CN215889934U - Metal gas-tight sealing oil casing - Google Patents
Metal gas-tight sealing oil casing Download PDFInfo
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- CN215889934U CN215889934U CN202122157043.9U CN202122157043U CN215889934U CN 215889934 U CN215889934 U CN 215889934U CN 202122157043 U CN202122157043 U CN 202122157043U CN 215889934 U CN215889934 U CN 215889934U
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Abstract
The utility model discloses a metal gas sealing oil casing, which comprises a pipe body with an external thread and a coupling with an internal thread, wherein the pipe body is in threaded connection with the coupling; the pipe body and the coupling respectively comprise a threaded section, a sealing surface section and a shoulder which are arranged in sequence; the thread segments include a first thread segment without a taper and a second thread segment with a taper, wherein the second thread segment is in engagement with the sealing segment surface. The metal gas seal oil casing pipe is very suitable for being applied to a gas well in a corrosive environment, can be effectively applied to safe exploitation and development of natural gas, and has very good popularization prospect.
Description
Technical Field
The utility model relates to a pipe fitting, in particular to an air-tight oil sleeve.
Background
As is well known, oil casing is a passageway for establishing series connection of underground oil and gas resources and land, and is an important foundation in oil and gas exploitation. However, due to severe conditions such as gas leakage and corrosion of toxic gases, the oil casing is required to have high gas tightness and other performances in general oil and gas exploitation. Therefore, the oil casing with the air sealing performance is particularly important in the natural gas exploitation process.
In the prior art, commonly used oil casings can be classified into API series oil casings and other oil casings with air-tight performance. The API threaded joint of the API series oil casing does not have the gas-stable sealing capacity, is easy to slip, has low tensile strength and poor torsion resistance and compression resistance.
Of course, in the prior art, some oil casings can also ensure the air-tight performance by designing special threaded joints; these special threaded joints are also typically made up of male and female ends that ensure high tensile, compression and gas tightness of the threaded joint by changing the thread topography or adding face seal members.
For example: many patent technical documents such as patents CN201320838237.8, CN200920064055.3, CN201120210035.x, CN200910092028.1, cn01253367.x all achieve higher air sealing capability by changing thread morphology and adding a sealing surface and a limiting shoulder, and are typical special air sealing threaded joints. However, the angular form of the thread, the sealing surface, etc. provided in the above patent documents is practically difficult to achieve completely in a real machining process.
Therefore, the utility model expects to obtain a novel metal air seal oil sleeve which can ensure the integrity of the structure and the performance of the oil sleeve under the conditions of stretching, compression, internal pressure, external pressure, high temperature (180 ℃), bending (20 DEG/30 m) and the like through reasonable innovative structural design.
The metal gas-sealed oil casing is very suitable for being applied to a corrosive environment gas well, can be effectively applied to safe exploitation and development of natural gas, and has very good popularization prospect.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a metal air seal oil sleeve, which can ensure the integrity of the structure and the performance of the oil sleeve under the conditions of stretching, compression, internal pressure, external pressure, high temperature (180 ℃), bending (20 DEG/30 m) and the like through reasonable innovative structural design.
The metal gas-sealed oil casing is very suitable for being applied to a corrosive environment gas well, can be effectively applied to safe exploitation and development of natural gas, and has very good popularization prospect.
In order to achieve the above object, the present invention provides a metal gas seal oil bushing, which includes a pipe body having an external thread and a coupling having an internal thread, the pipe body being in threaded connection with the coupling; the pipe body and the coupling respectively comprise a threaded section, a sealing surface section and a shoulder which are arranged in sequence; the thread segments include a first thread segment without a taper and a second thread segment with a taper, wherein the second thread segment is in engagement with the sealing segment surface.
In the technical scheme, the reasonable optimization design is carried out on the threads of the pipe body and the coupling, and the pipe body and the coupling are connected in series through the threads between thread sections, so that the oil casings can be connected in series, and the stable air sealing capability is maintained while the connection strength is ensured; in addition, in this embodiment, the screw thread of body and coupling screw thread section has adopted the taper structure that becomes, can satisfy the tensile demand of higher strength. Wherein, the taper can be expressed as the included angle between the thread and the axial direction of the pipe body or the coupling.
In the present invention, the threaded sections of the pipe body and the coupling are provided as a first threaded section having no taper and a second threaded section having a taper. The second thread section connected with the sealing section surface can be better matched in a fastening way in subsequent application; the first thread section adopts the non-taper thread, so that the meshing height of the inner thread and the outer thread of the pipe body and the coupling can be improved, and the connection strength of the threads is improved.
In some preferred embodiments, in order to achieve better implementation, the taper of the second thread segments may be preferably controlled to be between 1:16 and 1: 12.
Furthermore, in the metal gas seal oil sleeve, the taper of the second thread section is 1: 16-1: 12.
Further, in the metal gas seal oil bushing according to the present invention, in a state of being screwed, a gap is provided between teeth of the threaded section of the pipe body and teeth of the threaded section of the coupling.
In the technical scheme of the utility model, in the threaded connection state, gaps still remain between the teeth of the threaded section of the pipe body and the teeth of the threaded section of the coupling, and the remaining gaps can be used for storing thread grease so as to assist in sealing.
Further, in the metal gas-seal oil bushing according to the present invention, the sealing surface section of the pipe body and the sealing surface section of the coupling are in interference fit.
Further, in the metal gas seal oil bushing, the interference magnitude of the interference fit is 0.3-1 mm.
Further, in the metal gas seal oil bushing according to the present invention, the length of the seal face section in the axial direction is 1 to 5 mm.
Further, in the metal gas seal oil bushing according to the present invention, a taper β of the sealing surface section of the coupling is smaller than a taper γ of the sealing surface section of the pipe body.
In the technical scheme of the utility model, the taper beta of the sealing surface section of the coupling can be further controlled to be smaller than the taper gamma of the sealing surface section of the pipe body, which is different from other sealing oil sleeve designs in the prior art. By the design, the actual interference magnitude of the sealing surface section after the pipe body is meshed with the coupling can be evenly distributed, and more complete air sealing performance is achieved.
Further, in the metal gas seal oil bushing according to the present invention, a difference between γ and β is 5 to 15 °.
Further, in the metal gas seal oil bushing according to the present invention, an angle θ 2 of a shoulder of the coupling is greater than an angle θ 1 of a shoulder of the pipe body.
In the above technical solution of the present invention, θ 1 represents an angle between the shoulder end surface of the pipe body and the axial direction, and θ 2 represents an angle between the shoulder end surface of the coupling and the axial direction.
In the utility model, the angle theta 2 of the shoulder can be controlled to be larger than the angle theta 1 of the shoulder of the pipe body, and preferably theta 1 and theta 2 are controlled to be between 10 and 20 degrees, and the difference value between theta 2 and theta 1 is 0.5 to 2. Wherein, control theta 1 is less than theta 2 and is favorable to being twisted and connect spacing back, and the body is laminated completely with the inner wall of coupling, reduces the condition such as turbulent flow, crevice corrosion.
Further, in the metal gas seal oil bushing according to the present invention, a difference between θ 2 and θ 1 is 0.5 to 2 °.
Further, in the metal gas seal oil bushing according to the present invention, the tooth profile of the thread section is trapezoidal.
Further, in the metal gas seal oil bushing according to the present invention, the outer diameter thereof is 60 to 400 mm.
Compared with the prior art, the metal gas-sealing oil sleeve has the following advantages and beneficial effects:
in the utility model, the metal gas-sealing oil sleeve adopts a reasonable structural design, and adopts innovative optimized structural design on the aspects of threads, metal sealing surfaces and shoulders, so that the performance of a pipe fitting can be effectively ensured.
The metal gas seal oil casing can ensure the integrity of the structure and the performance of the oil casing under the conditions of stretching, compression, internal pressure, external pressure, high temperature (180 ℃), bending (20 degrees/30 m) and the like, is very suitable for being applied to a corrosive environment gas well, can be effectively applied to the safe exploitation and development of natural gas, and has very good popularization prospect.
Drawings
Fig. 1 is a partial structural view illustrating a threaded connection between a pipe body and a coupling according to an embodiment of the present invention.
Fig. 2 is a partially enlarged view of the structure shown in fig. 1.
Fig. 3 is a schematic structural diagram illustrating an interference fit between a pipe body sealing surface section and a coupling sealing surface section according to an embodiment of the metal gas seal oil bushing of the present invention.
FIG. 4 is a schematic diagram of a body shoulder and a collar shoulder of a metal gas seal oil bushing according to an embodiment of the present invention.
Detailed Description
The metal gas seal oil bushing according to the present invention will be further explained and illustrated with reference to the drawings and the specific embodiments of the present specification, however, the explanation and the illustration should not be construed as an undue limitation on the technical solution of the present invention.
Fig. 1 is a partial structural view illustrating a threaded connection between a pipe body and a coupling according to an embodiment of the present invention.
As shown in fig. 1, in the present embodiment, the metal gas-tight oil casing according to the present invention may include a pipe body a and a coupling B, each of which includes a threaded section, a sealing surface section, and a shoulder, which are sequentially disposed.
Referring further to fig. 1, it can be seen that in this embodiment, the tubular body a of the metal gas tight oil bushing of the present invention has an external threaded section 1, a sealing face section 5 of the tubular body, and a shoulder 3 of the tubular body, and the coupling B has an internal threaded section 2, a sealing face section 6 of the coupling, and a shoulder 4 of the coupling.
In the utility model, the pipe body A and the coupling B are connected through the thread between the external thread section 1 and the internal thread section 2, so that the oil casings can be connected with each other, thereby ensuring the connection strength and maintaining the stable air sealing capability. It should be noted that, in general, a coupling B has two internal thread segments 2 for connecting to two pipes a.
In addition, the pipe body A and the coupling B can be limited by the mutual matching of the shoulder 3 of the pipe body and the shoulder 4 of the coupling, and the relative position of the screwed pipe body A and the coupling B is ensured, so that the torsion resistance of the coupling B is ensured.
In addition, in the metal gas-tight oil bushing according to the present invention, the sealing surface section 5 of the pipe body a may be interference-fitted with the sealing surface section 6 of the coupling B.
Referring to fig. 1 again, in the present embodiment, the thread segment 1 of the pipe body a is lower than the thread segment 2 of the coupling B, so that after the two are in threaded connection, i.e. the internal and external threads are screwed, a gap is formed between the teeth of the thread segment 1 of the pipe body a and the teeth of the thread segment 2 of the coupling B, and the remaining gap can be used for storing thread grease, thereby assisting in sealing.
It should be noted that, in the practical design application process, the outer diameter of the metal gas seal oil bushing of the present invention can be controlled to be 60-400 mm. The tooth profiles of the thread sections of the pipe body A and the coupling B can be designed to be trapezoidal.
Fig. 2 is a partially enlarged view of the structure shown in fig. 1.
As shown in fig. 2, in the present embodiment, the threads of the external thread section 1 and the internal thread section 2 both adopt a variable taper structure, that is, the external thread section 1 of the pipe body a and the internal thread section 2 of the coupling B both include a first thread section L1 without taper (i.e. taper of 0) and a second thread section L2 with taper, wherein the second thread section L2 is engaged with the sealing section surface, that is, the second thread section is closer to the axial center of the coupling B than the first thread section. The structure can meet the requirement of higher strength and tensile strength. The taper of the threads is a term of art known in the art and refers to the angle of the threads relative to the axial direction of the pipe body a or coupling B.
With continued reference to fig. 2, it can be seen that the length of the second thread segments L2 may be 40% to 60% of the length of the entire thread segment. This tapered second thread segment L2 provides a better snap fit for subsequent use. In some embodiments, the taper of the second thread segments L2 may be between 1:16 and 1: 12.
In the technical scheme, the first thread section L1 has no taper, and the thread engagement height of the pipe body A and the coupling B can be improved by the thread without taper, so that the connection strength of the thread is improved.
Fig. 3 is a schematic structural diagram illustrating an interference fit between a pipe body sealing surface section and a coupling sealing surface section according to an embodiment of the metal gas seal oil bushing of the present invention.
As shown in fig. 3, in the present invention, the taper gamma of the sealing surface section 5 of the pipe body and the taper beta of the sealing surface section 6 of the coupling are different from each other, unlike the prior art. By adopting the design scheme, the deformation resistance and the strain of the sealing surface of the pipe body and the sealing surface of the coupling are different after the pipe body is meshed with the coupling threads. Through the design of the utility model, the actual interference magnitude of the sealing surface sections 5 and 6 can be evenly distributed after the pipe body A is meshed with the coupling B, and more complete air tightness is achieved.
Further, in the present invention, the taper β of the sealing surface section 6 of the coupling B can also be controlled to be smaller than the taper γ of the sealing surface section 5 of the pipe body a.
Further, γ — β may be controlled to be (5 to 15 °).
It should be noted that the taper of the sealing surface section is the included angle between the sealing surface and the axial direction of the pipe body A or the coupling B.
In the present invention, the diameter of the tubular body a at the sealing face section 5 is greater than the diameter of the coupling B at the sealing face section 6, thereby forming an interference fit.
It should be noted that, in some embodiments of the present invention, the length S1 of the sealing surface section of the pipe body a and the coupling B in the axial direction may be controlled to be between 1mm and 5mm, so as to effectively ensure the sealing contact length, and also reduce galling caused by an excessively long sealing surface section.
Furthermore, in certain embodiments of the present invention, the interference of the interference fit between the sealing surface section 5 of the pipe body a and the sealing surface section 6 of the coupling B can be controlled between 0.3 and 1mm, and the specific interference can be controlled by one skilled in the art according to the external diameter specification and steel grade of the oil casing.
FIG. 4 is a schematic diagram of a body shoulder and a collar shoulder of a metal gas seal oil bushing according to an embodiment of the present invention.
The shoulder functions to increase the compression, torsional resistance and secondary sealing action of the oil casing joint. In the utility model, the shoulder 3 of the pipe body A and the shoulder 4 of the coupling B adopt different angles so as to ensure that the shoulder 3 of the pipe body A and the shoulder 4 of the coupling B are uniformly and tightly attached without generating gaps after screwing. As shown in fig. 4, θ 1 represents an angle between the end surface of the shoulder 3 of the pipe body a as the male end and the axial direction, and θ 2 represents an angle between the end surface of the shoulder 4 of the coupling B as the female end and the axial direction.
In the present invention, the angle θ 2 of the shoulder may be controlled to be greater than the angle θ 1 of the shoulder of the pipe body, and preferably θ 1, θ 2 is controlled to be between 10 ° and 20 °, and θ 2 — θ 1 is (0.5 °, 2 °). Wherein, control theta 1 is less than theta 2 and is favorable to being twisted and connect spacing back, and public female end inner wall is laminated completely, reduces the condition such as turbulent flow, crevice corrosion.
The utility model adopts the embodiment 1 and the embodiment 2 to further verify the implementation effect of the metal gas seal oil sleeve.
Table 1 lists the selected limiting parameters for example 1 and example 2.
Table 1.
As shown in table 1, the metal gas-sealed oil casings of the above examples 1 and 2 were subjected to ISO 13679CAL iv test, which is the most severe test for oil well pipe joints internationally, to finally obtain the test requirements satisfied by both examples 1 and 2.
In conclusion, the metal gas-sealing oil sleeve adopts a reasonable structural design, adopts innovative optimized structural design on the aspects of threads, metal sealing surfaces and shoulders, and can effectively ensure the performance of the pipe fitting.
The metal gas seal oil casing can ensure the integrity of the structure and the performance of the oil casing under the conditions of stretching, compression, internal pressure, external pressure, high temperature (180 ℃), bending (20 degrees/30 m) and the like, is very suitable for being applied to a corrosive environment gas well, can be effectively applied to the safe exploitation and development of natural gas, and has very good popularization prospect.
It should be noted that the prior art in the protection scope of the present invention is not limited to the examples given in the present application, and all the prior art which is not inconsistent with the technical scheme of the present invention, including but not limited to the prior patent documents, the prior publications and the like, can be included in the protection scope of the present invention.
In addition, the combination of the features in the present application is not limited to the combination described in the claims of the present application or the combination described in the embodiments, and all the features described in the present application may be freely combined or combined in any manner unless contradictory to each other.
It should also be noted that the above-mentioned embodiments are only specific embodiments of the present invention. It is apparent that the present invention is not limited to the above embodiments and similar changes or modifications can be easily made by those skilled in the art from the disclosure of the present invention and shall fall within the scope of the present invention.
Claims (12)
1. A metal gas seal oil casing comprises a pipe body with external threads and a coupling with internal threads, wherein the pipe body is in threaded connection with the coupling; the pipe body and the coupling respectively comprise a threaded section, a sealing surface section and a shoulder which are arranged in sequence; the method is characterized in that: the thread segments include a first thread segment without a taper and a second thread segment with a taper, wherein the second thread segment is in engagement with the sealing segment surface.
2. The metal-gas seal oil bushing of claim 1 wherein the taper of the second thread segments is 1:16 to 1: 12.
3. The metal gas seal oil bushing according to claim 1, wherein in the threaded connection state, there is a gap between teeth of the threaded section of the pipe body and teeth of the threaded section of the coupling.
4. The metal gas seal oil bushing of claim 1, wherein the sealing face section of the tubular body and the sealing face section of the collar are an interference fit.
5. The metal-gas seal oil bushing according to claim 4, wherein the interference fit has an interference of 0.3-1 mm.
6. The metal-gas seal oil bushing according to claim 1, wherein the length of the seal face segment in the axial direction is 1-5 mm.
7. The metal gas seal oil bushing of claim 1, wherein the taper β of the sealing face section of the collar is less than the taper γ of the sealing face section of the tubular body.
8. The metal-gas seal oil bushing of claim 7, wherein the difference between γ and β is 5-15 °.
9. The metal gas seal oil bushing of claim 1, wherein an angle θ 2 of the shoulder of the coupling is greater than an angle θ 1 of the shoulder of the pipe body.
10. The metal-gas seal oil bushing according to claim 1, wherein the difference between θ 2 and θ 1 is 0.5 to 2 °.
11. The metal-gas sealed oil bushing according to claim 1, wherein the profile of the thread segments is trapezoidal.
12. The metal-gas seal oil bushing according to claim 1, wherein the outer diameter thereof is 60 to 400 mm.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122157043.9U CN215889934U (en) | 2021-09-07 | 2021-09-07 | Metal gas-tight sealing oil casing |
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| CN202122157043.9U CN215889934U (en) | 2021-09-07 | 2021-09-07 | Metal gas-tight sealing oil casing |
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| CN215889934U true CN215889934U (en) | 2022-02-22 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116291234A (en) * | 2023-05-22 | 2023-06-23 | 靖江特殊钢有限公司 | Corrosion-resistant oil casing and preparation method thereof |
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2021
- 2021-09-07 CN CN202122157043.9U patent/CN215889934U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116291234A (en) * | 2023-05-22 | 2023-06-23 | 靖江特殊钢有限公司 | Corrosion-resistant oil casing and preparation method thereof |
| CN116291234B (en) * | 2023-05-22 | 2023-08-04 | 靖江特殊钢有限公司 | Corrosion-resistant oil casing and preparation method thereof |
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