: Injecting CO 2 into oil reservoirs could improve recovery and facilitate the storage of CO 2 . For developing countries, especially China, coupling enhanced oil recovery (EOR) and CO 2 storage becomes an economical and environmentally safe method. Daqing Oilfield is the biggest oilfield in China. It has been operational for 50 years, and has faced many EOR challenges. In this study, a CO 2 storage and EOR evaluation method is introduced to calculate the CO 2 storage potential in the Daqing Oilfield. The stream tube simulation method and the mixed cell mesh method are adopted to determine the storage coefficient, recovery factor, and MMP (minimum miscible pressure). The evaluation results of the Daqing Oilfield show that most of the oilfields in Daqing can carry out CO 2 immiscible flooding. For EOR effects, the CO 2 miscible flooding can improve oil recovery by about 9%. The average CO 2 storage factors are 0.4 for miscible flooding while the immiscible flooding is 0.28; miscible flooding has better CO 2 storage capacity and EOR potential. The results show that injecting CO 2 into the reservoirs in Daqing Oilfield is a win‐win technology. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd