A variety of methods for thermal recovery of natural gas and bitumen from a formation containing the latter. In general, the methods incorporate a series of existing, but previously uncombined technologies. A modified flue gas from the steam generators conventionally used in a SAGD recovery operation is injected into the formation to enhance recovery with the produced fluids, natural gas, bitumen, inter alia are further processed. The injection of the flue gas conveniently is disposed of and further acts to repressurize the formation which otherwise becomes depressurized when depleted of natural gas. Accordingly, environmental and economic advantages are realized with the methodology.