A buoy section system for a deepwater riser based on an S-Lay installation process

Abstract

The application discloses a floater section system of a deepwater riser based on an S-Lay installation process, which comprises a floater section, a clamp and two protective covers, the floater section comprises a plurality of floater bodies arranged side by side, each floater body is a semicircular shell hinged together, the floater body is eccentric and in a cylindrical shape, the clamp is annular and embedded in the interior of the floater body, the two protective covers are in a cylindrical shape as a whole and are installed at two ends of the floater section, each protective cover is openable and closable and comprises a transition part and a connecting part, the transition part is in a hollow circular table shape, the connecting part is concentric with the transition part and in a hollow cylindrical shape, the outer diameter of the connecting part is the same as the outer diameter of the bottom of the floater body, the transition part and the connecting part of the protective cover and the side surface of the floater section have symmetrical cross sections along the axial direction of the riser penetrating through the whole floater section system, and the deepwater riser is clamped in the floater body through the clamp, when installation, the deepwater riser with the floater section system is horizontally placed on the roller of an S-Lay pipe-laying ship.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ocean engineering, and in particular to a float section system of a deepwater riser based on an S-Lay installation process. BACKGROUND

[0002] At present, with the continuous development of offshore oil technology, offshore oil exploitation gradually moves from deep water to ultra-deep water, and deepwater and ultra-deepwater floating production platforms become key offshore equipment, and the installation of deepwater risers matched therewith also becomes an urgent technology to be researched. The ship motion of a floating production platform in an ultra-deepwater environment, especially a turret mooring floating production storage and offloading (FPSO) system or a semi-submersible platform, includes a larger amplitude of heave, and the bottom of a standard configuration steel catenary riser (SCR) is prone to buckling, has greater fatigue damage, and has a shorter service life. At the same time, due to the deeper water depth and higher pressure, a longer suspension length and a thicker pipe wall are required, which greatly increases the load on the floating platform. The design of the standard configuration SCR faces many challenges in ultra-deepwater applications. Among many deepwater risers, a steel lazy-wave riser (SLWR) has been receiving more and more attention in the past decade and is one of the more commonly used forms of deepwater risers, and in recent years has been adopted by several ultra-deepwater oilfield development projects. The characteristic of this form of riser is that it has a float section hundreds of meters long, and the float section region can effectively isolate the dynamic response of the touchdown point (TDP) and the suspension point, relieve the coupling effect of the floating platform motion on the TDP of the riser, and thus improve the fatigue life of the riser float section region, and can also effectively reduce the top tension of the deepwater riser.

[0003] Due to the presence of the “float” online structure, this form of riser is more suitable for installation by the Reel-Lay or J-Lay process, and most of the SLWRs that have been installed and are in service internationally also use these two processes. However, in China, these two technologies are not yet mature, and the design, construction and installation technology related to the marine pipeline and riser is still mainly based on the S-Lay process. Under this background, the present application mainly aims at the S-Lay installation process and designs a float section configuration more suitable for S-Lay installation. SUMMARY

[0004] The present application aims to solve the above technical problems to some extent.

[0005] In order to solve the above technical problems, the present application provides a float section system of a deepwater riser based on an S-Lay installation process, which can be installed based on an S-Lay pipelaying vessel and realize the quick and safe installation of a deepwater riser.

[0006] A buoy section system of deepwater riser based on S-Lay installation process, characterized in that it comprises a buoy section, a clamp and two protective covers, the buoy section comprises a plurality of buoy bodies arranged side by side, each of the buoy bodies is two semicircular housings hinged together, the buoy body is eccentric and cylindrical, the clamp is annular and embedded in the interior of the buoy body, the two protective covers are overall cylindrical and installed at both ends of the buoy section, each of the protective covers is openable and comprises a transition part and a connecting part, the transition part is hollow and in the shape of a truncated cone, the connecting part is concentric with the transition part and in the shape of a hollow cylinder, the outer diameter of the connecting part is the same as the outer diameter of the bottom of the buoy body, the transition part, the connecting part of the protective cover and the side surface of the buoy section have a symmetrical cross section along the axial direction of the riser throughout the buoy section system, the deepwater riser is clamped in the buoy body through the clamp, when installed, the deepwater riser with the buoy section system is horizontally placed on the roller of the S-Lay pipelaying vessel, and the cross section of the buoy section system is in contact with the roller.

[0007] Further, the inner diameter of the protective cover is the same as the pipe diameter of the deepwater riser, and a friction pad is attached to the inner wall of the protective cover.

[0008] Further, the length of the transition part of the protective cover is greater than or equal to 1.8m and less than or equal to the length of the distance between three rollers of the S-Lay pipelaying vessel.

[0009] Further, the buoyancy of the protective cover in seawater is equal to its own gravity.

[0010] Further, the length of the buoy section is 1.5-2.5m.

[0011] Further, the buoy section and the protective cover are arranged side by side.

[0012] Further, the two sides of the protective cover are connected by bolts.

[0013] Further, the opening of the buoy body is downward, and a lifting point is arranged on the buoy body.

[0014] The beneficial effects of the present application: the present application provides a kind of based on S-Lay installation process's deepwater riser's float section system, including float section, clip and two protective cover, float section contains multiple and sets up in parallel float body, each float body is two half-round shell articulated together, float body is eccentric cylinder, clip is annular and is embedded in the inside of float body, two protective cover is overall cylinder and is installed in the both ends of float section, each protective cover can open and close and includes transition part and connecting portion, transition part is hollow circular table, connecting portion is concentric with transition part and is hollow cylinder, the outer diameter of connecting portion is same with the outer diameter of the bottom of float body, the transition part of protective cover, connecting portion and the side surface of float section have symmetrical cutting surface along the axial direction of riser that penetrates entire float section system, deepwater riser is clamped in float body by clip, when installation, deepwater riser with float section system is placed horizontally on the roller of S-Lay pipe-laying ship, and the cutting surface of float section system is in contact with roller, can realize the installation of deepwater riser based on S-Lay pipe-laying ship. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the overall appearance front view of the float section system of deepwater riser based on S-Lay installation process of the present application;

[0016] Figure 2 It is the three-dimensional schematic view of the float section system of deepwater riser based on S-Lay installation process of the present application;

[0017] Figure 3 It is the cross-sectional schematic view of the float section of the float section system of deepwater riser based on S-Lay installation process of the present application;

[0018] Figure 4 It is the overhead schematic view of the float body of the float section system of deepwater riser based on S-Lay installation process of the present application;

[0019] Figure 5 It is the side view of the protective cover of the float section system of deepwater riser based on S-Lay installation process of the present application;

[0020] Figure 6 It is the cross-sectional view of the protective cover of the float section system of deepwater riser based on S-Lay installation process of the present application in open state;

[0021] In the figure, 1-protective cover, 1A-connecting portion;1B-transition part;2.clip;3.deepwater riser, 4.float body, 5.float section, 6.spiral column plate vortex-induced vibration suppression device;7-roller;8-hinge, 9-bundling tape, 10-tie strap slot, 11-hanging point, 12-cutting surface, 13-bolt and nut. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present application and implement it.

[0023] A buoy section system of a deepwater riser based on S-Lay installation process according to an embodiment of the present application, as shown in Figures 1-6 includes a buoy section 5, a clamp 2 and two protective covers 1, the buoy section 5 contains a plurality of buoy bodies 4 arranged side by side, each buoy body 4 is two semicircular shells hinged together, the buoy body 4 is eccentric and cylindrical, the clamp 2 is annular and embedded in the inside of the buoy body 4, the two protective covers 1 are overall cylindrical and installed at the two ends of the buoy section 5 Figure 1 and Figure 2 The protective cover 1 is spaced a distance from the buoy section 5), each protective cover 1 is openable and includes a transition part 1B and a connecting part 1A, the transition part 1B is hollow and circular truncated cone-shaped, the connecting part 1A is concentric with the transition part 1B and hollow cylindrical, the outer diameter of the connecting part 1A is the same as the outer diameter of the bottom of the buoy body 4, the transition part 1B, the connecting part 1A of the protective cover 1 and the side surface of the buoy section 5 have a symmetrical cross section along the axial direction of the riser through the entire buoy section 5 system, the deepwater riser 3 is clamped in the buoy body 4 by the clamp 2, when installed, the deepwater riser 3 with the buoy section 5 system is placed horizontally on the roller 7 of the S-Lay pipelaying ship, and the cross section 12 of the buoy section 5 system is in contact with the roller 7. The protective cover 1 is provided to enhance the passability of the buoy section 5 through the roller 7 of the S-Lay pipelaying ship, and the cross section of the buoy section 5 system is in contact with the roller 7, the contact between the buoy section 5 system and the roller 7 is a surface contact, which reduces the pressure of the roller 7 on the buoy system, and the continuous buoy section 5 can effectively avoid the risk of the buoy body 4 being stuck on the roller 7 and other structures when the buoy section 5 passes through the roller 7 during S-LAY process. In use, the clamp 2 is clamped on the riser, then the deepwater riser 3 containing the clamp 2 is placed in the buoy body 4, and the buoy body 4 is closed.

[0024] A buoy section system of a deepwater riser based on S-Lay installation process according to an embodiment of the present application, as shown in Figures 1-6As shown, the inner diameter of the protective cover 1 is the same as the pipe diameter of the deepwater riser 3, and a friction pad is attached to the inner wall of the protective cover 1. The friction pad can increase the friction between the protective cover 1 and the deepwater riser 3, and can avoid the slippage of the protective cover 1 after the protective cover 1 is locked. The length of the transition part 1B of the protective cover 1 is greater than or equal to 1.8 m and less than or equal to the length of the interval between the three rollers 7 of the S-Lay pipe-laying ship. The length of the transition part 1B of the protective cover 1 is greater than or equal to 1.8 m, which increases the passability of the protective cover 1. At the same time, the length of the transition part 1B of the protective cover 1 is less than or equal to the length of the interval between the three rollers 7, which avoids the poor flexibility of the riser caused by the excessive length of the protective cover 1. The buoyancy of the protective cover 1 in seawater is equal to its own gravity, so as to avoid adding extra weight to the buoyant section 5 by this component.

[0025] According to the embodiment of the present application, a buoyant section system of a deepwater riser based on an S-Lay installation process is provided, which comprises a buoyant section 5 and a protective cover 1. Figures 1-6 As shown, the length of the buoyant section 5 is 1.5-2.5 m. In actual application, a helical strake vortex-induced vibration suppression device 6 is installed on the outer surface of the buoyant section 5, and the helical strake vortex-induced vibration suppression device 6 is fixed on the outer surface of the buoyant section 5 and arranged side by side with the protective cover 1. The protective cover 1 is connected by bolts and nuts 13 on both sides. The opening of the buoyant body 4 is downward, and the buoyant body 4 is provided with a lifting point 11. When the auxiliary crane lifts the buoyant section 5, the buoyant section 5 is in a horizontal direction, the buoyant opening is downward, and can be clamped on the pipe, so that the installation is convenient. In addition, in order to ensure the installation stability of the buoyant section 5, a lashing groove 10 is arranged on the buoyant body 4. When the buoyant body 4 is folded, the buoyant body 4 can be bound by using a packing belt 9.

[0026] The above embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent replacement or transformation of the present application made by the person skilled in the art on the basis of the present application is within the protection scope of the present application. The protection scope of the present application is subject to the claims.

Claims

1. A buoy section system for a deepwater riser based on an S-Lay installation process, characterized in that, The float section includes a plurality of float bodies arranged side by side, each of the float bodies being two half-circular housings hinged together, the float bodies being eccentrically cylindrical, the clamp being annular and embedded inside the float bodies, the two protective covers being overall cylindrical and mounted at both ends of the float section, each of the protective covers being openable and closable and including a transition portion and a connecting portion, the transition portion being a hollow circular truncated cone, the connecting portion being concentric with the transition portion and being a hollow cylinder, the outer diameter of the connecting portion being the same as the outer diameter of the bottom of the float body, the transition portion, the connecting portion of the protective cover and the side surface of the float section having a symmetrical cross section along the riser axis throughout the float section system, the deepwater riser being clamped in the float body through the clamp, when installed, the deepwater riser with the float section system being horizontally placed on the rollers of the S-Lay pipelaying vessel, and the cross section of the float section system being in contact with the rollers.

2. A buoyant section system for a deepwater riser based on S-Lay installation process according to claim 1, characterized in that, The inner diameter of the protective cover is the same as the pipe diameter of the deepwater riser, and a friction pad is attached to the inner wall of the protective cover.

3. A buoyant section system for a deepwater riser based on S-Lay installation process as claimed in claim 1, wherein, The length of the transition portion of the protective cover is greater than or equal to 1.8 meters and less than or equal to the length of the distance between three rollers of the S-Lay pipelaying vessel.

4. A buoyant section system for a deepwater riser based on S-Lay installation process as claimed in claim 1, wherein, The buoyancy of the protective cover in seawater is equal to its own gravity.

5. A buoyant section system for a deepwater riser based on S-Lay installation process as claimed in claim 1, wherein, The length of the float section is 1.5-2.5m.

6. A buoyant section system for a deepwater riser based on S-Lay installation process as claimed in claim 1, wherein, The float section and the protective cover are arranged side by side.

7. A buoyant section system for a deepwater riser based on S-Lay installation process as claimed in claim 1, wherein, The two sides of the protective cover are connected by bolts.

8. A buoyant section system for a deepwater riser based on S-Lay installation process as claimed in claim 1, wherein, The opening of the float body is downward, and a lifting point is arranged on the float body.

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