【作者】 谭练武；

【导师】 尤云祥；

【作者基本信息】 上海交通大学 ， 船舶与海洋结构物设计制造， 2011， 硕士

【摘要】 在海洋油气开采系统中,将原油及其伴生气等从海底井口输送到海面平台预处理系统过程中需要经过一段沿海底铺设的管道和垂直立管,因而会在该种组合管道系统中出现气液混输情况,混输中容易出现严重段塞流现象。这是一种液塞长度可达一倍或几倍立管高度的流动现象,这种现象将造成管道压力剧烈波动、立管出口气液相流量随时间变化很大等有害后果,而对海洋油气开采系统带来诸多危害,对这种流动现象开展研究具有重要的理论和实际意义。本文利用内径为0.026m的水平-下倾-立管组合管线模型上对严重段塞流特性进行了研究,得出如下结论:本实验中水平-下倾-立管系统的水平管形成了分层流、间歇流和阻塞流等三种主要流态,立管中形成了地形严重段塞流、水动力严重段塞流和间歇流三种主要流态,而地形严重段塞流又可细分为I型、II型和III型。通过实验得到了水平管和立管的流型图。对严重段塞流的流动特性进行了实验研究和分析,结果表明典型地形严重段塞流具有严格的周期性,周期随气液相折算流速增大而减小,压力波动幅度随气液相折算流速的改变而变化,最大值出现在地形严重段塞流I型到II型的转换边界上。通过改变组合管道模型系统中立管高度,获得了两种立管高度下严重段塞流的流型图。在此基础上,对管线内严重段塞流的流态变化进行详尽阐述。通过分析实验结果,并对流动周期、压力、液塞长度及喷发时间等特性参数进行比较。结果表明:仅改变立管高度,对严重段塞流的形成机理及判定方法没有影响,对水平和下倾管内流型的影响也很小,但会增加严重段塞流与稳定流型之间的过渡区域,并将导致严重段塞流周期、压力波动幅值和喷发时间的增大。对实验中出现的水动力严重段塞流进行详细观察后发现,其形成较稳定,也具有很好的周期特性,并同样将在短时间内导致气液流量急剧增大。水动力严重段塞流的出现,使原本随气液相折算速度增大而不断减小的严重段塞流周期和压力波动幅值增大,而且危害也与地形严重段塞流类似,因而导致严重段塞流发生范围更广,因此需要在工程设计上给予关注。更多还原

【Abstract】 During the multiphase transportation of oil and gas form subsea wellhead to the surface processing platform in offshore petroleum exploitation ,oil and gas have to be delivered by pipeline layed on the seabed and vertical riser, as a result,severe slugging phenomenon is commonly encountered and will cause drastic pressure fluctuations and outlet flow with other harmful consequences.Do intensive research on this flow phenomenon has important theoretical and realistic significance.In this study,the severe slugging phenomenon in a horizontal-decline-riser system was studied.The inner diameter of test pipe is 0.026m.The mechanism and flow characteristics of severe slugging were analyzed.The main contents and conclusions are as follows:Three flow patterns are observed in the horizontal pipe, namely,stratified flow, intermittent flow and blocking flow.There are also three flow patterns in the riser pipe section,including terrain severe slugging,hydrodynamic severe slugging,and intermittent flow,while terrain slugging can be divided into type I,type II and type III.The flow pattern map of the two-phase flow of the horizontal pipe and riser were also obtained.The flow characteristics of severe slugging were studied. It was found that typical terrain slugging is on a strict cyclical,and the cycle length decreases with the gas and liquid superficial velocity increase, the pressure fluctuations change with the gas and liquid superficial velocity change,and the maximum value of pressure fluctuation occurs at the boundry of terrain slugging type I and type II.By changing the height of risers,two flow pattern maps of risers were obtained On this basis, the changes of flow patterns are introduced. By analyzing the experimental results,it shows that the mechanism judgement of severe slugging won’t change as only change the height of riser,and the flow pattern won’t change either,but the region of the severe slugging increases,the length of period,pressure fluctuation and eruption time will also increase.After observations on the hydrodynamic severe slugging which appears in the experiment,it’s found that the formation of hydrodynamic severe slugging is stable,and it also has good cycle characteristics, and will also lead to violent gas and liquid flow eruption. As the happening of hydrodynamic severe slugging, the original decreasing of the severe slugging cycle and the pressure fluctuation amplitude increased mutation are abrupt increasing,make the region of the severe slugging increases greatly,so speacail attention also need to be paid on this phenomenon.更多还原