High density brine internal phase

An oil-based treatment fluid for use in subterranean operations, the oil-based treatment fluid comprising:

• an invert emulsion comprising an aqueous internal phase and an oil external phase,
• wherein the aqueous internal phase is solids free and comprises a two-salt brine and a true crystallization temperature reduction additive,
• wherein the true crystallization temperature reduction additive comprises a sugar alcohol, a sugar acid, or any combination thereof,
• wherein the two-salt brine comprises a bromide and a nitrate,
• wherein no additional salts are in the aqueous internal phase,
• wherein the two-salt brine has a density of about 14.2 lbs/gal to about 17 lbs/gal;
• wherein the two-salt brine has a first true crystallization temperature without inclusion of the true crystallization temperature reduction additive;
• and
• wherein the two-salt brine has a second true crystallization temperature with the true crystallization temperature reduction additive that is lower than the first true crystallization temperature.