Skeleton layer for marine flexible pipe, and composite flexible pipe

Abstract

The invention discloses a skeleton layer for a marine flexible pipe, and a composite flexible pipe. The skeleton layer comprises a first special-shaped band and a second special-shaped band; the firstspecial-shaped belt is spirally wound to form a tubular skeleton layer body, and the inner surface of the skeleton layer body is provided with a spiral groove; and the first special-shaped band and the second special-shaped band are staggered and spirally wound to close the opening of the spiral groove. The skeleton layer has a simple structure and a reasonable design, can effectively solve the flow induced vibration and buzz problem caused by the internal flow of the flexible composite pipe with the skeleton layer, can smooth the flow of the internal oil and gas fluid, avoid the vortex generation and the flow induced vibration phenomenon, greatly improve the safety of the oil and gas transportation of the marine flexible pipe, and can be widely used in the offshore oil and gas compositeflexible pipe structure.

Description

technical field [0001] The invention relates to the technical field of marine flexible pipes, in particular to a skeleton layer of a flexible marine pipe and a composite flexible pipe. Background technique [0002] As the key equipment for the exploitation of offshore oil and gas resources, offshore flexible umbilical cables are playing an increasingly important role and have been more and more widely used. The structure of the marine flexible pipe is complex, composed of multiple layers of metal layers and non-metal layers, ranging from 4-5 layers to more than a dozen layers, generally designed according to its pre-operation waters. Different layers of the flexible pipe undertake different functions, and the skeleton layer, as its key layer structure, plays the role of resisting external pressure and preventing crushing. [0003] The skeleton layer is generally used as the innermost layer of the flexible pipe for marine use, which is the layer directly in contact with oil ...

AI Technical Summary

Problems solved by technology

[0003] The skeleton layer is generally used as the innermost layer of the flexible pipe for marine use, which is the layer directly in contact with oil and gas. As a kind of fluid, oil and gas flow in the pipe at high speed during the production process. If there is a partial depression in the unevenness of the fluid, a vortex will be generated in the depression when the fluid flows. If the frequency of the vortex is close to the natural frequency of the skeleton layer's own components, vibration will occur, also known as flow-induced vibration. Vibration can also cause humming, which poses a great threat to the safety of flexible pipe oil and gas transportation

The generation of flow-induced vibration is related to the fluid velocity, density, pressure and the structural size of the skeleton layer, but once this potential danger occurs, it will cause irreversible loss

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