Characterization of graphene nano platelets reinforced wellbore cement

Abstract

To improve the mechanical performance of wellbore cement under subsurface environments, graphene nanoplatelets (GNPs) are added in various percentages to Class-H cement slurry. Microstructural characterization of cement slurry cured at 90 degrees C and 95%RH indicates GNP modifies the microstructure of hydrated cement by reinforcing pore spaces. As an apparent result, the axial strength increases up to 27%, elastic stiffness decreases as much as 25% when 0.008% to 0.1%bwoc (by weight of cement) of graphene is added to the cement. Furthermore, the overall behavior of GNP- Portland cement paste is more ductile when compared to neat cement paste. From our observations, graphene enhances the flexibility of cement. The improvements would potentially reduce the risks associated with wellbore leakage primarily in plugging and abandonment but potential in other areas such as fossil fuel production, geothermal energy production, and CO2 storage.