Month: July 2012

This process involves injecting gas into the bottom of a process vessel, as the bubbles rise they lift oil droplets and solids to the surface where they can be removed by mechanical means.

Flotation can be either dissolved gas flotation (DGF) or induced gas flotation (IGF).

In DGF the gas saturates the liquid and is released as small bubbles by applying a vacuum or a pressure drop. In IGF the bubbles are created mechanically in the bottom of the vessel.

DGF generally gives a better separation but they are larger and generally require more operator attention and maintenance than IGF units.

IGF units are usually preferred in the oil and gas industries.

OIW content can be typically reduced to 15 mg/l but units are sensitive to flow variations and cannot handle oil slugs.

Flotation systems can also provide removal of heavy metals from produced water by means of flocculation and solids skimming.