Method for Recovery of Viscous Hydrocarbons by Electromagnetic Heating In Situ

A method of electromagnetic heating in situ recovers liquid hydrocarbons from an earth formation containing viscous hydrocarbonaceous liquid and water in an inorganic matrix where the formation is substantially impermeable to fluids under native conditions. A block of the earth formation is substantially uniformly heated with electromagnetic power to a temperature at which the viscous hydrocarbonaceous liquid is relatively fluid and a portion of the water vaporizes to water vapor at a pressure sufficient to overcome the capillary pressure of the liquid in the matrix. Water vapor thereupon escaping from the block under such pressure is recovered with hydrocarbonaceous liquid driven thereby. The magnitude of the electromagnetic power is controlled to limit the current recovery ratio of water vapor to hydrocarbonaceous liquid below a predetermined limit assuring substantial recovery of the hydrocarbonaceous liquid prior to the driving off of substantially all the water.Sponsorship: IIT Research InstituteUnited States Paten