Construction and Building Materials | 2019
A rheological approach to study the early-age hydration of oil well cement: Effect of temperature, pressure and nanoclay
Abstract
Abstract The pumpability of cement slurries during cementing and their ability to resist penetration of formation gas once placed are critical for the success of oil and shale gas well cementing. Pumpability and ability to resist gas migration, which can be quantified through rheological parameters, develop over time due to hydration, which is highly dependent on the well conditions, namely temperature and pressure levels, as well as mix composition, including the use of rheological modifiers. In this study, we utilized a rotational rheometer with a high-pressure cell to investigate the effect of temperature, pressure and nanoclay on the viscosity and static yield stress of oil well cement slurries. The results emphasize the importance of considering shear rate in evaluating viscosity evolution and time to reach the limit of pumpability. The growth of yield stress was described by a non-linear structural build-up model, which connects the static yield stress with hydration, and its ability to predict the effect of temperature, pressure and nanoclay on yield stress evolution was assessed.