Rheological properties of oil well cement slurries Available to Purchase

The rheological properties, including yield stress, plastic viscosity, thixotropy and gel strength of oil well cement slurries incorporating six different chemical admixtures were investigated at different temperatures in the range of 23 to 60°C using an advanced shear-stress/shear-strain controlled rheometer. The compatibility and interactions between the binder and chemical admixtures were explored. The aim of the present study was to effectively use chemical admixtures to develop slurries with satisfactory properties in order to overcome difficulties encountered in oil well cementing such as the rapid loss of workability, pumping problems, acceleration of cement hydration, fast evaporation of mixing water and zonal isolation. It was found that the rheological properties of oil well cement slurries are highly dependent on temperature, water/cement ratio and the type of admixture used. Coupled effects of temperature and chemical admixtures had a substantial effect on the flow properties of the slurries. Among the six admixtures used, the new generation polycarboxylate-based high-range, water-reducing admixture (PCH) was found to be more effective in improving the rheological properties of oil well cement slurries at all test temperatures.