Corrosion inhibitor for brines

A method of inhibiting corrosion of ferrous metals and alloys thereof comprising contacting a ferrous metal or alloy thereof with a solution of at least one alkali or alkaline-earth metal halide in water, said solution having a density equal to or less than about 16 pounds per gallon and further having corrosion inhibiting concentrations of zinc ions and thiocyanate ions, the total zinc ion concentration of said solution independently lying in the range of from about 0.05 percent by weight to about 5.0 percent by weight, and said thiocyanate ion concentration independently lying in the range of from about 0.05 percent by weight to about 1.5 percent by weight.

A method of inhibiting corrosion of ferrous metals and alloys thereof comprising contacting a ferrous metal or alloy thereof with an inhibiting solution, said inhibiting solution being prepared by adding zinc ions and thiocyanate ions to a substantially zinc-free brine solution of at least one alkali or alkaline-earth metal halide in water, said solution having a density of less than or equal to about 16 pounds per gallon, such that the total zinc ion concentration lies in the range of from about 0.05 percent by weight to about 5.0 percent by weight, and the total thiocyanate ion concentration lies in the range of from about 0.05 percent by weight to about 1.5 percent by weight.