Abstract: 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.

Abstract: Methods and systems for enhancing oil recovery from a subterranean formation comprising at least a first region and a second region are provided. An exemplary method includes creating an injection stream by adding a salt to a water stream to increase a concentration of an ion and injecting the injection stream into the subterranean formation through a first injection well in the first region of the subterranean formation. Fluid is produced from the subterranean formation and separated to generate an aqueous stream comprising at least a portion of the ion. The salt is added to the aqueous stream to adjust the concentration of the ion in the aqueous stream to a desired level. The aqueous stream is injected into the subterranean formation through a second injection well in the second region of the subterranean formation.

Abstract: Methods and systems for enhanced oil recovery from a subterranean formation are provided. An exemplary includes separating fluid produced from the subterranean formation into a first fluid stream that includes an aqueous stream containing multivalent ions. At least a portion of the multivalent ions in the first fluid are removed to form a second fluid stream and the second fluid stream is injected into the subterranean formation. The first fluid stream and the second fluid stream have substantially the same interfacial tension with a hydrocarbon and substantially the same kinematic viscosity, and the second fluid stream has a total concentration of ions greater than about 100,000 ppm.

Abstract: 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.

Abstract: Methods and systems for enhancing oil recovery from a subterranean formation comprising at least a first region and a second region are provided. An exemplary method includes creating an injection stream by adding a salt to a water stream to increase a concentration of an ion and injecting the injection stream into the subterranean formation through a first injection well in the first region of the subterranean formation. Fluid is produced from the subterranean formation and separated to generate an aqueous stream comprising at least a portion of the ion. The salt is added to the aqueous stream to adjust the concentration of the ion in the aqueous stream to a desired level. The aqueous stream is injected into the subterranean formation through a second injection well in the second region of the subterranean formation.

Abstract: Methods and systems for enhanced oil recovery from a subterranean formation are provided. An exemplary includes separating fluid produced from the subterranean formation into a first fluid stream that includes an aqueous stream containing multivalent ions. At least a portion of the multivalent ions in the first fluid are removed to form a second fluid stream and the second fluid stream is injected into the subterranean formation. The first fluid stream and the second fluid stream have substantially the same interfacial tension with a hydrocarbon and substantially the same kinematic viscosity, and the second fluid stream has a total concentration of ions greater than about 100,000 ppm.