CN110273654B - Flexible vertical pipe seamless framework layer - Google Patents

Abstract

The invention relates to a seamless framework layer of a flexible vertical pipe, which is formed by connecting a plurality of same 'ri' -shaped framework units in a self-locking manner, wherein each 'ri' -shaped framework unit comprises a first square surface and a second lower square surface which are connected through a common vertical surface, the two square surfaces have the same structure, one side of each square surface is provided with a clamping hook, and the other side of each square surface is provided with a barb; after two adjacent Y-shaped framework units are connected in a self-locking mode, the adjacent barbs and the hooks are tightly matched, and no gap exists.

Description

A flexible riser seamless skeleton layer

technical field

The invention belongs to the technical field of flexible riser skeleton layers, in particular to a non-adhesive flexible riser skeleton layer.

Background technique

As the world's demand for oil and gas resources continues to increase, land and offshore exploitable resources are decreasing, and the development of marine resources has received more and more attention. Although my country is rich in oil and gas resources, especially in the South China Sea, there are 30 billion tons of crude oil and 16 trillion cubic meters of natural gas. However, due to the limited technical reserves of oil and gas resources development in my country, there is a long way to go to improve the research and development technology of deep-sea oil and gas resources equipment in my country.

The riser system is the key structure connecting the subsea oil and gas production system and the FPSO. Riser systems are divided into rigid risers and flexible risers. Among them, the production, construction, installation, repair and maintenance of rigid risers have a long cycle and high costs, are difficult to recycle, and are easily affected by complex sea conditions. Flexible risers have strong corrosion resistance, are lighter than steel risers, and are easy to install, repair, maintain and recycle. They have been widely used in the field of deep-sea oil and gas development. At present, 80% of the riser systems in oil fields use Flexible riser.

Flexible risers are further divided into viscous flexible risers and non-viscous flexible risers, both of which are composed of multiple layers of composite structures of different shapes and materials. The viscous flexible riser is bonded to each layer by physical extrusion or chemical process, and the adjacent layers cannot be separated and slipped from each other. The layers of the non-adhesive flexible riser are finely assembled in a certain order, and the non-adhesive layers between adjacent layers allow mutual separation and slippage, with better flexibility to withstand greater axial force and bending moment, and a wider range of applications , the cost is lower.

In general, the composition of the non-adhesive flexible riser includes: a skeleton layer, a compression armor layer, a tensile armor layer, an anti-friction layer, an anti-corrosion layer, and an inner and outer sheath layer. Among them, the skeleton layer is a self-locking structure formed by winding an S-shaped section along a cylindrical helix, and its laying angle is 80-90 degrees. It is mainly used to support the entire riser structure and has certain tensile and compressive effects.

The invention patent with the patent publication number CN108825894A discloses a skeleton layer and a composite flexible pipe of a marine flexible pipe, wherein the skeleton layer includes a first special-shaped belt and a second special-shaped belt, and the first special-shaped belt is spirally wound to form a tubular skeleton layer (the skeleton layer of the ordinary flexible riser is only this one layer of special-shaped belt), and the second special-shaped belt is closed for the opening of the spiral groove. The second special-shaped belt designed by the patent is mainly to reduce the gap of the flexible riser frame and solve the problems of flow-induced vibration and humming caused by the flow in the pipeline. However, the two special-shaped belts of the frame layer need to be manufactured separately. Layer the special-shaped belt to form self-locking, and then install the second special-shaped belt in the groove position of the adjacent gap of the skeleton. This patent is time-consuming to manufacture consumables, complicated to install, and not practical. Similar patents include a flexible pipe skeleton for controlling flow-induced vibration in a riser (patent number: CN104412020A) and a composite flexible pipe (patent number: CN108825893A), although these patents all propose an improved The cross-sectional form of the helically wound riser skeleton layer is designed and invented, but it does not involve a new type of skeleton layer cross-sectional shape and self-locking connection method.

Purpose of invention

The object of the present invention is to provide a seamless skeleton layer for flexible risers that can prevent the occurrence of flow-induced vibration and humming, and reduce the effects of friction and slippage between adjacent skeleton layers. The technical solution is as follows:

A seamless skeleton layer of a flexible riser is formed by connecting a plurality of identical "Sun"-shaped skeleton units in a self-locking form, and each "Sun"-shaped skeleton unit includes a first square connected by a common façade. The surface and the second lower square surface, the two square surfaces have the same structure, one side is provided with a hook, and the other side is provided with a barb; Barbs and snap hooks fit tightly without gaps.

Aiming at the key technology of reducing the overall resistance of the flexible riser due to the sliding of the skeleton layer, the invention provides a flexible riser with reasonable design, simple structure, easy implementation, low energy consumption, few consumables, and easy installation and operation. A new connection method for tube skeleton layers. The beneficial effects of the present invention are:

1. The shape of the skeleton layer corresponding to the novel connection method of the present invention effectively reduces the cross-sectional area of the skeleton layer, correspondingly reduces the consumption of materials, and further reduces the overall cost of the flexible riser. Secondly, the new skeleton layer has a simple cross-sectional structure, reasonable design and easy realization.

2. The novel skeleton layer connection method of the present invention is scientific and reasonable in design, simple in operation, effectively reduces the contact gap between the skeleton layers, reduces the influence of slip and friction between layers, eliminates the groove gap, and makes the The connection between the skeleton layers is more stable, avoiding flow-induced vibration and humming. Secondly, the new connection method can also improve the support and protection of the skeleton layer, thereby improving the resistance of the entire flexible riser, especially the compressive and tensile capabilities are significantly improved.

Description of drawings

Figure 1 Schematic diagram of multi-layer flexible riser

Figure 2 Schematic diagram of the cross-section of the conventional skeleton layer

Figure 3 Schematic diagram of the cross-section of the "Japanese" skeleton unit

Figure 4 Schematic diagram of self-locking connection of two "Japanese" skeleton units

Figure 5 is a three-dimensional schematic diagram of the "Japanese" type skeleton layer

Description of the numbers in the figure: 1-1-skeleton layer; 1-2-seal inner lining; 1-3-compression-resistant armoring layer; 1-4-inner protective sleeve; 1-5-tensile armoring layer; 1-6-external protective cover; 2-1-upper arc belt; 2-2-hook; 2-3-lower arc belt; 2-4-card slot; 3-1-"day" structure upper part Square face; 3-2-upper hook; 3-3-"day" type structure lower square face; 3-4-lower hook; 3-5-upper barb; 3-6-lower barb; 3- 7 facades.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, so as to clearly understand the technical method of the present invention.

As shown in Figure 1, the flexible riser is the key structure connecting the subsea subsea production system and the surface floating production system. The floating production system on the water includes FPSO (floating production storage and offloading device, generally a ship model). In actual production, it may also be a floating platform, a semi-submersible platform or a tension leg platform. The flexible riser can move in both horizontal and vertical directions, which can well match the movement of the floating body system and is highly maneuverable.

Figure 1 shows a conventional multi-layer flexible riser, from the inside to the outside: the skeleton layer 1-1 to bear the internal load and its own weight; the sealing inner bushing 1-2 to prevent the leakage of the internal fluid; to bear the internal and external loads Armor layers, including compression armor layers 1-3 that mainly bear internal and external pressure loads and two orthogonally wound tensile armor layers 1-5 that mainly bear internal and external tensile loads; to reduce interlayer friction and pressure The inner protective cover 1-4 and the outer protective cover 1-6 to prevent corrosion or damage caused by the external environment.

2 shows a schematic cross-sectional view of a conventional skeleton layer 1-1. The cross-section of the conventional skeleton layer is an S-shaped cross-section, which includes an upper end arc belt 2-1, a hook 2-2, a lower end arc belt 2-3, a clamp Slots 2-4. The skeleton layer is the innermost layer of the flexible riser, usually made of stainless steel flat strips formed and wound into self-locking special-shaped pipes. The outer layer is in contact with the fluid-tight pressure sleeves 1-2 of the flexible riser, and the inner layer is in contact with the flexible riser. direct contact with the internal fluid. The grooves connecting the gaps between the skeleton layers 1-1 are prone to generate a large number of vortices due to the movement of the internal fluid, which leads to the problems of flow-induced vibration and humming, which greatly reduces the safety of oil and gas transportation in the flexible riser.

Figure 3 shows a schematic cross-sectional view of the proposed new "Sun" type skeleton unit. The structure of the skeleton layer is simple and the whole is square. "type structure, the lower square surface is 3-3, the lower hook is 3-4, the upper barb is 3-5, and the lower barb is 3-6.

The "Sun"-shaped skeleton layer is connected in the form of self-locking. The self-locking cross-sectional form is shown in Figure 4. The upper square surface 3-1 of the "Sun"-shaped structure is seamlessly connected with the upper barb 3-5 of the other skeleton layer. , the lower square surface 3-3 of the "day" type structure is seamlessly connected with the lower barb 3-6 of another skeleton layer, which overcomes the groove position generated when the conventional skeleton layer 1-1 is connected, and the upper hook 3-2 is connected with The lower hooks 3-4 of the other skeleton layer are closely and abutted closely, and the lower hooks 3-4 and the upper hooks 3-2 of the other skeleton layer are tightly and abutted, realizing the self-locking connection between the skeleton layers. The layers are tightly and seamlessly connected in a self-locking form, and the arc-shaped design of the ends of the upper hook 3-2 and the lower hook 3-4 ensures a certain flexibility of the flexible riser. FIG. 5 is a schematic diagram of the three-dimensional structure of the "Japanese" type skeleton layer.

The novel skeleton layer connection method and the cross-sectional shape of the flexible riser skeleton layer provided by the present invention reduce the cross-sectional area of the skeleton layer, and utilize the new self-locking form to engage the skeleton layers with each other, thereby eliminating the need for friction between the skeleton layers. The gap groove not only reduces the influence of friction and slip between adjacent skeleton layers, but also improves the connectivity between adjacent skeleton layers, effectively improving the support and protection of the skeleton layers, thereby improving the flexible riser Overall tensile, compressive and flexural resistance. Compared with the conventional skeleton layer, the new "Japanese" skeleton layer has the following advantages:

1) The generation of groove positions when the conventional skeleton layers 1-1 are mutually self-locking is avoided, the problem of flow-induced vibration and humming generated by the fluid inside the flexible riser is solved, and the safety of oil and gas transportation is improved.

2) The contact gap between layers is reduced, the influence of friction between the flexible riser skeleton layer 1-1 and the inner bushing 1-2 is reduced, and the fatigue life of the flexible riser skeleton layer 1-1 is improved.

3) The contact friction between adjacent surfaces inside the helical structure of the skeleton layer is reduced, the life of the skeleton layer is improved, and the follow-up crushing research is also facilitated.

4) The "Sun" section also adopts the self-locking connection method, which is simple to operate and easy to implement.

5) The same thickness of the skeleton layer 1-1, the "day" type section has less area than the conventional section, and the consumables and manufacturing are more economical.

6) The laying angle of the "Japanese" skeleton layer is 90 degrees. Compared with the traditional skeleton layer, the influence of the skeleton layer laying angle on the performance of the riser can be eliminated.

7) The geometry of the skeleton layer is simplified, thereby simplifying the subsequent analysis and research on the skeleton layer collapse.

8) Compared with the traditional skeleton layer, the manufacturing process of the "Japanese" skeleton layer is simpler.

Claims (1)

1. The utility model provides a flexible riser seamless skeleton layer which characterized in that is formed by the form connection of a plurality of same "day" type skeleton units adoption auto-lock, and every "day" type skeleton unit includes: the hook comprises a square surface (3-1) at the upper part of the 'sun' -shaped structure, an upper hook (3-2), a square surface (3-3) at the lower part of the 'sun' -shaped structure, a lower hook (3-4), an upper barb (3-5) and a lower barb (3-6); the square face (3-1) at the upper part of the 'solar' type structure is seamlessly connected with the upper barb (3-5) of the other framework unit, the square face (3-3) at the lower part of the 'solar' type structure is seamlessly connected with the lower barb (3-6) of the other framework unit, the upper hook (3-2) is tightly abutted against the lower hook (3-4) of the other framework unit, the lower hook (3-4) is tightly abutted against the upper hook (3-2) of the other framework unit, and no gap exists after the adjacent 'solar' type framework units are connected in a self-locking way.

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