Abstract: Taking the in?situ combustion pilot test in Wellblock Hongqian?1in Xinjiang oilfield as an example, the recovery effect by in?situ combustion process converted from steam injection process including steam stimulation and steam drive is evaluated using generalized production decline and numerical simulation methods. The results show that the steam injection followed by in?situ combustion process applied in this pilot test area has obtained ultimate recovery efficiency of59.9%, of which in?situ combustion stage can get at least30%of the EOR. Also, the comparison of these two methods indicates that the generalized production decline method is actually feasible for evaluation of in?situ combustion recovery effect, less data are needed than numerical simulation method, and more simple to use