Methodology for production logging in oil-in-water flows under low flow rate and high water-cut conditions

This study aimed to obtain the production profiles of oil-in-water flow under low flow rate and high water-cut conditions in oil wells.A combination production profile logging composed of an arc-type conductance sensor(ATCS)and a cross-correlation flow meter(CFM)with a center body is proposed and experimentally evaluated.The ATCS is designed for water holdup measurement,whereas the CFM with a center body is proposed to obtain the mixture velocity.Then,a drift-flux model based on flow patterns is established to predict the individual-phase superficial velocity of oil-in-water flows.Results show that the ATCS possesses high resolution in water holdup measurement and that flow pattern information can be deduced from its signal through nonlinear time series analysis.The CFM can enhance the correlation of upstream and downstream signals and simplify the relationship between the cross-correlation velocity and mixture velocity.On the basis of the drift-flux model,individual-phase superficial velocities can be predicted with high accuracy for different flow patterns.

等离子体加载螺旋线行波管特性研究

利用线性场理论和螺旋线的导电面模型 ,推导了在强引导磁场下 ,等离子体加载螺旋线慢波结构的色散关系 .数值计算了在不同的等离子体填充密度与填充半径条件下 ,螺旋线的色散特性、耦合阻抗和行波管的小信号增益 .研究发现 ,在螺旋线中填充了等离子体以后 ,形成了一种新的混合模式 ,螺旋线的色散特性与耦合阻抗都发生了很大的变化 。