Rheological Behavior of Oil Well Cement Slurries with Addition of Core/Shell TiO@SiO Nanoparticles-Effect of Superplasticizer and Temperature.

This study investigates the rheological behavior of oil well cement pastes (OWCPs) modified with core/shell TiO@SiO (nTS) nanoparticles and polycarboxylate-ether (PCE) superplasticizers at different temperatures (25, 45, and 60 °C). Results show that nTS particles increased static and dynamic yield stresses and the apparent viscosity of the cement slurries due to an increased solid volume fraction and reduced free water availability. The increase in the slurry dispersion by adding PCE superplasticizers enhanced the effect of the nanoparticles on the rheological parameters. Oscillation rheometry demonstrated that nTS nanoparticles enhanced the structural buildup, while PCE retarded hydration. Furthermore, slurries hydrated at 60 °C experienced higher initial values of the elastic modulus and a faster exponential increase in this rheological parameter due to the acceleration of the cement hydration.