separately from the conduit that delivers oxygen 39 because carbon dioxide 40 is corrosive if mixed with steam preferably it flows down a conduit separate from the conduit for steam 38 carbon dioxide 40 could be mixed with fuel 37 if the fuel is delivered by a separate conduit from steam 38 the percentage of carbon dioxide 40 mixed with fuel 37 should not be so high so as to significantly impede the burning of the fuel if the fuel is syngas methane or another hydrocarbon the burning process in burner 29 creates carbon dioxide in some instances the amount of carbon dioxide created by the burning process may be sufficient to eliminate the need for pumping carbon dioxide down the well the conduits for fuel 37 steam 38 oxygen 39 and carbon dioxide 40 may comprise coiled tubing or threaded joints of production tubing the conduit for carbon dioxide 40 could comprise an annulus 12 in the casing of well 11 for example the annulus 12 is typically defined as the volumetric space located between the inner wall of the casing or production tubing and the exteriors of the other conduits the carbon dioxide may be delivered to the burner by pumping it directly through the annulus 12 combustion device or burner 29 is secured in well 11 for receiving the flow of file.