Shear Effect on the Viscosity and Gel Point of Daqing Waxy Crude Benefici-ated 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.