Study on Borehole Arrangement Methods for Gas Extraction by Hydraulic Slotting in Long-Distance Through-Coal Seam Tunnel

<table class="table-group" id="tab2"><tr><td><table class="table"><tr><td class="thead-hr" colspan="4"><hr/></td></tr><tr class="thead"><td class="align_left">S/N</td><td class="align_center">Extraction method</td><td class="align_center">Residual gas content (m<sup>3</sup>/t)</td><td class="align_center">Residual gas pressure (MPa)</td></tr><tr><td class="thead-hr" colspan="4"><hr/></td></tr><tr><td class="align_left">1</td><td class="align_center">Single-borehole extraction</td><td class="align_center">7.2</td><td class="align_center">0.71</td></tr><tr><td class="align_left">2</td><td class="align_center">Hydraulic slotting extraction</td><td class="align_center">6.5</td><td class="align_center">0.68</td></tr><tr class="table-tr"><td colspan="4"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Outburst prevention index after extraction.</div>

Geofluids

tab2

Table 2

Table 2: Study on Borehole Arrangement Methods for Gas Extraction by Hydraulic Slotting in Long-Distance Through-Coal Seam Tunnel 