Abstract: This study has conducted a physical simulation experiment on the in-situ combustion of offshore heavy oil in the Bohai heavy oil reservoir region to explore the possibility of further development of the in-situ combustion. It has analyzed the composition of crude oil in the Bohai heavy oil region using the method employed for determining the components of asphalt and crude oil. The kinetic parameters of high-temperature oxidation reactions, such as the activation energy, were evaluated using the thermogravimetric analysis and scanning thermal analyzer. This work has used a one-dimensional combustion tube for the simulation experiment to evaluate the combustion stability and oil displacement efficiency. The results demonstrate that the composition of crude oil in the Bohai heavy oil region is similar to that of the onshore oil fields in mainland China. The high-temperature oxidation activation energy of heavy oil is 157 kJ/mol, which is similar to that of the onshore oil fields; the burning front moves forwards steadily, and the highest temperature of the combustion front is estimated at approximately 773 K. The concentration of CO₂ at the outlet is estimated over 12%, and the high-temperature oxidation combustion is observed to be good. The oil displacement efficiency is estimated at 95.1%, and the air-oil ratio is 548 m³/t, It is established that the oil displacement efficiency is fairly satisfactory.

Key words: offshore heavy oil, in-situ combustion, physical simulation, high temperature oxidation, kinetic parameters