阅读说明：本技术 一种设于立管底部的张力平衡系统 (Tension balancing system arranged at bottom of vertical pipe ) 是由 杨伟 尹汉军 熊海荣 赵党 苑健康 熊刚 夏日长 王波 潘悦然 刘彩虹 王猛 于 2021-06-18 设计创作，主要内容包括：本发明公开了一种设于立管底部的张力平衡系统,包括立管管线终端、张力平衡锚链及深水吸力桩；张力平衡锚链,所述张力平衡锚链一端通过卸扣与管线终端的吊耳连接,另一端通过加强环与所述深水吸力桩上的水下ROV吊钩连接；所述张力平衡锚链由依次连接的加强环、特殊端环、端环、普通链环及卸扣组成；深水吸力桩,所述深水吸力桩包括ROV平台和ROV吊钩,所述ROV吊钩固定于所述ROV平台上。本发明中钢悬链线立管与立管管线终端相连通过张力平衡锚链将不平衡张力传到到深水吸力桩上,由于锚链单向受力特点实现了张力的被动平衡,以达到保护深水海管端部设施及与其相连的水下设施完整性及安全的目的。(The invention discloses a tension balancing system arranged at the bottom of a vertical pipe, which comprises a vertical pipe line terminal, a tension balancing anchor chain and a deepwater suction pile; one end of the tension balance anchor chain is connected with a lifting lug at a pipeline terminal through a shackle, and the other end of the tension balance anchor chain is connected with an underwater ROV lifting hook on the deep water suction pile through a reinforcing ring; the tension balance anchor chain consists of a reinforcing ring, a special end ring, an end ring, a common chain ring and a shackle which are connected in sequence; the deepwater suction pile comprises an ROV platform and an ROV lifting hook, and the ROV lifting hook is fixed on the ROV platform. In the invention, the steel catenary riser is communicated with the riser pipeline terminal, and the tension balancing anchor chain transmits unbalanced tension to the deepwater suction pile, and the passive balance of the tension is realized due to the unidirectional stress characteristic of the anchor chain, so that the aims of protecting the integrity and safety of deepwater marine pipe end facilities and underwater facilities connected with the deepwater marine pipe end facilities are fulfilled.)

1. The utility model provides a locate tension balanced system of riser bottom which characterized in that: the device comprises a vertical pipe line terminal, a tension balance anchor chain and a deepwater suction pile;

one end of the tension balance anchor chain is connected with a lifting lug at a pipeline terminal through a shackle, and the other end of the tension balance anchor chain is connected with an underwater ROV lifting hook on the deep water suction pile through a reinforcing ring; the tension balance anchor chain consists of a reinforcing ring, a special end ring, an end ring, a common chain ring and a shackle which are connected in sequence; the deepwater suction pile comprises an ROV platform and an ROV lifting hook, and the ROV lifting hook is fixed on the ROV platform.

2. A tension balancing system according to claim 1, wherein: the requirements of bearing 300 tons of tension and ensuring 30-year underwater service life are met by the material selection, corrosion control, in-situ strength, installation analysis and fatigue life of the riser pipeline terminal, the tension balance anchor chain and the deepwater suction pile.

3. A tension balancing system according to claim 1, wherein: the tension balance anchor chain is connected with a lifting lug of the riser pipeline terminal through a 300T shackle; the lifting lug is made of DH36-Z35, and the strength of the connecting structure and the tolerance requirement of the shackle pin shaft are guaranteed by adopting a mode of flitch plates on two sides.

4. A tension balancing system according to claim 1, wherein: the total length of the tension balance anchor chain is about 90 meters, and DNVGL-OS-E302R 4 grade material is adopted.

5. A tension balancing system according to claim 1, wherein: the deepwater suction pile is made of API 2H Gr 50 materials, the diameter is 5m, the pile length is 20m, and the mud penetration depth is 19 m.

Technical Field

The invention relates to a tension balancing system arranged at the bottom of a vertical pipe.

Background

One end of a Steel Catenary Riser (SCR) is connected with a floating production system, and the other end of the steel catenary riser is connected with a submarine pipeline terminal, so that the steel catenary riser is a key production medium conveying channel between an underwater production facility and the floating system, and is one of riser forms which are most widely applied in deep sea development due to the simple structural form and strong adaptability to high-temperature and high-pressure environments. However, if the length of a seabed section of a Steel Catenary Riser (SCR) is limited or the axial rigidity of soil at the seabed section is small, sufficient anchoring resistance cannot be provided for the whole riser, the movement of the floating production system under extreme environmental conditions can generate large axial tension at the end of the seabed section of the riser, so that the riser moves irreversibly towards the platform, the integrity of a pipeline end connector and a jumper is affected, and the problems of leakage, damage and the like of the whole system are caused.

Disclosure of Invention

The invention provides a tension balancing system arranged at the bottom of a riser, which can balance the larger tension at the bottom of a steel catenary riser and avoid the damage of the riser system.

In order to solve the technical problem, the invention provides a tension balancing system arranged at the bottom of a stand pipe, which comprises a stand pipe line terminal, a tension balancing anchor chain and a deepwater suction pile;

one end of the tension balance anchor chain is connected with a lifting lug at a pipeline terminal through a shackle, and the other end of the tension balance anchor chain is connected with an underwater ROV lifting hook on the deep water suction pile through a reinforcing ring; the tension balance anchor chain consists of a reinforcing ring, a special end ring, an end ring, a common chain ring and a shackle which are connected in sequence;

the deepwater suction pile comprises an ROV platform and an ROV lifting hook, and the ROV lifting hook is fixed on the ROV platform.

Further, the material selection, corrosion control, in-place strength, installation analysis and fatigue life of the riser line termination, the tension balancing anchor chain and the deepwater suction pile meet the requirements of bearing 300 tons of tension and guaranteeing 30 years of underwater service life.

Further, the tension balance anchor chain is connected with a lifting lug of the riser pipeline terminal through a 300T shackle; the lifting lug is made of DH36-Z35, and the strength of the connecting structure and the tolerance requirement of the shackle pin shaft are guaranteed by adopting a mode of flitch plates on two sides.

Furthermore, the total length of the tension balance anchor chain is about 90 meters, and DNVGL-OS-E302R 4 grade material is adopted.

Furthermore, the deepwater suction pile is made of API 2H Gr 50 materials, the diameter is 5m, the pile length is 20m, and the mud penetration depth is 19 m.

The invention has the technical effects that:

the passive tension balancing anchor chain can be used for passively balancing larger tension at the end part of the steel catenary riser to avoid system damage, the steel catenary riser is communicated with the riser pipeline terminal, the unbalanced tension is transmitted to the suction pile through the tension balancing anchor chain, and the passive balance of the tension is realized due to the unidirectional stress characteristic of the anchor chain, so that the purposes of protecting the integrity and the safety of facilities at the end part of the deepwater sea pipe and underwater facilities connected with the deepwater sea pipe are achieved.

The horizontal reliable transmission of riser bottom tension is realized to riser pipeline terminal one end through welding of one section pre-installation level straight tube nipple joint and the originated end of laying of SCR, and the other end is connected with 300T break-out on the tension balance anchor chain through the lug on the terminal frame extension structure, has realized tension conversion, and lug material DH36-Z35 adopts both sides flitch to guarantee structural strength and the tolerance requirement of break-out round pin axle.

The tension balance anchor chain has the total length of about 90 meters, is made of DNVGL-OS-E302R 4 grade materials, and consists of a reinforcing ring, a special end ring, an end ring, a common chain ring and a shackle assembly; the common chain ring and the end ring are of a baffled type, and the other chain ring and the end ring are of a non-baffled type so as to prevent the anchor chain from being twisted during installation; the size of the anchor chain component is gradually transited to the size of a common chain ring from two ends so as to facilitate underwater connection; the strength of the anchor chain is designed according to API-RP-2SK, the diameter of the anchor chain of the common chain ring after considering 12mm corrosion allowance is 58mm, and the minimum safe working tension is 3396 kN; one end of the tension balance anchor chain is connected with the pipeline terminal lifting lug through a shackle, and the other end of the tension balance anchor chain is connected with an underwater ROV lifting hook on the suction pile through a reinforcing ring, so that the bottom tension of the vertical pipe is finally transmitted to the deepwater suction pile.

The diameter of the deep water suction pile is 5m, the pile length is 20m, the mud penetration depth is 19m, the pile body is made of API 2H Gr 50 material, and the top of the deep water suction pile is provided with a drainage valve and an ROV operation platform, so that pile sinking and anchor chain connection operation are facilitated; the interior walls of the ROV hook are ground to match the size of the reinforcing ring to reduce stress concentrations.

The design specification of the deepwater suction pile is based on API-RP-2A, DNV-OS-C102 and API-RP-2SK, and the strength, the lateral deformation resistance and the stability of the pile body are checked based on a finite element analysis method to ensure the tension balance requirement in the whole life cycle of the steel catenary riser.

Drawings

FIG. 1 is an overall schematic view of a preferred embodiment of the present invention;

FIG. 2 is a diagram of a tension chain layout according to a preferred embodiment of the present invention;

fig. 3 is a perspective view of a deep water suction pile according to a preferred embodiment of the present invention.

Reference numerals: 1. a riser line termination; 2. a tension balancing anchor chain; 3. a deepwater suction pile; 21. a reinforcement ring; special end rings 22; 23. an end ring; 24. a plain chain link; 25. shackle dismounting; an ROV hook; an ROV platform.

Detailed Description

The present invention is further described with reference to the following drawings and specific examples so that those skilled in the art can better understand the present invention and can practice the present invention, but the examples are not intended to limit the present invention.

In the embodiment, as shown in fig. 1 to 3, the invention discloses a tension balancing system arranged at the bottom of a riser, which comprises a riser pipeline terminal 1, a tension balancing anchor chain 2 and a deepwater suction pile 3;

one end of the tension balance anchor chain 2 is connected with a lifting lug at a pipeline terminal through a shackle 25, and the other end of the tension balance anchor chain 2 is connected with an underwater ROV lifting hook 31 on the deep water suction pile 3 through a reinforcing ring 21; the tension balance anchor chain 2 consists of a reinforcing ring 21, a special end ring 22, an end ring 23, a common chain ring 24 and a shackle 25 which are connected in sequence;

deep water suction pile 3. deep water suction pile 3 includes ROV platform 32 and ROV hook 31, ROV hook 31 on ROV platform 32.

The selection of materials, corrosion control, in-place strength, installation analysis and fatigue life of the riser pipeline terminal 1, the tension balance anchor chain 2 and the deepwater suction pile 3 meet the requirements of bearing 300 tons of tension and guaranteeing 30-year underwater service life.

The tension balance anchor chain 2 is connected with a lifting lug of the riser pipeline terminal 1 through a 300T shackle 25; the lifting lug is made of DH36-Z35, and the strength of the connecting structure and the tolerance requirement of the pin shaft of the shackle 25 are guaranteed by adopting a mode of flitch plates on two sides.

The total length of the tension balance anchor chain 2 is about 90 meters, and DNVGL-OS-E302R 4 grade material is adopted.

The deepwater suction pile 3 is made of API 2H Gr 50 materials, the diameter is 5m, the pile length is 20m, and the mud penetration depth is 19 m. The pile body strength, the lateral deformation resistance, the pile body stability and the corrosion design of the deepwater suction pile 3 can ensure the tension balance requirement in the whole life cycle of the steel catenary riser.

The deep water suction pile 3 and the tension balance anchor chain 2 are used as a steel catenary riser J-shaped laying starting pile and a starting cable, tension is provided for riser starting laying, and riser starting laying and mounting operation is simplified.

The invention is implemented by the following steps:

1. temporarily fixing the terminal in a J-shaped laying tower according to an online installation process of a riser pipeline terminal 1, completing centering, welding, inspection and node coating of the head end of the riser and the riser pipeline terminal 1 according to an SCR (selective catalytic reduction) laying program, and pre-installing a tension balance anchor chain 2 and other auxiliary rigging;

2. the pre-installed tension balance anchor chain 2 and the riser pipeline terminal 1 are laid and lowered to the top of the deepwater suction pile 3 along with the J-shaped laying of the pipeline, the DMA, the auxiliary buoy and the rigging are lowered by a crane on a pipe laying vessel, and the lowering process is monitored by the ROV in the whole process;

3. connecting a crane rigging with an installation cable pre-installed on a tension balance anchor chain 2 through an ROV (remote operated vehicle), continuously lowering the tension balance anchor chain 2 until the tension balance anchor chain partially contacts the ground, and connecting a reinforcing ring 21 on the tension balance anchor chain 2 with an ROV lifting hook on a deepwater suction pile 3 through the ROV;

4. the pipe-laying ship continues to lay the SCR forwards, and simultaneously gradually tightens the tension balance anchor chain 2;

5. after the vertical pipe line terminal 1 is put down in place, the pipe laying ship normally lays the SCR, at the moment, the tension balance anchor chain 2 is in a tensioning state to provide initial laying tension for SCR laying, and the ROV recovers the temporary rigging and the buoy.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.