Simulation Study of Fireflooding (Part 3)

On the Influence of Residual Oil Saturation, Oil Density and Air Injection Rate

Abstract

Simulation study was carried out to investigate the behavior of fireflooding and to obtain basic information for designing and/or screening fireflood projects. The simulator used has been reported elsewhere (JJAPT 52, 5, 1987). Parameters investigated were (1) residual oil saturation, (2) oil density, and (3) air injection rate, which was the only one parameter that could be controlled directly.
Results are summerized as follows;
(1) In general oil production methods other than fireflooding, oil recovery is low as residual oil saturation is high. Because the amount of oil used as fuel is little in fireflooding, the oil recovery is less affected by residual oil saturation, though the combustion reaction zone w ould be extinguished if the residual oil saturation is too small to leave sufficient amount of oil being supplied as fuel.
(2) In fireflooding, the cork formed by the thermal decomposition of heavy components would be the fuel, so that the fireflooding would be impossible unless the oil density is high enough. However, the recovery and the prodution rate are higher as the oil is lighter in the range of operating condition.
(3) Production rate would vary with air injection rate. But the optimum air injection rate may exist from the economical point of view.