Study On The Non-newtonian Rheological Properties And Improving Technologies Of Changqing Crude Oil

In this paper, five kinds of Changqing crude oil (Wuqi crude oil, Ansai crude oil, Xifengcrude oil, Jiyuan crude oil and Jingan crude oil) were tested to investigate the non-Newtonianrheological properties and improving technology of them, using a combination of rheologicalmethods and DSC thermal analysis technology.Through the study on the rheological properties of the five kinds of crude oil, it wasfound that this five kinds of Changqing crude oil were all high waxy oil. Xifeng and Jingancrude oil were light relative density waxy crude oil but Wuqi, Ansai and Jiyuan crude oil weremedium relative density crude oil. After being heated at their optimal heat temperature, thepour points of them were reduced in a certain extent.Through the study on the modifying technology after adding PPD into this five kinds ofcrude oil, the following results were found. BEM-W was the best PPD for this five kinds ofoil. When oil was treated with the optimal additive condition, the pour point can be largestreduced by14℃, and the temperature range of Newtonian fluid was widened10℃to the lefton average, the non-newtonian properties of oil were improved obviously.The modifying technology by adding nanocomposites into Wuqi crude oil wasresearched, the following results were found. The smaller the nanocomposites paticle size is,the better the modified effect of low shear rate is. While the larger the nanocomposites paticlesize is, the better the modified effect of high shear rate is. The density of nano materialssurface layer must be moderate, the modified effect of the nanocomposites would be worsewhen it was too low or too high. In addition, the different surface intercalated method wouldalso affect the modified effect of nanocomposites.For Wuqi crude oil, nanocomposites exist an optimal additive concentrations range from 30mg/kg to50mg/kg. The best modified effect would not be achieved when theconcentrations were too low or too high. The modified effect of nanocomposites04is betterthan the effect of BEM-W. Under the same heating temperature, the pour point of oil added04is3℃~4℃lower than added BEM-W.