Rheological properties of heavy crude oil containing sand from Bo-hai oilfield in China

Abstract

This paper presents an experimental study on the rheological properties of heavy crude oil containing sand to determine the effectsof sandsizedistributionandmass concentrationonapparentviscosity,thixotropicbehavior,yieldstressandviscoelastic properties.The resultsoftheseanalysesdemonstrate thatheavy crudeoil containingsandshows strongshear-thinningbehavior and a certain degree ofthixotropic properties. After blending heavy crude oil with sand,the apparent viscosity and the area ofthe thixotropic loop first decrease and then steadily increase with increasing sand mass concentration. At a fixed mass concentration, apparent viscosity appears to increase with increasing particle size, while yield stress decreases. Moreover, adding sand generally enhances the elastic modulus of heavy crude oil, while the complex viscosity remains slightly less than the apparent viscosity. These results provide new information helpful for removing sand from heavy crude oil.