Methods, program code, computer readable medium, and apparatus estimating permeability at unsampled (uncored) but logged interval locations in a reservoir based upon a similarity with log signatures from cored intervals, are provided. An example of a method can include performing a core plug-by-core plug blind test, defining an objective function which qualifies the quality of the permeability prediction to minimize discrepancies between measured and predicted permeability, optimizing calculated parameters, and estimating permeability values of uncored logged intervals. The method can also include applying a debiasing/variance restoration to compensate for inherent averaging artifacts.