a stable xanthan solution with superior filterability and subterranean injectivity characteristics comprising biopolymer and a chelating agent selected from aliphatic alpha - hydroxy acids having from about 2 - 7 carbon atoms ; aliphatic and aromatic beta - keto compounds having from about 4 - 9 carbon atoms ; or 2 - and 4 - pyrones having a hydroxyl group alpha to the carbonyl and having 5 or 6 carbon atoms ; said chelating agent being present in an amount of at least about 1 . 0 ppm of the total solution . a method of enhancing oil recovery comprising employing as a mobility control solution in oil - bearing formations a mixture of xanthan biopolymer and a chelating agent is also disclosed .