| abstract |
The present invention pertains to a dry cement formulation for cementing earth boreholes, in particular oil, gas and/or terrestrial heat boreholes, containing a) about 20 to 99.9 wt. % cement, b) about 0 to 65 wt. % powdered quartz/or quartz dust, c) about 0.1 to 30 wt. % water-redispersible dispersion powder, and d) about 0 to 20 wt. % further additives. Furthermore, the invention pertains to the use of the dry cement formulation for preparing a cement slurry as well as to the use of water-redispersible dispersion powders in a cement slurry for cementing earth boreholes, wherein the cement slurries can be used for reducing the water loss of the cement slurry, for reducing the gas and/or water penetration and/or for sealing off the gas and/or water channels by means of the cement slurry which has been introduced into the borehole and has set. |