Research On Measurement Method Of Oil Moisture Based On Microwave Transmission Characteristics

That the accuracy measurement of the moisture in crude oil plays an indispensable role on online testing, due to an online testing on the crude oil moisture can reflect the situation of the working oil well quickly and accurately. This study pays attention to the current situation of research on the moisture detection of crude oil. Finally a method for the moisture detection of crude oil has been proposed on the basement of the transmission difference of electromagnetic wave in water and oil which works accurately.The highlights of the study are as follows:1. First, that Electromagnetic wave propagation theory and Antenna theory on the basis of oil-water mixture’s physical characteristics for the online testing on the crude oil moisture are introduced. Then the influence of the S₁₁ parameters on the testing of media characteristics is analyzed and the relationship between the absolute error of attenuation coefficient and S₁₁ parameter on the basement of the real medium property is received. That the absolute error of attenuation coefficient is less than 1d B when the S₁₁ parameter is less than-10 d B is revealed in the theoretical analysis, so a conclusion could be made that the smaller the S₁₁ parameter, the smaller the influence of S₁₁ parameters on the measurement of the attenuation of the medium is.2. Second, a kind of broadband antenna based on the theoretical analysis results has been designed, which meets that S₁₁ parameters no more than-10 d B, to make sure the absolute error less than 1d B in different water content of the medium.3. Furthermore, a model for measuring water content of crude oil has been established and then the simulation based on that model by the HFSS Ansoft has been carried out. The simulation results shows that the antenna worked in 3.8GHz could meet that condition of S₁₁ parameters no more than-10 d B when the moisture content of crude oil ranges from 0% to 100%. And the relation between S₂₁ parameters and the water content of crude oil has been provided in the final.4. Finally, a series of experiments that measures the transmission characteristics of electromagnetic wave in different moisture content of crude oil has been carried out by the established laboratory model. The result reveals that both the simulation results and the experimental results are in an agreement. That means this kind of broadband antenna can be used in measurement of moisture content. The theoretical and experimental reference for the measurement system to study further have been provided in this study.