Influence of graphene oxide on the self-healing of cement paste fractures in CCUS cementing: A combined analysis of experiments and molecular dynamics simulations

Abstract

Cracking the cement paste for CCUS cementing can jeopardize the integrity of the wellbore, jeopardizing CO2 storage security. After carbonization and self-healing for 28 days, the experimental results indicate that cement's compressive strength growth rate combined with 0.10 wt% GO reached 1077%, whereas, in the control group, it reached only 850%. More CaCO3 crystals developed on the crack surface of GO cement as the carbonization self-healing time increased than in the control group. The self-healing volume of GO cement cracks was 74.3%, higher than the control group (34.5%). The molecular simulation results indicate that GO can enhance the capacity of cement-based materials to absorb CO2 and speed up CO2 diffusion. GO supplies nucleation sites for CaCO3 crystals and accelerates the carbonization self-healing process of cracks.