Hydrogeochemical Characteristics and Water–Rock Interactions of Coalbed-Produced Water Derived from the Dafosi Biogenic Gas Field in the Southern Margin of Ordos Basin, China

<div>Relationship between hydrochemical compositions: (a) molar ratio of TDS vs. (Na++K+); (b) molar ratio of (SO42-+HCO3-) vs. (Ca2++Mg2+-SO42--HCO3-); (c) (Na++K+-Cl-) vs. (Mg2++Ca2+); (d) chloro-alkaline indices (CAI), <svg height="13.3389pt" id="M31" style="vertical-align:-2.2681pt" version="1.1" viewbox="-0.0498162 -11.0708 177.917 13.3389" width="177.917pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M614 175C564 76 510 21 408 21C256 21 146 149 146 336C146 488 235 629 402 629C510 629 570 586 597 480L626 488C620 541 614 582 606 638C578 643 510 665 429 665C206 665 44 527 44 316C44 157 153 -15 402 -15C474 -15 558 5 586 11C604 45 629 119 643 165L614 175Z"></path></g><g transform="matrix(.013,0,0,-0.013,8.645,0)"><path d="M673 0V28C608 34 594 43 563 129C499 303 432 494 370 665L339 656L132 132C98 43 84 37 20 28V0H238V28C162 35 154 45 175 108C188 150 203 192 219 237H432C454 176 474 122 487 83S491 36 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The ionic unit is meq/L.</div>

Geofluids

fig7

Figure 7

Figure 7: Hydrogeochemical Characteristics and Water–Rock Interactions of Coalbed-Produced Water Derived from the Dafosi Biogenic Gas Field in the Southern Margin of Ordos Basin, China 

Figure 7 | Hydrogeochemical Characteristics and Water–Rock Interactions of Coalbed-Produced Water Derived from the Dafosi Biogenic Gas Field in the Southern Margin of Ordos Basin, China 