With the application of CO₂ fracturing, CO₂ huff and puff, CO₂ flooding, and other stimulation technologies in shale reservoirs, a large amount of CO₂ remained in the formation, which also lead to the serious corrosion problem of CO₂ in shale reservoirs. In order to solve the harm caused by CO₂ corrosion, it is necessary to curb CO₂ corrosion from the cementing cement ring to ensure the long-term stable exploitation of shale oil. Therefore, a new latex was created using liquid polybutadiene, styrene, 2-acrylamide-2-methylpropanesulfonic acid, and maleic anhydride to increase the cement ring’s resistance to CO₂ corrosion. The latex’s structure and characteristics were then confirmed using infrared, particle size analyzer, thermogravimetric analysis, and transmission electron microscopy. The major size distribution of latex is between 160 and 220 nm, with a solid content of 32.2% and an apparent viscosity of 36.8 mPa·s. And it had good physical properties and stability. Latex can effectively improve the properties of cement slurry and cement composite. When the amount of latex was 8%, the fluidity index of cement slurry was 0.76, the consistency index was 0.5363, the free liquid content was only 0.1%, and the water loss was reduced to 108 mL. At the same time, latex has a certain retarding ability. With 8% latex, the cement slurry has a specific retarding ability, is 0.76 and 0.5363, has a free liquid content of just 0.1%, and reduces water loss to 108 mL. Moreover, latex had certain retarding properties. The compressive strength and flexural strength of the latex cement composite were increased by 13.47% and 33.64% compared with the blank cement composite. A long-term CO₂ corrosion experiment also showed that latex significantly increased the cement composite’s resilience to corrosion, lowering the blank cement composite’s growth rate of permeability from 46.88% to 19.41% and its compressive strength drop rate from 27.39% to 11.74%. Through the use of XRD and SEM, the latex’s anti-corrosion mechanism, hydration products, and microstructure were examined. In addition to forming a continuous network structure with the hydrated calcium silicate and other gels, the latex can form a latex film to attach and fill the hydration products. This slows down the rate of CO₂ corrosion of the hydration products, enhancing the cement composite’s resistance to corrosion. CO₂-resistant toughened latex can effectively solve the CO₂ corrosion problem of the cementing cement ring in shale reservoirs.

Excessive CO₂ emissions cause global warming, while CO₂ interaction with crude oil can enhance oil recovery (EOR). To capture and reuse CO₂, nano-SiO₂ was cationically modified to synthesize nanoparticles (SCR₂). The structure and performance of SCR₂ were characterized by FT-IR, DLS, and TEM, confirming its excellent CO₂ adsorption capacity and surface activity. Compared with unmodified nano-silica, SCR₂ increased CO₂ adsorption capacity by 254.3% and reduced the core surface contact angle from 112.1° to 24.5°. Core flooding experiments showed that in low-permeability reservoirs, SCR₂ achieved a plugging rate of 87.5%, an enhanced oil recovery of 24.8%, and an ultimate oil recovery of 74.8% (23.8% higher than unmodified nano-silica). Mechanistically, SCR₂ plugs gas channeling pathways via its inherent nanoparticle properties and adsorption of dissolved CO₂ in the aqueous phase while improving rock surface wettability, thereby enhancing sweep efficiency and total oil recovery during CO₂ flooding. This study provides a promising approach for EOR and CO₂ resource utilization in low-permeability reservoirs.