Summary Several laboratory experiments demonstrated that the use of sodium hydroxide could increase the solution pH and reduce the adsorption of anionic surfactants. However, a better understanding of rock-oil-brine interactions and their effect on surfactant adsorption during alkaline-surfactantpolymer (ASP) flooding is needed for realistic and representative estimations of surfactant adsorption levels. Therefore, this study presents a novel approach to capture these interactions and better predict their effect on surfactant adsorption as well as effluent concentrations of surfactant and various aqueous species using the Phreeqc simulator. Currently, surface complexation models (SCMs) consider rock-brine, oil-brine, and surfactant-brine reactions. In this work, four new surface complexation reactions with intrinsic stability constants that honor oil-surfactant interactions have been proposed for the first time and then validated against experimental data reported in the literature. In addition, we analyzed the effect of various parameters on surface adsorption under harsh conditions of high temperature and high salinity using the proposed SCM. The results showed that the developed surfactant-based SCM is capable of estimating surfactant adsorption and its concentration in the effluent during chemical floods. The model was validated against two sets of ASP corefloods from the literature including single-phase and two-phase dynamic surfactant adsorption studies. The findings highlighted that oil-surfactant surface complexation reactions are important and should be captured for a more representative and accurate estimation of surfactant adsorption during chemical flooding. Moreover, the detailed and comprehensive analysis showed that surfactant adsorption increased and its concentration in the effluent decreased with the increase in temperature of the chemical flood. The latter shows that the adsorption process is endothermic and it is more of chemisorption as opposed to physio-adsorption. It was also showed that a decrease in water total salinity decreases the surfactant adsorption on the rock surface, which is related to the increase in the repulsive forces between the rock surface and adsorbed species. Additionally, with the increase in surfactant concentration in the chemical flood, surfactant concentration in the effluent increases, with a slight increase in surfactant adsorption. This slight increase in adsorption can be neglected compared with the injected and produced masses of the surfactant that are proportional. Moreover, the effect of sulfate spiking is significant where the increase in sulfate concentration reduces the surfactant adsorption. Furthermore, it is worth highlighting that the lowest surfactant adsorption levels were achieved through injected water dilution; less than 0.1 mg/g of rock. This is the first study to test a novel formulation of SCM considering the oil-surfactant effect on surfactant adsorption properties. The proposed framework to estimate surfactant adsorption is conducted for high-temperature and high-salinity reservoir conditions. Thus, it could be used in numerical reservoir simulators to estimate oil recovery due to wettability alteration by chemical flooding in carbonates, which will be investigated in our future work. The surfactant adsorption mechanisms during chemical flooding are very case-dependent and hence, the findings of this study cannot be generalized.

中文翻译：

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使用表面络合建模对苛刻条件下碳酸盐中表面活性剂吸附估计的新见解

总结 几个实验室实验表明，使用氢氧化钠可以增加溶液的 pH 值并减少阴离子表面活性剂的吸附。然而，需要更好地了解岩石-油-盐水相互作用及其对碱性表面活性剂聚合物 (ASP) 驱期间表面活性剂吸附的影响，以便对表面活性剂吸附水平进行现实和有代表性的估计。因此，本研究提出了一种新方法来捕获这些相互作用，并使用 Phreeqc 模拟器更好地预测它们对表面活性剂吸附以及表面活性剂和各种水性物质的流出物浓度的影响。目前，表面络合模型 (SCM) 考虑了岩石-卤水、油-卤水和表面活性剂-卤水反应。在这项工作中，首次提出了四种具有内在稳定性常数的新表面络合反应，这些反应符合油-表面活性剂相互作用，然后根据文献中报道的实验数据进行了验证。此外，我们使用所提出的 SCM 分析了在高温和高盐度苛刻条件下各种参数对表面吸附的影响。结果表明，开发的基于表面活性剂的 SCM 能够估计化学驱期间表面活性剂的吸附及其在出水中的浓度。该模型针对文献中的两组 ASP 岩心驱进行了验证，包括单相和两相动态表面活性剂吸附研究。研究结果强调了油-表面活性剂表面络合反应很重要，应该捕获以更准确地估计化学驱期间表面活性剂的吸附。此外，详细而全面的分析表明，随着化学驱温度的升高，表面活性剂的吸附增加，出水中的浓度降低。后者表明吸附过程是吸热的，它更多的是化学吸附而不是物理吸附。还表明，水总盐度的降低会降低表面活性剂在岩石表面的吸附，这与岩石表面与吸附物质之间排斥力的增加有关。此外，随着化学驱中表面活性剂浓度的增加，流出物中的表面活性剂浓度增加，表面活性剂吸附略有增加。与注入和生产的表面活性剂质量成比例相比，这种吸附的轻微增加可以忽略不计。此外，在硫酸盐浓度增加会降低表面活性剂吸附的情况下，硫酸盐尖峰的影响是显着的。此外，值得强调的是，通过注入水稀释实现了最低的表面活性剂吸附水平；小于 0.1 毫克/克的岩石。这是第一项考虑油表面活性剂对表面活性剂吸附性能影响的 SCM 新型配方的研究。所提出的估计表面活性剂吸附的框架是针对高温和高盐度油藏条件进行的。因此，它可用于数值油藏模拟器，以估计碳酸盐化学驱使润湿性改变引起的石油采收率，这将在我们未来的工作中进行研究。化学驱期间的表面活性剂吸附机制非常依赖于案例，因此，本研究的结果不能一概而论。