Liao Kaili, An Junnan, Fu Lipei, Zhang Houye, Wei Meng, Bai Jinmei, He Yanfeng
School of Petroleum Engineering, Changzhou University, Changzhou 213164, China.
School of Overseas Education, Changzhou University, Changzhou 213164, China.
Polymers (Basel). 2022 Jun 27;14(13):2599. doi: 10.3390/polym14132599.
Welan gum is one of the most promising polymers used in polymer flooding for enhancing oil recovery, due to its excellent temperature resistance and salt-tolerance performance. However, welan gum, as a polymer with higher molecular weight, can be adsorbed and detained in the pore throat of the reservoir, which is characterized by a smaller size. Montmorillonite, a kind of clay mineral with high content in reservoir rocks, has strong adsorption capacity. Therefore, the adsorption behavior of welan gum on montmorillonite, as well as its influencing factors, are studied in this paper. The results show that the adsorption capacity is 2.07 mg/g. The adsorption capacity decreased with the increase in temperature. Both acidic and alkaline conditions reduced the adsorption capacity. The existence of inorganic salt affected the adsorption capacity. In addition, the higher the cation value, the lower the adsorption capacity. The characterization tests showed that the adsorption of welan gum on montmorillonite was characterized by physical adsorption and surface adsorption, indicating that there were no changes in the internal structure of montmorillonite. This study provides feasible methods to reduce the amount of welan gum adsorbed on montmorillonite, which is of great significance for reducing the permeability damage caused by welan gum adsorption and promoting the application of welan gum in polymer flooding for enhancing oil recovery.
韦兰胶是聚合物驱提高采收率过程中最具潜力的聚合物之一，因其具有优异的耐高温和耐盐性能。然而，韦兰胶作为一种高分子量聚合物，会被吸附滞留在尺寸较小的储层孔喉中。蒙脱石是储层岩石中含量较高的一种粘土矿物，具有较强的吸附能力。因此，本文研究了韦兰胶在蒙脱石上的吸附行为及其影响因素。结果表明，吸附量为2.07mg/g。吸附量随温度升高而降低。酸性和碱性条件均降低了吸附量。无机盐的存在影响吸附量。此外，阳离子价态越高，吸附量越低。表征测试表明，韦兰胶在蒙脱石上的吸附以物理吸附和表面吸附为主，表明蒙脱石内部结构未发生变化。该研究为减少韦兰胶在蒙脱石上的吸附量提供了可行方法，对于减少韦兰胶吸附造成的渗透率损害以及促进韦兰胶在聚合物驱提高采收率中的应用具有重要意义。
