Study on the Permeability Evolution and Its Formation Mechanism of Xiaojihan Aquifer Coal Seam under Plastic Flow

<table class="table-group" id="tab1"><tr><td><table class="table"><tr><td class="thead-hr" colspan="7"><hr/></td></tr><tr class="thead"><td class="align_left">Specimens</td><td class="align_center">No.</td><td class="align_center">C1<br/>Porosity (%)</td><td class="align_center">C2<br/>Total amount of mercury (ml/g)</td><td class="align_center">C3<br/>Permeability (m<sup>2</sup>)</td><td class="align_center">C4<br/>Total pore area (m<sup>2</sup>/g)</td><td class="align_center">C5<br/>Average pore size (nm)</td></tr><tr><td class="thead-hr" colspan="7"><hr/></td></tr><tr><td class="align_left">Xiaojihan</td><td class="align_center">M1</td><td class="align_center">9.89</td><td class="align_center">0.0892</td><td class="align_center"><span style="width: 62.838ptpx;"><svg height="11.9413pt" id="M3" style="vertical-align:-0.3499002pt" version="1.1" viewbox="-0.0498162 -11.5914 62.838 11.9413" width="62.838pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g 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transform="matrix(.0091,0,0,-0.0091,53.213,-5.741)"><path d="M389 0V32C297 38 291 46 291 118V635C234 613 175 595 109 583V556L161 554C203 552 207 547 207 497V118C207 46 201 38 110 32V0H389Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,57.645,-5.741)"><path d="M158 548H390L417 615L410 623H122L83 318C105 326 143 337 185 337C296 337 350 275 350 188C350 116 308 42 225 42C164 42 122 74 100 93C90 101 82 99 72 92C60 82 51 68 50 59C48 46 52 38 66 24C82 9 125 -12 172 -12C225 -11 292 15 346 59C408 108 437 166 437 226C437 309 371 397 242 397C214 397 170 382 133 369L158 548Z"></path></g></svg></span></td><td class="align_center">44.95</td><td class="align_center">7.91</td></tr><tr><td class="align_left">Longde</td><td class="align_center">M2</td><td class="align_center">8.97</td><td class="align_center">0.0796</td><td class="align_center"><span style="width: 62.838ptpx;"><svg height="11.9413pt" id="M4" style="vertical-align:-0.3499002pt" version="1.1" viewbox="-0.0498162 -11.5914 62.838 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27V0H445V27C364 34 360 39 360 106V178H456ZM280 225H82C149 335 214 431 278 520H280V225Z"></path></g><g transform="matrix(.013,0,0,-0.013,24.59,0)"><path d="M528 54L331 254L528 455L492 493L294 291L96 493L60 455L257 254L60 54L96 16L294 217L492 16L528 54Z"></path></g><g transform="matrix(.013,0,0,-0.013,35.127,0)"><path d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"></path></g><g transform="matrix(.013,0,0,-0.013,41.367,0)"><path d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,47.654,-5.741)"><path d="M556 236V289H56V236H556Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,53.214,-5.741)"><path d="M389 0V32C297 38 291 46 291 118V635C234 613 175 595 109 583V556L161 554C203 552 207 547 207 497V118C207 46 201 38 110 32V0H389Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,57.645,-5.741)"><path d="M158 548H390L417 615L410 623H122L83 318C105 326 143 337 185 337C296 337 350 275 350 188C350 116 308 42 225 42C164 42 122 74 100 93C90 101 82 99 72 92C60 82 51 68 50 59C48 46 52 38 66 24C82 9 125 -12 172 -12C225 -11 292 15 346 59C408 108 437 166 437 226C437 309 371 397 242 397C214 397 170 382 133 369L158 548Z"></path></g></svg></span></td><td class="align_center">41.14</td><td class="align_center">7.70</td></tr><tr class="table-tr"><td colspan="7"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>The experiment results of mercury intrusion tests.</div>

Geofluids

tab1

Table 1

Table 1: Study on the Permeability Evolution and Its Formation Mechanism of Xiaojihan Aquifer Coal Seam under Plastic Flow 