Conditioning a coal seam prior to in-situ gasification

A method for conditioning a subsurface wet coal seam prior to in-situ gasification wherein combustion of a portion of the coal in said seam has been initiated and is maintained by injection of a combustion-supporting gas into said seam through an injection well whereby there results an in-situ combustion front containing hot combustion gases which move toward a spaced production well and movement of this front displaces the hot combustion gases into the production well for recovery, the improvement comprising injecting into said coal seam via said injection well a wettability alteration fluid, said wettability alteration fluid capable of decreasing the water content of said coal and altering the wettability of said coal thereby increasing the permeability thereof to the flow of gas therethrough;

• recovering fluids including the wettability alteration fluid from said coal seam via said production well, and continuing to inject said wettability alteration fluid into said coal seam until the permeability thereof to the flow of said combustion-supporting gas therethrough has increased to a maximum extent.