Methods for enhanced oil recovery from a subterranean formation including adding a first salt to a first aqueous stream to form a first injection stream with an increased concentration of a first ion. A second salt is added to a second aqueous stream to form a second injection stream with an increased concentration of a second ion. The second injection stream is of different composition than the first injection stream and the first injection stream and the second injection stream have substantially the same interfacial tension with a hydrocarbon and substantially the same kinematic viscosity. The first injection stream is injected into the formation at a first time and the second injection stream is injected into the formation at a second time. The first injection stream and second injection stream contact at least some overlapping portion of the formation. Oil is recovered from the overlapping portion of the formation.