Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China

The influence of high-rank coal’s pore characteristics on the physical properties, gas-bearing and exploitation coal reservoirs is becoming more prominent. How to establish classification describe networks combining quantitative qualitative has emerged as a major problem, which may offer scientific foundation deepen understanding this issue. In research, structure fractal reservoir pores were determined after analyzing 20 samples from Xinjing Coal Mine in Qinshui Basin with application high-pressure mercury intrusion method (HPMI) argon ion polishing–field emission scanning electron microscopy (AIP–FESEM). results show that tested bipolar distributed, transitional micropores dominating volume, followed by macropores. Menger sponge models manifested two or three distinct straight-line segments demarcation points 65 nm 1000 nm. A natural types diffusion (D-pores), seepage (S-pores), pico (P-pores), demarcated size intervals 1 seven sub-types, was established relate based these kinetic methane molecules. This scheme can characterize relationship between corresponding occurrence transport mechanisms gas. addition, P-pores D-pores are predominately nanoscale OM genetic organic constituent interparticle (5–200 nm), metamorphic (<5 intermorphic nm). S-pores complex origin shape features, include outgas pores, plant tissue residual mineral-related microfractures. mean radius (Pa), total volume (Vt), apparent porosity (Φ), ratio macro- mesopores positively correlated dimension D1 (>65 Since analysis comprehensive characterization quantitatively reflects structure, undulating state, roughness inner surface, parameters be used an important index reservoirs.