Study on Permeability Improvement Technology by Injecting Air into the Gas Drainage Borehole in Low-Permeability Coal Seam

<div>Plots of content variation of gas at 0.8 m in the horizontal direction of gas injection. (a) Influence of different negative pressure on eliminating outburst risk. (b) Influence of different gas injection pressure on eliminating outburst risk.</div>

Advances in Civil Engineering

fig2

Figure 2

Figure 2: Study on Permeability Improvement Technology by Injecting Air into the Gas Drainage Borehole in Low-Permeability Coal Seam 