Study on Flow Patterns of Two-phase Flow in Catenary Riser

The flow patterns and flow characteristics using water and air as media were studied in this paper,which appear in combination of horizontal pipeline and catenary riser.The flow pattern was j udged by observation and measuring the pressure along the pipeline and catenary riser.The change of pressure a-long the pipeline and pressure drop with different gas and liquid velocities as well as the angle of horizontal pipeline in a part of flow patterns were studied,the parameters such as void fraction,bubble length,bubble velocity,bubble frequency of slug flow and serious slug flow in the catenary riser were measured.The re-sults show that there are four flow patterns occupy the most extensive area in the nine combinations of flow pattern.The changes of gas and liquid flow rates have an impact on the pipeline pressure drop.The im-pact of the angle of horizontal pipe section to the pipeline pressure drop is much smaller than the flow rates of gas and liquid.When the liquid flow rate remains unchanged,the void fraction of slug flow and serious slug flow increase with the increasing of gas flow rate.When the gas flow rate remains unchanged,the void fraction of slug flow and serious slug flow decrease with the increasing of liquid flow rate.