Unraveling the influences of isothermal temperature, rock debris and water saturation on tight oil oxidation behavior and kinetics

It is critical and fundamental to explore main influence factors on tight oil oxidation behavior and kinetics, which has not been well understood. In this work, thermal analysis and Coats-Redfern method were employed to comprehensively investigate main influence factors. Besides, the most appropriate reaction order (n) was analyzed to obtain kinetic parameters. It suggested three reaction regions with the activation energy variation, and distillation effect was remarkable. Apart from the surface area effect, the addition of rock debris and clay also had the strong catalytic ability to decrease threshold, peak, and ending temperatures. Besides, the n variation implied a more complex, possibly multi-step reaction mechanism. Water existence could strengthen the distillation effect and lower exothermic peaks via suppressing the reaction rate. Moreover, corresponding activation energies indicated the water could promote the oxidation reaction evolution under lower temperatures. From this study, it could provide new insights into the reaction model optimization and numerical simulation for the air injection process.