Preliminary investigations have been made into the oxidation behavior of a North Sea light crude oil and its individual SARA fractions (saturates, aromatics, resins, and asphaltenes) in the presence of consolidated cores. These investigations were made in an attempt to determine the following: (1) the feasibility of air injection into deep light oil reservoirs, (2) the extent of any interactions between the fractions in a whole oil sample by comparing the behavior of pure fractions with the behavior of mixtures of these fractions in the crude oil. A DISC reactor tan oxidation cell) has been used to study the various oxidation reactions and kinetics of a light oil under high pressure and a constant heating rate, by following the concentrations of the gases evolved (CO2, CO) and consumed (O-2). Such an investigation allows a quantitative study of the temperature intervals at which evaporation, oxidation, and combustion effects operate for each fraction. The data from these experiments may be used to assist the development of a comprehensive simulator for thermal oil recovery. One aim of the overall work is to replace the conventional two pseudo component representation of crude oil (heavy and light) by a SARA representation with its accompanying interaction and interconversion reactions together with the conventional oxidation reactions. This approach should provide a more realistic representation of the oil oxidation process.