Determination of the pore space parameters in microporous rocks by means of thermal methods

Abstract

The aim of the study was to examine the possibility of determining the pore space in microporous rocks using a set of methods: differential thermal analysis, retort distillation, and Dean-Stark. These methods are used for low-permeability rock containing hydrocarbons, such as shale gas, shale oil and tight gas. By using these methods it is possible to specify the amount of water contained in the sample and, consequently, determine the different levels of saturation and porosity.

The study showed shale porosity values ranging from 0% to more than 5%. It was found that the samples with the highest porosities in the combustion process evolve relatively large amounts of carbon dioxide, which indicate that the porosity is related to the presence of organic matter. There was no complete correlation between the various methods׳ test results. It seems that for determining the porosity of tight shale rocks, the most effective would be the use of several complementary methods.