Deng Xiao, Alotaibi Mohammed B, Fahmi Mohanad, Patil Shirish, Mahmoud Mohamed, Kamal Muhammad Shahzad, Hussain Syed Muhammad Shakil
Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Saudi Arabia.
EXPEC Advanced Research Center, Saudi Aramco, 31261, Dhahran, Saudi Arabia.
ACS Omega. 2024 Oct 8;9(42):43081-43092. doi: 10.1021/acsomega.4c06804. eCollection 2024 Oct 22.
Zwitterionic surfactants are found to be highly effective in reducing the IFT and changing the wettability. This work studied the solubility and wettability alteration performance of locally synthesized zwitterionic surfactants in Berea sandstone and Indiana limestone. Contact angle measurements were conducted to study the wettability under different conditions. SEM images and TGA results were combined to reflect on the wettability alteration mechanism. The zeta potential test was adopted to study the surface charge of the Indian limestone powder. Results showed that five of the six surfactants dissolved in deionized water to form 1.0 wt % solution, indicating efficient solubility for EOR purposes. Although its wettability alteration performance on oil-aged Berea sandstone is weak to moderate, the performance of ZW6 on Indiana limestone is excellent. ZW6 can change the strongly oil-wet (162°) rock back to water-wet (62.9°) conditions. Increasing its concentration from 0.01 to 0.5 wt % continuously enhanced the performance. The addition of NaCl to 150000 ppm did not affect the wettability alteration. However, the addition of CaCl largely suppressed the wettability alteration, while NaSO and MgCl both enhanced the performance. With the same headgroup, a more hydrophobic tail group impairs the wettability alteration. The quite different wettability alteration performance of MgCl and CaCl cases (which had approximately the same amount of calcite dissolution), and the comparable wettability alteration performance of NaSO and MgCl (which had very different calcite dissolution amounts) indicate that calcite dissolution is unrelated to wettability alteration.
发现两性离子表面活性剂在降低界面张力和改变润湿性方面非常有效。这项工作研究了本地合成的两性离子表面活性剂在贝雷砂岩和印第安纳石灰岩中的溶解性和润湿性改变性能。进行接触角测量以研究不同条件下的润湿性。结合扫描电子显微镜（SEM）图像和热重分析（TGA）结果来反映润湿性改变机制。采用zeta电位测试来研究印第安纳石灰岩粉末的表面电荷。结果表明，六种表面活性剂中的五种可溶于去离子水，形成1.0 wt%的溶液，表明其在提高采收率（EOR）方面具有有效的溶解性。尽管其对油老化的贝雷砂岩的润湿性改变性能较弱至中等，但ZW6对印第安纳石灰岩的性能优异。ZW6可以将强油湿（162°）的岩石变回水湿（'62.9°）状态。将其浓度从0.01 wt%连续增加到0.5 wt%可不断增强该性能。添加150000 ppm的NaCl不会影响润湿性改变。然而，添加CaCl₂在很大程度上抑制了润湿性改变，而Na₂SO₄和MgCl₂均增强了该性能。在头基相同的情况下，疏水性更强的尾基会损害润湿性改变。MgCl₂和CaCl₂情况（方解石溶解量大致相同）的润湿性改变性能差异很大，而Na₂SO₄和MgCl₂（方解石溶解量差异很大）的润湿性改变性能相当，这表明方解石溶解与润湿性改变无关。
