Multi-Physical Field Intensification Process for Shale Oil Emulsion Dehydration: Parameter Optimization and Mechanisms Exploration

Shale oil, a major unconventional energy source with extensive global reserves, presents significant processing challenges due to the exceptional stability of its emulsions. Characterized by small droplet sizes and high interfacial film strength, these emulsions resist efficient treatment via conventional thermal-chemical or electrostatic dehydration. To address the difficulties in separation, unclear dehydration mechanisms, and inconsistent single-field (electric) performance, this study investigates dehydration using a novel electric–magnetic–ultrasonic coupling field system. Dehydration efficiency under an electric field alone increased with electric field strength, frequency, duration, and temperature. Magnetic or ultrasonic fields alone yielded negligible effects. Coupling an electric field with ultrasound enhanced efficiency, while adding a magnetic field to electricity provided no improvement and decreased efficiency with longer exposure or higher magnetic intensity. The multi-field coupling achieved significant demulsification. Both optimal dehydration performance and minimum energy consumption operating conditions were identified, capable of reducing shale oil water content below 0.5%.