剪切作用对加剂大庆原油粘度和凝点的影响

通过管流剪切、过泵剪切模拟试验以及管输模拟试验,研究了剪切作用对加剂大庆原油粘度和凝点的影响.研究表明,在测粘温度和析蜡点中间值附近35℃和37℃的剪切作用对粘度的影响较大,剪切温度趋近于测粘温度和析蜡点时剪切作用对粘度影响变小,而对于凝点,不存在一个使剪切作用影响明显减小的较低剪切温度.剪切后温度下降幅度越大,剪切作用对粘度的影响越大.快速降温条件下加剂原油受到的剪切作用较小,很可能会夸大降凝剂的实际使用效果.

Shear Effect on the Viscosity and Gel Point of Daqing Waxy Crude Beneficiated by Pour Point Depressant

This paper studies shear effect on the viscosity and gel point of Daqing waxy crude beneficiated* by pour point depressant (PPD) through experiments. It is found that shear effect on the viscosity of PPD-beneficiated crude is larger when the shear temperature is in the middle of viscosity-determining temperature and wax appearance temperature and will reduce when the shear temperature approaches to the viscosity-determining temperature and wax appearance temperature,but shear effect on the gel point is not similar. The shear effect on the viscosity is more obvious at lower viscosity-determining temperature. Standard PPD effect evaluating method regulates that the sample is cooled dynamically I the relatively quick speed, so the shear effect on the viscosity is little compared with the practical pipeline, which cause the experimental results often overestimate the PPD effect in the practical pipeline.