Abstract Greenhouse gas mitigation and utilization attract huge attentions in energy and environment domains worldwide while few technologies enable to satisfy the both concurrently. In this study, a new greenhouse gas utilization technology, foamy emulsions, is initially developed and evaluated. Foamy emulsions usually have low production gas–liquid ratio but capable to facilitate the energy recovery. However, little researches have focused on the formation mechanism and flow property of foamy emulsions under greenhouse gas injection and the use of additives, which results in the relevant mechanism remains unclear. To address this problem, the formation process of foamy emulsions and the influence of the gas type, temperature and amount of viscosity reducer on the flow of foamy emulsions in the process of unconventional fossil fluids are investigated through a series of microscopic visualization experiments. According to the experimental results, the process of foamy emulsions formation can be divided into four stages, namely, the initial, early, middle and late stages. The middle stage corresponds to the period of steady flow of the foamy oil, with the largest number of bubbles and highest velocity. Moreover, the foamy emulsions formed using CO2 as the dissolved gas is the most effective, corresponding to an energy recovery factor of 40%. The effect of N2 is the most inferior, with the corresponding oil recovery factor being only 18%. Although the velocity of the bubbles increases with the increase in the temperature and amount of viscosity reducer, the stability of the bubbles degrades. The optimal effect of the foamy emulsions occurs at 80 °C with the amount of viscosity reducer being 1–3 wt%. This study will support the foundation of more general application pertaining to greenhouse gases mitigation and utilization in energy and environmental practices.