Experimental Study on the Effect of Long-Term Water Injection on Micropore Structure of Ultralow Permeability Sandstone Reservoir

<table class="table-group" id="tab3"><tr><td><table class="table"><tr><td class="thead-hr" colspan="8"><hr/></td></tr><tr class="thead"><td class="align_left">Ion</td><td class="align_center">Na<sup>+</sup> +K<sup>+</sup></td><td class="align_center">Ca<sup>2+</sup></td><td class="align_center">Mg<sup>2+</sup></td><td class="align_center">Ba<sup>2+</sup> + Sr<sup>2+</sup></td><td class="align_center">Cl<sup>−</sup></td><td class="align_center">SO<sub>2</sub><sup>2-</sup></td><td class="align_center">HCO<sub>3</sub><sup>−</sup></td></tr><tr><td class="thead-hr" colspan="8"><hr/></td></tr><tr><td class="align_left">Salinity (ppm)</td><td class="align_center">8738</td><td class="align_center">551</td><td class="align_center">243</td><td class="align_center">172</td><td class="align_center">13888</td><td class="align_center">1465</td><td class="align_center">204</td></tr><tr class="table-tr"><td colspan="8"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Ionic components of connate water.</div>

Geofluids

tab3

Table 3

Table 3: Experimental Study on the Effect of Long-Term Water Injection on Micropore Structure of Ultralow Permeability Sandstone Reservoir 