CN113217751A

CN113217751A - Integral buckle arrestor with internal spiral flow guide device

Info

Publication number: CN113217751A
Application number: CN202110519151.8A
Authority: CN
Inventors: 徐万海; 庞涛; 贾昆
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2021-05-12
Filing date: 2021-05-12
Publication date: 2021-08-06

Abstract

The invention discloses an integral buckle arrestor with an internal spiral flow guide device, which comprises a circular pipe body, wherein the outer surface of the circular pipe body is divided into three sections with different outer diameters according to the axial direction, the middle section of the circular pipe body is a transition section at two ends of the buckle arrestor section, the wall thickness of the buckle arrestor section is 2-4 times of that of a submarine pipeline, the outer diameter and the wall thickness of the transition section are matched with the submarine pipeline, and welding chamfers are reserved at two ends of the circular pipe body; the inner wall of the round pipe body is fixed with a spiral flow guide device, the spiral flow guide device comprises N spiral flow guide plates with the same parameters, N is 3 or 4, and the cross section of each spiral flow guide plate is trapezoidal. The spiral turbulence transmission device can effectively stimulate spiral turbulence transmission of a multiphase mixed medium in the pipeline, reduce local corrosion, have a certain effect of cleaning the inner wall of the pipeline and prolong the service life of the pipeline; the buckling propagation which may occur in the life cycle of the pipeline can be effectively prevented, so that the unification of function integration and simplified design is realized, and the production cost is reduced.

Description

Integral buckle arrestor with internal spiral flow guide device

Technical Field

The invention relates to a novel integral buckle arrestor with an internal spiral flow guide device, and belongs to the field of ocean pipeline engineering.

Background

In recent years, with the rapid and continuous development of global economy, the demand of energy substances such as petroleum, natural gas and the like is increasing, and people gradually increase the exploitation and utilization of marine oil and gas resources. The submarine pipeline has remarkable advantages in the process of conveying marine oil and gas resources compared with the traditional transportation mode, and along with the attack and improvement of more key technologies in recent years, the submarine pipeline becomes a key component of a marine oil and gas resource transportation system and is a main artery for transporting submarine energy substances.

1. Internal diversion of subsea pipelines

At present, in the marine oil exploitation and production process, particularly in the oil transportation or finished oil transportation process, a long-distance pipeline mixed transportation technology is often used, and the technology can greatly simplify the oil and gas exploitation and production process and reduce the production cost. In the process of oil gas exploitation and transportation, aqueous phase or impurities can be doped difficultly, because oil water has density difference, when the aqueous phase content is higher or is influenced by the change of environmental temperature and pressure, the aqueous phase can be separated out and deposited at the bottom of a long-distance pipeline, particularly a non-straight pipe type pipeline (with gradient change), so as to form a liquid film, accumulated water can not only corrode the bottom of the pipeline, but also the aqueous phase and solid phase impurities can greatly influence the quality of oil products, so that the finished oil has potential threat in the use process, and therefore, the deposited aqueous phase must be cleaned and removed from the pipeline.

Because the traditional hydraulic cyclone technology (tangential rotation starting technology) has higher requirements on the transverse size of the application environment, the application of the device in a submarine or underground long-distance pipeline is difficult, and the novel pipeline internal flow guiding device (axial rotation starting technology) relies on incoming flow self momentum to obtain tangential speed through the incoming liquid flowing axially after passing through the flow guiding structure to form a strong cyclone field. The rotational flow field can roll up the water phase to carry by means of the rotational flow effect, and the sedimentation and accumulation of the water phase at the low point of the pipeline, particularly the pipeline, are avoided, so that the water phase can flow to a sewage system along with the flow field in the pipeline arranged in a special environment and is finally discharged out of the pipeline. In the turbulent motion, if most of water drops and solid particles can be conveyed forwards in a suspension state, the corrosion rate can be reduced, and the local groove corrosion is changed into the uniform corrosion of the whole pipeline, so that the service life of the pipeline is prolonged.

2. Buckling propagation and buckle arrestor for subsea pipelines

Due to the huge external pressure of deep sea and the complex working environment, the submarine pipeline is easy to be locally crushed under the action of local defects and external loads, and further buckling propagation is formed to cause large-scale failure of the pipeline. In theory, the buckling propagation critical pressure of the pipeline can be effectively increased by increasing the wall thickness of the pipeline, but the increase of the wall thickness can greatly increase the steel consumption and the weight of the pipeline, increase the cost and be not feasible economically. At present, in engineering, people can arrange Buckle arrestors (Buckle arrestors) at certain intervals along the length direction of a pipeline, and the working principle of the Buckle arrestors is that the pipeline is allowed to be locally buckled, but buckling propagation cannot cross the Buckle arrestors, so that the local buckling can only occur between the two Buckle arrestors. The buckle arrestor can cause the pipeline to partially buckle to a certain extent, but well maintains the integrity of the pipeline and achieves a better balance between safety and economy.

The effective buckle arrestor is designed to successfully prevent the transmission of pipeline buckling in the working range, the common form of the pipeline buckle arrestor comprises a thick-wall ring and a winding bar, and the buckle arrestor can be generally divided into a buckling type buckle arrestor, a common welding type buckle arrestor, an integral type buckle arrestor and a winding type buckle arrestor according to different installation modes. The integral buckle arrestor is directly welded with the submarine pipeline in an alignment mode, so that the possibility of U-shaped crossing is avoided, and the buckle arrestor is obviously superior to other types of buckle arrestors in buckling arresting performance.

In engineering practice, the integral buckle arrestor is arranged between the pipes at a distance, which depends on the specific working environment and engineering requirements. The spiral flow swing starters for internal diversion in the submarine pipeline are also distributed at intervals, so that the integral buckle arrestor with the internal diversion function has certain engineering significance and popularization value.

Disclosure of Invention

In view of the prior art, the main object of the present invention is to provide a local reinforcement device combining a spiral flow starter and an integral buckle arrestor inside a pipeline, which not only can effectively stimulate spiral turbulence delivery of multiphase mixed media inside the pipeline, reduce local corrosion, have a certain effect of cleaning the inner wall of the pipeline, and prolong the service life of the pipeline; the buckling propagation which may occur in the life cycle of the pipeline can be effectively prevented, so that the unification of function integration and simplified design is realized, and the production cost is reduced.

In order to solve the technical problem, the integral buckle arrestor with the internal spiral flow guide device comprises a circular pipe body, wherein the outer surface of the circular pipe body is divided into three sections of outer surfaces with different outer diameters according to the axial direction, the middle section of the circular pipe body is a buckle arrestor, the wall thickness of the buckle arrestor is 2-4 times that of a submarine pipeline, transition sections with the outer diameters and the wall thicknesses matched with the submarine pipeline are arranged at two ends of the circular pipe body, and welding chamfers are reserved at the two ends of the circular pipe body; the spiral flow guide device is fixed on the inner wall of the circular pipe body and comprises N spiral flow guide plates with the same parameters, the cross section of each spiral flow guide plate is trapezoidal, and the structural parameters of each spiral flow guide plate comprise a wrap angle alpha, a height h, an axial length L and a radius R of the spiral flow guide device formed by the N spiral flow guide plates; the radius R is the same as the inner diameter of the submarine pipeline, the wrap angle alpha is 20-30 degrees, the height h is 1/3-1/2R, N is 3 or 4, and the axial length L is the same as the length of the buckling-stopping section.

Further, the integral buckle arrestor of the present invention is provided with:

the inner diameter of the circular pipe body is the same as that of the submarine pipeline, and the length of the circular pipe body is 1.5-2.5 times of the outer diameter D of the submarine pipeline.

The spiral guide plate is made of anti-corrosion stainless steel.

According to the size of the submarine pipeline and the type of the medium to be conveyed, the structural parameters of the spiral guide plate are determined within the respective value range.

The spiral guide plate is welded on the inner wall of the circular pipe body.

The integral buckle arrestor is arranged between two sections of submarine pipelines in a mode of butt welding in the pipeline laying stage.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention can effectively prevent buckling propagation after local buckling of the submarine pipeline, ensure the integral integrity of the submarine pipeline, and greatly reduce the risk of large-range failure of the submarine pipeline, and meanwhile, the scheme is integrally established on the basis of the integral buckle arrestor, so that the buckle arrestor has good buckle arresting performance and is suitable for submarine pipelines under medium or even high water depth;

(2) the internal flow guide device can effectively avoid the precipitation and sedimentation of water phase and solid particles in the pipeline conveying medium, so that the pipeline conveying medium is conveyed forwards in a suspension state, the local corrosion rate of the pipeline is effectively slowed down, and the service life of the pipeline is prolonged;

(3) the device is built on the basis of the integral buckle arrestor, and only the prefabricated spiral guide plate is required to be installed in the existing integral buckle arrestor by welding or other methods, so that the manufacturing process is simple, and the function integration and improvement under low cost are realized.

Drawings

Fig. 1 is a cross-sectional view of the novel integral buckle arrestor designed by the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

fig. 3 and 4 are a three-dimensional schematic and perspective view, respectively, of the integrated buckle arrestor.

In the figure: 1-submarine pipeline, 2-transition section, 3-bending-stopping section, 4-spiral guide plate and 5-welding line.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, which are not intended to limit the invention in any way.

As shown in fig. 1 and 3, the integral buckle arrestor with the internal spiral flow guiding device provided by the invention comprises a circular pipe body, wherein the inner diameter of the circular pipe body is the same as that of the submarine pipeline 1, and the length of the circular pipe body is 1.5-2.5 times of the outer diameter D of the submarine pipeline 1. The outer surface of the circular pipe body is divided into three sections of outer surfaces with different outer diameters according to the axial direction, the middle section of the circular pipe body is an anti-bending section 3, the wall thickness of the anti-bending section 3 is 2-4 times of that of the submarine pipeline 1, two ends of the circular pipe body are transition sections 2 with outer diameters and wall thicknesses matched with the submarine pipeline 1, and welding chamfers are reserved at two ends of the circular pipe body; a spiral flow guide device is fixed on the inner wall of the circular pipe body, the spiral flow guide device comprises N spiral flow guide plates 4 with the same parameters, as shown in fig. 2, the cross section of each spiral flow guide plate 4 is trapezoidal, and the structural parameters of each spiral flow guide plate 4 comprise a wrap angle alpha, a height h, an axial length L and a radius R of the spiral flow guide device formed by the N spiral flow guide plates 4; the radius R is the same as the inner diameter of the submarine pipeline 1, the wrap angle alpha is 20-30 degrees, the height h is 1/3-1/2R, N is 3 or 4, and the axial length L is the same as the length of the buckle arrest section 3, as shown in figures 1, 3 and 4. The number and the structural parameters of the spiral guide plates 4 in the spiral guide device are determined according to the working environment and mainly depend on the size of the submarine pipeline 1, the type of the medium to be conveyed and the like, the structural parameters of the spiral guide plates 4 are determined to be the best parameters within the recommended size range of the invention, the parameters are manufactured by adopting anti-corrosion stainless steel materials and then are installed at the corresponding positions of the inner wall of the buckle arrestor, and the connection mode is welding or other known modes.

The spiral guide plate 4 in the integral buckle arrestor can be processed and manufactured in advance according to the designed structural parameters, and then is sequentially welded at the corresponding positions of the inner wall of the buckle arresting section of the integral buckle arrestor. For the buckle arrestor with a smaller pipe diameter, the spiral guide plate 4 in the buckle arrestor can be processed in an integrated forming mode when the integral buckle arrestor is manufactured.

When the integral buckle arrestor is used, the structural parameters of the transition sections 2 at the two ends are strictly matched with the submarine pipeline 1 to be connected, the connection form of the transition sections 2 and the pipeline is the same as that of the existing integral buckle arrestor, and an alignment welding form is usually adopted, wherein the reference numeral 5 in fig. 1 is a welding seam 5, namely, the integral buckle arrestor is installed between the two submarine pipelines 1 in the pipeline laying stage in the alignment welding form, and the installation steps are not obviously different from those of the existing integral buckle arrestor.

While the present invention has been described with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, which are illustrative only and not restrictive, and various modifications which do not depart from the spirit of the present invention and which are intended to be covered by the claims of the present invention may be made by those skilled in the art.

Claims

1. The integral buckle arrestor with the internal spiral flow guide device comprises a circular pipe body, wherein the outer surface of the circular pipe body is divided into three sections of outer surfaces with different outer diameters according to the axial direction, the middle section of the circular pipe body is a buckle arrestor section (3), the wall thickness of the buckle arrestor section (3) is 2-4 times of that of a submarine pipeline (1), transition sections (2) with the outer diameters and the wall thicknesses matched with the submarine pipeline (1) are arranged at two ends of the circular pipe body, and welding chamfers are reserved at two ends of the circular pipe body; the spiral flow guiding device is characterized in that a spiral flow guiding device is fixed on the inner wall of the circular pipe body and comprises N spiral flow guiding plates (4) with the same parameters, the cross section of each spiral flow guiding plate (4) is trapezoidal, and the structural parameters of each spiral flow guiding plate (4) comprise a wrap angle alpha, a height h, an axial length L and a radius R of the spiral flow guiding device formed by the N spiral flow guiding plates (4); the radius R is the same as the inner diameter of the submarine pipeline (1), the wrap angle alpha is 20-30 degrees, the height h is 1/3-1/2R, N is 3 or 4, and the axial length L is the same as the length of the buckle stopping section (3).

2. The integral buckle arrestor of claim 1, wherein the inner diameter of the circular tube is the same as the inner diameter of the submarine pipeline (1), and the length of the circular tube is 1.5-2.5 times the outer diameter D of the submarine pipeline (1).

3. The integrated buckle arrestor of claim 1, wherein the spiral flow guide plate (4) is made of corrosion-proof stainless steel.

4. The integrated buckle arrestor of claim 1, wherein the structural parameters of the spiral deflector (4) are determined within the respective value ranges according to the size of the submarine pipeline (1) and the type of the medium to be transported.

5. The integrated buckle arrestor of claim 1, wherein the helical baffle (4) is welded to the inner wall of the round tube body.

6. The integrated buckle arrestor of claim 1, wherein the integrated buckle arrestor is installed between two sections of submarine pipeline (1) by means of butt welding in the pipeline laying stage.