FRACTAL MEASUREMENT OF RESOURCE SHALES

Fractal behavior is associated with power-law behavior for the number of features as a function of the feature size on the pore-rock interface. Fractal dimension could be used to measure the complexity of the pore structure. In shales, the organic matter is a controlling factor on the fractal dimension, demonstrated by a positive correlation between TOC and fractal dimension, also, it is the main storage and transport space of hydrocarbons. So, the organic matter is the main target of the measurement. Fractal dimension can be obtained through several experimental methods, in this paper, FE-SEM and nitrogen adsorption isotherm were performed. This fractal parameter is related to multiple essential rock properties. Positive correlations between fractal dimensions and TOC as well as effective pore width were concluded in this paper, and we also discussed the relationship between the fractal dimension increasing during the thermal decomposition process of organic matter and the generation mechanism of hydrocarbons. The goal of this paper is to explain the fractal behavior of shales, to describe the methodology of extracting fractal dimension through experimental approaches, to explain the potential causal relationship between the hydrocarbon generation process and fractal dimensions, to explore correlations between the physical properties of resource shales and the fractal dimensions, and to connect two types of fractal dimensions obtained from the SEM and the nitrogen adsorption isotherm.