Progress and Prospects of CO2 Enhanced Heavy Oil Recovery Technology Application

CO2 flooding can not only increase single well productivity, but also improve oil recovery rate. It is an important technology for transforming the development mode of low-permeability reservoirs, improving oil recovery and utilization rate, and is also an important technical means for achieving green and low-carbon development. In deep low-permeability heavy oil reservoirs, the dissolution and diffusion of CO2 are relatively slow. In the actual development process of throughput, the CO2 heavy oil system is mainly in an undersaturated state. A large number of production practices have found that CO2 does not dissolve into heavy oil instantly, but there is a certain dissolution rate and dissolution time. The dissolution rate of CO2 is more instructive for actual production. Currently, research at home and abroad focuses on the solubility of CO2 in a saturated state, lacking quantitative analysis of the CO2 dissolution and diffusion process. Especially, there is limited research on the synergistic dissolution and viscosity reduction of CO2 demulsifiers, and there is a lack of sufficient understanding of the dissolution law and viscosity reduction effect of CO2 after emulsification of heavy oil.