海底管道立管系统弯管段流场分析——以胜利油田CB306井组平台为例

Analysis of flow around the elbow in riser system of subsea pipeline:a case study of CB 306 well group platform in Shengli oilfield

以胜利油田CB306井组平台为例,运用大涡模拟(LES)方法对海底管道立管系统弯管段周围流场进行了模拟分析,结果表明:海流流速在立管两侧增大,在立管后方形成交替脱落的漩涡;立管后方形成的三维立涡成倒锥形,上部漩涡比下部漩涡先脱离立管;三维立涡底部海水对海底的剪切作用及对海底沉积物的提升作用最强,这也是海底冲淘作用不断加剧的根本原因。

Using the large eddy simulation （LES） technique, simulation of the flow field around the elbow in riser system of subsea pipeline is conducted as a case study of CB 306 well group platform in Shengli oilfield. The results show that the velocity of ocean current is enhanced both sides of riser and alternately shed vortex are formed after riser; 3D stand vortex behind riser likes headstand cone; the topside vortex shed earlier than underside from the riser. The shear action and lifting affect on sediments of subsea are most powerful on the bottom of 3D stand vortex. That is the main reason of seabed scouring being intensified continuously.