Fractal Pore and Its Impact on Gas Adsorption Capacity of Outburst Coal: Geological Significance to Coalbed Gas Occurrence and Outburst

Pore structure and methane adsorption of coal reservoir are closely correlated to the coalbed gas occurrence outburst. Full-scale pore its fractal heterogeneity samples were quantitatively characterized using low-pressure N2 (LP-N2GA) high-pressure mercury intrusion porosimetry (HP-MIP). Fractal capacities between outburst nonoutburst coals compared, their geological significance was discussed. The results show that volume (PV) is mainly contributed by macropores (>1000 nm) mesopores (100–1000 nm), while specific surface area (SSA) dominated micropores (<10 transition pores (10–100 nm). On average, PV SSA 4.56 times 5.77 those samples, respectively, which provide sufficient place for storage. shape semiclosed in coal, whereas open inkbottle prevailing coal. size widely distributed not only dominant, but also, developed a certain extent. Based on data from HP-MIP LP-N2GA, spatial characteristics with dimensions D m 1 (2.81–2.97) id="M2"> n (2.50–2.73) calculated Menger model Frenkel–Halsey–Hill (FHH) model, respectively. more heterogeneous as id="M3"> id="M4"> generally larger than maximum ( id="M5"> V L : 15.34–20.86 cm3/g) id="M6"> 9.97–13.51cm3/g). adsorptivity governed micropores, pores, id="M7"> because they positively SSA. belongs tectonically deformed (TDC) weak strength, rich microporosity, complex structure, strong capacity, poor connectivity pores. Therefore, TDC at high risk there sealing zone abundant enrichment limited migration extraction.