An enhanced oil recovery method is provided. This method includes; introducing a first essentially pure oxygen stream into a subterranean hydrocarbon-bearing formation traversed by at least one injection well and at least one production well, and initiating and sustaining in-situ combustion in the vicinity of the injection well. This method also includes introducing a second essentially pure oxygen stream and a hydrocarbon-containing fuel gas stream into the combustion device of a power generation system, wherein the combustion device produces an exhaust gas stream comprising water and carbon dioxide. This method also includes separating the exhaust gas stream into a stream of essentially pure water, and a stream of essentially pure carbon dioxide, and introducing at least a portion of the essentially pure carbon dioxide stream into the subterranean hydrocarbon-bearing formation prior to initiating the in-situ combustion. The method may be used on a structure containing a carbonaceous substance such as coal, petcoke, or biomass.