Well cementation cement paste suitable for carbon dioxide flooding well and application of well cementation cement paste

The invention relates to the technical field of oil exploitation, and particularly discloses well cementation cement paste suitable for a carbon dioxide flooding well. The well cementation cement slurry is prepared from the following substances: 0.1-0.4 wt% of a main agent, 0.1-0.4 wt% of an auxiliary agent and 0.1-0.4 wt% of a stabilizing agent, the auxiliary agent is a polycarboxylic acid liquid fluid loss agent PC-G80L with the content of 4wt%; the content of G-grade oil well cement is 63%-69%; and the balance of water. According to the well cementation cement paste, the fluidity is larger than 21 cm, the filter loss is smaller than 50 mL/30 min, the well cementation engineering requirement is met, the pore permeability of set cement is obviously reduced compared with blank set cement, the compressive strength and tensile strength of the set cement are obviously improved compared with the blank set cement, and the carbon dioxide corrosion resistance of the set cement is greatly improved. Moreover, the ceme