Poromechanical analysis of oil well cements in CO2-rich environments

• Calcite precipitation shows porosity reduction with microstructural analysis. Cement paste mechanical parameters are reduced under scCO 2 despite calcite precipitation. Analysis of micro and macro experimental behaviour enables better performance the chemo-mechanical model. The change in average properties cement matrix is predicted using coupled model for attack. Wells drilled carbon storage sites could be converted to potential leakage pathways presence CO -bearing fluids impact changes occurring underground stress. To test this hypothesis, study, behavior Class G oil well contact supercritical has been investigated. cores were cured lime-saturated water 28 days at a temperature 20 ? C atmospheric pressure. Subsequently, they exposed pressure MPa 90 30 days. penetration depth carbonation front poromechanical core measured against time. A numerical modeling exercise also conducted simulate alteration within cores. results presented study show that calcium carbonates reduces outermost layers This phenomenon shifts main pore size class towards smaller sizes. In contrast expectations, does not improve overall strength specimens. observed specimens might associated either amorphous structure precipitated or weak bonding between them solid walls pores high degradation silicate hydrates.