New Rheological Correlation for Cement Slurries as a Function of Temperature

Abstract

ABSTRACT This paper presents results of a study conducted to determine the effects of elevated temperatures and pressures on cement slurry rheological properties. New correlations developed from this study provide a more accurate means for predicting friction pressures which might be encountered in actual cementing operations. Currently, there are no correlations available in the literature or being used in the industry which consider the effects of temperature and pressure on cement slurry rheology. The new correlation expands on the modified Bingham Plastic model introduced by Shah and Sutton.1 The critical fluid properties required for the pressure drop correlation, plastic viscosity and yield point, are shown to be influenced significantly by temperature. As a prerequisite to measuring cement slurry rheology accurately under temperature and pressure conditions, a new viscometer was designed and constructed. The new viscometer operates using the same principles as a conventional rotational viscometer, but slurry can be circulated and conditioned as it is heated and pressurized. The study shows that when compared to temperature effects, pressure effects on rheological properties of cement slurries can be neglected. However more work needs to be done to confirm pressure effects. The temperature effects have been correlated and are presented in this paper.