海洋立管内气液两相流流激力实验研究与计算模型

Flow-induced force caused by gas-liquid two-phase flow in marine riser system: experimental study and computing model

在海洋油气开发中,随着输送压力和管流速度的不断增大,由管道内流引起的振动问题成为流动安全保障的重要内容之一。通过搭建组合立管实验平台,对由气液两相流引起的流激力展开研究。根据持液率信号与实验观测结果,对立管内局部流型进行划分,对流激力的影响因素进行分析,建立了流激力波动主频和最大流激力均方根值Frms的计算模型,结果表明:Frms出现在段塞流与搅混流的边界处;随着入口含气率的增大,Frms基本呈现先增大、后减小的规律,但对于SSⅡ型严重段塞流,仍然能够产生较大流激力。研究成果可为海洋立管系统的设计、运行提供理论参考。

In the field of offshore oil and gas development, the pipeline transmission pressure and flow velocity increase, and the vibration caused by the internal flow of a pipeline becomes one of the important items for flow safety guarantee. Herein, the flow-induced force caused by the gas-liquid two-phase flow was studied by constructing an integrated experimental platform of riser. Then, the local flow pattern in the riser was divided according to the signal of liquid holdup and the observation results of the experiment, and the factors affecting the flow-induced force were analyzed. Additionally, the computing model of the main fluctuation frequency and the maximum root-mean-square value Frms of flow-induced force was established. The results show that: Frms appears at the boundary between the slug flow and the churn flow, and with the increase of air voids at the ingress, Frms is basically in the trend of increasing at first and then decreasing. However, for the SS II type severe slug flow, large flow-induced force can still be produced. The research results can provide a theoretical reference for the design and operation of marine riser system.