Fundamental studies of air injection for heavy crude oil recovery and its applications

Heavy crude oil is a valuable energy resource that is very abundant but also very viscous which complicates exploitation of these resources. One efficient and environmentally friendly heavy oil recovery technique uses exothermic oxidation reactions with a small amount of the oil reacting with oxygen in the injected pressured air. However, the lack of a thorough fundamental understanding of the complex multiple physicochemical and thermal processes in the reservoir limits broad use of this technique. In the past decade, our research group has conducted fundamental research in this field, including "The basic heat release characteristics and key factors affecting moderate temperature oxidation", "coke formation and chemical properties", "reaction model for low asphaltene heavy oil", "combustion regimes for high temperature oxidation at various operating conditions", and "reservoir scale simulations of the moderate temperature oxidation technique". Experimental systems were constructed to measure the heat release, the product properties and the transport properties during the heavy oil oxidation. Multiscale numerical simulations were developed for pore-scale, lab-scale and reservoir-scale studies to understand the coupling mechanisms at different scales. These research results have improved our fundamental understanding and promoted industrial applications of this heavy oil recovery technique in China.