m 3 of the oil in place will be mobilized within the formation drainage area for each 100 m 3 of liquid carbon dioxide injected during the fracturing operation after all the liquid carbon dioxide has been injected the fracturing operation is discontinued and the well is prepared for steam injection as illustrated in the drawing the well is provided with means for generating steam for injection into the well the steam generation means comprises a feed water supply tank 16 that supplies feed water to steam generator 19 through line 17 and pump 18 generator 19 supplies steam to line 20 which has a suitably valved means 21 for injection of high pressure high quality steam into well tubing 7 steam is injected through the well at a pressure sufficient to place the steam into the formation through the fractures created by the liquid carbon dioxide steam injection is continued until a sufficient amount of steam has been placed within the formation depending on the formation conditions this amount will usually range from about 5 000 m 3 to about 10 000 m 3 after all the steam has been injected the well is shut in and allowed to soak for a period of time sufficient to permit the petroleum contained within the formation drainage area to absorb heat from the steam following the soak period the well is opened to produce effluents from the formation drainage area after first cycle production has declined to a predetermined level the well may again be steam stimulated in the manner conventional for huff puff.