abstract |
FIELD: mining.SUBSTANCE: method for cementing a wellbore involves: pumping to the wellbore a cement slurry containing: an aqueous carrier, swellable nano-clay and a solid bivalent inorganic salt with sustained release, containing calcined magnesium oxide, calcined calcium oxide, calcium-magnesium polyphosphate glass, or a combination comprising at least one of said; and enabling setting of the cement slurry. Solid bivalent inorganic salt with sustained release is present in the cement solution in an amount of about 1 wt. % to about 25 wt. % with respect to the weight of the aqueous carrier. Also disclosed is a method of driving drilling fluid from a wellbore.EFFECT: invention relates to compositions for treating a well containing viscosity modifiers, and methods of using such compositions in borehole operations.13 cl, 3 dwg |