Effect Of Aggregation And Proportion Of Resin And Asphaltene On Electrorheological Effect Of Waxy Oil

It’s shown that the viscosity and yield stress can be significantly reduced by applying high electric to waxy oil below the wax appearance temperature.The latest research found that under the electric treatment,charged colloidal particles(resins and asphaltenes)accumulate on the surface of wax crystal,that is,interface polarization,which is the mechanism of electric modification of waxy oil.However,it is found that the influence of the content of resin and asphaltene on the viscosity reduction and yield stress reduction of waxy oil under electric is not consistent.The reason is that the aggregation state of charged colloidal particles affects the occurrence of interface polarization.Therefore,the influence of the aggregation state of resin and asphaltene on the electrorheological effect of waxy oil needs to be further studied.So,five mixed oils with different Sudan-decane ratio and the total amount of polar components was 0.1%,seven waxy model oils with different resin and asphaltene ratio were prepared for electric modification experiments.At the same time,small angle X-ray scattering(SAXS),low field nuclear magnetic resonance(LF-NMR)and impedance test were used to characterize the aggregation state of resin and asphaltene in mixed oils and model oils.The viscosity reduction experiments of waxy oils under electric shows: the viscosity reduction of mixed oils below the wax appearance temperature first increases and then decreases with the increase amount of wax precipitation;The oils need to precipitate more wax crystals in order to achieve the equivalent viscosity reduction effects with the increase of the dispersion degree of resin and asphaltene and the optimal viscosity reduction has little change and remains at about 50%.When 7 model waxy oils were treated under electric above the gelation temperature and below the wax appearance temperature,the viscosity reduction of the oils under the same amount of wax precipitation decreased with the increase of the dispersion degree of the resin and asphaltene.The yield stress reduction experiments of waxy oil under electric shows: With the increase amount of wax precipitation,the yield stress reduction of mixed oil increased slightly at first and then decreased;The oils need to precipitate more wax crystals in order to achieve the equivalent yield stress reduction effects with the increase of the dispersion degree of resin and asphaltene in the system,and the optimal yield stress reduction under electric kept about 98%;For waxy model oils,the yield stress reduction decreases under electric with the increase amount of wax precipitation;The trend of yield stress reduction is consistent with mixed oils with the increase of the dispersion degree of resin and asphaltene,and the optimal yield stress reduction has little change and remains at about 97%.Finally,the effects of different aggregation states of resin and asphaltene on the electrorheological effects of waxy oils were comprehensively analyzed.Waxy model oils experimental dates confirmed that the intensity of wax crystals under the same amount of wax precipitation is the key factor affecting the electrorheological effects of waxy oils.That is to say,under the same amount of wax precipitation,the stronger modification effect of polar components on wax crystals,the weaker the modification effect of electric.