Effective viscosity prediction of crude oil-water mixtures with high water fraction
Effective viscosity prediction of crude oil-water mixtures with high water fraction
复制标题
高水含量原油水混合物的有效粘度预测
DOI：
10.1016/j.petrol.2016.09.052
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发表时间：
2016
影响因子：
--
通讯作者：
Wei Min
中科院分区：
文献类型：
--
作者：
Wen Jiangbo;Zhang Jinjun;Wei Min
在石油工业中，高含水率的流动原油-水体系通常不是以稳定和均匀的乳状液存在，而是以油和自由水的混合物的形式存在，一些水被乳化成油，因此，在流体力学中，它作为油的一部分。因此，现有的针对稳定均相乳状液的粘度模型不能准确地预测这类液液混合物的粘度。本文采用搅拌法测定了高含水率原油-水混合物的有效粘度。结果表明，混合物的有效粘度随剪切速率、含水率和温度的增加而降低。在Taylor粘度模型的基础上，结合前人对原油-水体系乳化行为的研究，建立了考虑剪切速率、乳化水含量和原油组成影响的高含水率原油-水混合物粘度模型。利用从两种原油混合物中获得的40个不用于模型开发的数据点进行了验证，结果表明，该模型对混合物粘度的预测准确，平均相对偏差为7.4%。对该模型在预测管内油水两相流摩阻中的应用进行了探讨。
In the petroleum industry, a flowing crude oil-water system with high water fraction usually does not exist as a stable and homogeneous emulsion, but in the form of a mixture of oil and free water with some water being emulsified into the oil and thus, hydrodynamically, acting as part of the oil. Therefore, the existing viscosity models developed for stable and homogeneous emulsions cannot accurately predict viscosity of this kind of liquid-liquid mixtures. In the present work, the effective viscosity of crude oil-water mixtures with high water fraction was measured by using a stirring method. It was found that the effective viscosity of the mixtures decreased with increasing shear rate, water fraction and temperature. Based on the Taylor viscosity model and combined with our previous study on the emulsification behaviors of crude oil-water systems, a viscosity model was developed for crude oil-water mixtures with high water fraction, which is characterized in covering the effects of shear rate, emulsified water fraction and crude oil compositions. Validation was done by using 40 data points which were obtained from mixtures of two crude oils and not used for model development, and the results showed that the proposed model gave accurate predictions of the mixture viscosity, with an average relative deviation of 7.4%. Approach is proposed to application of this model in the prediction of the frictional loss of oil and water two phase flow in pipes.