Chemical Force Microscopy Study on the Interactions of COOH Functional Groups with Kaolinite Surfaces: Implications for Enhanced Oil Recovery
Chemical Force Microscopy Study on the Interactions of COOH Functional Groups with Kaolinite Surfaces: Implications for Enhanced Oil Recovery
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DOI：
10.3390/min7120250
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发表时间：
2017-12
期刊：
影响因子：
2.5
通讯作者：
N. Santha;P. Cubillas;Adrian Saw;Harry Brooksbank;H. C. Greenwell
中科院分区：
文献类型：
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作者：
N. Santha;P. Cubillas;Adrian Saw;Harry Brooksbank;H. C. Greenwell
粘土-油相互作用在决定砂岩油藏的润湿性方面起着至关重要的作用，而润湿性又决定着提高采收率方法的有效性。在这项研究中，我们通过化学力显微镜测量了-COOH官能团与高岭石黏土矿物硅氧烷和铝醇面之间的粘附力，并将其作为pH、盐度（从0.001 M到1m）和阳离子特性（Na+ vs. Ca2+）的函数。硅氧烷表面的测量结果表明，在pH为5.5时，Ca2+表现出相反的低盐度效应（在较高浓度下附着力降低），而在pH为8时，Ca2+表现出低盐度效应。然而，在恒定的Ca2+浓度为0.001 M时，pH值的增加会导致更大的粘附。相反，Na+浓度的变化对-COOH基团对硅氧烷表面粘附的影响较小。对铝醇表面的测量显示，在pH为5.5的Ca2+存在下，铝醇表面具有相反的低盐度效应，而恒定离子浓度下pH值的增加导致Ca2+和Na+的粘附性降低。通过观察高岭石的表面络合和官能团的质子化状态来解释结果，并强调了多组分离子交换机制在控制粘附方面比双层膨胀机制更重要的作用。
Clay–oil interactions play a critical role in determining the wettability of sandstone oil reservoirs, which, in turn, governs the effectiveness of enhanced oil recovery methods. In this study, we have measured the adhesion between –COOH functional groups and the siloxane and aluminol faces of kaolinite clay minerals by means of chemical force microscopy as a function of pH, salinity (from 0.001 M to 1 M) and cation identity (Na+ vs. Ca2+). Results from measurements on the siloxane face show that Ca2+ displays a reverse low-salinity effect (adhesion decreasing at higher concentrations) at pH 5.5, and a low salinity effect at pH 8. At a constant Ca2+ concentration of 0.001 M, however, an increase in pH leads to larger adhesion. In contrast, a variation in the Na+ concentration showed less effect in varying the adhesion of –COOH groups to the siloxane face. Measurements on the aluminol face showed a reverse low-salinity effect at pH 5.5 in the presence of Ca2+, whereas an increase in pH with constant ion concentration resulted in a decrease in adhesion for both Ca2+ and Na+. Results are explained by looking at the kaolinite’s surface complexation and the protonation state of the functional group, and highlight a more important role of the multicomponent ion exchange mechanism in controlling adhesion than the double layer expansion mechanism.