油气水三相段塞流引起的海洋立管耦合振动响应

海洋立管是海上油气集输系统的重要组成部分,用于连接海底油气井口与海上油气集输站。在油气储运工程中,海洋油气集输介质多为油气水三相流体。为了研究油气水三相流海洋立管系统在严重段塞流作用下产生的耦合振动问题,进行了数值计算与实证研究。基于多相流体力学与动力学理论,构建了油气水三相严重段塞流模型和海洋立管结构动力学模型,结合这2个模型,模拟了立管耦合振动响应过程,并设计了下倾管倾斜角度为3°的L型油气水三相流立管系统进行实验。对模型计算值和实测值进行对比,结果表明:所提出的耦合振动响应模型比现有严重段塞流瞬态数学模型更适用于油气水三相段塞流引起的海洋立管耦合振动响应问题的研究,计算结果与实验结果较吻合;立管底部压强与底部位移呈周期性变化,且变化周期基本一致;流体压强是引发立管系统耦合振动响应问题的关键因素。研究结果为油气水三相流海洋立管系统在严重段塞流作用下的耦合振动响应特性分析及其结构设计提供了参考。

Coupled vibration response of marine riser caused by oil-gas-water three-phase slug flow

Marine riser is an important part of offshore oil and gas gathering and transportation system, which is used to connect submarine oil and gas wellheads and offshore oil and gas gathering and transportation stations. In oil and gas storage and transportation projects, marine oil and gas gathering and transportation media are mostly oil-gas-water three-phase fluids. In order to investigate the coupled vibration problem of the oil-gas-water three-phase flow marine riser system under severe slug flow, numerical calculation and empirical research were carried out. Based on the multiphase fluid mechanics theory and kinetic theory, a three-phase severe slug flow model of oil-gas-water and structural dynamics model were constructed. Combining these two models, the coupled vibration response process of the riser was simulated, and the L-type oil-gas-water three-phase flow riser system with the inclined pipe tilt angle of 3° was designed and tested. Comparing the calculated and tested values, the results showed that the proposed coupled vibration response model was more suitable for studying the coupled vibration response of marine riser caused by the oil-gas-water three-phase of flug flow than the severe slug flow transient mathematical model, and the simulation of results were in good agreement with the experimental results. The pressure and displacement of the riser bottom changed periodically, and the period of change was basically the same; the pressure of fluid was the key factor that caused the coupled vibration response of the riser system. These research results provide a reference for the analysis of the coupled vibration response characteristics and structural design of the oil-gas-water three-phase flow marine riser system under severe slug flow.