Petroleum refiningCrude Dewatering

All unrefined crude oil stored in tanks has a percentage of water entrained within it, and while stored in tanks, separation naturally occurs with water collecting at the bottom of the tank beneath the oil. The two fluids are very distinct except for a “black water” or “rag” interface layer which is an emulsion of mixed oil and water. To dewater the tank, water is drawn off of the bottom of the tank and is then sent off to water treatment.

Challenge

Level controls designed for interface detection will sense the beginning of the oil/water interface during dewatering procedures and provide feedback to a control system which will terminate water draw-off when appropriate.