A novel strategy to reduce carbon emissions of heavy oil thermal recovery: Condensation heat transfer performance of flue gas-assisted steam flooding

• Flue gas-assisted steam flooding was investigated to reduce carbon emissions. • Flue gas-assisted steam flooding improved the oil recovery factor by 20.02%. • Flue gas treatment and injection processes for steam injection wells were designed. • Site application showed that the underground CO 2 storage rate was 74.5%. • The novel strategy is suitable for a small-scale steam generator used in oilfields. In this paper, the flue gas-assisted steam flooding process from a novel perspective of condensation heat transfer performance was investigated to reduce carbon emissions of heavy oil thermal recovery. More specifically, steam condensation heat transfer coefficients with and without flue gas were tested, and heat transfer and oil recovery for steam flooding assisted by flue gas in a sandpack were studied. The experimental results indicate that the existence of the gas film on the condensation block increased the heat transfer resistance and decreased the condensation heat transfer coefficient. The gas channeling of flue gas provided a flow path for the steam and promoted heat transfer deep into the sandpack. Flue gas-assisted steam flooding improved the oil recovery factor by 20.02% compared with steam flooding, and 46.4% of the injected flue gas could be stored in the sandpack. The storage of flue gas could be divided into two parts: the flue gas dissolved in the residual heavy oil and the flue gas trapped in the porous media. Flue gas treatment and injection processes for steam injection wells were designed. Site application of flue gas-assisted steam injection showed that the oil production increased by 28.3%, and the underground CO 2 storage rate was 74.5%. The novel strategy of flue gas treatment and injection with steam greatly reduces the carbon emissions of heavy oil thermal recovery, which is very applicable for small-scale steam generator used in oilfields.