Research Status and Development Trend of Air-Foam EOR Technology

In order to improve the development efficiency of low permeability and medium-high permeability medium-light reservoir, the research status, existing problems and development trends of air-foam enhanced recovery technology are summarized. The low temperature oxidation kinetics of air injection and the mechanism of foam micro flooding have been studied, but there are few studies of air-foam injection technology to improve oil recovery. Based on the previous studies, this paper systematically analyzes and evaluates the air-foam enhanced oil recovery (EOR) technology from the aspects of oil displacement mechanism, laboratory experiment, numerical simulation and field application. The studies show that there are two reactions between injected air and crude oil: low temperature oxidation (LTO) and high temperature oxidation (HTO) with two reaction pathways of oxidation reaction and decarbonization reaction. Many lab studies need to be conducted such as low temperature oxidation and composition analysis, dynamic displacement experiment, air foam injection and safety control experiment. The numerical simulation is mainly used to study the enhanced recovery mechanism of air-foam injection, determine the necessary oxidation kinetic parameters, fit the indoor experiment of air displacement, predict the dynamic and design of field test and improve the reliability of air injection reservoir simulation and the feasibility of field implementation. And it is proved from lab studies, numerical simulation and field application that air-foam EOR technology is suitable for low permeability reservoir, high permeability heterogeneity and high temperature and high salt reservoir.