Patent ID: 8445414

Claim:
A method for controlling fluid loss in a well comprising: injecting an aqueous fluid loss control (FLC) kill pill through a wellbore and to a subterranean formation where the aqueous FLC kill pill comprises: an aqueous base fluid; a viscoelastic surfactant (VES) gelling agent in an amount effective to increase the viscosity of the aqueous base fluid; an amount of a fluid loss control (FLC) agent effective to improve the fluid loss as compared with an identical fluid absent the FLC agent, where the FLC agent is a particle having an average particle size ranging from about 1 nanometer to about 10 microns and where the agent is selected from the group consisting of alkaline earth metal oxides, alkaline earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof; and an internal breaker selected from the group consisting of transition metal ion sources, saponified fatty acids, mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids, and combinations thereof; wherein the internal breaker is present in an amount of from about 5 to about 25,000 ppm; where in the case the FLC agent is selected from the group consisting of alkaline earth metal oxides, alkaline earth metal hydroxides and mixtures thereof, the effective amount of the FLC agent ranges from about 2 to about 200 pptg (about 0.2 to about 24 kg/m 3 ) and the internal breaker is selected from the group consisting of transition metal ion sources, saponified fatty acids, mineral oils, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids, and combinations thereof, and where in the case the FLC agent is selected from the group consisting of transition metal oxides, transition metal hydroxides, and mixtures thereof, the effective amount of the FLC agent ranges from about 0.0001 pptg to about 40 pptg (from about 0.01 g/m 3 to about 4.5 kg/m 3 ) and the internal breaker is selected from the group consisting of transition metal ion sources, saponified fatty acids, hydrogenated polyalphaolefin oils, saturated fatty acids, unsaturated fatty acids, and combinations thereof; reducing the flow of fluids into the wellbore; and improving fluid loss into the formation as compared with an identical fluid absent the FLC agent, where all proportions are based on the aqueous FLC kill pill.