CN114087459A - End-to-end connection method for pipelines with inner corrosion-resistant layers - Google Patents
End-to-end connection method for pipelines with inner corrosion-resistant layers Download PDFInfo
- Publication number
- CN114087459A CN114087459A CN202111389710.4A CN202111389710A CN114087459A CN 114087459 A CN114087459 A CN 114087459A CN 202111389710 A CN202111389710 A CN 202111389710A CN 114087459 A CN114087459 A CN 114087459A
- Authority
- CN
- China
- Prior art keywords
- coupling
- corrosion
- thread
- pipeline
- section
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
- F16L58/02—Protection of pipes or pipe fittings against corrosion or incrustation by means of internal or external coatings
- F16L58/04—Coatings characterised by the materials used
- F16L58/08—Coatings characterised by the materials used by metal
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L15/00—Screw-threaded joints; Forms of screw-threads for such joints
Abstract
The invention provides a pipeline end-to-end connection method with an inner corrosion-resistant layer, which relates to the technical field of oil casings and can overcome the problems of back torque loose, insufficient shoulder surface jacking or insufficient fastening torque on a field end when a pipeline end-to-end threaded connection with a corrosion-resistant layer is carried out, and the precise and effective connection and corrosion-resistant integrity of a pipe string are realized; aiming at a bimetallic pipe body with an inner layer made of corrosion-resistant alloy, the method is characterized in that a corrosion-resistant alloy layer is arranged on the end face of the pipe body; processing external threads on the end part of the pipeline with the inner corrosion-resistant layer and the assembly nipple, and symmetrically processing internal threads at two ends of the coupling; the first end of the coupling is connected with the assembling pup joint and screwed to the positioning position of the assembling pup joint; the external thread of the first section of pipeline is coated with anti-loose fastening and anti-thread-sticking oil casing thread grease and is connected with the second end of the coupling, and the first section of pipeline is screwed into contact with the assembly nipple; disassembling the assembling short section; and coating anti-thread-sticking oil casing thread grease on the external thread of the second section of pipeline, connecting the second section of pipeline with the first end of the coupling, and screwing the second section of pipeline into contact with the end of the first section of pipeline with the inner corrosion-resistant layer.
Description
Technical Field
The invention relates to the technical field of oil casings, in particular to a method for connecting the end to the end of an oil casing with an inner corrosion-resistant layer.
Background
Due to the severe corrosion oil-gas field service environment, uniform corrosion and pitting failure of the inner wall of the oil pipe frequently occur, and some oil pipes are corroded and perforated even for several months. According to H in the environment2S partial pressure, CO2Partial pressure, Cl-mass concentration, temperature, pressure andunder the condition of liquid flowing, the corrosion resistant alloy materials can be selected from low-carbon alloy steel, martensitic stainless steel, double-phase stainless steel, iron-corrosion resistant alloy and corrosion resistant alloy according to the sequence of stronger and stronger corrosion resistance. H is contained in northeast China, Tarim, etc. of Sichuan2S、CO2Currently, martensitic stainless steel pipes (super 13Cr) and corrosion-resistant alloy pipes (825, G3) are mostly selected in high-temperature and high-pressure natural gas fields with Cl < - > existing at the same time, but stress corrosion cracking failure of the super 13Cr oil pipes is also frequently caused; and the pure corrosion-resistant alloy oil pipe is very expensive and too high in cost, and is difficult to popularize and use. The cost of the corrosion-resistant oil pipe can be greatly reduced by the bimetal composite oil pipe, and the high strength of the carbon steel at the outer layer and the corrosion resistance of the corrosion-resistant alloy at the inner layer are organically combined, so that the performance is improved, the cost is reduced, and the bimetal composite oil pipe is widely applied.
Although the corrosion problem has been solved effectively to in-band corrosion resistant layer pipeline, threaded connection part still has perishable problem, how to solve threaded connection part's corrosion problem, realizes the anticorrosive of whole pipe cluster, is the problem that needs to solve at present. The inner wall of the pipe string is prevented from corrosion by adopting opposite-top threads and through the contact between the corrosion-resistant inner layers of the bimetallic pipe, and the following problems exist: firstly, whether two sections of metal pipes of interconnect can effective contact, secondly can lead to the threaded connection of opposite side to the frictional force that produces on the top surface to loosen and detain, thirdly because the external screw thread of mill end interferes, leads to the external screw thread of scene end to detain not in place and detain the moment of torsion not enough.
Accordingly, there is a need to develop a method of connecting ends of oil casings with inner corrosion resistant layers to address the deficiencies of the prior art and to solve or mitigate one or more of the problems set forth above.
Disclosure of Invention
In view of this, the invention provides a method for connecting ends of an oil casing pipe with an inner corrosion-resistant layer to each other, which can overcome the problems of loosening of reverse torque, insufficient top surface of a shoulder surface or insufficient fastening torque on the field end which may occur during threaded connection of a butting-type pipeline with an inner corrosion-resistant layer in the prior art, realize accurate and effective connection of pipeline strings with inner corrosion-resistant layers, realize accurate and effective connection of the pipeline strings with inner corrosion-resistant layers, realize the corrosion-resistant integrity of the bimetal pipe strings, and ensure the corrosion resistance of the whole pipe string.
The invention provides a method for connecting the end to the end of an oil sleeve with an inner corrosion-resistant layer, which realizes the connection between pipelines with the inner corrosion-resistant layer to be jacked and to be jacked, and the assembly method comprises the following steps:
during factory processing and assembly:
s1, processing external threads on the end parts of the two pipelines to be connected and the assembly nipple for positioning, and symmetrically processing internal threads on the inner walls of the two ends of the connecting collar;
s2, connecting the first end of the connecting coupling with the assembly nipple in a threaded manner, wherein the screwing-in position of the thread reaches the positioning position of the assembly nipple;
s3, smearing anti-loose fastening oil casing thread grease and anti-thread-sticking oil casing thread grease on the external thread of the first section of pipeline in a segmented manner, connecting the anti-loose fastening oil casing thread grease and the anti-thread-sticking oil casing thread grease with the second end of the connecting coupling in a threaded manner, and screwing the anti-loose fastening oil casing thread grease and the anti-thread-sticking oil casing thread grease into the end face of the coupling to be contacted with the assembling nipple;
and (3) assembling on site:
s4, disassembling the assembly short section;
and S5, coating anti-thread sticking oil casing thread grease on the external thread of the second section of pipeline, connecting the external thread with the first end of the connecting coupling in a threaded manner, and screwing the connecting coupling into contact with the first section of pipeline.
In step S3, the anti-loosening fastening oil casing thread grease is applied to connect the threads of the fixed factory end to prevent the threads connected to the end from being loosened by counterclockwise rotation of the connected threads due to the reaction torque generated by the end face contact when the threads are made up on site (i.e., the first end of the connecting coupling is made up with the second section of pipeline).
The above aspects and any possible implementation manner further provide an implementation manner, where a positioning shoulder is provided on an outer surface of the fitting sub, and an outer diameter at the positioning shoulder is larger than an outer diameter at an external thread of the fitting sub;
in step S2, the fitting nipple is threaded until the first end face of the coupling collar contacts the locating shoulder.
The above aspects and any possible implementation manner further provide an implementation manner, wherein the external threads on the two sections of pipelines are arranged in a frustum shape;
correspondingly, the external thread of the assembling short section is the same as the frustum-shaped external threads of the two sections of pipelines, and the external threads are matched with the internal threads of the connecting coupling.
There is further provided in accordance with any of the above-described aspects and possible implementations an implementation in which a distance between the threaded end face of the fitting sub and the locating shoulder is equal to 1/2 the length of the connection collar. The length setting is in order to ensure that the pipe body threads of the first end and the second end are all threaded to the half position of the coupling, so that the problems of not-in-place butting and insufficient screwing torque at the field end are solved.
In accordance with the foregoing aspect and any possible implementation manner, there is further provided an implementation manner, where each of the two pipelines to be connected includes an outer layer metal pipe and an inner layer metal pipe;
the inner layer metal pipe of the end to be connected protrudes 3mm-6mm compared with the outer layer metal pipe, and a corrosion-resistant metal layer is welded on the protruding part of the inner layer metal pipe;
the corrosion-resistant metal layer is connected with the end parts of the inner-layer metal pipe and the outer-layer metal pipe simultaneously.
The above aspect and any possible implementation manner further provide a realization manner that the material of the corrosion-resistant metal layer is fused with the outer-layer metal tube and the inner-layer metal tube.
The above aspects and any possible implementation manners further provide an implementation manner that the thickness difference of the pipeline sections generated by the frustum shape is greater than or equal to 2mm, and the axial length is less than or equal to 4 mm.
In accordance with the foregoing aspect and any one of the possible implementations, there is further provided an implementation in which the contacting of the first end face of the coupling with the positioning shoulder is specifically: and the gap between the first end face of the connecting coupling and the positioning shoulder of the assembling nipple is less than or equal to 0.01 mm.
The above aspect and any possible implementation manner further provide an implementation manner, where the eligibility criteria of the external threads of the first section of pipeline and the second section of pipeline when screwing in the connection coupling are: the upper buckling torque value reaches a preset value and a nose-shoulder touch signal appears on a torque curve. Have processed a nose end respectively at two body external screw thread terminal surfaces, when two body external screw thread terminal surface contacts, nose end touching back promptly, and it has a quick increase that is vertical line formula to detain the moment of torsion curve to this regard as nose shoulder touch signal.
The above aspects and any possible implementations further provide an implementation in which, after assembly, the outer surface of the corrosion-resistant metal layer does not contact the inner surface of the coupling to form a hollow cylindrical section inside the coupling. The outer layer metal pipe with the pipeline with the inner corrosion-resistant layer is not exposed in the hollow cylindrical section in the coupling, and only the corrosion-resistant metal layer is exposed, so that the non-corrosion-resistant outer layer metal pipe is not contacted with substances such as oil gas conveyed in the pipe.
Compared with the prior art, one of the technical schemes has the following advantages or beneficial effects: by accurately controlling the upper buckling position of the threaded connection at the factory end, the problems that the counter torque is loosened and the shoulder surface is not in place during threaded connection and assembly of the pipe string in the threaded connection on site are solved;
another technical scheme among the above-mentioned technical scheme has following advantage or beneficial effect: the frustum-shaped structure is adopted, so that stable contact pressure is formed on the contact surface of the threaded connection nose end, effective connection is realized, and the problem of corrosion resistance of the threaded connection part is solved;
another technical scheme in the above technical scheme has the following advantages or beneficial effects: the contact surface of the opposite tops is made of corrosion-resistant alloy by removing part of the outer pipe of the pipeline with the inner corrosion-resistant layer and welding the corrosion-resistant metal layer, so that the corrosion resistance of the whole pipe string is guaranteed, wherein the contact surface of the opposite tops is the contact surface between the end surfaces of the two sections of external thread joints, because the inner corrosion-resistant alloy layer is thin, and chamfers are required to be processed, if the end surface corrosion-resistant metal coating and welding treatment is not carried out, the pipe body with the outer non-corrosion-resistant layer can be contacted with a medium conveyed in the pipe, so that corrosion is generated.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic view of a threaded connection structure of a bimetallic composite oil casing according to an embodiment of the invention.
Wherein, in the figure:
1. a pipeline with an inner corrosion-resistant layer; 2. assembling short sections; 3. a coupling; 4. a corrosion-resistant alloy layer; 5. anti-loose fastening oil casing thread grease; 6. thread grease of the anti-thread-sticking oil casing;
1-1, a pipe body outer layer matrix; 1-2, a pipe body inner layer matrix; 1-3, external threads of the pipe body; 1-4, external thread nose shoulder of the tube body;
2-1, assembling a short section external thread; 2-2, assembling a short section positioning shoulder;
3-1, coupling internal threads; 3-2, and forming a hollow cylindrical section in the coupling.
Detailed Description
For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.
It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Aiming at the problem that the threaded connection part of a pipeline with an inner corrosion-resistant layer is easy to corrode in the prior art, the invention provides an efficient and simple threaded connection structure, and solves the problems that the thread connection of a threaded connection at the factory end is loosened by counter torque and the shoulder surface is not in place during threaded connection and assembly of a pipe string in a threaded connection field through accurately controlling the thread-up position of the threaded connection at the factory end, so that the contact surface of the threaded connection nose end forms stable contact pressure, the corrosion prevention problem of the threaded connection part is effectively solved, and the corrosion prevention of the whole pipe string is realized.
A bimetal composite oil and casing threaded connection structure and a factory end assembly method comprise a pipeline, a coupling made of common carbon steel, anti-loose fastening oil casing threaded grease, anti-sticking oil casing threaded grease and an assembly nipple; the end part of the pipeline is processed with an external thread, and the front end of the external thread is processed with a nose shoulder; the carbon steel coupling is of a left-right axial symmetry structure, internal threads matched with the external threads of the pipe body are respectively processed at two ends of the coupling, and a hollow cylindrical section is processed in the middle of the coupling.
As a specific implementation mode, the outer-layer matrix of the pipeline is made of common carbon steel, the yield strength is 55-110 ksi, and the thickness is 5.5-12.7 mm. The inner layer matrix of the pipeline is made of corrosion resistant alloy materials not limited to stainless steel, the yield strength is 45-105 ksi, and the thickness is 0.5-4.5 mm. The compounding mode of the pipeline is not limited to hydraulic compounding, blasting compounding, metallurgical compounding and the like.
The threads at the two ends of the pipeline can be API threads or non-API special threads.
Specifically, the cross-sectional thickness of the nose shoulder on the end face of the pipeline is more than or equal to 2mm, and the axial length is less than or equal to 4 mm.
The end face of the pipeline is firstly turned or machined in other ways to remove the axial length of the outer carbon steel substrate layer which is more than or equal to 3mm, then a corrosion-resistant alloy layer which is in homogeneous fusion with the outer substrate and the inner substrate and has a certain thickness is welded, the thickness of the welded corrosion-resistant alloy layer is more than 0.5-1.0 mm of the thickness of the nose shoulder, and the axial length is flush with the end face of the inner corrosion-resistant alloy substrate.
The axial length of the corrosion-resistant alloy layers welded on the end faces of the two ends of the pipeline is less than or equal to the length of the external thread nose shoulder.
And the thread structures at the two ends of the pipeline are machined after the corrosion-resistant alloy coating welding of the pipe ends is finished.
The coupling internal thread is matched with the pipeline end face external thread.
The inner diameter of the hollow cylindrical section in the coupling is 0.2-0.6 mm larger than the outer diameter of the external thread nose shoulder, and the axial length of the hollow cylindrical section is 0.2-0.3 mm smaller than the axial length of the external thread nose shoulder.
The material of the assembly short section is the same as that of the outer-layer substrate of the pipeline, and the assembly short section is processed with an external thread structure which is completely the same as that of the end face of the pipeline.
The assembling short section is processed with a positioning shoulder, and the outer diameter of the positioning shoulder is larger than or equal to that of the coupling.
The axial length of the assembly nipple from the pipe end to the positioning shoulder is 1/2 of the axial length of the coupling.
The bimetallic composite oil and casing threaded connection structure and the factory end assembly method are characterized in that before a pipeline is in threaded connection with a coupling, the coupling is in threaded connection with an assembly nipple.
According to the bimetallic composite oil and casing threaded connection structure and the factory end assembling method, the threaded connection control standard of the coupling and the assembling nipple is that the gap between the end face of the coupling and the positioning shoulder of the assembling nipple is less than or equal to 0.01 mm.
According to the bimetal composite oil and casing thread connecting structure and the factory end assembling method, when the external thread of the pipeline is screwed into a coupling, thread grease of the anti-thread-sticking oil casing is uniformly smeared on the length of the thread section nose shoulder side 2/3, and the thread grease of the oil casing is uniformly smeared and locked on the length of the thread section pipe body side 1/3. The meaning at 1/3 and 2/3 is that the region of application of the corresponding thread compound encompasses the particular location of 1/3 or 2/3.
The qualified criterion of the external thread of the pipeline when the coupling is screwed in is as follows: the upper buckling torque value reaches a preset value and a nose-shoulder touch signal appears on a torque curve.
According to the bimetallic composite oil and casing threaded connection structure and the factory end assembling method, after the external threads of the pipeline are screwed into the coupling, the assembling short section is removed, and the factory end is assembled.
The assembly short section can be repeatedly used.
According to the bimetal composite oil and sleeve threaded connection structure and the factory end assembling method, the corrosion-resistant alloy layer with a certain thickness is welded at the external thread nose shoulder of the pipe body, and a corrosive medium flowing in the pipe body is isolated through the contact pressure of the corrosion-resistant alloy between the nose shoulders. The assembly nipple is made of the same material as the bimetal composite outer-layer carbon steel, has a thread structure completely the same as the external thread of the pipe body, and is provided with a positioning shoulder in machining. When the factory end assembly of the bimetallic composite oil and casing threaded connection is carried out, the assembly position of the assembly nipple and the coupling is controlled through the positioning shoulder on the assembly nipple, then adopting anti-thread sticking oil casing thread grease and locking oil casing thread grease in different thread sections of the bimetal composite oil and the casing end, adopting an upper buckling grid criterion that an upper buckling torque value is in contact combination with a shoulder, thereby accurately controlling the threaded connection position of the oil casing at the factory end, realizing the accurate assembly and fastening match of the bimetallic composite oil and the threaded connection factory end of the casing, effectively solving the problems of loosening of the counter torque at the factory end and improper jacking of the shoulder surface which possibly occur during the threaded connection assembly of the pipe string at the scene, and leading the contact surface of the threaded connection nose end to form stable contact pressure, thereby effectively solving the anti-corrosion problem of the threaded connection part and realizing the integral connection and anti-corrosion functions of the whole pipe string.
Example 1:
the structure of this embodiment is shown in fig. 1. The double-metal composite oil and casing threaded connection structure comprises a pipeline 1, an assembly nipple 2, a coupling 3 made of common carbon steel, a corrosion-resistant alloy layer 4, anti-loose fastening oil casing thread grease 5 and anti-thread-sticking oil casing thread grease 6; the pipeline 1 is formed by compounding an outer-layer matrix 1-1 and an inner-layer matrix 1-2, a pipe body external thread 1-3 is processed at the end part of the pipe body, and a pipe body external thread nose shoulder 1-4 is processed at the front end of the pipe body external thread; the coupling 3 is of a left-right axial symmetrical structure, internal threads 3-1 matched with the external threads of the pipe body are respectively processed at two ends of the coupling 3, and a hollow cylindrical section 3-2 is processed in the middle of the coupling 3; the assembly short section 2 is an external thread joint with a positioning shoulder 2-2; when the pipe body external threads 1-3 at the end part of the pipeline are assembled with the coupling 3, the anti-loose fastening oil casing thread grease 5 and the anti-loose oil casing thread grease 6 are required to be used simultaneously.
The outer layer matrix 1-1 of the pipe body is made of common carbon steel, the yield strength is 55 ksi-110 ksi, and the thickness is 5.5-12.7 mm.
The inner layer matrix 1-2 of the pipe body is made of corrosion resistant alloy materials not limited to stainless steel, the yield strength is 45 ksi-105 ksi, and the thickness is 0.5-4.5 mm.
The compounding manner of the pipeline 1 is not limited to hydraulic compounding, explosive compounding, metallurgical compounding, and the like.
The external pipe body threads 1-3 may be API threads or non-API special threads.
The cross section thickness of the external thread nose shoulder 1-4 of the tube body is more than or equal to 2.5mm, and the axial length is less than or equal to 6 mm.
The end faces of two ends of the pipeline 1 are firstly turned or machined by other methods to remove the axial length of the outer layer matrix 1-1 of the carbon steel pipe body and is more than or equal to 3mm, then the corrosion-resistant alloy layer 4 which is fused with the outer layer matrix 1-1 of the pipe body and the inner layer matrix 1-2 of the pipe body is coated and welded with a certain thickness, the thickness of the coating and welding corrosion-resistant alloy layer 4 is 0.5-1.0 mm larger than the thickness of the external thread nose shoulder 1-4 of the pipe body, and the axial length is flush with the end face of the inner layer corrosion-resistant alloy matrix 1-2.
The axial length of the corrosion-resistant alloy layers 4 welded on the end faces of the two ends of the pipeline is less than or equal to the length of the external thread nose shoulder 1-4.
And machining the thread structures at the two ends of the pipeline after the coating and welding of the pipe end corrosion-resistant alloy layer 4 are finished.
The coupling is made of carbon steel, and the yield strength of the reinforced material is more than or equal to 1-1 of the outer-layer matrix of the pipeline.
The coupling internal thread 3-1 is matched with the pipe body external thread 1-3.
The inner diameter of the hollow cylindrical section 3-2 in the coupling is 0.2-0.6 mm larger than the outer diameter of the external thread nose shoulder 1-4, and the axial length is 0.2-0.3 mm smaller than the axial length of the external thread nose shoulder 1-4.
The material of the assembly nipple 2 is the same as that of the outer-layer matrix 1-1 of the pipe body, and the pipe end is provided with an external thread 2-1 of the assembly nipple which is completely the same as the end face of the pipeline.
The assembly nipple 2 is processed with an assembly nipple positioning shoulder 2-2, and the outer diameter of the assembly nipple positioning shoulder 2-2 is larger than or equal to that of the coupling 3.
The axial length of assembly sub 2 from the end face of the pipe body to assembly sub positioning shoulder 2-2 is 1/2 of the axial length of coupling 3.
In this embodiment, coupling 3 is threaded with fitting sub 2 before tubing 1 is threaded with coupling 3. The threaded connection control standard of the coupling 3 and the assembly nipple 2 is that the clearance between the end face of the coupling and the positioning shoulder 2-2 of the assembly nipple is less than or equal to 0.01 mm. When the pipe body external threads 1-3 of the pipeline 1 are screwed into the coupling 3, the length of the nose shoulder side 2/3 of the threaded section is uniformly coated with anti-loosening oil casing thread grease 6, and the length of the pipe body side 1/3 of the threaded section is uniformly coated with anti-loosening fastening oil casing thread grease 5. The qualification criterion of the pipe body external thread 1-3 when the coupling 3 is screwed in is as follows: the upper buckling torque value reaches a preset value and a nose-shoulder touch signal appears on a torque curve. And after the pipe body external thread 1-3 is screwed into the coupling 3, the assembling short section 2 is disassembled, and the factory end assembling is completed. The assembly nipple 2 can be reused for many times.
Before the pipeline end is in threaded connection and the coupling is assembled, the coupling and the assembling nipple accurately control the end surface position of the assembling nipple through the positioning shoulder, when the factory end of the pipeline is assembled with the coupling, the assembling nipple accurately controls the upper buckling position and the upper buckling torque of the factory end, during assembly, need use locking fastening oil casing screw thread fat and antiseized knot oil casing screw thread fat to realize the connection and the firm of threaded connection mill end simultaneously (on-the-spot assembly end does not scribble locking fastening oil casing screw thread fat 5, and only scribbles antiseized knot oil casing screw thread fat and realize sealedly), the mill that has effectively solved threaded connection probably appears when the pipe cluster threaded connection on-the-spot is assembled holds the connection structure and has appeared the loose knot of counter-torque, the problem that the nose shoulder is not in place to the top, make threaded connection nose contact surface form stable contact pressure, thereby ensure the monolithic of whole pipe cluster and anticorrosive function.
The method for connecting the end of the oil casing with the inner corrosion-resistant layer provided by the embodiment of the application to the end of the oil casing is described in detail above. The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.
It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element. "substantially" means within an acceptable error range, that a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect.
The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. In the present application, the terms "upper", "lower", "left", "right", "inner", "outer", "middle", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. Some of the above terms may be used to indicate other meanings in addition to orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of dependency or connection relationship in some cases. The specific meaning of these terms in this application will be understood by those of ordinary skill in the art as appropriate. The term "and/or" as used herein is merely an associative relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.
Claims (10)
1. A method of joining end-to-end pipes having an inner corrosion resistant layer to form a joint between pipe sections having an inner corrosion resistant layer, the method comprising the steps of:
s1, processing external threads on the end parts of the two pipelines to be connected and the assembly nipple for positioning, and symmetrically processing internal threads on the inner walls of the two ends of the connecting collar;
s2, connecting the first end of the connecting coupling with the assembly nipple in a threaded manner, wherein the threaded screwing position reaches the positioning position of the assembly nipple;
s3, smearing anti-loose fastening oil casing thread grease and anti-thread-sticking oil casing thread grease on the external thread of the first section of pipeline in a segmented manner, connecting the anti-loose fastening oil casing thread grease and the anti-thread-sticking oil casing thread grease with the second end of the connecting coupling in a threaded manner, and screwing the anti-loose fastening oil casing thread grease and the anti-thread-sticking oil casing thread grease into the end face of the coupling to be contacted with the assembling nipple;
s4, disassembling the assembly short section;
and S5, coating anti-thread sticking oil casing thread grease on the external thread of the second section of pipeline, connecting the external thread with the first end of the connecting coupling in a threaded manner, and screwing the connecting coupling into contact with the first section of pipeline.
2. The method for connecting pipelines with inner corrosion-resistant layers end to end according to claim 1, wherein the outer surface of the assembly nipple is provided with a positioning shoulder, and the outer diameter of the positioning shoulder is larger than that of the external thread of the assembly nipple;
in step S2, the fitting nipple is threaded until the first end face of the coupling collar contacts the locating shoulder.
3. The method of claim 1, wherein the external threads on the two lengths of pipe are tapered;
correspondingly, the external thread of the assembling short section is the same as the frustum-shaped external threads of the two sections of pipelines, and the external threads are matched with the internal threads of the connecting coupling.
4. The method of connecting pipe ends-to-end with an inner corrosion resistant layer as in claim 2, wherein the distance between the threaded end face of the fitting sub and the locating shoulder is equal to 1/2 of the length of the coupling collar.
5. The method of claim 1, wherein the two lengths of pipe to be joined each comprise an outer metal pipe and an inner metal pipe;
the inner layer metal pipe of the end to be connected protrudes 3mm-6mm compared with the outer layer metal pipe, and the protruding part of the inner layer metal pipe is welded with a corrosion-resistant metal layer.
6. The method of claim 5, wherein the corrosion-resistant metal layer is fused to both the outer and inner metal tubes.
7. The method for connecting pipelines with inner corrosion-resistant layers end to end as claimed in claim 3, wherein the pipeline section thickness difference generated by the frustum shape is more than or equal to 2mm, and the axial length is less than or equal to 4 mm.
8. The method for connecting pipes end-to-end with an inner corrosion-resistant layer as claimed in claim 2, wherein the contacting of the first end face of the coupling with the positioning shoulder is specifically: and the gap between the first end face of the connecting coupling and the positioning shoulder of the assembling nipple is less than or equal to 0.01 mm.
9. The method of claim 1 wherein the first and second lengths of pipe are threaded into the coupling using the following criteria: the upper buckling torque value reaches a preset value and a nose-shoulder touch signal appears on a torque curve.
10. The method of claim 5, wherein the outer surface of the layer of corrosion resistant metal is not in contact with the inner surface of the coupling after assembly to form a hollow cylindrical section within the coupling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111389710.4A CN114087459A (en) | 2021-11-22 | 2021-11-22 | End-to-end connection method for pipelines with inner corrosion-resistant layers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111389710.4A CN114087459A (en) | 2021-11-22 | 2021-11-22 | End-to-end connection method for pipelines with inner corrosion-resistant layers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114087459A true CN114087459A (en) | 2022-02-25 |
Family
ID=80303025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111389710.4A Pending CN114087459A (en) | 2021-11-22 | 2021-11-22 | End-to-end connection method for pipelines with inner corrosion-resistant layers |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114087459A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114352211A (en) * | 2021-12-23 | 2022-04-15 | 西安德信成科技有限责任公司 | Sealing threaded connection assembly method for oil pipe and casing pipe combination |
-
2021
- 2021-11-22 CN CN202111389710.4A patent/CN114087459A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114352211A (en) * | 2021-12-23 | 2022-04-15 | 西安德信成科技有限责任公司 | Sealing threaded connection assembly method for oil pipe and casing pipe combination |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6312024B1 (en) | Threaded assembly of metal tubes designed to contain a corrosive fluid | |
| JP5643841B2 (en) | Mechanically mounted fitting for sour environment | |
| CN114087459A (en) | End-to-end connection method for pipelines with inner corrosion-resistant layers | |
| US7100946B2 (en) | Bulkhead assembly for use in pipe-in-pipe systems | |
| CN101915064A (en) | Bimetal compound pipe | |
| US5333913A (en) | Galvanic isolation device | |
| CN216715610U (en) | End-to-end pipeline connecting structure with inner corrosion-resistant layer | |
| WO2012034517A1 (en) | Dual-metal composite delivery pipe | |
| CN205781550U (en) | A kind of anti-corrosion pipeline attachment structure | |
| CN104896218A (en) | Bimetal composite pipe end connecting device | |
| CN204647602U (en) | A kind of composite bimetal pipe pipe end linkage structure | |
| CN201835756U (en) | Bimetal composited tube | |
| CN202349404U (en) | Bi-metal composite pipe with end parts being with external threads | |
| RU2228484C2 (en) | Joint for pipes provided with anti-corrosion coats | |
| CN203477637U (en) | Bimetal composite pipe | |
| US20050225083A1 (en) | Pipe system and method for its manufacture | |
| CN210800456U (en) | Ground oil delivery pipe with anti-corrosion welding joint | |
| CN103486341A (en) | Bimetal composite tube | |
| CN213420210U (en) | Anti-corrosion pipeline connecting flange | |
| CN211925046U (en) | Pipe system | |
| RU2746030C1 (en) | Mechanical connection of medium pipes | |
| RU2747547C1 (en) | Mechanical connection of small-diameter pipes | |
| RU184595U1 (en) | Enamelled pipe connector | |
| CN219734496U (en) | Titanium alloy composite pipe | |
| EP0163958B1 (en) | Corrosion-resistant pipe coupling structures |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |