In this study, we initially performed interfacial tension (IFT) tests to investigate the potential of using the Persian Gulf seawater (PGSW) as smart water with different concentrations of NaCl, KCl, MgCl₂, CaCl₂, and Na₂SO₄. Next, for each salt, at the concentration where IFT was minimum, we conducted contact angle, zeta potential, and micromodel flooding tests. The results showed that IFT is minimized if NaCl or KCl is removed from PGSW; thus, for solutions lacking NaCl and KCl, the IFT values were obtained at 26.29 and 26.56 mN/m, respectively. Conversely, in the case of divalent ions, minimum IFT occurred when the concentration of MgCl₂, CaCl₂, and Na₂SO₄ in PGSW increased. Specifically, a threefold rise in the concentration of Na₂SO₄ further reduced IFT as compared to optimal concentrations of MgCl₂ or CaCl₂. It should be mentioned that eliminating NaCl from PGSW resulted in the lowest IFT value compared to adding or removing other ions. Whereas the removal of NaCl caused the contact angle to decrease from 91.0° to 67.8° relative to PGSW and changed surface wettability to weakly water-wet, eliminating KCl did not considerably change the contact angle, such that it only led to a nine-degree reduction in this angle relative to PGSW and left wettability in the same neutral-wet condition. At optimal concentrations of MgCl₂, CaCl₂, and Na₂SO₄, only an increase in Na₂SO₄ concentration in PGSW could change wettability from neutral-wet to weakly water-wet. For solutions with optimal concentrations, the removal of NaCl or KCl caused the rock surface to have slightly higher negative charges, and increasing the concentration of divalent ions led to a small reduction in the negative charge of the surface. The results of micromodel flooding indicated that NaCl-free PGSW could raise oil recovery by 10.12% relative to PGSW. Furthermore, when the Na₂SO₄ concentration in PGSW was tripled, the oil recovery increased by 7.34% compared to PGSW. Accordingly, depending on the conditions, it is possible to use PGSW so as to enhance the efficiency of oil recovery by removing NaCl or by increasing the concentration of Na₂SO₄ three times.

在这项研究中，我们最初进行了界面张力（IFT）测试，以研究使用波斯湾海水（PGSW）作为具有不同浓度的NaCl，KCl，MgCl ₂，CaCl ₂和Na ₂ SO _4的智能水的潜力。接下来，对于每种盐，在IFT最小的浓度下，我们进行了接触角，ζ电位和微模型驱油测试。结果表明，如果从PGSW中除去NaCl或KCl，则IFT最小。因此，对于缺少NaCl和KCl的溶液，IFT值分别为26.29和26.56 mN / m。相反，在二价离子的情况下，当MgCl ₂，CaCl ₂和Na ₂的浓度最小时，IFT最小。PGSW中的SO ₄增加。具体而言，与MgCl ₂或CaCl _2的最佳浓度相比，Na ₂ SO ₄浓度的三倍升高进一步降低了IFT 。应该提到的是，与添加或去除其他离子相比，从PGSW中去除NaCl导致最低的IFT值。相对于PGSW，NaCl的去除导致接触角从91.0°降低到67.8°，并且表面润湿性变为弱水润湿，而消除KCl并没有显着改变接触角，因此只能导致9度相对于PGSW，该角度减小，并且在相同的中性湿润条件下具有左润湿性。在最佳浓度的MgCl ₂，CaCl₂和Na ₂ SO ₄，只有PGSW中Na ₂ SO ₄浓度的增加才能将润湿性从中性润湿变为弱水润湿。对于具有最佳浓度的溶液，NaCl或KCl的去除会导致岩石表面带有稍高的负电荷，而增加二价离子的浓度会导致岩石表面负电荷的减小。微观模型驱油的结果表明，相对于PGSW，不含NaCl的PGSW可使采油量提高10.12％。此外，当Na ₂ SO ₄PGSW中的浓度增加了两倍，与PGSW相比，采油量增加了7.34％。因此，根据条件，可以使用PGSW以通过去除NaCl或通过将Na ₂ SO ₄的浓度增加三倍来提高油回收的效率。