| Crude oil emulsion is a type of fluid that often appears in the process of oil-gas gathering and transportation.Its rheological properties have an important impact on the oil-gas gathering and treatment process.Therefore,analyzing the rheology of the emulsion has guiding significance for oil-gas gathering,transportation and treatment processes.Especially in the middle and late stages of mining,the increase of water content will lead to the production of various complex flow patterns,which will change its rheological properties,resulting in changes in the pressure drop inside the tube.For Daqing crude oil and Hulunbeier crude oil with higher wax content,the microstructure of crude oil emulsion prepared at different stirring speeds was observed with microscopic observation in this paper and the characteristics of the microstructure were described by the analysis of the dispersed phase parameters including the average particle size,the degree of dispersion,and the nonuniformity of average particle size.Then,using the rotational viscometer method to discuss the effects of temperature,shear rate and the microstructure on the apparent viscosity and abnormal point of crude oil emulsion.And established the efficient range of temperature and shear rate.In the same way,using the rotational viscometer method to discuss the effects of temperature drop rate,yield temperature and the microstructure on the yield stress of emulsion.In addition,the pour point of crude oil emulsions with different microstructures were studied.Correlation analysis and least squares methods was used for establishing a nonlinear regression model to predict the apparent viscosity and yield stress of crude oil emulsion.At the same time,the BP neural network model and the support vector machine SVM model are used to regress the apparent viscosity and yield stress of emulsion.The accuracy of the BP neural network model is the highest one by comparing the R~2 of the three models. |
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