Review of the Hydrogeological Controls on Coalbed Methane (CBM) and Development Trends

<table class="table-group" id="tab6"><tr><td><table class="table"><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr class="thead"><td class="align_left">Hydrochemical zone</td><td class="align_center">HCO3-−Na+ zone</td><td class="align_center">HCO3-−Cl-−Na+ zone</td><td class="align_center">SO42-−Cl-−Ca2+−Na+ zone</td><td class="align_center">Cl-−Na+ zone</td></tr><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr><td class="align_left">Number of samples</td><td class="align_center">10</td><td class="align_center">212</td><td class="align_center">10</td><td class="align_center">17</td></tr><tr><td class="align_left">Average water production (m3/d)</td><td class="align_center">9.92</td><td class="align_center">5.64</td><td class="align_center">3.62</td><td class="align_center">1.61</td></tr><tr><td class="align_left">Average gas production (m3/d)</td><td class="align_center">235</td><td class="align_center">598</td><td class="align_center">1056</td><td class="align_center">1983</td></tr><tr class="table-tr"><td colspan="5"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Water production and gas production of CBM wells in different hydrochemical zones of the No. 11 coal seam in the Hancheng mining area [<a href="/journals/geofluids/2021/8298579/#B44" target="_blank">44</a>].</div>

Geofluids

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Table 6

Table 6: Review of the Hydrogeological Controls on Coalbed Methane (CBM) and Development Trends 