Abstract: The invention is a method of recovering hydrocarbons from underground hydrocarbon formations penetrated by at least one injection well and at least one production well, which comprises injecting into the formation a mixture of hot water and about 0.1% to about 5% by weight of a hydrocarbon liquid having an aromatic content greater than about 30%. The hot water and hydrocarbon mixtures should be injected at a temperature of at least about 80.degree.C. Hydrocarbons and other fluids are recovered from a production well after a suitable period of time.

Abstract: The invention is a method of recovering hydrocarbons from an underground vertical hydrocarbon reservoir having a substantial vertical thickness, an oil saturation relatively near residual oil saturation to gas, and at least one injection well and one production well penetrating the reservoir. The method comprises injecting a surfactant slug into the bottom of the reservoir above any water zone or aquifer, and driving the surfactant slug upwards through the reservoir by the use of some driving force. The driving force may be supplied by one or more of a combination of methods comprising producing the gas cap of the reservoir, producing hydrocarbons banked above the surfactant slug, or injecting fluid below the surfactant slug. Hydrocarbons are recovered at one or more production wells.

Abstract: The invention is a method for recovering residual hydrocarbons from a reservoir which has been previously swept by gas. The invention steps comprise drilling and completing at least one horizontal injection well relatively near the top of the reservoir, injecting a miscible solvent through the horizontal injection well to create a curtain of solvent falling through the previously gas swept reservoir, and producing hydrocarbons and other fluids that have been banked below the falling solvent curtain through a vertical or horizontal production well.

Abstract: The invention is a method for recovering residual hydrocarbons from a reservoir which has been previously swept by gas. The invention steps comprise drilling and completing at least one horizontal injection well relatively near the top of the reservoir and relatively near a substantially vertically oriented boundary of the reservoir, drilling and completing at least one second injection well between the horizontal injection well and the vertical boundary of the reservoir, injecting a miscible solvent through the horizontal injection well to create a curtain of solvent falling through the previously gas swept reservoir, and injecting a drive fluid into the reservoir through the second injection well to drive the curtain of falling solvent horizontally through the reservoir. A production well is employed to produce hydrocarbons and other fluids that have been banked in front of the horizontally driven falling solvent curtain.