Abstract: A method of flooding a petroleum reservoir by way of an injection well to aid in the recovery of hydrocarbons from a recovery well includes running a radioactive well logging tool in the injection well to derive a first well log of the reservoir in the vicinity of the injection well. The reservoir is then flooded with a solvent injected into the reservoir at a predetermined rate from the injection well. The radioactive well logging tool is again operated to derive a second well log. High salinity salt water is injected into the reservoir from the injection well. The radioactive well logging tool is run again to derive a third well log. The well logs are utilized to provide a record of the effectiveness of the solvent flood.

Abstract: Viscous oil may be recovered from subterranean, viscous oil-containing formations by injecting a heated aqueous fluid into the formation to raise the temperature of the viscous petroleum, and to displace it toward a remotely located production well. The heated aqueous fluid, which may be liquid, gaseous or a mixture thereof, is obtained from a deeper, higher temperature permeable oil formation. At least two spaced apart fluid flow communication means are established between the surface of the earth and the deeper, high temperature formation. At least two spaced apart separate communication means are established between the surface of the earth and the shallow viscous oil formation. Ordinarily the deeper, high temperature oil formation is one in which secondary recovery, e.g., waterflooding, will be ended or approaching the point where further production of oil and water is not commercially justified.