Pore structure and fractal characterization of Garau and Sargelu shales using low pressure nitrogen adsorption

The present paper tends to analyze the pore structure of Organic rich carbonaceous rock in 4 samples from Upper Jurassic Sargelu and 5 samples from Lower Cretaceous Garau formation using low pressure nitrogen adsorption. TOC content of Garau samples ranged between 0.64 wt% and 5.21 wt% (mean 3.2 wt%).TOC varied between 0.12 and 10.94 for Sargelu samples. XRD results shows that carbonates are the dominant minerals, followed by quartz and clay minerals. The calculated total pore volume vary between 0.6 cm3/100g to 2.5 cm3/100g with the mean values of 1.4 cm3/100g. A positive linear correlation were found between TOC content of measured samples with pore structure parameters. Due to the larger variation of TOC content this relationship was more obvious for the Sargelu samples. The calculated fractal dimension ranged between 2.45 and 2.81 emphasizing the irregular pore surface of the measured samples. Based on the result of this study organic matter content is recognized as a controlling factor for pore structure and fractal characteristics of the Garau and Sargelu samples.