Abstract Fireflooding is an enhanced recovery technique that can be used for exploitation of heavy oils and tar sands.Injection of oxygen rather than air is a process variation that has many potential advantages and some disadvantages. Interest and optimism for oxygen fireflooding has been growing over the past few years, and many investigations have been performed to compare oxygen and air fireflooding. The results of these studies have suggested that the performance of a fireflood could be improved with oxygen injection. The studies have not shown any adverse effects as a result of oxygen injection or that the use of oxygen would be too hazardous or expensive. The operational advantages could result in significant economic improvement even though few differences have been observed in the process and sweep parameters.