中文摘要：

用于将海底原油及天然气举升到海上平台的S型柔性立管是海洋石油工业中的重要设备。为研究柔性立管尺寸对严重段塞流特性的影响,在集输-S型柔性立管系统上分别实验研究了立管内径等于和大于集输管道内径时严重段塞流的特征参数规律。该实验环路内径为50 mm,由水平环路、倾角为-2°的下倾段和S型柔性立管组成,其中水平段长为114 m,下倾段长为16 m,柔性立管垂直高度为15.3 m,全长为24 m。实验发现：不同立管管径中的一个严重段塞流周期都由积液、排液、气体进入和气液喷发4个阶段组成,且周期会随气、液表观流速的增大而减小,液塞长度会随液相表观速度的增大而增大,随气相表观速度的增大而减小。通过对比2种立管管径对严重段塞流特征参数的影响,发现增大立管管径会略微扩大严重段塞流区域,降低严重段塞流的周期和液塞长度。

英文摘要：

S-shaped flexible risers are important equipment in offshore oil industry since they can transfer crude oil and natural gas from the seabed to offshore platform.In order to investigate the effect of riser inside diameter（ID） on severe slugging characteristics,the rule was studied in pipeline-riser system when flexible riser ID was equal to and larger than gathering pipeline ID respectively.The test loop consists of a 114 m long and 50 mm ID horizontal pipeline,a 16 m long and-2° downward inclined pipe,and an S-shaped riser with 15.3 m in vertical height and 24 m in total length.The results show that each cycle of severe slugging in both risers consists of four stages,i.e.slug formation,liquid drainage,gas penetration,and gas-fluid eruption.The cycle period decreases with the increase of gas or liquid superficial velocity,while the slug length increases with the increase of liquid superficial velocity,but decreases with the increase of gas superficial velocity.The comparison of characteristics of severe slugging in different risers shows that the increase of riser ID extends severe slugging area slightly,and decreases the cycle period and slug length.