Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR). Here, we investigated the adsorption behaviors of anionic surfactants and alka...Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR). Here, we investigated the adsorption behaviors of anionic surfactants and alkalis on silica for the first time as a function of temperature using quartz crystal microbalance with dissipation(QCM-D). The results demonstrated that the temperature dependent critical micelle concentration of alcohol alkoxy sulfate(AAS) surfactant can be quantitatively described by the thermodynamics parameters of micellization, showing a mainly entropy-driven process. AAS adsorption was mediated under varying temperature conditions, by divalent cations for bridging effect, monovalent cations competitive for adsorption sites but not giving cation bridging, pH regulation of deprotonated sites of silica, presence of alkoxy groups in the surfactants, and synergistic effect of surfactant coinjection. The addition of organic alkalis can enhance the overall adsorption of the species with AAS,whereas inorganic alkali of Na_(2)CO_(3) had capability of the sequestration of the divalent ions, whose addition would reduce AAS adsorption. The typical AAS adsorption indicated a non-rigid multilayer,estimated to have between 2 and 5 layers, with a likely compact bilayer followed by disorganized and unstable further layering. The new fundamental understanding about temperature effect on surfactants and alkalis adsorption contributes to optimizing the flooding conditions of chemicals and developing more efficient mitigation strategies.展开更多
基金supported by the Shanxi Provincial Key Research and Development Project (No. 20201102002)Science Foundation of China University of Petroleum,Beijing (No. 2462020BJRC007, 2462020YXZZ003)+1 种基金State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum (No. PRP/DX-2216)Shell Global Solutions。
文摘Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR). Here, we investigated the adsorption behaviors of anionic surfactants and alkalis on silica for the first time as a function of temperature using quartz crystal microbalance with dissipation(QCM-D). The results demonstrated that the temperature dependent critical micelle concentration of alcohol alkoxy sulfate(AAS) surfactant can be quantitatively described by the thermodynamics parameters of micellization, showing a mainly entropy-driven process. AAS adsorption was mediated under varying temperature conditions, by divalent cations for bridging effect, monovalent cations competitive for adsorption sites but not giving cation bridging, pH regulation of deprotonated sites of silica, presence of alkoxy groups in the surfactants, and synergistic effect of surfactant coinjection. The addition of organic alkalis can enhance the overall adsorption of the species with AAS,whereas inorganic alkali of Na_(2)CO_(3) had capability of the sequestration of the divalent ions, whose addition would reduce AAS adsorption. The typical AAS adsorption indicated a non-rigid multilayer,estimated to have between 2 and 5 layers, with a likely compact bilayer followed by disorganized and unstable further layering. The new fundamental understanding about temperature effect on surfactants and alkalis adsorption contributes to optimizing the flooding conditions of chemicals and developing more efficient mitigation strategies.
