中文
Oil and gas transportation can be carried out continuously in large quantities and safely through offshore pipelines. For oil fields that are close to offshore or have large reserves, pipelines are usually used to transport oil and gas to onshore terminals (such as oil ports or onshore refineries). If the pipeline has sufficient pressure resistance, strong corrosion resistance (often using cathodic protection) and good sealing, it can realize continuous oil transportation without being affected by water depth, climate, terrain and other conditions. The CDSR oil suction and discharge hose has excellent wind resistance and flexibility, also it will meet the application requirements with various sea conditions.
However, the construction of marine pipelines will be directly disturbed by waves, and the water flow will affect the safety of pipeline construction and the stability of pipelines. There are many factors to be considered in completing a submarine pipeline project. The operating environment is in the ocean. Not only is the construction space limited, but the complex and changeable sea conditions will also bring great challenges to normal construction.
For construction operations, water depth is the most influential factor, and pipe laying operations vary greatly depending on water depth.
(1) For those places that close to the shore and in shallow water, the hose can be directly transported to land with a winch.
(2) S-Lay (S-type laying method) is mainly used in shallow sea areas and places far from the shore Welding, inspection and coating of the horizontal face, usually on board a pipelay vessel. As the ship moves forward, the pipe curves down through the water until it reaches a landing point on the seabed. It assumes a "S" shape as more pipe is released under its own weight.
(3) When pipe laying operations are carried out in deep water areas, if the water depth increases, it will be resulting in an exponential increase in construction difficulty. The J-Lay piping installation method is often used in deep water project. J-Lay (J-lay method) puts less stress on the pipe because the pipe is installed in a nearly vertical position. The sea pipe leaves the pipe-laying ship in a nearly vertical form, and goes down the vertical bend until it is laid on the seabed. The overall pipeline is in the shape of a "J", which is suitable for deep sea areas ranging from hundreds of meters to thousands.
(4) With the continuous development of technology, the way of offshore pipelaying operations is also constantly improving. For sea pipes with small diameter and weak strength, they can be installed on land and rolled directly on the drum, and then transported to the sea for laying by pipe-laying ship. This operation method is called Reel-Lay (rolled pipe laying method). Reel-Lay is considered the fastest method of laying as most of the welding and inspections are done onshore, minimizing installation time. At present, the reel-type pipe-laying ship can be divided into two types: horizontal and vertical.
In the final selection of the operation method, we should not only consider the water depth, but also combine comprehensive factors such as operation cycle and operation cost. CDSR supplies various types of hoses for single point mooring systems and offshore installations such as FPSO, FSO, SPM, etc. We also provide configuration research, engineering scheme research, hose selection, foundation design and other services for your project.
Date: 27 Mar 2023