STUDY THE INTERFACIAL INTERACTIONS OF SELF-HEALING POLYMER-CEMENT COMPOSITES EXPOSED TO CO2 AND H2SO4 USING SYNCHROTRON XRF, XANES AND CT STUDIES

There is lack of fundamental understanding of kinetics and reaction mechanisms that occur at wellbore cement microstructural and chemical interfaces under extreme conditions of temperature, pressure and corrosive environments present in various energy systems, such as CO₂ storage and enhanced geothermal systems. The dissolution and precipitation reactions that occur need to be understood as they can lead to drastic loss in structural integrity of the wellbore seal, which may limit the economic viability of sequestration. Hence, it is critical to study interfacial interactions to understand the degradation mechanisms involved in subsurface materials. Such knowledge will not only help predict economic viability of sequestration and well integrity but will also help in designing next generation materials with enhanced performance under extreme downhole conditions.

In our approach, we investigated the integrity of a newly designed self-healing polymer-cement composite exposed to CO₂ and H₂SO₄ using synchrotron XRF, XANES and CT studies. Self-healing cements have the potential to provide long-term zonal isolation in environmentally demanding subsurface environments. Results showed that the porosity concentration increase with the polymer concentration. In addition, the polymer addition was found to enhance the reactivity with CO₂ more than H₂SO₄.