Durability and Rheological Evaluation of Cement Slurries from Atmospheric to High Thermal Condition

Abstract

The Knowledge of the behaviour of cement slurries under elevated temperatures is necessary to understand properly cement rheology in moderate to deep-well cementing operations. The design of optimum cement slurry for oil well is highly challengeable for high temperature wells because slurry stability is a major requirement for successful oil well cementing the main objectives of cementing include, control abnormal pressure, zonal isolation, prevent from caving and wash out holes, support casing. For this purpose to understand rheological behaviour of cement slurry is essential for proper displacement and optimum placement at different temperature condition. Silica fume commonly available and cost-effective having sufficient quantity of amorphous substance to improvements in the physical and mechanical properties of cement slurry also a play very important role in strength development and increase rate of hydration. This paper describes to development of a cement slurry composition under laboratory condition to investigation the phenomena of optimum pump- ability through different concentration of silica fume from atmospheric condition to high thermal condition. Laboratory experiments showed that cement slurry is probably the more influenced by temperature; as temperature increased the changes occur in placing of cement slurry and the effect of high temperature decreasing plastic viscosity and yield point with the increasing temperature. The formulated cement slurry had advantages of low density, high strength, excellent rheology and high temperature tolerance, controlling the rheological behaviour of cement slurry can help to improve the relevant movement between particles, the stability and substitutability; according to the API standard.