Raw crude oil contains water, salts and other contaminants. If these salts and heavy metals are not removed, they can form acids when heated, causing corrosion of downstream process equipment. Salts can also form deposits, causing plugging of heat exchangers or clogging trays in process towers. As experts, we understand these challenges and can provide solutions for your desalting process.

Crude oil desalting process

Refinery desalting is typically done in one or two stages. This is determined by the characteristics and expected level of contamination after any pre-treatment done at the well head or pre-transportation stage.

The desalting process consists of mixing heated crude oil with wash water and emulsion breaking chemicals.  Proper mixing is critical to the salt removal and is achieved using mixing valves and static mixers. The emulsion is broken by a high voltage electrostatic field within the gravity settler tank. The brine water phase containing extracted salts and other impurities is removed from the bottom for treatment. The desalted crude oil is then transferred to the atmospheric distillation column.

The brine fluid produced is extremely corrosive and requires special materials of construction to avoid possible desalter shutdown and risk of plant shutdown. Austenitic stainless steel or Duplex materials are commonly specified.

Desalting can start earlier in the process train at higher water cuts with gas present. Our VIEC separation technology achieves low water contents in the oil stream, which reduces the number of downstream desalters required as well as water consumption.