Carbon dioxide capture and storage is a new technology that can realize low-carbon utilization of fossil fuels in a large scale. The China Shenhua Group has built a 100,000tons/year integrated CCS demonstration project in Ordos, China. This paper chose Ordos basin as the simulation site and developed a full-field model of a coupled injection well and reservoir to simulate the CO 2 behavior during CO 2 injection through the wellbore and reservoir, taking into account thermal exchanges with rocks and natural convection of water in the annulus. Information for CO 2 temperature and pressure distributions in the wellbore and the reservoir, and their variation with time, were obtained. The simulation results for the temperature and pressure profiles of CO 2 in the wellbore were consistent with the well data log within 8.5%. The three factors leading to CO 2 temperature increase from the wellhead to bottomhole, heat extraction from rocks, compressibility and potential energy loss were analyzed both qualitatively and quantitatively. Comparison between the bottomhole temperature in our full-field model and the simplified model with a heat flux to substitute for the rock was conducted. Finally, the wellbore transient shut-in effect was simulated to predict the potential pressure drop and cooling at the wellhead.