Abstract: High pressure water jet perforation is a new choice for oil well completion.The water jet can penetrate formation to generate a clean,1-3 m deep and relatively large diameter cylindrical flow channel.A computer model was used to study the effects on well productivity of jet perforating parameters.The effects of channel diameter,perforation depth,damage zone depth,formation anisotropy and penetrating type were compared for penetrating through damage zone and not through.The results show that:(1) the perforation depth is one of the key factors to productivity.And only if the perforation depth is large than 1.5m,the productivity will be 2-3 times of conventional perforation productivity.(2) The vertical permeability influence on productivity was enhanced in a deeper hole.(3) When penetrating through the damage zone,the productivity increases about 20%.The high pressure water jet perforation technology is specially suited for the oil sheet perforation.