Storable compositions and slurries and use of same for cementing oil and gas wells

The present invention relates to compositions and slurries for cementing oil and gas wells as well as to the use of such slurries in those wells, and specifically to compositions and slurries containing blast furnace slag to be used in water-based fluids as hydraulic material, in the absence of set inhibitors, such slurries being storable at ambient temperature. Storable compositions and slurries for cementing oil and gas wells are described which comprise blast-furnace slag besides other additives which are usual in the cementing technique. The compositions and slurries are insufficiently activated (or are activated immediately before introducing them into the well), so that they can be stored for at least 72 hours (alternatively they may be stored indefinitely) without the setting of the composition and dispense with the addition of activation inhibitors. The use of the compositions and slurries in the cementing of oil and gas wells is also described.