Research On Preparation Of Waxy Crude Oil Emulsion Based On Quantitative Characterization Of Parameters And Rheological Properties

The condensate and viscous waxy crude oil is most produced in China offshore oil field,and blended transportation for oil, gas and water has become the main mode for long-distance sea oilfield gathering and transportation. In the process of pipeline, oil-water mixture is easy to form crude oil emulsion in high-speed shear. The rheological properties of crude oil emulsion has a strong dependence on its forming condition. Apparent viscosity is one of main characterization parameters for emulsified degree of W/O crude oil emulsion. Therefore the study on quantitative characterization of preparation methods of crude oil emulsion based on apparent viscosity, is the precondition for further study on oil emulsion properties. Preparation of waxy crude oil emulsion based on quantitative characterization of parameters and rheological properties is studied in this paper.For different waxy crude oil,the effect on apparent viscosity of emulsion of different water content from stirring speed and stirring time is studied. Based on the theory of thermodynamics and viscous fluid mechanics, condition parameter relation is established to describe the preparation process of emulsion by viscous flow entropy. The mathematical relationship between apparent viscosity of emulsion and viscous flow entropy is analyzed. On the basis, with statistical methods, the mathematical model to quantitatively describe the relationship between emulsion preparation conditions and apparent viscosity is established,which provides theory for quantitative characterization of preparation of waxy crude oil emulsion based on apparent viscosity in laboratory.Pour point of W/O waxy crude oil emulsion in different preparation conditions is studied for different waxy crude oil. And according to the experimental results,the relation among pour point,water content and stirring speed is established.The yield-thixotropy characteristic loaded in the constant shear rate of W/O waxy crude oil emulsion in different preparation conditions is studied for different waxy crude oil. The thixotropic-stress is used to show the structural features of system. And according to the experimental results,the relation among thixotropic-stress,water content and shear rate is established.