Study on the divided-wall electric desalting technology for Suizhong crude oil

Electrostatic desalting and dewatering for Suizhong crude oil was studied by investigating the dynamic electric desalting process parameters in the divided-wall electric desalting apparatus. Several demulsifying agents were tested for obtaining the optimum static desalting results. In addition, the dynamic electrostatic desalting experiments were studied to find the optimal conditions. Under the optimal conditions, the salt content of the crude oil in the first desalt stage could be decreased to 5.2 mg/L, the water content to 0.28%; and the salt content of the crude oil in the second desalt stage could be decreased to 2.3 mg/L, the water content to 0.22%, the oil in the outlet water to 138 μg/g, which meet the technical requirements of Sinopec standard. The micrograph of the treated oil indicated that the water content had been decreased to a very low level, and the diameter in the water droplets in the treated crude oil ranged from 10 to 30 μm.

► Experimental study on new equipment for heavy oil desalting and dehydrating.
► Mass fraction of 6% is more appropriate for the injection water.
► Optimal operating temperature is in the range between 130–140 °C.
► Mixing intensity from 40 to 50 kPa is suitable for the desalting process.
► All key indexes of treated oil can meet Sinopec required standards.