Abstract: Steam huff and puff is the main recovery process of heavy oil in Henan Oilfield and infill producers are drilied in order to further increase heavy oil recovery factor. Coring, logging and production of infill wells demonstrate that some heavy oil infillers have been watered out by steam condensated water. Proper evaluation of the position and strength of watered-out zones is the key to improve recovery efficiency of infilled heavy oil wells. A series of methods that eva1uate watered-out zones in heavy oil infillers using log data are presented in this paper. Production practice demonstrate that they are effective.