油藏原油中石蜡沉淀的模型化研究

MODELLING OF WAX PRECIPITATION IN RESERVOIR FLUIDS

考核了正规溶液理论、聚合物溶液理论和状态方程法计算石蜡沉淀的热力学模型 ,并进行了实例计算。计算结果表明 ,对于高压下的油藏流体及油罐油 ,采用状态方程法较适合。在所选用的 4个状态方程中 ,PT和DG状态方程计算精度较高 ,PT方程的稳定性最佳。

Wax precipitation is a serious problem in production, storage and transportation of crude oil, especially for waxy crude oil. A number of thermodynamic models and empirical correlations are available in the literature for predicting the onset of wax precipitation. Four existing methods for calculating the onset conditions of wax precipitation are evaluated. Some calculations are carried out, which shows that the equation of state (EOS) approach is superior to the activity coefficient approach for the reservoir fluid under a high pressure and crude oil in tank. In general, the PT and DG state equation can give the best prediction values.