1. A method for determining effective core sample thermal conductivity, the method comprising: providing a core sample and an X-ray micro-computed tomography scanner for scanning said core sample and generating an image for each scan, scanning said core sample using the scanner to generate a three dimensional scan image, transferring said three dimensional scan image from the scanner to an image analysis computer for processing, setting a layer thickness within the produced three dimensional scan image to be analyzed, defining a layer with maximum thermal resistance within the produced three dimensional scan image, and defining effective thermal conductivity for the core sample.