1. A method for determining effects of perforation on a rock formation, comprising: obtaining a sample of the rock formation; creating a perforation tunnel in the sample of the rock formation; at least one of subdividing the core sample into subsamples and making a three dimensional tomographic image of each subsample and making a three dimensional tomographic image of the sample of rock formation and segmenting the image thereof into sub images of selected subvolumes of the rock formation sample; and estimating at least one physical property of the rock formation from each tomographic image.