Study on the Radial Displacement Law and Permeability Enhancement Effect of Coal Body around Hydraulic Flushing Drilling

<table class="table-group" id="tab2"><tr><td><table class="table"><tr><td class="thead-hr" colspan="7"><hr/></td></tr><tr class="thead"><td class="align_left">Category</td><td class="align_center">Volumetric weight</td><td class="align_center">Bulk modulus (GPa)</td><td class="align_center">Shear modulus (GPa)</td><td class="align_center">Tensile strength (MPa)</td><td class="align_center">Adhesion (MPa)</td><td class="align_center">Internal friction angle (°)</td></tr><tr><td class="thead-hr" colspan="7"><hr/></td></tr><tr><td class="align_left">Coal seam</td><td class="align_center">1400</td><td class="align_center">0.47</td><td class="align_center">0.23</td><td class="align_center">0.58</td><td class="align_center">0.40</td><td class="align_center">16</td></tr><tr class="table-tr"><td colspan="7"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Physical-mechanical parameters of the coal body.</div>

Geofluids

tab2

Table 2

Table 2: Study on the Radial Displacement Law and Permeability Enhancement Effect of Coal Body around Hydraulic Flushing Drilling 