关键词: 含蜡原油, 流动性, 特征温度, 剪切作用, 粘-温关系, 熵产

Abstract: The variation of viscosity with temperature was measured by temperature scanning procedures in a coaxial cylinder viscometer.The waxy crude tended to become gel at low temperature.On the basis of gelation theory,the test data was treated by conventional method,and the characteristic temperature of waxy crude was found.The characteristic temperature was corresponding to the maximum value of gelling activity energy.The flow ability of waxy oil at low temperature get weaker as the characteristic temperature gets higher for the same oil.The characteristic temperature and entropy generation of waxy crude generated during pipeline transportation have the power correlation.The empirical relational expression of characteristic temperature versus entropy generation was developed on the basis of test data.Using this relational expression,the characteristic temperature of crude oil can be predicted,provided that the entropy generation is known.92 groups of data of characteristic temperature obtained from six virgin crude oils and four PPD-beneficiated crude oils were compared with the predicted values.The maximum absolute deviation of characteristic temperature is 0.86℃,and the average absolute deviation of characteristic temperature is 0.3℃.This model can be used to evaluate the flow assurance of crude oil in pipelines.

Key words: waxy crude, flow ability, characteristic temperature, shear effect, viscosity-temperature relation, entropy generation