Effective Porosity and grain density of the core samples will be measured with Boyle’s Law porosimeter with He as the working fluid. Operational He pressure up to 10 bar. The method consists in measuring the pressure drop occurring during the isothermal expansion of a known quantity of He moles (reference cell) into the sample cell. This pressure drop is a function of the void volume in the sample cell and this function is determined by calibration against standards of known volume. The grain volume of the core sample is then calculated. External volume of the samples will be measured based on their external dimensions and or Hg porosimetry. Grain density is calculated using the sample weight and the determined grain volume.