Combustion recovery applied to light oil reservoir

In-situ combustion as an oil-recovery tool has now reached the stage of development where it should be considered as one of several tools in the oil-recovery arsenal. This holds true for secondary or tertiary operations and for light or heavy-oil reservoirs. Even though in-situ combustion will likely not be the best alternative in most cases for light oil reservoirs, it will be the best alternative in some. This is very likely to be the case where primary recovery has been poor, oil-in-place is relatively high, and the viscosity of the oil is too high for efficient waterflooding. The Fry In-Situ Combustion Project, conducted by Marathon Oil Co., in Illinois, is an example of this situation. an attempt to waterflood the reservoir failed; yet the oil-in-place exceeded 1000 bbl per acre-ft, and in-situ combustion has proved highly effective and economically attractive. The most important parameter bearing on the economic attractiveness of any in-situ combustion operation is the air requirements per barrel of oil produced. The air-oil ratio, in turn, is a function of oil-in-place, fuel content, oxygen utilization, efficiency, composition of fuel consumed, and the nature of the combustion products. The relationship between these parameters is well defined by the stoichiometrymore » of combustion. The equations are given.« less