Patent ID: 8895476

Claim:
A fluid formulated to have low thermal conductivity, the fluid comprising a mixture of one or more salts selected from the group consisting of: an inorganic salt, an organic salt, and mixtures thereof; and one or more aprotic polar organic solvents and one or more protic polar solvents, wherein the aprotic polar organic solvents comprises about 20% to about 80% of the mixture of aprotic polar organic solvents and one or more protic polar organic solvents such that the ratio of the concentration of the aprotic polar solvents to the concentration of protic polar organic solvents in the mixture is in the range of about 1:4 to about 4:1 in order to lower the thermal conductivity of the mixture, the one or more salts are added in amounts sufficient to maintain the density of the fluid between about 9.0 lb/gal to about 18.0 lb/gal, and wherein the fluid is devoid of an amine solvent additive.