At present, method, developed at Gas Research Institute (GRI method), has an international status for assessing petrophysical properties of shale rocks. A comprehensive study of shale rocks based on this method revealed significant shortcomings, which in some cases become critical. The article proposes method for determining gas-saturated and open porosity, as well as gas, water and oil saturation of shale rocks on crushed samples. The method is adapted for main shale formations in Russia, as it is based on the investigation of more than 2700 core samples from 33 wells. Gas-saturated porosity of fresh samples (the core is in state of natural saturation) and open porosity of dry samples (the core is after extraction) are calculated based on bulk and grain densities. Grain density was determined by means of the gas injection porosimetry method. Two methods are proposed for determining bulk density of crushed fresh samples. There are the gas injection porosimetry method and the modified fluid saturation method.
