Research on the application of hydraulic flushing measures in the deep low permeability coal seam
Abstract：Based on the present situation in Hebi No.8 coal mine that cannot develop protective seam mining and exists the low permeability coal seam,this paper chooses the hydraulic flushing permeability-increasing measures and introduces its mechanism and basic process.By using numerical simulation software,the changes of the quantity of coal,pressure-relief range and the displacement of coal in the pressure-relief area are analysed.The analysis results show that: the radius of hydraulic flushing holes is proportional to the pressure-relief range,but this phenomenon only exists in the effective target distance of water jet.As the flushing radius increases,the displacement of coal body around boreholes increases gradually.Under the joint action of the stress and the gas pressure,the displacement happens in the coal around the holes,and the stress transfer to the deep.Through the investigation of the gas content and gas pressure in pressure-relief range,the conclusion is that the gas content and pressure decrease gradually and are under critical value in pressure-relief area.These are basically consistent with the numerical simulation results,thereby validating the accuracy of numerical simulation.
Keywords：borehole hydraulic flushinglow permeabilitypressure relief and permeability-increasingstress
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 501-506 )