Boreholes layout of coal mine methane drainage for high gassy and low permeability coal seams in Tiefa coalfield
Abstract：Based on the high gassy and low permeability coal seams geo-conditions and developing technology in Tiefa coalfield,the features of mining-induced fractures with different mining orders,gas migration under U model exhaust ventilation,and boreholes layout of methane drainage were studied by means of physical simulation and CFD（Computational Fluid Dynamics） numerical modeling.The results show that mining-induced fractures are mainly generated on the inside of the retreat drift,around 1/3 along the retreat direction and the zone where gas mainly flows range from 30 to 80 m away from the tailgate.Arising from this,it can be derived that the boreholes should be drilled vertically with a distance that is the summation of caved zone height and 1/3 fractured zone height to the coalface roof,the separation distance should be no less than 100~150 m for surface boreholes,and the best location for the boreholes should be with a distance of 1/3~1/2 inclination.
Keywords：high gassylow permeabilityboreholes layoutmining-induced fracturesCFD
Publication Date：2011-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)