A method for recovering high molecular weight naphthenic tetra-acids, particularly ARN acids from a calcium naphthenate deposit. Calcium naphthenate deposits contain large amounts of calcium naphthenate salts of ARN acids. The method dual solvent extraction process in which the naphthenic tetra-acids chemically bound as calcium naphthenate salts are converted into free acid monomers by an aqueous acid. The resulting free acid monomers are then dissolved into an organic solvent phase and the counterions dissolve in the aqueous acid phase. The naphthenic tetra-acids are then recovered from the organic solvent phase.