基于能量及原油物性定量分析的油-水混合液黏度预测模型

Viscosity Prediction Model for Crude Oil-Water Mixture Based on Quantitative Analysis of Mechanical Energy and Crude Oil Physical Properties

高含水油-水混合液往往不能形成稳定的乳状液,而是原油将其中一部分水乳化,形成了油包水(W/O)乳状液液滴和游离水的掺混体系。传统的乳状液黏度模型并不适用于这种非稳定乳化的油-水混合体系。采用搅拌测黏法测定并研究了搅拌转速、含水率及温度对油-水混合液表观黏度的影响。结果表明:油-水混合液的表观黏度随着搅拌速率的增大、含水率的增加及温度的升高而逐渐减小。提出采用乳化过程消耗的机械能来表征油-水混合液受到的剪切作用。以实验数据为基础,并对乳化过程消耗的机械能及原油物性进行定量分析,建立了适用于高含水油-水混合液的黏度预测模型。该模型预测偏差分析结果显示,模型计算表观黏度值与实测表观黏度值之间的平均相对偏差为5.6%。

Crude oil-water mixture with high water fraction is usually unable to form a stable emulsion,but crude oil can emulsify part of water to form a mixture system of W/O emulsion droplets and free water.Traditional emulsion viscosity models cannot be applied for this kind of unstable emulsified crude oil-water mixture.Effects of stirring speed,water fraction and temperature on the apparent viscosity of crude oil-water mixture were measured and investigated with the stirring method.Experimental results show that the apparent viscosity of the mixture decreases with increasing stirring speed,water fraction and temperature.Mechanical energy consumed in the emulsification process was used to characterize crude oil-water mixture shearing effect.Based on experimental data,quantitative analysis of mechanical energy consumed in the emulsification process and physical properties of crude oils,a viscosity prediction model for crude oil-water mixture with high water fraction was established.Model prediction error analysis suggests that the average relative deviation between calculated and measured apparent viscosity is 5.6%.