ABSTRACT
Foam is a gas dispersion in a liquid or solid continuous phase.1 Liquid foaming problems occur in many oileld processes.2 For example, this occurs when gas breaks out from crude oil in separators or in gas-processing plants such as amine and glycol contactors. Water systems can also foam owing to chemicals or deaeration by gas or vacuum stripping. Foam in two-and three-phase separators can create several operational problems:
• Poor level control that can lead to platform shutdowns • Liquid carryover in the gas outlet that can lead to ooding of downstream scrubbers and
compressors • Gas carry-under in the liquid outlet that can lead to increased compression requirements
High-throughput and high gas-to-oil ratio favor foam formation. Foams are made up of bubbles (lamellae) stabilized by surfactants, either naturally occurring
surfactants (resins, asphaltenes, naphthenic acids, etc.) or added production chemicals such as some lm-forming corrosion inhibitors. It is the Marangoni effect, mass transfer on or in a liquid layer due to surface tension differences, that stabilizes foams.3 Viscosity has also been found to play a major role in determining whether a crude oil will foam under experimental conditions.4
