Dual-Zone Gas Flow Characteristics for Gas Drainage Considering Anomalous Diffusion

Gas drainage in deep coal seam is a critical issue ensuring the safety of mining and an important measure to obtain gas as kind clean available energy. In order get better understanding flow diffusion for seams, dual-zone model, including damage zone (DDZ) non-damaged (NDZ), are characterized by different permeability models anomalous analyze influence induced drilling boreholes on flow. The model verified with experiment field data. A series finite-element numerical simulations based developed carried out, indicating that, compared normal more accurate appropriate test fracture increases rapidly distance decreasing from borehole, area DDZ increasing significantly extraction time. Moreover, fractional derivative order, transforms gradually, decay pressure aggravated. higher value non-uniform coefficient results larger increment permeability. permeability–damage increase makes bigger.