Based on experimental analysis of characteristic tempera tures, rheological parameters, crystallized paraffin amount and microstructure of simulative oil before and after the addition of depressant GY1, structure depression mechanism of waxy crude oil has been investigated. Results show that:①Depressant GY1 cannot prevent wax crystallizing and crystalline nucleuses
forming but increases the crystallized paraffin amount.②For simulative oil with macrocrystal waxes, depressant GY1 can obstruct the growth of paraffin crystal, reduce their size and symmetry and increase their interaction and connecting trend. As a macroscopical result, the effect of pour point depression and viscosity reduction becomes worse.③For simulative oil with microcrystal waxes, depressant GY1 can promote the growth of paraffin crystal, increase their size, reduce their surface binding force and depress their interaction and connecting trend. As a macroscopical result, the effect of pour point depression and viscosity reduction is obvious.④The structure depression mechanism of waxy crude oil is the mechanism of increasing the size of paraffin particles, improving their symmetry, reducing their dispersivity, depressing their interaction and connection.
