Heating

Heating oil emulsions has four basic benefits; It reduces viscosity, increases droplets, dissolves paraffin crystals, and increases density between oil and water.

Viscosity ranges

Crude oil emulsions with similar viscosity ranges do not always require the same type of treating equipment or the same treating temperature. Emulsions that are produced from different wells on the same lease or from the same formation in the same field might require different treating temperatures. For this reason, treating temperatures should be tested so that the lowest practical treating temperature for each emulsion and treating unit or system can be determined by trial.

Free water

The heat input and thus the fuel required for treating depends on the temperature rise, the amount of water in the oil, and the flow rate. Because heating a given volume of water requires approximately twice the energy needed to heat the same volume of oil, it is beneficial to separate free water from the emulsion to be treated. Often this is done in a separate free-water-knockout (FWKO) vessel upstream of where heat is added. Sometimes it is accomplished in a separate section of the same vessel.