13, the third circular arc R12 and the sealing arc 22 arranged on the external thread joint 2 form the second groove 60, so that the second groove 60 can be used for storing the redundant thread grease after the sealing surface is buckled, thereby avoiding the influence of the thread grease pressure on the sealing performance.

As shown in fig. 5, in the embodiment of the present invention, the oil casing joint further includes a second cylindrical surface 21 and a fourth circular arc R22 provided on a part of the outer wall surface of the male screw joint 2, and the second cylindrical surface 21, the sealing arc surface 22, and the fourth circular arc R22 are connected in this order from the screw structure 30 toward the shoulder structure 70.

Through the above arrangement, the first groove 40 with the closed space is formed between the second cylindrical surface 21 and the partial inner wall surface of the female adapter 1, the second groove 60 with the closed space is formed between the sealing arc surface 22, the fourth arc R22 and the first cylindrical surface 13, and the first groove 40 and the second groove 60 are used for storing excessive sealing grease, so that the influence of the pressure of the sealing grease on the sealing performance is avoided.

As shown in fig. 5, in the embodiment of the present invention, the oil country tubular good further includes a first inner inclined surface 24 provided on a part of the inner wall surface of the external thread joint 2, the first inner inclined surface 24 gradually becomes away from the axis of the oil country tubular good from the thread structure 30 toward the shoulder structure 70, and the first inner inclined surface 24 has an angle β 1 with the horizontal direction.

Through the setting, certain deformation space is provided between the external thread joint 2 and the internal thread joint 1, and when the pipe end deforms, reasonable contact pressure of a sealing surface can be guaranteed, so that effective sealing can be realized.

In the embodiment of the utility model, R12 is more than or equal to 0.6mm and less than or equal to 1.5mm, R22-R12 is more than or equal to 0mm and less than or equal to 0.5mm, and beta 1 is more than or equal to 6 degrees and less than or equal to 10 degrees.

Through the arrangement, when the pipe ends deform due to threaded connection, reasonable contact pressure between the sealing surfaces is ensured.

As shown in fig. 4, in the embodiment of the present invention, the first recess 40 includes a second inner inclined surface 41, a surface 42 and a third inner inclined surface 43 which are provided on a part of the inner wall surface of the female screw joint 1, and the second inner inclined surface 41, the surface 42 and the third inner inclined surface 43 are connected in sequence from the screw thread structure 30 toward the shoulder structure 70 and enclose the first recess 40 together with a part of the outer wall surface of the male screw joint.

Through the arrangement, the second inner inclined surface 41, the surface 42 and the third inner inclined surface 43 and part of the outer wall surface of the male connector jointly enclose a first groove 40 for storing redundant thread grease after the sealing surface is screwed on, so that the influence of the pressure of the thread grease on the sealing performance is avoided.

In the embodiment of the present invention, as shown in fig. 4, the third inner slope 43 gradually gets closer to the axis of the oil bushing, and the third inner slope 43 forms an angle with the axis of the oil bushing.

With the arrangement, a large closed space is formed inside the first groove 40 and is used for storing redundant thread grease after the sealing surface is buckled.

As shown in fig. 4 and 5, in the embodiment of the present invention, the shoulder structure 70 includes an external shoulder surface 23 provided at an end surface of the external threaded joint 2, and the external shoulder surface 23 has an angle β 2 with the vertical direction.

Through the arrangement, when the male adapter 2 is in threaded connection with the female adapter 1, the outer shoulder surface 23 is abutted and matched with the inner shoulder surface 14 arranged on the end surface of the inner adapter 1 and used for limiting two oil sleeves to be connected; the arrangement of a certain shoulder angle ensures that the inner shoulder surface and the outer shoulder surface keep interference fit after being buckled, and further ensures the sealing performance of the oil sleeve joint.

As shown in fig. 5, in the embodiment of the present invention, an inner shoulder surface 14 is provided on a part of the inner wall surface of the female screw joint 1 and connected to the sealing tapered surface 12, and the inner shoulder surface 14 has an angle α 2 with the vertical direction.

Through the arrangement, when the male adapter 2 is in threaded connection with the female adapter 1, the inner shoulder surface 14 is abutted and matched with the outer shoulder surface 23 and used for limiting two pipe sections (namely two oil casing pipes) to be connected; the arrangement of a certain shoulder angle ensures that the inner shoulder surface and the outer shoulder surface keep interference fit after being buckled, and further ensures the sealing performance of the joint.

In the embodiment of the present invention, in order to ensure the sealing performance of the oil casing joint while ensuring the connection strength, the outer shoulder surface 23 is interference-fitted with the inner shoulder surface 14.

In the embodiment of the utility model, alpha 2 is more than or equal to 6 degrees and less than or equal to 15 degrees, and beta 2-alpha 2 is more than or equal to 0.2 degrees and less than or equal to 0.5 degrees.

Among the above-mentioned technical scheme, the contained angle of interior shoulder 14 and vertical direction is for being more than or equal to 6 alpha 2 and is less than or equal to 15, and the contained angle of outer shoulder 23 and vertical direction sets up to be more than or equal to 0.2 beta 2-alpha 2 and is less than or equal to 0.5, through setting up reasonable circular bead angle, can guarantee that the back is detained inside and outside circular bead keeps interference fit to ensure oil casing coupling's sealing performance.

In an embodiment of the present invention, an oil bushing assembly is further provided, where the oil bushing assembly includes an oil bushing and an oil bushing joint connected to the oil bushing, where the oil bushing joint is the oil bushing joint described above.

Through the arrangement, the oil casing pipe assembly uses the oil casing pipe joint and has better sealing performance, tensile resistance and compression resistance.

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

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.

The effect of the oil casing joint of the present application will be described below with respect to specific embodiments:

the oil sleeve pipe body of the embodiment adopts 177.8 multiplied by 10.36 specification, steel grade P110, the thread bearing surface of the internal and external thread joint is a hook-shaped thread, the tooth tops and tooth bottoms are parallel to the thread axis, the taper is 1:12, the external tooth height h1 is 1.25mm, the internal tooth height h2 is 1.45mm, and the thread pitch P is every 25.4mm, and 5 threads are adopted. The thread form angle A2 of the thread guide surface is 10 degrees, the thread form angle A1 of the thread bearing surface is-4 degrees, the included angle alpha 1 between the sealing conical surface of the internal thread joint 1 and the axial direction is 4.5 degrees, the arc radius R21 of the sealing arc surface 22 of the external thread joint 2 is R80mm degrees, and the angle of the internal shoulder and the external shoulder of the thread joint is 10 degrees. Tests show that the joint has the compressive strength of 58.8MPa, the internal pressure strength of 77.4MPa, the tensile strength of 4132KN and the compressive strength of 4132KN, and meets the working requirements.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects: the threaded connection between the internal thread joint and the external thread joint is realized through a thread structure; the sealing conical surface is in sealing fit with the sealing cambered surface to realize sealing, and the conical surface is sealed against the cambered surface to ensure the contact pressure of the sealing surface after the upper buckle is closed, so that effective sealing can be realized; the first groove can be used for storing excessive sealing grease, so that the influence of the pressure of the thread grease on the sealing performance is avoided; a second groove is formed between the sealing structure and the shoulder structure, so that the sealing structure is far away from the shoulder structure, the influence of the shoulder stress state on the sealing performance of the oil casing joint is greatly reduced, the stability of the sealing performance is improved, and the compression resistance and the over-torsion resistance of the oil casing joint are improved; the circular bead structure is arranged at the end of the threaded joint pipe and used for limiting two connecting pipe sections to be connected and further enhancing the sealing performance of the threaded joint.

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 (11)

1. An oil casing joint, comprising:

a male coupling (2);

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

wherein, along the direction that is on a parallel with the axis of oil casing coupling, screwed joint (2) with be equipped with helicitic texture (30), first recess (40), seal structure (50), second recess (60) and shoulder structure (70) between female connection (1) in proper order, seal structure (50) including sealed conical surface (12) and with part sealed cambered surface (22) of sealed conical surface (12) sealed complex, sealed conical surface (12) set up on the partial internal face of female connection (1), sealed cambered surface (22) set up on the partial outer wall face of male connection (2).

2. The oil casing joint according to claim 1, wherein the sealing structure (50) further comprises a first circular arc R11 provided on a part of the inner wall surface of the female screw joint (1), the first circular arc R11 and the sealing tapered surface (12) are connected in sequence from the screw thread structure (30) to the shoulder structure (70), the sealing tapered surface (12) is gradually close to the axis of the oil casing joint, and an included angle α 1 is formed between the sealing tapered surface (12) and the axis of the oil casing joint; the sealing arc surface (22) is provided with a second circular arc R21.

3. The oil casing joint according to claim 2,

the second groove (60) comprises a first cylindrical surface (13) arranged on part of the inner wall surface of the female adapter (1), and the first circular arc R11, the sealing conical surface (12) and the first cylindrical surface (13) are sequentially connected from the thread structure (30) to the direction of the shoulder structure (70);

the oil casing joint also comprises a second cylindrical surface (21) arranged on part of the outer wall surface of the external thread joint (2), and the second cylindrical surface (21) is sequentially connected with the sealing cambered surface (22) from the thread structure (30) to the direction of the shoulder structure (70);

along the axial direction of the oil casing joint, the distance between one end of the first cylindrical surface (13) close to the sealing conical surface (12) and the shoulder structure (70) is L12, the distance between one end of the sealing conical surface (12) far away from the first cylindrical surface (13) and the shoulder structure (70) is L11, the distance between one end of the second cylindrical surface (21) far away from the sealing cambered surface (22) and the shoulder structure (70) is L21, wherein L11 is not less than 12mm and not more than 18mm, L12/L11 is not less than 0.8 and L21 is not less than 14mm and not more than 20 mm.

4. The oil casing joint according to claim 2, characterized in that α 1 is 3 ° or more and 10 ° or less, R11 is 4mm or more and 8mm or less, and R21 is 50mm or more and 120mm or less.

5. The oil casing joint according to any one of claims 1 to 4, characterized in that the thread structure (30) comprises:

an internal thread section (31) provided on a part of an inner wall surface of the female adapter (1);

the external thread section (32) is arranged on part of the outer wall surface of the external thread joint (2), the internal thread section and the external thread section are provided with bearing surfaces, a guide surface angle A2 and a thread taper A3, and an included angle A1 is formed between the bearing surfaces and the vertical direction;

wherein A1 is more than or equal to-1 degree and less than or equal to-8 degrees, A2 is more than or equal to 10 degrees and less than or equal to 25 degrees, and A3 is more than or equal to 2 degrees and less than or equal to 8 degrees.

6. The oil casing joint according to claim 5, characterized in that the external thread section (32) has an external tooth height h1 and the internal thread section (31) has an internal tooth height h2, wherein 0.7mm ≦ h1 ≦ 1.8mm and h2 ≦ h1+ (0.05-0.55) mm.

7. The oil casing joint according to any one of claims 1 to 4,

the second groove (60) comprises a first cylindrical surface (13) and a third circular arc R12 which are arranged on part of the inner wall surface of the female adapter (1), and the sealing conical surface (12), the first cylindrical surface (13) and the third circular arc R12 are connected in sequence from the thread structure (30) to the direction of the shoulder structure (70);

the oil sleeve joint further comprises a second cylindrical surface (21) and a fourth circular arc R22 which are arranged on part of the outer wall surface of the external thread joint (2), and the second cylindrical surface (21), the sealing cambered surface (22) and the fourth circular arc R22 are sequentially connected from the thread structure (30) to the direction of the shoulder structure (70);

the oil sleeve joint further comprises a first inner inclined surface (24) arranged on part of the inner wall surface of the external thread joint, the first inner inclined surface (24) is gradually far away from the axis of the oil sleeve joint from the thread structure (30) to the direction of the shoulder structure (70), and an included angle beta 1 is formed between the first inner inclined surface (24) and the horizontal direction;

wherein R12 is more than or equal to 0.6mm and less than or equal to 1.5mm, R22-R12 is more than or equal to 0mm and less than or equal to 0.5mm, beta 1 is more than or equal to 6 degrees and less than or equal to 10 degrees.

8. The oil casing joint according to any one of claims 1 to 4, characterized in that the first groove (40) comprises a second inner chamfer (41), a surface (42) and a third inner chamfer (43) provided on a part of the inner wall surface of the female joint (1), the second inner chamfer (41), the surface (42) and the third inner chamfer (43) are connected in sequence from the thread formation (30) in the direction of the shoulder formation (70), the third inner chamfer (43) is gradually closer to the axis of the oil casing joint, an angle is provided between the third inner chamfer (43) and the axis of the oil casing joint, and the second inner chamfer (41), the surface (42), the third inner chamfer (43) and a part of the outer wall surface of the male joint together enclose the first groove (40).

9. The oil bushing joint according to any of claims 1-4, characterized in that the shoulder structure (70) comprises:

the external shoulder surface (23) is arranged on the end surface of the external thread joint (2), and an included angle beta 2 is formed between the external shoulder surface (23) and the vertical direction;

the inner shoulder surface (14) is arranged on part of the inner wall surface of the female adapter (1) and is connected with the sealing conical surface, and an included angle alpha 2 is formed between the inner shoulder surface (14) and the vertical direction;

wherein the outer shoulder surface (23) is in interference fit with the inner shoulder surface (14).

10. The oil casing joint according to claim 9, wherein α 2 is 6 ° or more and 15 ° or less, and β 2- α 2 is 0.2 ° or more and 0.5 ° or less.

11. 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 according to any one of claims 1 to 10.

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