THE IN-SITU COMBUSTION PERFORMANCE OF LIGHT OILS AS A FUNCTION OF PRESSURE (1000 TO 6000 PSIG)

The research documented here is a systematic study of the effects of p ressure on the air-injection process for light oils in an adiabatic co mbustion tube. Tests were conducted at pressures up to 5400 psig. The purpose of this research is to study prospects of enhancing oil rates and recoveries by air injection, with particular application to large high-pressure reservoirs in remote locations where conventional inject ants are not available. It was learned that air injection is applicabl e as a light-oil recovery process. In-situ combustion performance of l ight oils at high pressure is quite different from heavy-oil, low-pres sure in-situ combustion (extensively documented in the existing litera ture(1,2)). Flue-gas generation and oil-displacement characteristics w ere excellent at all pressures for all oils. The primary effect of pre ssure on these series of tests was that higher injection rates were re quired as pressure increased. Air/fuel ratio was fairly constant with pressure, but air requirement varied with pressure, oil and sand. Sign ificant process improvements were obtained when using reservoir sand f or testing. Results from a tertiary test (conducted after waterfloodin g) were similar to those from secondary testing.