(44p) Experimental Investigation of Magnetic Field Influence on Viscosity of Waxy Crude Oil Emulsion

Magnetic treatment is a widely used physical treatment technique in oilfields. The mechanism of magnetic field on waxy crude oil emulsion has drawn much attention. This study aims to explore the relationship of the change of viscosity of waxy crude oil emulsion and magnetic field and mechanism explanation. The static permanent magnet device was constructed. The viscosity of crude oil and emulsion, oil-water interfacial tension and the distribution characters of emulsion droplets before and after magnetic field were experimentally studied. The results showed that when the magnetic treatment temperature was 58 ℃ (wax precipitation point), the magnetic field intensity was 200 mT, and treatment time was 10 min, the viscosity of emulsion decreased the most and reached 14.5%. Meanwhile, the viscosity of crude oil and oil-water interfacial tension decreased after magnetic treatment. The droplet distribution did not change obviously after applying different magnetic treatment conditions. The magnetic field reduced the viscosity of the emulsion by reducing the viscosity of crude oil and the oil-water interfacial tension. For waxy crude oil, the viscosity decreased significantly when the magnetic treatment temperature was equal to or above the wax precipitation point. The change rates of viscosity of crude oil presented multi-extremal changes, not strictly increasing or decreasing with magnetic field intensity.