This invention provides zinc-free aqueous brine compositions. These zinc-free aqueous brine compositions have a density of about 14.3 pounds per gallon or more, and a true crystallization temperature of about 20° F. or less, and comprise water and one or more inorganic bromide salts, with the provisos that when calcium bromide is present, one or more other water-soluble inorganic salts are also present, when lithium bromide is present, calcium bromide is absent, when bismuth(III) bromide is present, one or more other water-soluble inorganic salts are also present, and for a true crystallization temperature of about 10° F. or less, when manganese(II) bromide is present, one or more other water-soluble inorganic salts are also present. Processes for forming these zinc-free aqueous brine compositions are also provided.