Research on fractals of pore and fracture-structure of coal reservoirs

Coal reservoirs are ternary structure system containing macrofractures, microfractures and pores. Based on the statistics of macrofractures and microfractures measured continuously, and data of the special hole volume measured in sections of different diameters by mercury porosimeter, the pores and fractures of coal reservoirs were systematically researched through fractal analysis. The results show that the pore and fracture-structure with different origination correspond to different invariable ranges of scale. To denote quantitatively the characteristics of pore and fracture-structure in coal reservoirs, a few fractal dimensions are necessary. Fractal dimensions can reflect the status of pores and fractures of coal reservoirs and their distribution rules, and so are significant in the research of adsorption and permeability of coalbed methane. 8 refs., 3 figs., 1 tab.