The introduction of Pozzolanic materials in the cement, as Supplementary cementitious materials (SCM), has become during the last few years a successful worldwide practice. It has been proved that these can react chemically with the hydrated cement, forming a modified microstructure of the paste, leading to the improvement of the cements properties with respect to the compressive strength, the durability and the behaviour in aggressive environments or at high temperatures.
In this study we have analysed the effect of adding metakaolin, in 10%-20% proportion, on the properties of the pastes that may be used in cementing oil wells. Four products of the metakaolin category have been used for testing, under the trade name of Power PozzTMHRM , MetaverTM R, MetaverTM W and Microsit® M10, manufactured by Advanced Cement Technologies USA and NewChem Switzerland. The researches made in the laboratory have studied the influence of such admixtures on the set time, on the spreading, density, compressive strength and shrinkage of the pastes achieved with such mixtures.