During the exploitation of offshore oil,it is easy to form severe slugging in the riser system at a low gas-liquid velocity.The magnitude of the pressure fluctuation can be significantly high,causing dramatic change o...During the exploitation of offshore oil,it is easy to form severe slugging in the riser system at a low gas-liquid velocity.The magnitude of the pressure fluctuation can be significantly high,causing dramatic change of flow rate and leading to other damages.In this paper,the characteristics of slug velocity during the four stages of severe slugging in the pipeline-riser system were studied.It was found that the slug head rose in the riser at a constant velocity in the slug formation stage.At the same time,the direction of slug tail movement was opposite to the flow direction,and the tail velocity kept constant when flowing through the inclined pipe.In the process of blowout,the liquid velocity in the pipeline-riser system increased and reached a maximum value when the slug tail reached the top of the pipeline-riser.At this moment,the instantaneous flow rate was much larger than that in the slug production stage.展开更多
文摘During the exploitation of offshore oil,it is easy to form severe slugging in the riser system at a low gas-liquid velocity.The magnitude of the pressure fluctuation can be significantly high,causing dramatic change of flow rate and leading to other damages.In this paper,the characteristics of slug velocity during the four stages of severe slugging in the pipeline-riser system were studied.It was found that the slug head rose in the riser at a constant velocity in the slug formation stage.At the same time,the direction of slug tail movement was opposite to the flow direction,and the tail velocity kept constant when flowing through the inclined pipe.In the process of blowout,the liquid velocity in the pipeline-riser system increased and reached a maximum value when the slug tail reached the top of the pipeline-riser.At this moment,the instantaneous flow rate was much larger than that in the slug production stage.
文摘在内径50 mm、长27.3 m的水平管上利用空气-水作试验介质对段塞流的压力和液塞持液率进行了试验研究。采用压力传感器测量压力变化,采用平行电导探针测量液塞持液率变化。通过试验发现:液塞通过测量点时持液率的变化比压力变化迅速,持液率能更真实地反映段塞流动特性,可以用持液率的波动情况来确定液塞频率。将液塞持液率模型预测值与试验值进行了比较,结果表明,水平管大多数试验工况下的Zhang H Q模型预测值与试验值吻合最好。
