In order to evaluate the potential of different thermal-recovery technologies for heavy oil in SINOPEC，two EOR technologies，cyclic steam stimulation with infill wells and steam flooding，were studied. The methods of financial net present value，reservoir numerical simulation and cost analysis were used to draw the charts of single-well oil economic limit production of the cyclic steam stimulation and economic limit of oil-steam ratio for the steam flooding. And then the evaluation standards of the potential of cyclic steam stimulation with infill wells aimed at two kinds of buried depths and two kinds of well types were set up and the evaluation standards of the potential of steam flooding was revised. Finally，the potential was evaluated by taking W Oilfield of SINOPEC as an example. The results show that at a certain burial depth，single-well oil economic limit production of the cyclic steam stimulation increases exponentially as the oil price decreases for the vertical and the horizontal well. At the oil price of US＄60/bbl，the economic limit of oil-steam ratio for the steam flooding in the heavy oil reservoirs of SINOPEC is 0.096 t/t. The cyclic steam stimulation with infill wells and the steam flooding directly after cyclic steam stimulation can increase 32.4×104 and 71.1×104 tons of recoverable reserves respectively，and the total potential of W Oilfield is 103.5×104 t. At the oil price of US＄80/bbl，the total potential is 426.5×104 t for the W Oilfield. At the same time，it is suggested that the potential of steam flooding for the horizontal well should be evaluated as the potential of technological breakthrough.