Using High Frequency Electromagnetic Wave Measurement To Do The Research On Water Content Of Crude Oil

In the petroleum industry,regardless of the oil field development,pipeline transportation and refining of crude oil or oil import and export trade at home and abroad,crude oil density,viscosity,water content and other information are must be tested in each oil laboratory.In particular,the crude oil water content information is important.Crude oil water content information can not only predict the dynamic reservoir production,analysis the oil production,but also optimize the crude oil gathering and transportation process,which has important significance for controlling the output of oil,monitoring the status of oil well,reducing unnecessary energy consumption,reducing management cost and production cost etc.Traditional measurement of crude oil water content cannot meet the rapid economic development of Chinese oil demand,especially for pipeline transportation and the import and export trade of crude oil,and the precise and real-time measurement of the quality of the crude oil has become a problem,which needs to be solved by Chinese scientific research personnel.According to the microwave measuring the complex dielectric constant method,using microwave rectangular resonant cavity perturbation theory to simulate measurement of the water content in crude oil.Due to the ordinary temperature dielectric constant of oil-water has larger differences(the oil dielectric constant is about 2.2,the dielectric constant of water is about 80),the size of the dielectric constant of the oil-water mixture mainly decided by the water content.In a rectangular resonant cavity of the crude oil samples,when the high frequency electromagnetic wave passing through the sample content water of crude oil,the electromagnetic wave will be attenuated according to the difference of water content of the crude oil samples,and the corresponding makes in a rectangular resonant cavity resonant frequency and the quality factor in regular change.Through the HFSS software on a rectangular resonant cavity of microwave simulation,it can measure the rectangular cavity resonant frequency and quality factor by different crude oil water content samples.Then according to the rectangular resonant cavity perturbation theory,derive the complex permittivity of micro interference source(water crude oil samples).And then it can get the information of water content in crude oil according to the relationship between dielectric constant and water content in crude oil.Compared with the traditional measurementmethods,the microwave resonant cavity perturbation method have the advantages of little influence on the degree of mineralization of crude oil,and high water content range and accuracy etc.Through the analysis of the simulation results and the theoretical calculation,it can get that the microwave rectangular resonator micro perturbation method to the measurement of crude oil water content can be ranged from 0 to 80%,and the percentage error is less than 5%,which can meet the actual testing requirements.