Cocompetitive Characteristics and Quantitative Design of Engineering Parameters for Coal Gas Predrainage Boreholes

Figure 4

The gas content distribution of coal seam extracted by the boreholes.

(a) The change of gas content after 60 days of gas extraction

(b) Residual gas content between point (0, 1201, 1.5) and point (15, 120, 1.5)