an aqueous mobility control solution for tertiary oil recovery from saline oil fields comprises from about 200 to 2000 ppm xanthan biopolymer in the form of clean , unreconstituted fermentation broth and from about 20 to 200 ppm of a selected water - soluble polyglycol - based surfactant . a process for tertiary oil recovery which comprises the injection of the mobility control solution into saline oil - bearing subterranian formations is also disclosed .