CN217558275U

CN217558275U - Special thread oil pipe suitable for under combined load condition

Info

Publication number: CN217558275U
Application number: CN202220937299.3U
Authority: CN
Inventors: 胡伟; 薛永振; 王有军; 张厚磊; 袁俪华; 袁盛望
Original assignee: Tianjin Longkailai Petroleum Equipment Co ltd
Current assignee: Tianjin Longkailai Petroleum Equipment Co ltd
Priority date: 2022-04-21
Filing date: 2022-04-21
Publication date: 2022-10-11
Anticipated expiration: 2032-04-21

Abstract

The utility model discloses a special thread oil pipe suitable for composite load condition, which comprises a female end arranged at one side of the oil pipe, a male end arranged at the other side of the oil pipe and a sealing sleeve connected with the female end; the end part of the female end is provided with a sealing groove, an internal thread and an internal sealing structure from left to right in sequence; the male end is provided with a buckle tail, an external thread and an external sealing structure from left to right in sequence; during assembly, the external thread of one oil pipe is screwed into the female end internal thread of the other oil pipe clockwise along the axis direction, and the internal thread of the sealing sleeve is gradually in threaded connection with the buckle tail and covers the buckle tail. The utility model discloses the long volatile risk of imitating of external screw thread knot tail has effectively been solved in screw thread seal cover elastic sealing structure's design, effectively improves screwed joint's sealing performance with the design that the conical surface is sealed to the conical surface metal to constitute double seal structure simultaneously, ensures the airtight effect under complicated well conditions such as deep well, ultra-deep well, high-pressure gas well.

Description

Special thread oil pipe suitable for under combined load condition

Technical Field

The utility model relates to an oil gas bores tubular product threaded connection technical field, in particular to special thread oil pipe under being applicable to the composite load condition.

Background

In the field of oil and gas drilling and production of pipes, an oil pipe column is formed by connecting single oil well pipes through threads, and the threaded connection part of the oil pipe column is a weak key link. In the general API standard, the oil pipe adopts a connection mode that a round thread is externally thickened or is not thickened. These types of connections present certain problems in ensuring both the structural integrity and the sealing integrity of the pipe string. For example, the thread connection strength of a round thread pipe without thickening is only 60% -80% of the pipe body strength, and the connection strength of an externally thickened round thread is close to or reaches the pipe body strength but is complex to process by upsetting the pipe end.

Tests prove that the API round thread connection uses proper thread grease, has better water sealing performance after being tightened, but has very low air sealing performance. This is mainly due to: API standard threaded connections, there is a clearance at the crest or flank. After the joint is screwed, the contact surfaces of the engaged threads have contact pressure due to interference. Meanwhile, the thread grease is filled in the thread gap to realize water sealing. At higher temperatures, however, the thread grease filling the thread spaces evaporates and shrinks, allowing leak paths between the engaged threads through which gas leaks. In addition, the acidic components of hydrogen sulfide contained in oil gas can cause slow stress corrosion of the common API oil pipe, so that the oil pipe is deformed and damaged in the long-term use process.

In the development process of the petroleum industry, along with the development of oil well gas drilling and production operations to deep wells, ultra-deep wells, high-pressure gas wells, directional wells and wells in acidic environments, higher requirements are put forward on the service performance of petroleum oil pipes. Oil pipes with API standard threaded connections are difficult to meet production requirements in many cases, and development of various types of special threaded connections is urgently needed to meet production requirements.

Simultaneously current special knot or API standard oil pipe's external screw thread length all is greater than internal thread length on the market, and the external screw thread twists behind the internal thread and detains the tail end and spill the incomplete screw thread of unnecessary several knots naturally, and this several knot depressed part forms stress concentration point naturally, belongs to dangerous cross-section, simultaneously with inside screw thread UNICOM, becomes to leak the passway mouth objectively, has joint strength and sealed dual failure risk point.

Based on the above, various countries in the world and various large petroleum special-purpose pipe manufacturing plants in China all strive to develop special petroleum oil pipes with special thread structures and superior connection strength and sealing performance.

SUMMERY OF THE UTILITY MODEL

To the technical problem who exists among the above-mentioned prior art, the utility model aims at providing a be applicable to special screw thread oil pipe under the composite load condition.

In order to achieve the above purpose, the utility model provides a technical scheme as follows:

a special thread oil pipe suitable for a composite load condition comprises a female end arranged on one side of the oil pipe, a male end arranged on the other side of the oil pipe and a seal sleeve connected with the female end;

the end part of the female end is sequentially provided with a sealing groove, internal threads and an internal sealing structure from left to right, the internal sealing structure is provided with an internal sealing conical surface and an internal torque shoulder, wherein the right end of the sealing sleeve is connected with the sealing groove, and the inner circumference of the left end of the sealing sleeve is provided with the internal threads;

the male end is provided with a buckle tail, an external thread and an external sealing structure in sequence from left to right, wherein the external sealing structure comprises an external sealing conical surface and an external torque shoulder;

during assembly, the external thread of one oil pipe is screwed into the internal thread of the female end of the other oil pipe clockwise along the axis direction, the internal thread of the sealing sleeve is gradually in threaded connection with the buckle tail and covers the buckle tail, the outer sealing conical surface is in interference fit connection with the inner sealing conical surface, and the inner smooth transition structure is closed.

The tooth profile of the internal thread and the tooth profile of the external thread are both hook-type threads, the tooth height of the internal thread is =1.000 mm-1.191 mm, the tooth height of the external thread is =0.800 mm-0.991 mm, the pitch of the internal thread is =3.175mm or 4.233mm, the taper of the internal thread is =0.0625 of the external thread, the inner bearing angle is =3 degrees, and the included angle of the inner guide surface is =10 degrees.

The smooth transition structure sequentially comprises an inner hole, a transition conical surface, an inner boring hole and a middle hole, wherein the diameter of the inner hole = the outer diameter of a product specification-2 x of the product specification wall thickness, the diameter of the boring hole = the diameter of the middle hole, and the taper angle N =3 degrees of the transition conical surface.

Wherein the sealing sleeve is made of butadiene acrylonitrile rubber or hydrogenated butadiene acrylonitrile rubber.

Wherein the outer shoulder angle of the outer torque shoulder = -15 °, and the inner shoulder angle of the inner torque shoulder = -15 °.

Wherein the product specification outer diameter =60.3 mm-114.3 mm, and the product specification wall thickness =4.0 mm-15.0 mm.

Compared with the prior art, the utility model has the advantages that,

1. the smooth transition design is adopted at the inner surface joint of the inner and outer threaded joints, so that the generation of turbulence is eliminated, failure risk points are reduced, the quality risk of the threaded joint can be effectively reduced, the comprehensive quality safety coefficient of the whole oil casing string is improved, meanwhile, the fluid flow is facilitated, and the drilling efficiency is greatly improved;

2. the design of the elastic sealing structure of the thread sealing sleeve effectively solves the problem of long volatile effect risk of the external thread buckle tail, and simultaneously, the design of a double sealing structure formed by the elastic sealing structure and the conical surface to the conical surface metal seal effectively improves the sealing performance of the threaded joint and ensures the air sealing effect under complex well conditions such as deep wells, ultra-deep wells, high-pressure wells and the like;

3. the-3-degree thread bearing angle and the torque shoulder adopt a combined wedge-shaped design of a-15-degree reverse shoulder, so that the high-efficiency anti-extrusion and anti-internal-pressure connection strength can be provided under the condition of high composite bearing capacity, and the device is particularly suitable for being used in the ultra-deep well of the horizontal well; meanwhile, the anti-thread sticking position of the upper thread can be accurately controlled, and the quality control and the large-scale production are facilitated.

Drawings

Fig. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic structural view of the assembled state of the present invention;

FIG. 3 is a schematic view of the female end of the present invention;

fig. 4 is a schematic view of the inner sealing structure of the present invention;

fig. 5 is a schematic view of the male end structure of the present invention;

fig. 6 is a schematic diagram of the external sealing structure of the present invention;

fig. 7 is a schematic view of the smooth transition structure of the present invention;

fig. 8 is a schematic view of the internal thread profile of the present invention;

fig. 9 is a schematic view of the external thread profile of the present invention;

in the figure: 1-sealing sleeve, 2-female end, 3-male end, 4-internal thread, 5-internal sealing structure, 6-sealing groove, 7-internal sealing conical surface, 8-internal torque shoulder, 9-external thread, 10-external sealing structure, 11-buckle tail, 12-external sealing conical surface, 13-external torque shoulder, 14-internal hole, 15-transition conical surface, 16-internal boring hole, 17-mesopore, 18-smooth transition structure, H-internal thread tooth height, H-external thread tooth height, P-external thread pitch, P-internal thread pitch, A-internal bearing angle, a-external bearing angle, B-internal guide surface angle, B-external guide surface angle, C-internal shoulder angle, C-external shoulder angle, N-taper angle, M-mesopore diameter, D-internal hole diameter, K-boring diameter, D-product specification external diameter, t-specification wall thickness.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts all belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description of this patent, it is noted that unless otherwise specifically stated or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly and can include, for example, fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meaning of the above terms in this patent may be understood by one of ordinary skill in the art as appropriate.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

Please refer to fig. 1-9, which illustrate an embodiment of the present invention.

The special threaded oil pipe applicable to the composite load condition comprises a female end 2 arranged on one side of the oil pipe, a male end 3 arranged on the other side of the oil pipe and a seal sleeve 1 connected with the female end 2;

the end part of the female end 2 is sequentially provided with a sealing groove 6, an internal thread 4 and an internal sealing structure 5 from left to right, the internal sealing structure 5 is provided with an internal sealing conical surface 7 and an internal torque shoulder 8, wherein the right end of the sealing sleeve 1 is connected with the sealing groove 6, and the inner circumference of the left end of the sealing sleeve 1 is provided with the internal thread;

the male end 3 is sequentially provided with a buckle tail 11, an external thread 9 and an external sealing structure 10 from left to right, wherein the external sealing structure 10 comprises an external sealing conical surface 12 and an external torque shoulder 13;

during assembly, the external thread 9 of one oil pipe is screwed into the internal thread 4 of the female end of the other oil pipe clockwise along the axis direction, the internal thread of the sealing sleeve 1 is gradually in threaded connection with the buckle tail 11 and covers the buckle tail 11, the outer sealing conical surface 12 is in interference fit connection with the inner sealing conical surface 7, and the inner smooth transition structure 18 is closed.

In a preferred embodiment, the tooth profiles of the internal thread 4 and the external thread 9 are both hook-type threads, the tooth height H of the internal thread is =1.000 mm-1.191 mm, the tooth height H of the external thread is =0.800 mm-0.991 mm, the pitch P of the internal thread is =3.175mm or 4.233mm, the taper of the internal thread is =0.0625, the internal bearing angle a = the external bearing angle a = -3 °, and the internal guide surface included angle B = the external guide surface included angle B =10 °.

In the preferred embodiment, the smooth transition structure 18 includes, in order, an inner bore 14, a transition taper 15, an inner bore 16, and a middle bore 17, wherein the inner bore diameter D = product gauge outer diameter D-2x product gauge wall thickness t, the bore diameter K = middle bore diameter M, and the taper angle N of the transition taper 15 =3 °.

In a preferred embodiment, the material of the sealing sleeve 1 is butadiene acrylonitrile rubber or hydrogenated butadiene acrylonitrile rubber.

In a preferred embodiment, the outer shoulder angle C of the outer torque shoulder 13 = -15 °, and the inner shoulder angle C of the inner torque shoulder 8 = -15 °.

In a preferred embodiment, the product specification outer diameter D =60.3 mm-114.3 mm, and the product specification wall thickness t =4.0 mm-15.0 mm.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the description in the above embodiments and the description is only preferred examples of the present invention, and is not intended to limit the present invention, and that the present invention can have various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications all fall into the scope of the claimed invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A special threaded oil pipe suitable for a composite load condition is characterized by comprising a female end (2) arranged on one side of the oil pipe, a male end (3) arranged on the other side of the oil pipe and a sealing sleeve (1) connected with the female end (2);

the end part of the female end (2) is sequentially provided with a sealing groove (6), an internal thread (4) and an internal sealing structure (5) from left to right, the internal sealing structure (5) is provided with an internal sealing conical surface (7) and an internal torque shoulder (8), wherein the right end of the sealing sleeve (1) is connected with the sealing groove (6), and the inner circumference of the left end of the sealing sleeve (1) is provided with the internal thread;

the male end (3) is sequentially provided with a buckle tail (11), an external thread (9) and an external sealing structure (10) from left to right, wherein the external sealing structure (10) comprises an external sealing conical surface (12) and an external torque shoulder (13);

during assembly, the external thread (9) of one oil pipe is screwed into the internal thread (4) of the other oil pipe clockwise along the axis direction, the internal thread of the sealing sleeve (1) is gradually in threaded connection with the buckle tail (11) and covers the buckle tail (11), the external sealing conical surface (12) is in interference fit connection with the internal sealing conical surface (7), and the internal smooth transition structure (18) is closed.

2. The special threaded oil pipe suitable for the composite load condition according to claim 1, wherein the tooth profile of the internal thread (4) and the external thread (9) are both hook type threads, the internal thread tooth height (H) =1.000mm to 1.191mm, the external thread tooth height (H) =0.800mm to 0.991mm, the internal thread pitch (P) = the external thread pitch (P) =3.175mm or 4.233mm, the internal thread taper = the external thread taper =0.0625, the internal bearing angle (a) = the external bearing angle (a) = -3 °, and the internal guide face angle (B) = the external guide face angle (B) =10 °.

3. The special threaded oil pipe for composite load conditions according to claim 1, wherein the smooth transition structure (18) comprises an inner bore (14), a transition taper (15), an inner bore (16) and an intermediate bore (17) in this order, wherein the inner bore diameter (D) = product gauge outer diameter (D) -2x product gauge wall thickness (t), the bore diameter (K) = intermediate bore diameter (M), and the taper angle (N) =3 ° of the transition taper (15).

4. The special threaded oil pipe suitable for the combined load condition as claimed in claim 1, wherein the sealing sleeve (1) is made of butadiene acrylonitrile rubber or hydrogenated butadiene acrylonitrile rubber.

5. A premium thread oil pipe adapted for use in compound load conditions, as claimed in claim 1, wherein the external shoulder angle (C) = -15 ° of the external torque shoulder (13), and the internal shoulder angle (C) = -15 ° of the internal torque shoulder (8).

6. The special threaded oil pipe suitable for composite load conditions as claimed in claim 1, wherein the product specification outer diameter (D) =60.3mm to 114.3mm, and the product specification wall thickness (t) =4.0mm to 15.0mm.