Preparation and mechanism of hyperbranched polymer as paraffin inhibitor and pour point depressant for high waxy crude oil

A quaternary polymer paraffin inhibitor and pour point depressant (PIaPPD) with hyperbranched structure was prepared by free radical solution polymerization using docosyl methacrylate (DM), maleic anhydride (MA), methyl methacrylate (MMA) and diethylene glycol dimethacrylate (DEGDMA) as raw materials. The experimental results show that when the dosage of PIaPPD is 250 ppm, the paraffin inhibiting rate of SY1 for high waxy crude oil can reach 83.3%, and the pour point can be reduced by 16°C. At the same time, it has good universality for the crude oil of the remaining 12 different blocks of oil wells. The paraffin inhibiting rate is up to 83.3%, and the crude oil pour point can be reduced by up to 19°C. Through DSC, FTIR, fluorescent inverted microscope, polarizing microscope, XRD, SEM and carbon number distribution analysis, it can be seen that: PIaPPD achieves the purpose of paraffin inhibition and pour point depression by cocrystal-adsorption and dispersion of wax crystals. It mainly achieves the effect of paraffin inhibition and pour point depression by reducing the wax appearance temperature, inhibiting the amount of wax precipitation, destroying the normal growth structure of wax crystals, reducing the strength of wax crystals, reducing paraffin isoparaffins, and inhibiting the precipitation of most medium and low carbon paraffins and a small number of high carbon paraffins. Finally, the wax crystals exist in the crude oil in a less, small and non-aggregated, irregular state in a more dispersed form.