A method of altering wettability of a subterranean formation penetrated by a well is described. A first oxidizer including a persulfate is introduced to the subterranean formation. A second oxidizer including a bromate is introduced to the subterranean formation. The well is shut in for a period of time to allow the first oxidizer and the second oxidizer to alter the wettability of the subterranean formation toward non-wetting of oil and of water.