Oil recovery process

Claim 1

IN TAHE RECOVERY OF OIL FROM AN OIL-BEARING UNDERGROUND FORMATION BY THERMAL MEANS WHEREIN A HEAT WAVE IS ESTABLISHED WITHIN THE FORMATION, THE STEPS COMPRISING HEATAING THE FORMATION AROUND THE BORE OF AN INPUT WELL TO ESTABLISH A HEATED ZONE IN THE FORMATION THEREABOUT HAVING A TEMPERATURE ABOVE ABOUT 500*F., MOVING THE SAID HEATED ZONE OUT INTO TAHE FORMATION AND COOLING THE INPUT WELL BORE BY INJECTION OF A COOLING NON-COMBUSTING GAS THEREIN, AND THEREAFTER DISCONTINUING THE USE OF THE INPUT WELL BORE AS A HEAT SOURCE, PROPAGATING THE HEAT WAVE WITHIN THE FORMATION BY INJECTION OF AN OXYGEN-CONTAINING PROPAGATING GAS THROUGH THE INPUT WELL TOWARDS AN ADJACENT OUTPUT WELL AT AN AVERAGE INPUT RATE OF OXYGEN SUFFICIENT TO MAINTAIN A PEAK TEMPERATURE IN THE ABOVE THE IGNITION POINT, INJECTING WATER INTO THE UNDERGROUND FORMATION FROM SAID INPUT WELL BORE AFTER THE HEAT CONTENT OF THE WAVE DURING PROPAGATION IS SUFFICIENT TO PROVIDE A PEAK TEMPERATURE IN THE WAVE WHEN IT REACHES THE OUTPUT WELL EQUIVALENT TO THE BOILING POINT OF WATER AT THE PRESSURE PREVAILING IN THE OUTPUT WELL, THEREAFTER DISCONTINUING THE INJECTION FROM THE INPUT WELL OF ANY PROPAGATING GAS AND CARRYING THE HEAT WAVE TO THE OUTPUT WELL BY FURTHER INJECTION OF WATER INTO THE FORMATION FROM THE INPOUT WELL.