Design Of Complex Impedance Measurement System For Vertical Oil-water Two-phase Flow And Visibility Graph Analysis

With the rapid development of science and technology,the detection technology of two-phase flows has attracted plenty of attentions in the industrial system.More recently,oil extraction technology has been greatly developed,which results in the higher needs for the measurement accuracy and control requirements of the production process.In order to meet these new industrial demands,high-performance detection device for two-phase flows,such as novel sensor and its supporting measurement systems,is needed,which displays great significance in the engineering application of oil-water flows.In this dissertation,we design a sensor measurement system based on complex impedance for measuring the flow parameters in oil-water flows.The system consists of our designed complex impedance sensor,control circuit and host computer for data storage.We first exploit the software to simulate and optimize the sensor structure based on the sensitive characteristic distribution of electric field and then obtain the optimal size of the sensor.Meanwhile,we design the matched control circuit which allows providing the excitation voltage to the sensor,acquiring the response current from the sensor,and then sending the worked complex impedance measurements to the host computer.Specially,we use the complex impedance measurement chip AD5933 and high speed ARM microprocessor in this control circuit.Based on the designed sensor measurement system,we carry out the vertical oil-water two-phase flow experiments and acquire the corresponding complex impedance measurements for each flow condition.And then we investigate the sensor response in the measurement of water-cut.The results demonstrate that our designed measurement system allows efficiently measuring the water-cut with a high resolution.Subsequently,we construct the horizontal visibility graph from the experimental measurements for three typical flow patterns,namely oil-in-water slug flow,oil-in-water bubble flow and oil-in-water VFD flow.The results suggest that this network method can efficiently characterize the complicated flow features of different flow patterns.