Log data normalization is an important part of multiple well evaluation. Afterthis normalization, the lIog curves, having the same name, will have the samescale in the study area. So it is the base of reservoir description in the area.Normalization methods are discussed, including variogram function analysis andtrend surface analysis. By applying these methods to the N20 development exper-iment area of the Niuzhuang depression, the reservoir characteristics can beunderstood more clearly, and the reservoir parameters from log data will be moreprecise.