Effects of flow patterns and salinity on water holdup measurement of oil-water two-phase flow using a conductance method
Effects of flow patterns and salinity on water holdup measurement of oil-water two-phase flow using a conductance method
复制标题
流型和盐度对电导法测量油水两相流持水率的影响
DOI：
10.1016/j.measurement.2016.07.053
复制
发表时间：
2016-11-01
期刊：
影响因子：
5.6
通讯作者：
Zhang，H. X.
中科院分区：
文献类型：
--
作者：
Liu，W. X.;Jin，N. D.;Zhang，H. X.
研究了油水两相流流型和矿化度对电导法测量持水率的影响。首先，在内径为20 mm的管道中进行了垂直上升油水两相流实验，水溶液的矿化度分别为151 ppm、1003 ppm、2494 ppm和4991 ppm。实验含水率为80-100%，混合速度为0.0184- 0.2576m/s。在实验中，三种不同的流动模式，利用高速摄像机对分散型水包油段塞流（D OS/W）、分散型水包油流（D O/W）和极细分散型水包油流（VFD O/W）进行了观测和记录。同时，我们采集了垂直多电极阵列（VMEA）电导传感器在正弦电压信号激励下的响应。结果表明，对于VFD O/W，在一定盐度下，VMEA传感器和快速关阀法（QCV）的持水率具有较好的一致性，1003 ppm以及2494 ppm。对于以分散油滴为特征的D O/W流和D O/W流，在上述四种盐度下，VMEA传感器和QCV方法的持水率存在较大的偏差。然后，通过实验分析沿着理论偏差，得出当测量电路中的参考电阻和水相的盐度满足约束条件时，测量系统的偏差达到最小，通过调整参考电阻使之与水相的盐度相匹配，可以提高电导法持水率测量的精度。最后，利用递归图算法对上述典型流型进行了识别，在理解不同流型之间的差异方面取得了满意的效果，表明递归图算法可以有效地应用于油水两相流流型识别。
This research investigates the effects of flow pattern and salinity of oil-water two-phase flow on water holdup measurement using a conductance method. Firstly, vertical upward oil-water two-phase flow experiment is conducted in a 20 mm inner diameter (ID) pipe, in which the salinities of aqueous solutions are set as 151 ppm, 1003 ppm, 2494 ppm and 4991 ppm respectively. Experimental water-cut and mixture velocity are set as 80–100% and 0.0184–0.2576 m/s. In the experiment, three different flow patterns, i.e., dispersed oil-in-water slug flow (D OS/W), dispersed oil-in-water flow (D O/W) and very fine dispersed oil-in-water flow (VFD O/W) are observed and recorded by a high speed camera. Meanwhile, we collect the response of Vertical Multiple Electrode Array (VMEA) conductance sensor excited by a sine voltage signal. The result shows that, for VFD O/W, the water holdup from VMEA sensor shows a satisfied agreement with that of quick closing valve (QCV) method under certain salinities, i.e., 1003 ppm as well as 2494 ppm. For D OS/W flow and D O/W flow characterized by dispersed oil droplets with various sizes, considerable deviations of water holdup between VMEA sensor and QCV method under four kinds of salinity aforementioned are presented. Afterward, according to experimental analysis along with theoretical deviation, it is concluded that the deviation of the measurement system reaches its minimum when reference resistance in the measurement circuit and salinity of the aqueous solution satisfy constraint conditions, and the accuracy of water holdup using the conductance method can be improved through adjusting reference resistance to match the salinity of water phase. Finally, the recurrence plot algorithm is utilized to identify typical flow patterns mentioned above and it shows satisfied results on comprehending the discrepancies among different flow patterns, demonstrating that the recurrence plot algorithm can be effectively applied in flow pattern identification regarding oil-water flows.